MILITARY MEDICINE, 178, 11:1157, 2013
Recruitment and Attrition Issues in Military Clinical Trials and Health Research Studies Nigel E. Bush, PhD*; CPTSeati C. Sheppard, MSC USAf; Emily Fantelli, BS*; Kathleen R. Bell, MDf; Mark A. Reger, PhD*
INTRODUCTION Military health research has accelerated in recent years, especially since the onset of confiicts in Iraq and Afghanistan and related concems about the medical and psychological impact on service members. Moreover, large-scale military-academic partnerships such as INTRuST,' Army STARRS,^ STRONG STAR, and the Military Suicide Research Consortium"* are conducting long-term multidisciplinary research projects across a range of military health issues. The plethora of individually funded studies, program grants, and multisite military health research consortia speak to the considerable national investment in the well-being of the U.S. service member. In the context of the current economic situation, maximizing efficiency through optimal human subject participation is of paramount importance to research. A range of factors, however, can contribute to less-than-ideal levels of study participation. Poor recruitment and high dropout rates are not only frustrating and costly, but they also pose a threat to the interpretation, integrity, and validity of research findings. A number of articles have reported obstacles to civilian study participation and have outlined strategies for overcoming those obstacles.^"" However, to the best of our knowledge, none have been devoted to the unique challenges inherent to research with military service members. In this commentary, we review the civilian literature for recruitment and retention factors that potentially may also have relevance to military populations. We then examine research study recruitment and attrition in the U.S. military, highlighting militaryspecific issues that may impact study participation. Finally, we suggest strategies for improving research participation by service members.
BACKGROUND Importance of Recruitment and Attrition The goal of a research study is to gain a clear understanding of a population from a study test sample. That generaliz*National Center for Telehealth and Technology, 9933 West Hayes Street, Joint Base Lewis-McChord, Tacoma, WA 98431. fDepartment of Behavioral Health, Madigan Army Medical Center, 9040A Jackson Avenue, Tacoma, WA 98431. tDepartment of Rehabilitation Medicine, University of Washington Health Sciences, 1359 NE Pacific Street, Seattle, WA98195 doi: 10.7205/MILMED-D-13-00234
MILITARY MEDICINE, Vol. 178, November 2013
ability from sample to population depends on having a sufficiently large, representative, and unbiased test sample. An insufficient sample size because of problematic study recruitment and retention reduces a study's power to detect or rule out a clinically meaningful effect.^''^ Moreover, any differential recruitment, selective attrition, or systematic loss to follow-up can lead to biased outcomes that detract from the validity of the study findings and threaten their generalizability.'-'"'^ Consequently, optimal participant recruitment to a test sample and minimal attrition once enrolled is critical to interpretation of study outcomes.
Factors Relating to Recruitment and Attrition in Civilian and Military Health Research Studies Numerous studies, reviews, and reports in the civilian literature have examined factors relating to recruitment and attrition issues. A few publications have provided general overviews, literature reviews, or comprehensive discussions of those issues (e.g., see References 7, 9, and 16). Most however have focused more narrowly on the enrollment and retention of samples with specific health disorders,'^"^° or in particular medical environments.^''°'"'^' In contrast, the military literature is largely devoid of dedicated analyses of service member recruitment and attrition issues. Moreover, there is a scarcity of military health research articles that directly report recruitment/enrollment rates and/or retention/attrition rates, or that cite numbers that allow those rates to be quantified. We recently conducted a search of Ovid Medline, PsychlNFO, and the Cochrane Central Register of Controlled Trials from 2001 to 2012 for studies that (a) explicitly involved active duty military service members in randomized controlled clinical trials and (b) also included quantifiable recruitment or attrition rate information. Only 24 publications met those criteria, and almost all cited study dropout rates but not enrollment rates. Table I shows the variety of individual characteristics that has been associated with a likelihood or disinclination to enroll in research studies. In the absence of instances from military publications, we have gleaned these examples exclusively from the civilian literature. However, many of the difficulties with enrollment and retention in civilian health research summarized in the table likely also apply to their military equivalents.
1157
Commentary TABLE 1
Factors Relating to Recruitment and Attrition in Health Research Studies Recruitment/Enrollment
Participation in Health Research Has Been Shown to Be More Likely for Individuals Who Are: Male Gender Younger^^"^* Age More educated^* Education Have past experience of health issues related to the research topic^^-^^ Health Have a history of volunteerism" Perceive a personal benefit in taking part"-"^-"^ Other Individuals Decline to Participate in Clinical Research^ Because They Have Concerns About: Having to stop ongoing treatments or medications Medical Being randomized to a placebo"* Experiencing adverse effects of an experimental treatment'* The distance to the research location "-""-^^ Logistics and Cost The potential time away from work or family"'-^"-" Disclosing their personal information to researchers^* Privacy The specific study or research in general (distrust, dislike, disinterest)^^ Other *Retention/Attrition Withdrawal From Research Studies Is Commonly Associated With Individuals Who Are: Female"-^^ Male» Gender Age Education Race/Ethnicity Socioeconomic Status
Less educated'"-"-" Racial or ethnic minority"--^^--"*-", (no association''") Of lower socioeconomic status'''' Unemployed"-" Withdrawal From Research Studies Is Commonly Associated With Individuals Who: Perceive a lack of treatment efficacy in clinical trials (dropout to seek effective treatment elsewhere)" Medical Perceive/experience successful treatment during trial (withdraw before the trial has run its course)''^ Have higher levels of depression, hostility, and overall psychosocial distress^' Psychological /Behavioral Have a history of substance abuse -
•Demographic characteristics per se are likely not the reason a study participant drops out. Rather, they may be indicative of issues related to competing life demands, logistical difficulties, financial obstacles, and lack of motivation and commitment.
Recruittnetit and Retention Challenges Unique to the Military Despite the dearth of information in academic texts, our own experience and anecdotal evidence from others suggest that there are substantial difficulties recruiting and retaining health study research participants from military populations, Many of these challenges mirror the civilian experience, but others may be unique to the military culture and environment, A common reason cited for civilian participation in clinical research is to receive personal health benefits and improved access to care.'^'^^ However, as a benefit of military service, free high-quality health care may leave active duty service members less powerfully motivated by potential personal health benefits to participate in clinical research. In addition, although perceived severity of symptoms may reduce attrition rates with civilians, stringent health screening before admittance into the military has resulted in a young, healthy population potentially less likely to. need or desire novel medical interventions commonly evaluated in randomized controlled trials. The effort and inconvenience of research participation (e.g., taking time off work,^° travelling to a research site^'^-') may be exacerbated in the military. For instance, transportation may be a challenge for young service members stationed away from their home of record without motor vehicles,
1158
Furthermore, the detnanding nature of a typical workday in the military and mandatory training requirements may result ¡n supervisors being less supportive of service members being absent to participate in research. Even for routine non-research-related health appointments attendance by service members can be poor. Service members often obtain appointment slips in advance to provide to their command but then fail to attend. Records from our own location show that over an 8-month period in 2012, more than 23% of routine appointments at a busy mental health cUnic in a large military hospital were cancelled or documented as no-shows (J- Etherage, unpublished data, 2012). The transitory and mobile nature of military service also raises significant obstacles to recruitment and retention, especially to extended periods of study participation and follow-up. Active duty service members may change duty stations every 2 to 3 years, and the nature of time-limited obligatory military service contracts leads to significant turnover in the military. Moreover, military deployments in support of peacetime and combat operations often occur without significant warning. Participation in training exercises typically conducted several times throughout the year also takes precedence over participating in clinical research, Finally, National Guard and Reservists, who make up a significant portion of the military population, present unique
MILITARY MEDICINE, Vol. 178, November 2013
Commentary
logistical impediments to recruitment and retention because of their relatively infrequent periods of service (activation/ mobilization one weekend per month) and the fact that they often live further from military installations than their active duty counterparts. Service members are considered by institutional review boards (IRBs) and other regulatory bodies to represent a population especially vulnerable to coercive recruitment practices. This concem stems from the hierarchical structure of the military that affords the chain of command considerable power and influence over subordinate service members. Heightened regulatory protection affects research with service members in several ways. Research with civilians has found that monetary incentives are one important reason for participating in research.''^'-'^ However, federal research funding cannot be used to financially compensate service member subjects for their time or participation. In addition, although endorsement by trusted and influential individuals (e.g., doctors) can be a powerful incentive for research participation,'^ regulatory bodies may limit certain recruitment procedures (e.g., in which the chain of command appears to directly support recruitment) because of concem about potential coercion. In short, the monetary and recruitment strategy restrictions inherent in conducting research with service members can nullify important factors shown to positively impact participation in civilian research. Finally, recent research suggests that the demands of the prolonged recent conflicts and multiple deployments may have contributed to a sense of burnout and fatigue within the military. Indeed, the last several years have seen considerable attention and research funding aimed at improving our understanding of the impact of combat on a range of physical TABLE II.
and mental health outcomes. This, in tum, has resulted in a proliferation of research groups and a sizeable number of research studies that compete for access to the relatively small population that makes up the samples of interest within the U.S. military. When combined with the fact that service members are required to complete multiple physical and mental health screenings both before and after combat deployment, it seems conceivable that recruitment efforts may be hampered by service members who are simply bumed out by multiple requests to participate in research or to complete health questionnaires and other assessments. Table 11 highlights some of the challenges especially pertinent to conducting military health research.
Strategies to Improve Recruitment and Retention in Military Clinical Outcome Research Strategies posited to increase enrollment and minimize attrition have been as varied as the reasons to enroll or decline to participate.^ Table III summarizes evidence-based strategies from the civilian literature that we believe apply equally well to clinical research with the military population. Table III also offers suggestions for how those and other strategies might be adapted and applied to the unique characteristics of the military population and environment. Compared to their civilian counterparts, military service members offer an unusually mobile, transient, and culturally unique research population. Consequently, the vital first step in planning a military health research project must comprise a detailed, realistic, and context-specific assessment of the availability of the target sample for a sufficient period of time, adequate access to the sample, and target participant interest
Military Recruitment and Retention Challenges
Civilian Participants enroll to receive personal health benefits and improved access to care.'*'^^ Perceived severity of symptoms may reduce attrition rates.
Taking time off work,^° travelling to a research site,''^' reduces participation and increases attrition. Research studies often require extended periods of study participation and follow-up. Human subjects health research must meet stringent regulatory requirements and approvals. Overburdening participants with study requirements inhibits enrollment and increases attrition.
Military Military health screening yields young, healthy population potentially less likely to seek novel medical research interventions. Free high-quality health care may leave active duty service members less powerfully motivated by potential personal health benefits to participate in clinical research. Logistics exacerbated in military. Increased difficulties with transportation, longer and more unpredictable work hours, resistance to release from duty. Military service highly (and unpredictably) transient and mobile. Regular changes of duty stations, training and deployment absences, time-limited service contracts. Service members considered by regulatory bodies to be especially vulnerable population. Increased scrutiny on possibility of coercion by chain of command an inappropriate incentives. Very frequent service-mandated health screenings and assessments, and multiple research studies on effects of Operation Enduring Freedom/Operation Iraqi Freedom, have resulted in increased volunteer burnout.
Recruitment advantages: despite the unique challenges to military recruitment and retention, there may also be some advantages for certain study methodologies. The military does offer unique settings in which large groups of individuals are together for predictable periods of time. Important data can be collected from large groups and some factors that contribute to attrition can be minimized while group members are co-located. For instance, studies conducted during basic training have sometimes reported low attrition ^'
MILITARY MEDICINE, Vol. 178, November 2013
1159
Commentary TABLE III.
Strategies to Improve Recruitment and Retention
Evidence-Based Strategies From Civilian Literature
Military-Specific Issues
Provision of transportation shows respect for service member's time and effort. Direct financial incentives for service members generally Incentives prohibited by regulation. Alternatives allowed by some IRBs have included gift cards to reimburse for expenses incurred, and customized coins to recognize participation. Enrollment Referrals Referrals to studies by health professionals have been effective Establish early relationships and support with key individuals important within target military population and unit; with recruitment,'*" as has support by skilled and empathetic and Support e.g., surgeons, behavioral health officers, chaplains, study staff with the decision to participate or not^^ or to stay non-commissioned officers, health care providers. on study once enrolled. Involvement of trusted community Include influential supporters from military community representatives in the design and recruitment stages such as spouses, civilian peers. of studies has been helpful in enrolling volunteers.'" Important venues for advertizing and recruiting include Different methods of study promotion through various media Study Promotion military treatment facilities, outlying satellite and and venues tailored to the target audience have predicted and Recruitment 22,24,40.42 community clinics, community support resources Venues recruitment success. such as education centers, family readiness/support groups, gyms, installations newspapers, commissaries, and exchange services. Consider use of military websites and networks established for service members for research surveying and recruitment. Offer early and detailed study information that clearly Early provision of adequate information about the demands Study Information distinguishes the study from routine or systematic and benefits of a study is key to recruiting new volunteers^'''" and to retaining enrolled individuals."''^ service demands, and which emphasizes the benefits, especially to fellow service members. Leverage both existing military records systems and service Accurate and efficient tracking of study subject contact Tracking information has been paramount in maintaining members' personal technologies to assist effective tracking '"^^ of highly mobile and transitory target populations. Logistics
Practical help with travel logistics can contribute to successful enrollment and reduced attrition."•"••'^•"' Modest monetary incentives have been shown to improve recruitment and retention rates. " " ' ^ '
Study Feasibility
Conduct early (military) context-specific assessment of availability of the target sample for a sufficient period of time, adequate access to the sample, and target participant interest in the project. Consider unique cultural factors: codes of values, respect, benefit to peers. Include dedicated recruitment coordinator, ideally experienced in both the research topic and in conducting military research. Former service members may be especially effective in military research recruiting. Allow extra time, resources, and special expertise for IRB, clinical/scientific reviews, and administrative bureaucracy that may be unique to the military, and which may require multiple reviews through several agencies.
Additional Military-Specific Strategies
Military Culture Staff Familiarity with Military Military-Specific Regulations and Processes
in the project (e.g., service members may be more interested in a study evaluating the impact of a performance enhancer than one testing a new vaccine for tropical diseases). The need to access sufficient potential participants must be balanced against available resources, and feasibility; for example, in the military context this process might involve decisions about whether to recruit at multiple unit locations spread across one or more installations or at one centralized location on one installation (e.g., the hospital). Considering the military as a unique culture is essential to planning and conducting health research with service members. All branches of the military place significant importance on living by a code of values (e.g., loyalty, honor, duty, selfiess service). Developing recruitment materials that emphasize research participation as one way for a service member to live these values shows the researcher's awareness of, and respect for, this aspect of military service. Our experience suggests that service members are highly moti-
1160
vated to participate in research if they believe it ultimately will benefit their military comrades. To better facilitate enrollment in the civilian arena. Bell et al^ recommend allocating room in the budget for a dedicated recruitment coordinator for large studies. Our own previous work also suggests that nearly every study recruiting service members similarly requires a dedicated coordinator, and sometimes a recruitment team, to be successful. For civilian researchers without prior experience with military research, we strongly recommend enlisting the support of someone experienced both in the research topic and in conducting military research. This individual should be used as early as possible to help establish key relationships, predict likely challenges, develop workable solutions, and inform all aspects of the planning process. If possible, we recommend employing a coordinator with previous military service and experience with military research recruitment. Recruitment staff with prior military service can be a distinct advantage in presenting
MILITARY MEDICINE, Vol. 178, November 2013
Commentary
a culturally sensitive'*'* "insider" understanding ofthe demands funded research. However, nominal gift cards have, on occaand values ofthe target audience. sion, been provided explicitly to compensate for expenses For research being conducted at locations (e.g., at military incurred by the participant to participate. In the military, installations) with one or more units (e.g., an Army brigade customized coins are commonly used by leaders to reward comprising a few thousand soldiers), we recommend using minor achievements, and many service members take pride resources within the unit to inform the planning process. in displaying their collection of coins. Offering a customized Although commanders are limited in their ability to directly coin might be a good way to encourage service members encourage participation in research, we recommend building to complete follow-up assessments. For studies requiring the relationships with them for their facility to assist in providing use of tracking or monitoring logs, issuing custom-designed face time with unit. Although regulations are in place to notebooks to fit in the pockets of a service member's uniform avoid the potential for coercion to occur, thoughtful planning might increase compliance. Ingenuity may be required on and coordination can effectively use leader support to posi- behalf of the researcher to develop effective incentives for tively impact recruitment efforts. Developing a relationship participation. These incentives must then be carefully coordiwith the brigade surgeon, brigade behavioral health officer, nated with the ERB to comply with all regulatory requirements. chaplain, and other members of the commander's support Early provision of sufficient information to potential partistaff is paramount. Although it is important to educate the cipants about the demands and benefits of a study can be key Command on the ethical issues involved in military research, to recruiting in civilian research.^^'*^ This may be even more establishing a relationship with the staff will in turn help important when recruiting and retaining service members. the researcher understand the current and predicted training We have described the peculiar demands of frequent health and operational tempo, the command climate, and other unit- assessments, surveying, and screening in the military. We specific factors that can significantly impact the study sched- regularly encounter research candidates who cite study bumules and ability to recruit and retain participants successfully. out and survey-jadedness as reasons for declining to particiUpdating the clinical staff periodically on study progress is pate. It is vital when recruiting service members to offer early also helpful in maintaining support over time. Research with and detailed study information that adequately distinguishes civilian participants further suggests that health care pro- the study from the routine or systematic service demands, viders are especially trusted, and consequently effective, which clearly delineates requirements, and, most imporrecruiters.^'^^ We believe the provider-participant relation- tantly, accurately describes the benefits, especially to fellow ship is no less effective in the military environment. We service members. recommend making early connections with hospital or clinic On large military installations medical care is often proleadership to facilitate the support of their providers in refer- vided in outlying satellite clinics separated from the hospital. ring potential participants. We further suggest explicitly Furthermore, there is a growing movement in the U.S. Army to outlining the potential benefits to providers for their assis- embed complete behavioral health care teams at the brigade tance in recruiting (e.g., the ability to offer novel interven- level to improve access to care. Both types of outlying clinics tions, help reduce busy case-loads). should be considered as potential recruitment locations. InforUnderstanding and navigating the regulatory review pro- mation about studies can be distributed in areas that may be cess also requires careful planning and allocation of resources. frequented by military families; spouses can be enthusiastic IRB and clinical/scientific reviews may be unique to the mili- supporters of participation in research. Community support tary depending on the nature of the funding source. Funding resources such as education centers, family readiness/support by civilian agency or intramural funding at a local military groups, gyms, installations newspapers, and shopping centers installation will require only local IRB approval. Extramural on military installations are potential venues worth considering. federal funding (the most common funding source for military Online media may also provide good avenues for surveying research) requires IRB approval at multiple levels ranging and study recruitment; our own recent experience has shown from local institution IRB through several levels of centralized that posting of online questionnaires and study enrollment federal agency review. Often this necessitates the preparation information on widely used service websites such as Army of multiple versions of proposals and related regulatory docu- Knowledge Online, and through social media, has promise. ments. Extramural research conducted at multiple sites adds Offering transportation to and from study sites supports additional layers of review to what already can be an arduous enrollment and retention efforts, especially for studies process. We recommend that researchers new to military recruiting and testing multiple participants over short periods research seek guidance from local regulatory bodies and of time (e.g., focus groups, groups of patients scheduled at certainly plan for the often lengthy review process so that short intervals). In those instances, providing group transporsufficient time remains within the funding cycle to recruit par- tation is more efficient than expecting individuals to use their ticipants successfully. Sharing documents across civilian and own vehicles. More generally, the offer of transportation military IRB committees may assist in resolving differences. to study candidates shows respect for service member's time Regulations generally prohibit direct financial incentives and effort. Bell et al^ present a useful list of suggestions to reimburse service members for participating in federally to maintain or reestablish contact with civilian participants
MILITARY MEDICINE, Vol. 178, November 2013
1161
Commentary
over the course of a study. The structure and accountability in the military affords some advantages in those respects. Contact information for service members typically is well maintained and is generally more accessible than for civilian counterparts. During the consent process we suggest asking the subject if they are scheduled to change duty locations (service members often know weeks or even months in advance of pending moves). Asking about pending deployments, plans to separate from the service, and upcoming training rotations will provide the researcher with important information about suitability for inclusion in the study. We also recommend seeking permission to contact the service member's military organization to assist in locating the subject in case of missed foUow-ups. If permission is granted, it will be important to accurately and completely document the subject's unit beginning at the lowest level (e.g., company) as well as one or two superordinate commands (e.g., battalion, brigade). It may also be helpful to collect the contact information for the service member's lowest level commander. Knowing the commander's contact information can be helpful for two reasons. First, the commander can help locate the service member in the event of a unit change or training deployment. Second, follow-up appointment reminders can be sent directly to the commander as well as to the service member. This can help facilitate unit support of attendance of follow-up appointments, particularly for junior enlisted personnel. Finally, we recommend the use of personal technologies (texting, mobile apps with calendar reminder functions, email) to most efficiendy maintain contact with participants, to notify them about pending follow-up appointments, and to decrease attrition overall. CONCLUSION Robust recruitment and retention in clinical research trials continues to be a source of concern to researchers in both civilian and military contexts. Study investigators should carefully consider both general and military-specific recruitment challenges before starting a study and invest adequate resources to accommodate them. Similar creativity should be applied to maintaining contact with highly mobile military research participants and encouraging their completion of the study, including easy access to outcome assessments. Addressing these concems even at the grant writing stage may result in higher study completion rates and more reliable data. REFERENCES 1. INTRuST: The Injury and Traumatic Stress Consortium 2012. Available at http://intnjst.sdsc.edu/; accessed October 24, 2012. 2. Army STARRS: Army Study To Assess Risk and Resilience in Servicemembers. 2012. Available at http://www.armystarrs.org/; accessed October 24, 2012. 3. STRONG STAR: The South Texas Research Organizational Network Guiding Studies on Trauma and Resilience. 2012 Available at www .strongstar.org; accessed October 24, 2012. 4. The Military Suicide Research Consortium. 2012. Available at https:// msrc.fsu.edu/; accessed October 24, 2012.
1162
5. Bell KR, Hammond F, Hart T, Bickett AK, Temkin NR, Dikmen S: Participant recruitment and retention in rehabilitation research. Am J Phys Med Rehabil 2008; 87(4): 330-8. 6. Berger AM, Neumark DE, Chamberlain J: Enhancing recruitment and retention in randomized clinical trials of cancer symptom management. Oncol Nurs Forum 2007; 34(2): E17-22. 7. Lovato LC, Hill K, Hertert S, Hunninghake DB, Probstfield JL: Recruitment for controlled clinical trials: literature summary and annotated bibliography. Control Clin Trials 1997; 18(4): 328-52. 8. Roberg K, Carlson-Dakes K, Anderson B: The key to successful recruitment and retention in clinical research programs. Monitor 2006(June): 13-16. 9. Ross S, Grant A, Counsell C, Gillespie W, Russell I, Prescott R: Barriers to participation in randomised controlled trials: a systematic review. J Clin Epidemiol 1999; 52(12): 1143-56. 10. Tansey CM, Matte AL, Needham D, Herridge MS: Review of retention strategies in longitudinal studies and application to follow-up of ICU survivors. Intensive Care Med 2007; 33(12): 2051-7. 11. Cofield SS, Conwit R, Barsan W, Quinn J: Recruitment and retention of patients into emergency medicine clirUcal trials. Acad Emerg Med 2010; 17(10): 1104-12. 12. Cohen J: Statistical Power Analysis for the Behavioral Sciences. Ed 2. Hillsdale, NJ, Lawrence Erlbaum Associates, 1988. 13. Demark-Wahnefried W, Bowen DJ, Jabson JM, Paskett ED: Scientific bias arising from sampling, selective recruitment, and attrition: the case for improved reporting. Cancer Epidemiol Biomarkers Prev 2011 ; 20(3): 415-8. 14. Higgins JPT, Altman DG (editors). Chapter 8: Assessing risk of bias in included studies. Cochrane Handbook for Systematic Reviews of Interventions. Version 5.01: The Cochrane Collaboration; 2008. Available at www.cochrane-handbook.org; accessed October 5, 2012. 15. Lundh A, Gotzsche PC: Recommendations by Cochrane Review Groups for assessment of the risk of bias in studies. BMC Med Res Methodol 2008; 8: 22. 16. Davis LL, Broome ME, Cox RP: Maximizing retention in communitybased clinical trials. J Nurs Scholarsh 2002; 34(1): 47-53. 17. Chang BH, Hendricks AM, Slawsky MT, Locastro JS: Patient recruitment to a randomized clinical trial of behavioral therapy for chronic heart failure. BMC Med Res Methodol 2004; 4: 8. 18. Halpem SD, Karlawish JH, Casarett D, Berlin JA, Townsend RR, Asch DA: Hypertensive patients' willingness to participate in placebo-controlled trials: implications for recruitment efficiency. Am Heart J 2003; 146(6): 985-92. 19. Gucciardi E, DeMelo M, Offenheim A, Grace SL, Stewart DE: Patient factors associated with attrition from a self-management education programme. J Eval Clin Pract 2007; 13(6): 913-19. 20. Lowton K: Trials and tribulations: understanding motivations for clinical research participation amongst adults with cystic fibrosis. Soc Sei Med 2005; 61(8): 1854.-65. 21. Blanton S, Morris DM, Prettyman MG, et al: Lessons learned in participant recruitment and retention: the EXCITE trial. Phys Ther 2006; 86(11): 1520-33. 22. Glasgow RE, Nelson CC, Kearney KA, et al: Reach, engagement, and retention in an Internet-based weight loss program in a multi-site randomized controlled trial. J Med Internet Res 2007; 9(2): e l l . 23. Corbie-Smith G, Viscoli CM, Kernan WN, Brass LM, Sarrel P, Horwitz RI: Influence of race, clinical, and other socio-demographic features on trial participation. J Clin Epidemiol 2003; 56(4): 304-9. 24. Haring R, Alte D, Volzke H, et al: Extended recruitment efforts minimize attrition but not necessarily bias. J Clin Epidemiol 2009; 62(3): 252-60. 25. Wright JR, Whelan TJ, Schiff S, et al: Why cancer patients enter randomized clinical trials: exploring the factors that infiuence their decision. J Clin Oncol 2004; 22(21): 4312-18. 26. Phipps E, Harris D, Brown N, et al: Investigation of ethnic differences in willingness to enroll in a rehabilitation research registry: a study
MILITARY MEDICINE, Vol. 178, November 2013
Commentary
27.
28.
29.
30.
31. 32.
33.
34.
35.
of the Northeast Cognitive Rehabilitation Research Network. Am J Phys Med Rehabil 2004; 83(12): 875-83. Honas JJ, Early JL, Frederickson DD, O'Brien MS: Predictors of attrition in a large clinic-based weight-loss program. Obes Res 2003; 11(7): 888-94. Janson SL, Alioto ME, Boushey HA: Attrition and retention of ethnically diverse subjects in a multicenter randomized controlled research trial. Control Clin Trials 2001; 22(Suppl 6): 236S-43S. Moser DK, Dracup K, Doering LV: Factors differentiating dropouts from completers in a longitudinal, multicenter clinical trial. Nurs Res 2000; 49(2): 109-16. Warden D, Trivedi MH, Wisniewski SR, et al: Predictors of attrition during initial (citalopram) treatment for depression: a STAR*D repon. Am J Psychiatry 2007; 164(8): 1189-97. Zook PM, Jordan C, Adams B, et al: Retention strategies and predictors of attrition in an urban pédiatrie asthma study. Clin Trials 2010; 7(4): 400—10. El-Khorazaty MN, Johnson AA, Kiely M, et al: Recruitment and retention of low-income minority women in a behavioral intervention to reduce smoking, depression, and intimate partner violence during pregnancy. BMC Public Health 2007; 7: 233. Corrigan JD, Harrison-Felix C, Bogner J, Dijkers M, Terrill MS, Whiteneck G: Systematic bias in traumatic brain injury outcome studies because of loss to follow-up. Arch Phys Med Rehabil 2003; 84(2): 153-60. Sangi-Haghpeykar H, Meddaugh HM, Liu H, Grino P: Attrition and retention in clinical trials by ethnic origin. Contemp Clin Trials 2009; 30(6): 499-503. Lurie I, Levine SZ: Meta-analysis of dropout rates in SSRIs versus placebo in randomized clinical trials of PTSD. J Nerv Ment Dis 2010; 198(2): 116-24.
MILITARY MEDICINE, Vol. 178, November 2013
36. Kissinger P, Kopicko JJ, Myers L, et al: The effect of modest monetary incentives on follow-up rates in sexually transmitted disease studies. Int J STD AIDS 2000; 11(1): 27-30. 37. van Gelderen CE, Savelkoul TJ, van Dokkum W, Meulenbelt J: Motives and perception of healthy volunteers who participate in experiments. Eur J Clin Pharmacol 1993; 45(1): 15-21. 38. Marmar CR. Mental health impact of Afghanistan and Iraq deployment: meeting the challenge of a new generation of veterans. Depress Anxiety 2009; 26(6): 493-7. 39. Haddock CK, Lando HA, Pyle SA, et al: Prediction of adult-onset smoking initiation among U.S. Air force recruits using the pierce susceptibility questionnaire. Am J Prev Med 2005; 28(5): 424-9. 40. Peindl KS, Wisner KL: Successful recruitment strategies for women in postpartum mental health trials. J Psychiatr Res 2003; 37(2): 117-25. 41. De las Nueces D, Hacker K, DiGirolamo A, Hicks LS: A systematic review of community-based participatory research to enhance clinical trials in racial and ethnic minority groups. Health Serv Res 2012; 47(3 Pt 2): 1363-86. 42. Linnan LA, Emmons KM, Klar N, Fava JL, LaForge RG, Abrams DB: Challenges to improving the impact of worksite cancer prevention programs: comparing reach, enrollment, and attrition using active versus passive recruitment strategies. Ann Behav Med 2002; 24(2): 157-66. 43. Featherstone K, Donovan JL: "Why don't they just tell me straight, why allocate it?" The struggle to make sense of participating in a randomised controlled trial. Soc Sei Med 2002; 55(5): 709-19. 44. Roosa MW, Liu FF, Torres M, Gonzales NA, Knight GP, Saenz D: Sampling and recruitment in studies of cultural infiuences on adjustment: a case study with Mexican Americans. J Fam Psychol 2008; 22(2): 293-302.
1163
Copyright of Military Medicine is the property of Association of Military Surgeons of the United States and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Recruitment and Attrition Issues in Military Clinical Trials and Health Research Studies Nigel E. Bush, PhD*; CPTSeati C. Sheppard, MSC USAf; Emily Fantelli, BS*; Kathleen R. Bell, MDf; Mark A. Reger, PhD*
INTRODUCTION Military health research has accelerated in recent years, especially since the onset of confiicts in Iraq and Afghanistan and related concems about the medical and psychological impact on service members. Moreover, large-scale military-academic partnerships such as INTRuST,' Army STARRS,^ STRONG STAR, and the Military Suicide Research Consortium"* are conducting long-term multidisciplinary research projects across a range of military health issues. The plethora of individually funded studies, program grants, and multisite military health research consortia speak to the considerable national investment in the well-being of the U.S. service member. In the context of the current economic situation, maximizing efficiency through optimal human subject participation is of paramount importance to research. A range of factors, however, can contribute to less-than-ideal levels of study participation. Poor recruitment and high dropout rates are not only frustrating and costly, but they also pose a threat to the interpretation, integrity, and validity of research findings. A number of articles have reported obstacles to civilian study participation and have outlined strategies for overcoming those obstacles.^"" However, to the best of our knowledge, none have been devoted to the unique challenges inherent to research with military service members. In this commentary, we review the civilian literature for recruitment and retention factors that potentially may also have relevance to military populations. We then examine research study recruitment and attrition in the U.S. military, highlighting militaryspecific issues that may impact study participation. Finally, we suggest strategies for improving research participation by service members.
BACKGROUND Importance of Recruitment and Attrition The goal of a research study is to gain a clear understanding of a population from a study test sample. That generaliz*National Center for Telehealth and Technology, 9933 West Hayes Street, Joint Base Lewis-McChord, Tacoma, WA 98431. fDepartment of Behavioral Health, Madigan Army Medical Center, 9040A Jackson Avenue, Tacoma, WA 98431. tDepartment of Rehabilitation Medicine, University of Washington Health Sciences, 1359 NE Pacific Street, Seattle, WA98195 doi: 10.7205/MILMED-D-13-00234
MILITARY MEDICINE, Vol. 178, November 2013
ability from sample to population depends on having a sufficiently large, representative, and unbiased test sample. An insufficient sample size because of problematic study recruitment and retention reduces a study's power to detect or rule out a clinically meaningful effect.^''^ Moreover, any differential recruitment, selective attrition, or systematic loss to follow-up can lead to biased outcomes that detract from the validity of the study findings and threaten their generalizability.'-'"'^ Consequently, optimal participant recruitment to a test sample and minimal attrition once enrolled is critical to interpretation of study outcomes.
Factors Relating to Recruitment and Attrition in Civilian and Military Health Research Studies Numerous studies, reviews, and reports in the civilian literature have examined factors relating to recruitment and attrition issues. A few publications have provided general overviews, literature reviews, or comprehensive discussions of those issues (e.g., see References 7, 9, and 16). Most however have focused more narrowly on the enrollment and retention of samples with specific health disorders,'^"^° or in particular medical environments.^''°'"'^' In contrast, the military literature is largely devoid of dedicated analyses of service member recruitment and attrition issues. Moreover, there is a scarcity of military health research articles that directly report recruitment/enrollment rates and/or retention/attrition rates, or that cite numbers that allow those rates to be quantified. We recently conducted a search of Ovid Medline, PsychlNFO, and the Cochrane Central Register of Controlled Trials from 2001 to 2012 for studies that (a) explicitly involved active duty military service members in randomized controlled clinical trials and (b) also included quantifiable recruitment or attrition rate information. Only 24 publications met those criteria, and almost all cited study dropout rates but not enrollment rates. Table I shows the variety of individual characteristics that has been associated with a likelihood or disinclination to enroll in research studies. In the absence of instances from military publications, we have gleaned these examples exclusively from the civilian literature. However, many of the difficulties with enrollment and retention in civilian health research summarized in the table likely also apply to their military equivalents.
1157
Commentary TABLE 1
Factors Relating to Recruitment and Attrition in Health Research Studies Recruitment/Enrollment
Participation in Health Research Has Been Shown to Be More Likely for Individuals Who Are: Male Gender Younger^^"^* Age More educated^* Education Have past experience of health issues related to the research topic^^-^^ Health Have a history of volunteerism" Perceive a personal benefit in taking part"-"^-"^ Other Individuals Decline to Participate in Clinical Research^ Because They Have Concerns About: Having to stop ongoing treatments or medications Medical Being randomized to a placebo"* Experiencing adverse effects of an experimental treatment'* The distance to the research location "-""-^^ Logistics and Cost The potential time away from work or family"'-^"-" Disclosing their personal information to researchers^* Privacy The specific study or research in general (distrust, dislike, disinterest)^^ Other *Retention/Attrition Withdrawal From Research Studies Is Commonly Associated With Individuals Who Are: Female"-^^ Male» Gender Age Education Race/Ethnicity Socioeconomic Status
Less educated'"-"-" Racial or ethnic minority"--^^--"*-", (no association''") Of lower socioeconomic status'''' Unemployed"-" Withdrawal From Research Studies Is Commonly Associated With Individuals Who: Perceive a lack of treatment efficacy in clinical trials (dropout to seek effective treatment elsewhere)" Medical Perceive/experience successful treatment during trial (withdraw before the trial has run its course)''^ Have higher levels of depression, hostility, and overall psychosocial distress^' Psychological /Behavioral Have a history of substance abuse -
•Demographic characteristics per se are likely not the reason a study participant drops out. Rather, they may be indicative of issues related to competing life demands, logistical difficulties, financial obstacles, and lack of motivation and commitment.
Recruittnetit and Retention Challenges Unique to the Military Despite the dearth of information in academic texts, our own experience and anecdotal evidence from others suggest that there are substantial difficulties recruiting and retaining health study research participants from military populations, Many of these challenges mirror the civilian experience, but others may be unique to the military culture and environment, A common reason cited for civilian participation in clinical research is to receive personal health benefits and improved access to care.'^'^^ However, as a benefit of military service, free high-quality health care may leave active duty service members less powerfully motivated by potential personal health benefits to participate in clinical research. In addition, although perceived severity of symptoms may reduce attrition rates with civilians, stringent health screening before admittance into the military has resulted in a young, healthy population potentially less likely to. need or desire novel medical interventions commonly evaluated in randomized controlled trials. The effort and inconvenience of research participation (e.g., taking time off work,^° travelling to a research site^'^-') may be exacerbated in the military. For instance, transportation may be a challenge for young service members stationed away from their home of record without motor vehicles,
1158
Furthermore, the detnanding nature of a typical workday in the military and mandatory training requirements may result ¡n supervisors being less supportive of service members being absent to participate in research. Even for routine non-research-related health appointments attendance by service members can be poor. Service members often obtain appointment slips in advance to provide to their command but then fail to attend. Records from our own location show that over an 8-month period in 2012, more than 23% of routine appointments at a busy mental health cUnic in a large military hospital were cancelled or documented as no-shows (J- Etherage, unpublished data, 2012). The transitory and mobile nature of military service also raises significant obstacles to recruitment and retention, especially to extended periods of study participation and follow-up. Active duty service members may change duty stations every 2 to 3 years, and the nature of time-limited obligatory military service contracts leads to significant turnover in the military. Moreover, military deployments in support of peacetime and combat operations often occur without significant warning. Participation in training exercises typically conducted several times throughout the year also takes precedence over participating in clinical research, Finally, National Guard and Reservists, who make up a significant portion of the military population, present unique
MILITARY MEDICINE, Vol. 178, November 2013
Commentary
logistical impediments to recruitment and retention because of their relatively infrequent periods of service (activation/ mobilization one weekend per month) and the fact that they often live further from military installations than their active duty counterparts. Service members are considered by institutional review boards (IRBs) and other regulatory bodies to represent a population especially vulnerable to coercive recruitment practices. This concem stems from the hierarchical structure of the military that affords the chain of command considerable power and influence over subordinate service members. Heightened regulatory protection affects research with service members in several ways. Research with civilians has found that monetary incentives are one important reason for participating in research.''^'-'^ However, federal research funding cannot be used to financially compensate service member subjects for their time or participation. In addition, although endorsement by trusted and influential individuals (e.g., doctors) can be a powerful incentive for research participation,'^ regulatory bodies may limit certain recruitment procedures (e.g., in which the chain of command appears to directly support recruitment) because of concem about potential coercion. In short, the monetary and recruitment strategy restrictions inherent in conducting research with service members can nullify important factors shown to positively impact participation in civilian research. Finally, recent research suggests that the demands of the prolonged recent conflicts and multiple deployments may have contributed to a sense of burnout and fatigue within the military. Indeed, the last several years have seen considerable attention and research funding aimed at improving our understanding of the impact of combat on a range of physical TABLE II.
and mental health outcomes. This, in tum, has resulted in a proliferation of research groups and a sizeable number of research studies that compete for access to the relatively small population that makes up the samples of interest within the U.S. military. When combined with the fact that service members are required to complete multiple physical and mental health screenings both before and after combat deployment, it seems conceivable that recruitment efforts may be hampered by service members who are simply bumed out by multiple requests to participate in research or to complete health questionnaires and other assessments. Table 11 highlights some of the challenges especially pertinent to conducting military health research.
Strategies to Improve Recruitment and Retention in Military Clinical Outcome Research Strategies posited to increase enrollment and minimize attrition have been as varied as the reasons to enroll or decline to participate.^ Table III summarizes evidence-based strategies from the civilian literature that we believe apply equally well to clinical research with the military population. Table III also offers suggestions for how those and other strategies might be adapted and applied to the unique characteristics of the military population and environment. Compared to their civilian counterparts, military service members offer an unusually mobile, transient, and culturally unique research population. Consequently, the vital first step in planning a military health research project must comprise a detailed, realistic, and context-specific assessment of the availability of the target sample for a sufficient period of time, adequate access to the sample, and target participant interest
Military Recruitment and Retention Challenges
Civilian Participants enroll to receive personal health benefits and improved access to care.'*'^^ Perceived severity of symptoms may reduce attrition rates.
Taking time off work,^° travelling to a research site,''^' reduces participation and increases attrition. Research studies often require extended periods of study participation and follow-up. Human subjects health research must meet stringent regulatory requirements and approvals. Overburdening participants with study requirements inhibits enrollment and increases attrition.
Military Military health screening yields young, healthy population potentially less likely to seek novel medical research interventions. Free high-quality health care may leave active duty service members less powerfully motivated by potential personal health benefits to participate in clinical research. Logistics exacerbated in military. Increased difficulties with transportation, longer and more unpredictable work hours, resistance to release from duty. Military service highly (and unpredictably) transient and mobile. Regular changes of duty stations, training and deployment absences, time-limited service contracts. Service members considered by regulatory bodies to be especially vulnerable population. Increased scrutiny on possibility of coercion by chain of command an inappropriate incentives. Very frequent service-mandated health screenings and assessments, and multiple research studies on effects of Operation Enduring Freedom/Operation Iraqi Freedom, have resulted in increased volunteer burnout.
Recruitment advantages: despite the unique challenges to military recruitment and retention, there may also be some advantages for certain study methodologies. The military does offer unique settings in which large groups of individuals are together for predictable periods of time. Important data can be collected from large groups and some factors that contribute to attrition can be minimized while group members are co-located. For instance, studies conducted during basic training have sometimes reported low attrition ^'
MILITARY MEDICINE, Vol. 178, November 2013
1159
Commentary TABLE III.
Strategies to Improve Recruitment and Retention
Evidence-Based Strategies From Civilian Literature
Military-Specific Issues
Provision of transportation shows respect for service member's time and effort. Direct financial incentives for service members generally Incentives prohibited by regulation. Alternatives allowed by some IRBs have included gift cards to reimburse for expenses incurred, and customized coins to recognize participation. Enrollment Referrals Referrals to studies by health professionals have been effective Establish early relationships and support with key individuals important within target military population and unit; with recruitment,'*" as has support by skilled and empathetic and Support e.g., surgeons, behavioral health officers, chaplains, study staff with the decision to participate or not^^ or to stay non-commissioned officers, health care providers. on study once enrolled. Involvement of trusted community Include influential supporters from military community representatives in the design and recruitment stages such as spouses, civilian peers. of studies has been helpful in enrolling volunteers.'" Important venues for advertizing and recruiting include Different methods of study promotion through various media Study Promotion military treatment facilities, outlying satellite and and venues tailored to the target audience have predicted and Recruitment 22,24,40.42 community clinics, community support resources Venues recruitment success. such as education centers, family readiness/support groups, gyms, installations newspapers, commissaries, and exchange services. Consider use of military websites and networks established for service members for research surveying and recruitment. Offer early and detailed study information that clearly Early provision of adequate information about the demands Study Information distinguishes the study from routine or systematic and benefits of a study is key to recruiting new volunteers^'''" and to retaining enrolled individuals."''^ service demands, and which emphasizes the benefits, especially to fellow service members. Leverage both existing military records systems and service Accurate and efficient tracking of study subject contact Tracking information has been paramount in maintaining members' personal technologies to assist effective tracking '"^^ of highly mobile and transitory target populations. Logistics
Practical help with travel logistics can contribute to successful enrollment and reduced attrition."•"••'^•"' Modest monetary incentives have been shown to improve recruitment and retention rates. " " ' ^ '
Study Feasibility
Conduct early (military) context-specific assessment of availability of the target sample for a sufficient period of time, adequate access to the sample, and target participant interest in the project. Consider unique cultural factors: codes of values, respect, benefit to peers. Include dedicated recruitment coordinator, ideally experienced in both the research topic and in conducting military research. Former service members may be especially effective in military research recruiting. Allow extra time, resources, and special expertise for IRB, clinical/scientific reviews, and administrative bureaucracy that may be unique to the military, and which may require multiple reviews through several agencies.
Additional Military-Specific Strategies
Military Culture Staff Familiarity with Military Military-Specific Regulations and Processes
in the project (e.g., service members may be more interested in a study evaluating the impact of a performance enhancer than one testing a new vaccine for tropical diseases). The need to access sufficient potential participants must be balanced against available resources, and feasibility; for example, in the military context this process might involve decisions about whether to recruit at multiple unit locations spread across one or more installations or at one centralized location on one installation (e.g., the hospital). Considering the military as a unique culture is essential to planning and conducting health research with service members. All branches of the military place significant importance on living by a code of values (e.g., loyalty, honor, duty, selfiess service). Developing recruitment materials that emphasize research participation as one way for a service member to live these values shows the researcher's awareness of, and respect for, this aspect of military service. Our experience suggests that service members are highly moti-
1160
vated to participate in research if they believe it ultimately will benefit their military comrades. To better facilitate enrollment in the civilian arena. Bell et al^ recommend allocating room in the budget for a dedicated recruitment coordinator for large studies. Our own previous work also suggests that nearly every study recruiting service members similarly requires a dedicated coordinator, and sometimes a recruitment team, to be successful. For civilian researchers without prior experience with military research, we strongly recommend enlisting the support of someone experienced both in the research topic and in conducting military research. This individual should be used as early as possible to help establish key relationships, predict likely challenges, develop workable solutions, and inform all aspects of the planning process. If possible, we recommend employing a coordinator with previous military service and experience with military research recruitment. Recruitment staff with prior military service can be a distinct advantage in presenting
MILITARY MEDICINE, Vol. 178, November 2013
Commentary
a culturally sensitive'*'* "insider" understanding ofthe demands funded research. However, nominal gift cards have, on occaand values ofthe target audience. sion, been provided explicitly to compensate for expenses For research being conducted at locations (e.g., at military incurred by the participant to participate. In the military, installations) with one or more units (e.g., an Army brigade customized coins are commonly used by leaders to reward comprising a few thousand soldiers), we recommend using minor achievements, and many service members take pride resources within the unit to inform the planning process. in displaying their collection of coins. Offering a customized Although commanders are limited in their ability to directly coin might be a good way to encourage service members encourage participation in research, we recommend building to complete follow-up assessments. For studies requiring the relationships with them for their facility to assist in providing use of tracking or monitoring logs, issuing custom-designed face time with unit. Although regulations are in place to notebooks to fit in the pockets of a service member's uniform avoid the potential for coercion to occur, thoughtful planning might increase compliance. Ingenuity may be required on and coordination can effectively use leader support to posi- behalf of the researcher to develop effective incentives for tively impact recruitment efforts. Developing a relationship participation. These incentives must then be carefully coordiwith the brigade surgeon, brigade behavioral health officer, nated with the ERB to comply with all regulatory requirements. chaplain, and other members of the commander's support Early provision of sufficient information to potential partistaff is paramount. Although it is important to educate the cipants about the demands and benefits of a study can be key Command on the ethical issues involved in military research, to recruiting in civilian research.^^'*^ This may be even more establishing a relationship with the staff will in turn help important when recruiting and retaining service members. the researcher understand the current and predicted training We have described the peculiar demands of frequent health and operational tempo, the command climate, and other unit- assessments, surveying, and screening in the military. We specific factors that can significantly impact the study sched- regularly encounter research candidates who cite study bumules and ability to recruit and retain participants successfully. out and survey-jadedness as reasons for declining to particiUpdating the clinical staff periodically on study progress is pate. It is vital when recruiting service members to offer early also helpful in maintaining support over time. Research with and detailed study information that adequately distinguishes civilian participants further suggests that health care pro- the study from the routine or systematic service demands, viders are especially trusted, and consequently effective, which clearly delineates requirements, and, most imporrecruiters.^'^^ We believe the provider-participant relation- tantly, accurately describes the benefits, especially to fellow ship is no less effective in the military environment. We service members. recommend making early connections with hospital or clinic On large military installations medical care is often proleadership to facilitate the support of their providers in refer- vided in outlying satellite clinics separated from the hospital. ring potential participants. We further suggest explicitly Furthermore, there is a growing movement in the U.S. Army to outlining the potential benefits to providers for their assis- embed complete behavioral health care teams at the brigade tance in recruiting (e.g., the ability to offer novel interven- level to improve access to care. Both types of outlying clinics tions, help reduce busy case-loads). should be considered as potential recruitment locations. InforUnderstanding and navigating the regulatory review pro- mation about studies can be distributed in areas that may be cess also requires careful planning and allocation of resources. frequented by military families; spouses can be enthusiastic IRB and clinical/scientific reviews may be unique to the mili- supporters of participation in research. Community support tary depending on the nature of the funding source. Funding resources such as education centers, family readiness/support by civilian agency or intramural funding at a local military groups, gyms, installations newspapers, and shopping centers installation will require only local IRB approval. Extramural on military installations are potential venues worth considering. federal funding (the most common funding source for military Online media may also provide good avenues for surveying research) requires IRB approval at multiple levels ranging and study recruitment; our own recent experience has shown from local institution IRB through several levels of centralized that posting of online questionnaires and study enrollment federal agency review. Often this necessitates the preparation information on widely used service websites such as Army of multiple versions of proposals and related regulatory docu- Knowledge Online, and through social media, has promise. ments. Extramural research conducted at multiple sites adds Offering transportation to and from study sites supports additional layers of review to what already can be an arduous enrollment and retention efforts, especially for studies process. We recommend that researchers new to military recruiting and testing multiple participants over short periods research seek guidance from local regulatory bodies and of time (e.g., focus groups, groups of patients scheduled at certainly plan for the often lengthy review process so that short intervals). In those instances, providing group transporsufficient time remains within the funding cycle to recruit par- tation is more efficient than expecting individuals to use their ticipants successfully. Sharing documents across civilian and own vehicles. More generally, the offer of transportation military IRB committees may assist in resolving differences. to study candidates shows respect for service member's time Regulations generally prohibit direct financial incentives and effort. Bell et al^ present a useful list of suggestions to reimburse service members for participating in federally to maintain or reestablish contact with civilian participants
MILITARY MEDICINE, Vol. 178, November 2013
1161
Commentary
over the course of a study. The structure and accountability in the military affords some advantages in those respects. Contact information for service members typically is well maintained and is generally more accessible than for civilian counterparts. During the consent process we suggest asking the subject if they are scheduled to change duty locations (service members often know weeks or even months in advance of pending moves). Asking about pending deployments, plans to separate from the service, and upcoming training rotations will provide the researcher with important information about suitability for inclusion in the study. We also recommend seeking permission to contact the service member's military organization to assist in locating the subject in case of missed foUow-ups. If permission is granted, it will be important to accurately and completely document the subject's unit beginning at the lowest level (e.g., company) as well as one or two superordinate commands (e.g., battalion, brigade). It may also be helpful to collect the contact information for the service member's lowest level commander. Knowing the commander's contact information can be helpful for two reasons. First, the commander can help locate the service member in the event of a unit change or training deployment. Second, follow-up appointment reminders can be sent directly to the commander as well as to the service member. This can help facilitate unit support of attendance of follow-up appointments, particularly for junior enlisted personnel. Finally, we recommend the use of personal technologies (texting, mobile apps with calendar reminder functions, email) to most efficiendy maintain contact with participants, to notify them about pending follow-up appointments, and to decrease attrition overall. CONCLUSION Robust recruitment and retention in clinical research trials continues to be a source of concern to researchers in both civilian and military contexts. Study investigators should carefully consider both general and military-specific recruitment challenges before starting a study and invest adequate resources to accommodate them. Similar creativity should be applied to maintaining contact with highly mobile military research participants and encouraging their completion of the study, including easy access to outcome assessments. Addressing these concems even at the grant writing stage may result in higher study completion rates and more reliable data. REFERENCES 1. INTRuST: The Injury and Traumatic Stress Consortium 2012. Available at http://intnjst.sdsc.edu/; accessed October 24, 2012. 2. Army STARRS: Army Study To Assess Risk and Resilience in Servicemembers. 2012. Available at http://www.armystarrs.org/; accessed October 24, 2012. 3. STRONG STAR: The South Texas Research Organizational Network Guiding Studies on Trauma and Resilience. 2012 Available at www .strongstar.org; accessed October 24, 2012. 4. The Military Suicide Research Consortium. 2012. Available at https:// msrc.fsu.edu/; accessed October 24, 2012.
1162
5. Bell KR, Hammond F, Hart T, Bickett AK, Temkin NR, Dikmen S: Participant recruitment and retention in rehabilitation research. Am J Phys Med Rehabil 2008; 87(4): 330-8. 6. Berger AM, Neumark DE, Chamberlain J: Enhancing recruitment and retention in randomized clinical trials of cancer symptom management. Oncol Nurs Forum 2007; 34(2): E17-22. 7. Lovato LC, Hill K, Hertert S, Hunninghake DB, Probstfield JL: Recruitment for controlled clinical trials: literature summary and annotated bibliography. Control Clin Trials 1997; 18(4): 328-52. 8. Roberg K, Carlson-Dakes K, Anderson B: The key to successful recruitment and retention in clinical research programs. Monitor 2006(June): 13-16. 9. Ross S, Grant A, Counsell C, Gillespie W, Russell I, Prescott R: Barriers to participation in randomised controlled trials: a systematic review. J Clin Epidemiol 1999; 52(12): 1143-56. 10. Tansey CM, Matte AL, Needham D, Herridge MS: Review of retention strategies in longitudinal studies and application to follow-up of ICU survivors. Intensive Care Med 2007; 33(12): 2051-7. 11. Cofield SS, Conwit R, Barsan W, Quinn J: Recruitment and retention of patients into emergency medicine clirUcal trials. Acad Emerg Med 2010; 17(10): 1104-12. 12. Cohen J: Statistical Power Analysis for the Behavioral Sciences. Ed 2. Hillsdale, NJ, Lawrence Erlbaum Associates, 1988. 13. Demark-Wahnefried W, Bowen DJ, Jabson JM, Paskett ED: Scientific bias arising from sampling, selective recruitment, and attrition: the case for improved reporting. Cancer Epidemiol Biomarkers Prev 2011 ; 20(3): 415-8. 14. Higgins JPT, Altman DG (editors). Chapter 8: Assessing risk of bias in included studies. Cochrane Handbook for Systematic Reviews of Interventions. Version 5.01: The Cochrane Collaboration; 2008. Available at www.cochrane-handbook.org; accessed October 5, 2012. 15. Lundh A, Gotzsche PC: Recommendations by Cochrane Review Groups for assessment of the risk of bias in studies. BMC Med Res Methodol 2008; 8: 22. 16. Davis LL, Broome ME, Cox RP: Maximizing retention in communitybased clinical trials. J Nurs Scholarsh 2002; 34(1): 47-53. 17. Chang BH, Hendricks AM, Slawsky MT, Locastro JS: Patient recruitment to a randomized clinical trial of behavioral therapy for chronic heart failure. BMC Med Res Methodol 2004; 4: 8. 18. Halpem SD, Karlawish JH, Casarett D, Berlin JA, Townsend RR, Asch DA: Hypertensive patients' willingness to participate in placebo-controlled trials: implications for recruitment efficiency. Am Heart J 2003; 146(6): 985-92. 19. Gucciardi E, DeMelo M, Offenheim A, Grace SL, Stewart DE: Patient factors associated with attrition from a self-management education programme. J Eval Clin Pract 2007; 13(6): 913-19. 20. Lowton K: Trials and tribulations: understanding motivations for clinical research participation amongst adults with cystic fibrosis. Soc Sei Med 2005; 61(8): 1854.-65. 21. Blanton S, Morris DM, Prettyman MG, et al: Lessons learned in participant recruitment and retention: the EXCITE trial. Phys Ther 2006; 86(11): 1520-33. 22. Glasgow RE, Nelson CC, Kearney KA, et al: Reach, engagement, and retention in an Internet-based weight loss program in a multi-site randomized controlled trial. J Med Internet Res 2007; 9(2): e l l . 23. Corbie-Smith G, Viscoli CM, Kernan WN, Brass LM, Sarrel P, Horwitz RI: Influence of race, clinical, and other socio-demographic features on trial participation. J Clin Epidemiol 2003; 56(4): 304-9. 24. Haring R, Alte D, Volzke H, et al: Extended recruitment efforts minimize attrition but not necessarily bias. J Clin Epidemiol 2009; 62(3): 252-60. 25. Wright JR, Whelan TJ, Schiff S, et al: Why cancer patients enter randomized clinical trials: exploring the factors that infiuence their decision. J Clin Oncol 2004; 22(21): 4312-18. 26. Phipps E, Harris D, Brown N, et al: Investigation of ethnic differences in willingness to enroll in a rehabilitation research registry: a study
MILITARY MEDICINE, Vol. 178, November 2013
Commentary
27.
28.
29.
30.
31. 32.
33.
34.
35.
of the Northeast Cognitive Rehabilitation Research Network. Am J Phys Med Rehabil 2004; 83(12): 875-83. Honas JJ, Early JL, Frederickson DD, O'Brien MS: Predictors of attrition in a large clinic-based weight-loss program. Obes Res 2003; 11(7): 888-94. Janson SL, Alioto ME, Boushey HA: Attrition and retention of ethnically diverse subjects in a multicenter randomized controlled research trial. Control Clin Trials 2001; 22(Suppl 6): 236S-43S. Moser DK, Dracup K, Doering LV: Factors differentiating dropouts from completers in a longitudinal, multicenter clinical trial. Nurs Res 2000; 49(2): 109-16. Warden D, Trivedi MH, Wisniewski SR, et al: Predictors of attrition during initial (citalopram) treatment for depression: a STAR*D repon. Am J Psychiatry 2007; 164(8): 1189-97. Zook PM, Jordan C, Adams B, et al: Retention strategies and predictors of attrition in an urban pédiatrie asthma study. Clin Trials 2010; 7(4): 400—10. El-Khorazaty MN, Johnson AA, Kiely M, et al: Recruitment and retention of low-income minority women in a behavioral intervention to reduce smoking, depression, and intimate partner violence during pregnancy. BMC Public Health 2007; 7: 233. Corrigan JD, Harrison-Felix C, Bogner J, Dijkers M, Terrill MS, Whiteneck G: Systematic bias in traumatic brain injury outcome studies because of loss to follow-up. Arch Phys Med Rehabil 2003; 84(2): 153-60. Sangi-Haghpeykar H, Meddaugh HM, Liu H, Grino P: Attrition and retention in clinical trials by ethnic origin. Contemp Clin Trials 2009; 30(6): 499-503. Lurie I, Levine SZ: Meta-analysis of dropout rates in SSRIs versus placebo in randomized clinical trials of PTSD. J Nerv Ment Dis 2010; 198(2): 116-24.
MILITARY MEDICINE, Vol. 178, November 2013
36. Kissinger P, Kopicko JJ, Myers L, et al: The effect of modest monetary incentives on follow-up rates in sexually transmitted disease studies. Int J STD AIDS 2000; 11(1): 27-30. 37. van Gelderen CE, Savelkoul TJ, van Dokkum W, Meulenbelt J: Motives and perception of healthy volunteers who participate in experiments. Eur J Clin Pharmacol 1993; 45(1): 15-21. 38. Marmar CR. Mental health impact of Afghanistan and Iraq deployment: meeting the challenge of a new generation of veterans. Depress Anxiety 2009; 26(6): 493-7. 39. Haddock CK, Lando HA, Pyle SA, et al: Prediction of adult-onset smoking initiation among U.S. Air force recruits using the pierce susceptibility questionnaire. Am J Prev Med 2005; 28(5): 424-9. 40. Peindl KS, Wisner KL: Successful recruitment strategies for women in postpartum mental health trials. J Psychiatr Res 2003; 37(2): 117-25. 41. De las Nueces D, Hacker K, DiGirolamo A, Hicks LS: A systematic review of community-based participatory research to enhance clinical trials in racial and ethnic minority groups. Health Serv Res 2012; 47(3 Pt 2): 1363-86. 42. Linnan LA, Emmons KM, Klar N, Fava JL, LaForge RG, Abrams DB: Challenges to improving the impact of worksite cancer prevention programs: comparing reach, enrollment, and attrition using active versus passive recruitment strategies. Ann Behav Med 2002; 24(2): 157-66. 43. Featherstone K, Donovan JL: "Why don't they just tell me straight, why allocate it?" The struggle to make sense of participating in a randomised controlled trial. Soc Sei Med 2002; 55(5): 709-19. 44. Roosa MW, Liu FF, Torres M, Gonzales NA, Knight GP, Saenz D: Sampling and recruitment in studies of cultural infiuences on adjustment: a case study with Mexican Americans. J Fam Psychol 2008; 22(2): 293-302.
1163
Copyright of Military Medicine is the property of Association of Military Surgeons of the United States and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
