Clinic-Based Glaucoma Care in the Era of Surgical Subspecialization ROBERT J. CAMPBELL, CHAIM M. BELL, SUDEEP S. GILL, MARLO WHITEHEAD, ERICA DE L.P. CAMPBELL, KUNYONG XU, AND SHERIF R. EL-DEFRAWY PURPOSE: To evaluate the impact of surgeon practice profile on clinic-based glaucoma care. DESIGN: Population-based study of glaucoma care patterns in Ontario, Canada from 2000-2010. METHODS: Using comprehensive physician services data from the Ontario Health Insurance Plan database, ophthalmologists were divided into 5 surgical practice subgroups. The role of each subgroup in the provision of glaucoma care was evaluated. Consultations and office visits were used to assess nonsurgical care, while laser trabeculoplasty procedures were used to assess clinicbased procedural care. RESULTS: Between 2000 and 2010, the population rate of glaucoma consultations and follow-up visits provided by ophthalmologists who do not perform incisional glaucoma surgery increased at average annual rates of 1.6% (P < .0002) and 3.3% (P < .0001), respectively. In contrast, no significant growth in the rate of glaucoma consultations or follow-up visits provided by glaucoma surgeons was observed (0.8%/year [P [ .2] for consultations; 0.2%/year [P [ .6] for follow-up visits). Between 2000 and 2010, the rate of laser trabeculoplasty procedures provided by ophthalmologists who do not perform incisional glaucoma surgery increased 19.3% annually (P < .0001), while growth among glaucoma surgeons was more modest (annual growth of 9.2% [P [ .0002]). CONCLUSIONS: While subspecialization is a growing reality in most areas of medicine, we found that the provision of clinic-based glaucoma care remains dependent on ophthalmologists who do not perform incisional
Accepted for publication Nov 22, 2013. From the Department of Ophthalmology (R.J.C., E. de L.P.C., K.X.) and Division of Geriatric Medicine (S.S.G.), Queen’s University, Kingston, Ontario, Canada; Department of Ophthalmology, Hotel Dieu and Kingston General Hospitals, Kingston, Ontario, Canada (R.J.C., E. de L.P.C., K.X.); Institute for Clinical Evaluative Sciences – Queen’s University Site, Queen’s University, Kingston, Ontario, Canada (R.J.C., S.S.G., M.W.); Institute for Clinical Evaluative Sciences – Sunnybrook Site, Toronto, Ontario, Canada (C.M.B.); Departments of Medicine (C.M.B.), Health Policy Management and Evaluation (C.M.B.), and Ophthalmology (S.R.E.), University of Toronto, Toronto, Ontario, Canada; Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada (C.M.B.); Division of Geriatric Medicine, St. Mary’s of the Lake Hospital, Kingston, Ontario, Canada (S.S.G.); Queen’s University, Kingston, Ontario, Canada (M.W.); and Department of Ophthalmology, Kensington Eye Institute, Toronto, Ontario, Canada (S.R.E.). Inquiries to Dr Robert J. Campbell, Department of Ophthalmology, Hotel Dieu Hospital, 166 Brock Street, Kingston, Ontario, Canada, K7L 5G2; e-mail: [email protected] 0002-9394/$36.00 http://dx.doi.org/10.1016/j.ajo.2013.11.019
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glaucoma surgery. With increasing focus on integrated care, these findings will have important implications for residency education programs and their accrediting bodies and will inform decisions of health care policymakers, hospitals, and academic departments. (Am J Ophthalmol 2014;157:631–639. Ó 2014 by Elsevier Inc. All rights reserved.)
G
LAUCOMA IS THE LEADING CAUSE OF IRREVERS-
ible blindness in the world, and it underlies a large portion of the population eye disease burden, trailing only cataract and refractive error in public health need and demand for health services.1,2 Further, because the risk of glaucoma grows exponentially with age, many nations will face accelerating growth in glaucoma prevalence as their populations age.3 This has focused attention on the need for health human resource strategies to meet the challenges ahead.4–6 While facing a future of growing demand for most health services, the delivery of health care has steadily shifted toward greater levels of subspecialization in recent years.7,8 Consequently, the American Board of Medical Specialties (ABMS) now recognizes more than 150 specialties and subspecialties.9 We have previously shown that surgical glaucoma care has increasingly become the purview of a shrinking number of high-volume subspecialists.10 The surging need for interventional care for diseases such as cataract and acute conditions such as neovascular age-related macular degeneration raise the specter of diminishing access to nonsurgical aspects of care in the management of chronic diseases such as glaucoma.11,12 However, little is known about how the delivery of clinic-based aspects of glaucoma care is distributed among ophthalmologist subtypes. Such evidence is not only important to the process of aligning health human resources with population needs, but it is also critical in implementing efficient models of care that incorporate the realities of front-line practice. Such information will also inform decisions regarding the competencies to be attained in residency, and in rationally planning the specific types of training positions to be offered to meet population needs.13,14 In particular, certification and accreditation organizations including the ABMS, the American Board of Ophthalmology (ABO), the Accreditation Council for Graduate Medical Education (ACGME), and the Royal College of Physicians and Surgeons of Canada (RCPSC) use such
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data to inform policies.8,14,15 Hence, we carried out a population-based study to evaluate the relative roles of glaucoma surgeons and other ophthalmologists in the provision of clinic-based glaucoma care.
METHODS WE CONDUCTED A POPULATION-BASED RETROSPECTIVE
study of glaucoma care in Ontario, Canada between January 1, 2000, and December 31, 2010. Ontario is Canada’s most populous province, with a population of about 13 million individuals during the study period. The study protocol was approved by the Research Ethics Board at Queen’s University, Kingston, Ontario, Canada. Patient confidentiality was maintained via encrypted health care identification numbers and strict adherence to privacy protocols. The province of Ontario provides government-funded universal health care insurance to all citizens through the Ontario Health Insurance Plan (OHIP). Physician services data were obtained from the OHIP database, which has excellent reliability for recording medical and surgical procedures.16 Ontario physicians receive payment for insured services only through OHIP, and cannot bill patients directly. All of the physician encounters, laser procedures, and surgical interventions evaluated in this study are insured under the OHIP program. Hence, the OHIP database contains complete data for all Ontario physicians regarding the procedures and physician encounters analyzed in this study. PHYSICIAN ENCOUNTERS AND LASER PROCEDURES FOR GLAUCOMA: To investigate developments in clinic-based
glaucoma care, we evaluated glaucoma office visits and outpatient laser trabeculoplasty procedures but excluded incisional glaucoma surgery. Specifically, in separate analyses, we evaluated physician-requested glaucoma consultations (OHIP code A235 associated with International Statistical Classification of Diseases and Related Health Problems, Ninth Revision [ICD-9] code 365) and followup or optometrist-requested ophthalmology clinic visits for glaucoma (‘‘specific assessment’’ [OHIP code A233] or ‘‘partial assessment’’ [OHIP code A234] or ‘‘optometristrequested assessment’’ [OHIP code 253] associated with ICD-9 code 365). In Ontario, physician-requested and optometrist-requested consultations are coded distinctly in the OHIP database, and optometrist-requested assessments cannot be billed as regular physician-requested assessments. Optometrist-requested assessments were given their own OHIP physician billing code in 2009, but prior to that date, such assessments had to be coded as regular office visits (‘‘specific’’ or ‘‘partial’’ assessments). Thus, in order to allow longitudinal evaluation of trends we grouped these 3 types of assessments together to provide a consistent 632
measure of glaucoma care distinct from physicianrequested consultations. During the study period, glaucoma therapies could only be prescribed by physicians and not by optometrists. Hence all patients requiring therapy were referred to and treated by ophthalmologists. Finally, in addition to these evaluations of clinic-based medical glaucoma care, we examined nonincisional glaucoma procedural care by evaluating clinic-based laser trabeculoplasty procedures (OHIP code E134). Notably, our population-based study evaluated data for all ophthalmologist office visits and laser trabeculoplasty procedures. In the US system, this would correspond to capturing all office visits and laser trabeculoplasty procedures regardless of provider, patient demographics, or insurance carrier. SURGICAL PRACTICE PROFILES:
We investigated the influence of ophthalmologists’ surgical practice profiles (mix of procedures provided) on the provision of clinicbased glaucoma care by dividing ophthalmologists into mutually exclusive categories based on the types of ocular surgery they perform (if any). With the aim of identifying clinically relevant groupings, we categorized ophthalmologists as: (1) glaucoma surgeons, defined as those providing incisional glaucoma surgery with or without cataract surgery; (2) nondiversified cataract surgeons, defined as those providing cataract surgery but no other forms of ocular surgery (glaucoma, vitreoretinal, corneal, or strabismus surgery); (3) diversified cataract surgeons, defined as those providing both cataract surgery and other forms of nonglaucoma ocular surgery (vitreoretinal, corneal, or strabismus surgery); (4) non–glaucoma/non–cataract surgeons, defined as those doing vitreoretinal, corneal, or strabismus surgery but neither glaucoma surgery nor cataract surgery; and (5) ophthalmologists who do not perform incisional ocular surgery, defined as those not providing incisional glaucoma, cataract, vitreoretinal, corneal, or strabismus surgery. These groupings were created for each year of the study, based on procedures performed between January 1 and December 31 of that year.
ANALYSIS AND DATA SOURCES: We divided the study period into yearly intervals and, within each interval, evaluated the number of ophthalmologists providing each glaucoma service and the number of glaucoma services provided by each physician. Poisson regression was used to estimate the average annual change in glaucoma service rates. Data regarding each ophthalmologist were obtained from the Institute for Clinical Evaluative Sciences (ICES) Physician Database, which comprises information from the OHIP Corporate Provider Database, the Ontario Physician Human Resource Data Centre database, and the OHIP database of physician billings. The ICES Physician Database is validated through telephone interviews with all physicians practicing in Ontario and has been used in previous studies of physician practice.10,17,18 Yearly
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postcensal and intercensal population estimates were obtained from Statistics Canada.19,20
RESULTS THE OVERALL RATE OF PHYSICIAN ENCOUNTERS FOR GLAU-
coma (consultations and follow-up clinic visits) increased by 18.5%, growing from 25.9 to 30.7 per 1000 population per year between 2000 and 2010 (average annual increase of 1.7%, P < .0001). However, between 2000 and 2010, glaucoma surgeons played a declining role in the provision of clinic-based glaucoma care. In particular, glaucoma surgeons provided a decreasing proportion of consultations and other clinic assessments for glaucoma and performed a diminishing fraction of laser trabeculoplasty procedures. Moreover, no significant growth in the rate of glaucoma consultations or follow-up visits provided by glaucoma surgeons was observed (0.8%/year [P ¼ .2] for consultations; 0.2%/year [P ¼ .6] for follow-up visits). In contrast, over this period the population rate of glaucoma consultations provided by ophthalmologists who do not perform incisional glaucoma surgery increased at an average annual rate of 1.6% (P < .0002). Further, over this period, the proportion of glaucoma consultations provided by this subgroup increased by 10.2%. Similarly, the rate of glaucoma follow-up visits provided by ophthalmologists who do not perform incisional glaucoma surgery increased at an average annual rate of 3.3% (P < .0001). This led to a 14.3% increase in the proportion of glaucoma follow-up visits provided by this subgroup. Among the subgroups, nondiversified cataract surgeons showed the greatest increase in physician encounters for glaucoma. Specifically, the rate of glaucoma consultations provided by this subgroup increased at an average annual rate of 3.1% (P < .0001), leading to 31.3% growth in the proportion of glaucoma consultations provided by nondiversified cataract surgeons (Figure 1). Further, the rate of glaucoma follow-up visits provided by nondiversified cataract surgeons increased at an average annual rate of 6.4% (P < .0001). Correspondingly, the proportion of glaucoma follow-up clinic visits provided by ophthalmologists in this subgroup increased by 40.1% over the study period (Figure 2). This increased contribution to glaucoma care provided by nondiversified cataract surgeons was mediated by growth in the proportion of ophthalmologists limiting their surgical practice to cataract surgery (ie, greater numbers of nondiversified cataract surgeons) and not by an increase in the per-physician rates of consultations or office visits for glaucoma among nondiversified cataract surgeons (Figures 3 and 4). Indeed, while the number of nondiversified cataract surgeons grew by 46.5% over the study period, the numbers of consultations and other office visits for glaucoma per physician remained stable in this subgroup (Figures 3 and 4). VOL. 157, NO. 3
Between 2000 and 2010, the rate of laser trabeculoplasty procedures provided by ophthalmologists who do not perform incisional glaucoma surgery increased at an average annual rate of 19.3% (P < .0001), while growth among glaucoma surgeons was more modest (annual growth of 9.2% [P ¼ .0002]). As a consequence, the proportion of laser trabeculoplasty procedures provided by non–glaucoma surgeons increased by 43.0% (Figure 5). Subgroup analyses showed that the percentage of laser trabeculoplasty procedures performed by ophthalmologists who do not perform any incisional ocular surgery more than doubled over the study period, corresponding to a 26.3% average annual increase in the procedure rate within this subgroup (P < .0001; Figure 5). Further, the proportion of laser trabeculoplasty procedures performed by nondiversified cataract surgeons increased by 33.7%, corresponding to an average annual increase in the population procedure rate of 19.4% within this subgroup (P < .0001; Figure 5). In both these subgroups the increased contribution to the provision of laser trabeculoplasty procedures was mediated by the combined effects of increasing numbers of ophthalmologists in the subgroup and the significant growth in the number of procedures done per physician, particularly among high-volume providers (Figures 6 and 7). Specifically, the 95th percentile for laser trabeculoplasty procedure volume increased by 587.0% (from 69 to 474 procedures/year) and 246.5% (from 71 to 246 procedures/year) among ophthalmologists who do not perform incisional ocular surgery and nondiversified cataract surgeons, respectively.
DISCUSSION SUBSPECIALIZATION IS A GROWING REALITY IN MOST
areas of medicine. We have previously shown that incisional glaucoma surgery has increasingly become the purview of high-volume glaucoma subspecialists.10 Nevertheless, our present population-based study found that clinic-based glaucoma care remains dependent on ophthalmologists who do not perform glaucoma surgery. Between 2000 and 2010, surgeons who do not perform incisional glaucoma surgery provided an increasing proportion of consultations and clinic assessments for glaucoma and performed a growing fraction of laser trabeculoplasty procedures. Ophthalmologists who do not perform incisional ocular surgery and nondiversified cataract surgeons showed the greatest increases in the proportion of clinic-based glaucoma care provided. However, despite the recent declines that we have found, glaucoma surgeons continue to provide a significant component of clinic-based glaucoma care. The increased use of laser trabeculoplasty observed across physician categories coincided with the introduction of selective laser trabeculoplasty (SLT), and it is likely that
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FIGURE 1. Percentage of glaucoma consultations provided by ophthalmologist subgroups, 2000-2010. Trend lines indicate percentage of glaucoma consultations performed by glaucoma surgeons, diversified cataract surgeons, nondiversified cataract surgeons, non–glaucoma/non–cataract surgeons, and ophthalmologists who do not perform incisional ocular surgery.
FIGURE 2. Percentage of glaucoma follow-up clinic visits provided by ophthalmologist subgroups, 2000-2010. Trend lines indicate percentage of glaucoma follow-up clinic visits performed by glaucoma surgeons, diversified cataract surgeons, nondiversified cataract surgeons, non–glaucoma/non–cataract surgeons, and ophthalmologists who do not perform incisional ocular surgery.
perceptions regarding the safety and repeatability of SLT underpinned the overall growth in procedure rates. A major strength of our study from a single-payer health care system was the ability to analyze data from all physicians within a large population. Further, our ability to access comprehensive surgical practice data from all 634
ophthalmologists enhanced our analysis by allowing us to stratify ophthalmologists based on their overall surgical practice profile. To the best of our knowledge, this is the first population-based study to track developments in the types of ophthalmologists providing clinic-based glaucoma care. There are limitations to our study that warrant
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FIGURE 3. Distribution of glaucoma consultations provided by nondiversified cataract surgeons. Box plot of glaucoma consultations performed by nondiversified cataract surgeons (2000-2010), with superimposed line graph showing the percentage of ophthalmologists formed by the nondiversified cataract surgeon group. The dividing line in each box indicates the median number of consultations per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
FIGURE 4. Distribution of glaucoma follow-up clinic visits provided by nondiversified cataract surgeons. Box plot of glaucoma follow-up clinic visits performed by nondiversified cataract surgeons (2000-2010), with superimposed line graph showing the percentage of ophthalmologists formed by the nondiversified cataract surgeon group. The dividing line in each box indicates the median number of consultations per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
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FIGURE 5. Percentage of laser trabeculoplasty procedures provided by ophthalmologist subgroups, 2000-2010. Percentage of laser trabeculoplasty procedures performed by glaucoma surgeons, diversified cataract surgeons, nondiversified cataract surgeons, non–glaucoma/non–cataract surgeons, and ophthalmologists who do not perform incisional ocular surgery.
FIGURE 6. Percentage of laser trabeculoplasty procedures provided by nondiversified cataract surgeons. Box plot of laser trabeculoplasty procedures performed by nondiversified cataract surgeons (2000-2010), with superimposed line graph showing the percentage of ophthalmologists formed by the nondiversified cataract surgeon group. The dividing line in each box indicates the median number of procedures per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
highlighting. While the accuracy of the administrative data sources used is excellent, the potential for coding errors exists. Additionally, although Ontario’s population demographics 636
and the technical approach to glaucoma care among the province’s ophthalmologists mirror those in the US, our results may not be generalizable to all jurisdictions.21,22
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FIGURE 7. Distribution of laser trabeculoplasty procedures provided by ophthalmologists who do not perform incisional ocular surgery. Box plot of laser trabeculoplasty procedures performed by ophthalmologists who do not perform incisional ocular surgery (20002010), with superimposed line graph showing the percentage of ophthalmologists formed by ophthalmologists who do not perform incisional ocular surgery. The dividing line in each box indicates the median number of procedures per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
Previous survey-based studies of comprehensive (general) ophthalmologists have suggested that most comprehensive ophthalmologists provide glaucoma care.23,24 However, these studies were not able to quantify the overall contributions of different types of ophthalmologists. Previous studies have also documented differences in glaucoma care processes between comprehensive ophthalmologists and glaucoma subspecialists.25–28 Our findings that ophthalmologists who do not perform incisional glaucoma surgery provide a large and growing portion of clinic-based glaucoma care suggest that these differences may have important effects at a population level. However, although evidence suggests that provider specialization improves outcomes in some clinical situations, the magnitude of the effect is highly variable and the relative contributions of the provider vs the provider’s clinical environment remain unclear.29,30 Though limited data suggest that glaucoma surgical success may be affected by surgeon volume and training,31 further research is needed regarding the relationship between glaucoma outcomes and the type of ophthalmologist providing clinic-based aspects of care. Despite increasing surgical subspecialization in glaucoma, the growing contribution of non–glaucoma surgeons to the clinic-based aspects of glaucoma care emphasizes the need for accreditation and certification organizations including the ACGME, ABO, and the RCPSC to ensure VOL. 157, NO. 3
broad-based training in glaucoma in both residency and continuing medical education settings. Further, in combination with our previous work showing that glaucoma surgery has increasingly become a subspecialty field, our current findings suggest that a growing number of patients are referred to a glaucoma subspecialist only at the time of needing surgery. This development emphasizes the importance of systems that support excellent communication among care providers involved in glaucoma treatment. Our finding that ophthalmologists are increasingly limiting their incisional surgical practice to cataract surgery, coupled with the downward trend in the proportion of trainees pursuing glaucoma fellowships, will likely lead to even greater separation between the providers of surgical and nonsurgical glaucoma care in the coming years.32 Further, the rapidly growing need for interventional care for many eye diseases, including cataract and retinal diseases, has commanded a growing proportion of ophthalmologist time in recent years.11,12 This raises concerns regarding the sustainability of access to clinic-based care for chronic diseases such as glaucoma, as competing acute-care demands for ophthalmology resources—human and otherwise—continue to mount.33 In summary, using a population-based approach, we found that ophthalmologists who do not perform incisional glaucoma surgery provide a large and growing portion of clinic-based glaucoma care, and that specific
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subtypes of ophthalmologists have dominated these trends. With increasing focus on integrated care, these findings will have important implications for residency
education programs and their accrediting bodies and will inform decisions of health care policymakers, hospitals, and academic departments.
ALL AUTHORS HAVE COMPLETED AND SUBMITTED THE ICMJE FORM FOR DISCLOSURE OF POTENTIAL CONFLICTS OF INTEREST and none were reported. Dr R.J. Campbell is supported by a Clinician Scientist Award from the Southeastern Ontario Academic Medical Organization, Kingston, Ontario, Canada. Dr Gill is supported by Canadian Institutes of Health Research New Investigator Awards from the Institute of Aging, Ottawa, Ontario, Canada. Dr Bell is supported by a Canadian Institutes of Health Research and Canadian Patient Safety Institute chair in Patient Safety and Continuity of Care, Ottawa, Ontario, Canada. Contributions of authors: design and conduct of the study (R.J.C.); collection, management, analysis, and interpretation of the data (R.J.C., C.M.B., S.S.G., M.W., E. de L.P.C., K.X., S.R.E.); drafting of the manuscript (R.J.C.); critical revision of the manuscript for important intellectual content (R.J.C., C.M.B., S.S.G., M.W., E. de L.P.C., K.X., S.R.E.); statistical analysis (R.J.C., M.W., E. de L.P.C., K.X.); administrative, technical, or material support (M.W., E. de L.P.C.); obtaining funding (R.J.C.); study supervision (R.J.C.). In accordance with the Personal Health Information Protection Act (PHIPA) of Ontario, the raw administrative data used for statistical analyses in this manuscript may only be accessed by agents of the Institute for Clinical Evaluative Sciences (ICES), a prescribed entity under Section 45 of the Act, for the purposes of conducting research that contributes to the effectiveness, quality, equity, and efficiency of health care and health services. Dr R.J. Campbell is an agent of ICES and had full control over the data definitions and analyses used in this manuscript. Dr R.J. Campbell had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The sponsors of this study had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and the decision to submit for publication. This study was supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred.
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22. Campbell RJ, Trope GE, Rachmiel R, Buys YM. Glaucoma laser and surgical procedure rates in Canada: a long-term profile. Can J Ophthalmol 2008;43(4):449–453. 23. Shingleton BJ, Crandall A, Johnstone M, Robin A, Brown R. Medical treatment patterns of ASCRS members for primary open-angle glaucoma—1998 survey. J Cataract Refract Surg 1999;25(1):118–127. 24. Brown RH, Shingleton BJ, Johnstone M, Crandall A, Robin A. Glaucoma laser treatment parameters and practices of ASCRS members—1999 survey. J Cataract Refract Surg 2000;26(5):755–765. 25. Boland MV, Quigley HA, Lehmann HP. The impact of physician subspecialty training, risk calculation, and patient age on treatment recommendations in ocular hypertension. Am J Ophthalmol 2011;152(4):638–645. 26. Hertzog LH, Albrecht KG, LaBree L, Lee PP. Glaucoma care and conformance with preferred practice patterns. Examination of the private, community-based ophthalmologist. Ophthalmology 1996;103(7):1009–1013. 27. Albrecht KG, Lee PP. Conformance with preferred practice patterns in caring for patients with glaucoma. Ophthalmology 1994;101(10):1668–1671.
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Biosketch Dr Robert J. Campbell, MD, MSc, is Deputy Chair of and Associate Professor with the Department of Ophthalmology at Queen’s University, Kingston, Canada. He is also a scientist with the Institute for Clinical Evaluative Sciences, Ontario, Canada, and leads an internationally-recognized health services research program focused on the assessment of eye and vision health care quality, access and safety. Dr Campbell graduated Summa Cum Laude and Valedictorian, and completed ophthalmology training at the University of Ottawa. Dr Campbell undertook fellowship training in glaucoma surgery at the University of Toronto and cornea surgery at Moorfields Eye Hospital.
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Biosketch Dr Sherif El-Defrawy, MD, PhD, is Professor and Chair of the Department of Ophthalmology and Vision Sciences at the University of Toronto and the Ophthalmologist-in-Chief at Kensington Eye Institute. He is also co-Chair of the Eye Health Council of Ontario. He is a Past President of the Canadian Ophthalmological Society and the Association of Canadian University Professors of Ophthalmology. Dr El-Defrawy received his Medical Degree from the University of Calgary in 1989 and residency in Ophthalmology at the University of Ottawa. He joined the University of Ottawa Eye Institute in 1995 and was Residency Program Director there from 1999-2004. He was Professor and Chair of the Department of Ophthalmology at Queen’s University, and Ophthalmologist-in-Chief at the University Hospitals in Kingston from 2004-2012.
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Accepted for publication Nov 22, 2013. From the Department of Ophthalmology (R.J.C., E. de L.P.C., K.X.) and Division of Geriatric Medicine (S.S.G.), Queen’s University, Kingston, Ontario, Canada; Department of Ophthalmology, Hotel Dieu and Kingston General Hospitals, Kingston, Ontario, Canada (R.J.C., E. de L.P.C., K.X.); Institute for Clinical Evaluative Sciences – Queen’s University Site, Queen’s University, Kingston, Ontario, Canada (R.J.C., S.S.G., M.W.); Institute for Clinical Evaluative Sciences – Sunnybrook Site, Toronto, Ontario, Canada (C.M.B.); Departments of Medicine (C.M.B.), Health Policy Management and Evaluation (C.M.B.), and Ophthalmology (S.R.E.), University of Toronto, Toronto, Ontario, Canada; Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada (C.M.B.); Division of Geriatric Medicine, St. Mary’s of the Lake Hospital, Kingston, Ontario, Canada (S.S.G.); Queen’s University, Kingston, Ontario, Canada (M.W.); and Department of Ophthalmology, Kensington Eye Institute, Toronto, Ontario, Canada (S.R.E.). Inquiries to Dr Robert J. Campbell, Department of Ophthalmology, Hotel Dieu Hospital, 166 Brock Street, Kingston, Ontario, Canada, K7L 5G2; e-mail: [email protected] 0002-9394/$36.00 http://dx.doi.org/10.1016/j.ajo.2013.11.019
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glaucoma surgery. With increasing focus on integrated care, these findings will have important implications for residency education programs and their accrediting bodies and will inform decisions of health care policymakers, hospitals, and academic departments. (Am J Ophthalmol 2014;157:631–639. Ó 2014 by Elsevier Inc. All rights reserved.)
G
LAUCOMA IS THE LEADING CAUSE OF IRREVERS-
ible blindness in the world, and it underlies a large portion of the population eye disease burden, trailing only cataract and refractive error in public health need and demand for health services.1,2 Further, because the risk of glaucoma grows exponentially with age, many nations will face accelerating growth in glaucoma prevalence as their populations age.3 This has focused attention on the need for health human resource strategies to meet the challenges ahead.4–6 While facing a future of growing demand for most health services, the delivery of health care has steadily shifted toward greater levels of subspecialization in recent years.7,8 Consequently, the American Board of Medical Specialties (ABMS) now recognizes more than 150 specialties and subspecialties.9 We have previously shown that surgical glaucoma care has increasingly become the purview of a shrinking number of high-volume subspecialists.10 The surging need for interventional care for diseases such as cataract and acute conditions such as neovascular age-related macular degeneration raise the specter of diminishing access to nonsurgical aspects of care in the management of chronic diseases such as glaucoma.11,12 However, little is known about how the delivery of clinic-based aspects of glaucoma care is distributed among ophthalmologist subtypes. Such evidence is not only important to the process of aligning health human resources with population needs, but it is also critical in implementing efficient models of care that incorporate the realities of front-line practice. Such information will also inform decisions regarding the competencies to be attained in residency, and in rationally planning the specific types of training positions to be offered to meet population needs.13,14 In particular, certification and accreditation organizations including the ABMS, the American Board of Ophthalmology (ABO), the Accreditation Council for Graduate Medical Education (ACGME), and the Royal College of Physicians and Surgeons of Canada (RCPSC) use such
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data to inform policies.8,14,15 Hence, we carried out a population-based study to evaluate the relative roles of glaucoma surgeons and other ophthalmologists in the provision of clinic-based glaucoma care.
METHODS WE CONDUCTED A POPULATION-BASED RETROSPECTIVE
study of glaucoma care in Ontario, Canada between January 1, 2000, and December 31, 2010. Ontario is Canada’s most populous province, with a population of about 13 million individuals during the study period. The study protocol was approved by the Research Ethics Board at Queen’s University, Kingston, Ontario, Canada. Patient confidentiality was maintained via encrypted health care identification numbers and strict adherence to privacy protocols. The province of Ontario provides government-funded universal health care insurance to all citizens through the Ontario Health Insurance Plan (OHIP). Physician services data were obtained from the OHIP database, which has excellent reliability for recording medical and surgical procedures.16 Ontario physicians receive payment for insured services only through OHIP, and cannot bill patients directly. All of the physician encounters, laser procedures, and surgical interventions evaluated in this study are insured under the OHIP program. Hence, the OHIP database contains complete data for all Ontario physicians regarding the procedures and physician encounters analyzed in this study. PHYSICIAN ENCOUNTERS AND LASER PROCEDURES FOR GLAUCOMA: To investigate developments in clinic-based
glaucoma care, we evaluated glaucoma office visits and outpatient laser trabeculoplasty procedures but excluded incisional glaucoma surgery. Specifically, in separate analyses, we evaluated physician-requested glaucoma consultations (OHIP code A235 associated with International Statistical Classification of Diseases and Related Health Problems, Ninth Revision [ICD-9] code 365) and followup or optometrist-requested ophthalmology clinic visits for glaucoma (‘‘specific assessment’’ [OHIP code A233] or ‘‘partial assessment’’ [OHIP code A234] or ‘‘optometristrequested assessment’’ [OHIP code 253] associated with ICD-9 code 365). In Ontario, physician-requested and optometrist-requested consultations are coded distinctly in the OHIP database, and optometrist-requested assessments cannot be billed as regular physician-requested assessments. Optometrist-requested assessments were given their own OHIP physician billing code in 2009, but prior to that date, such assessments had to be coded as regular office visits (‘‘specific’’ or ‘‘partial’’ assessments). Thus, in order to allow longitudinal evaluation of trends we grouped these 3 types of assessments together to provide a consistent 632
measure of glaucoma care distinct from physicianrequested consultations. During the study period, glaucoma therapies could only be prescribed by physicians and not by optometrists. Hence all patients requiring therapy were referred to and treated by ophthalmologists. Finally, in addition to these evaluations of clinic-based medical glaucoma care, we examined nonincisional glaucoma procedural care by evaluating clinic-based laser trabeculoplasty procedures (OHIP code E134). Notably, our population-based study evaluated data for all ophthalmologist office visits and laser trabeculoplasty procedures. In the US system, this would correspond to capturing all office visits and laser trabeculoplasty procedures regardless of provider, patient demographics, or insurance carrier. SURGICAL PRACTICE PROFILES:
We investigated the influence of ophthalmologists’ surgical practice profiles (mix of procedures provided) on the provision of clinicbased glaucoma care by dividing ophthalmologists into mutually exclusive categories based on the types of ocular surgery they perform (if any). With the aim of identifying clinically relevant groupings, we categorized ophthalmologists as: (1) glaucoma surgeons, defined as those providing incisional glaucoma surgery with or without cataract surgery; (2) nondiversified cataract surgeons, defined as those providing cataract surgery but no other forms of ocular surgery (glaucoma, vitreoretinal, corneal, or strabismus surgery); (3) diversified cataract surgeons, defined as those providing both cataract surgery and other forms of nonglaucoma ocular surgery (vitreoretinal, corneal, or strabismus surgery); (4) non–glaucoma/non–cataract surgeons, defined as those doing vitreoretinal, corneal, or strabismus surgery but neither glaucoma surgery nor cataract surgery; and (5) ophthalmologists who do not perform incisional ocular surgery, defined as those not providing incisional glaucoma, cataract, vitreoretinal, corneal, or strabismus surgery. These groupings were created for each year of the study, based on procedures performed between January 1 and December 31 of that year.
ANALYSIS AND DATA SOURCES: We divided the study period into yearly intervals and, within each interval, evaluated the number of ophthalmologists providing each glaucoma service and the number of glaucoma services provided by each physician. Poisson regression was used to estimate the average annual change in glaucoma service rates. Data regarding each ophthalmologist were obtained from the Institute for Clinical Evaluative Sciences (ICES) Physician Database, which comprises information from the OHIP Corporate Provider Database, the Ontario Physician Human Resource Data Centre database, and the OHIP database of physician billings. The ICES Physician Database is validated through telephone interviews with all physicians practicing in Ontario and has been used in previous studies of physician practice.10,17,18 Yearly
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postcensal and intercensal population estimates were obtained from Statistics Canada.19,20
RESULTS THE OVERALL RATE OF PHYSICIAN ENCOUNTERS FOR GLAU-
coma (consultations and follow-up clinic visits) increased by 18.5%, growing from 25.9 to 30.7 per 1000 population per year between 2000 and 2010 (average annual increase of 1.7%, P < .0001). However, between 2000 and 2010, glaucoma surgeons played a declining role in the provision of clinic-based glaucoma care. In particular, glaucoma surgeons provided a decreasing proportion of consultations and other clinic assessments for glaucoma and performed a diminishing fraction of laser trabeculoplasty procedures. Moreover, no significant growth in the rate of glaucoma consultations or follow-up visits provided by glaucoma surgeons was observed (0.8%/year [P ¼ .2] for consultations; 0.2%/year [P ¼ .6] for follow-up visits). In contrast, over this period the population rate of glaucoma consultations provided by ophthalmologists who do not perform incisional glaucoma surgery increased at an average annual rate of 1.6% (P < .0002). Further, over this period, the proportion of glaucoma consultations provided by this subgroup increased by 10.2%. Similarly, the rate of glaucoma follow-up visits provided by ophthalmologists who do not perform incisional glaucoma surgery increased at an average annual rate of 3.3% (P < .0001). This led to a 14.3% increase in the proportion of glaucoma follow-up visits provided by this subgroup. Among the subgroups, nondiversified cataract surgeons showed the greatest increase in physician encounters for glaucoma. Specifically, the rate of glaucoma consultations provided by this subgroup increased at an average annual rate of 3.1% (P < .0001), leading to 31.3% growth in the proportion of glaucoma consultations provided by nondiversified cataract surgeons (Figure 1). Further, the rate of glaucoma follow-up visits provided by nondiversified cataract surgeons increased at an average annual rate of 6.4% (P < .0001). Correspondingly, the proportion of glaucoma follow-up clinic visits provided by ophthalmologists in this subgroup increased by 40.1% over the study period (Figure 2). This increased contribution to glaucoma care provided by nondiversified cataract surgeons was mediated by growth in the proportion of ophthalmologists limiting their surgical practice to cataract surgery (ie, greater numbers of nondiversified cataract surgeons) and not by an increase in the per-physician rates of consultations or office visits for glaucoma among nondiversified cataract surgeons (Figures 3 and 4). Indeed, while the number of nondiversified cataract surgeons grew by 46.5% over the study period, the numbers of consultations and other office visits for glaucoma per physician remained stable in this subgroup (Figures 3 and 4). VOL. 157, NO. 3
Between 2000 and 2010, the rate of laser trabeculoplasty procedures provided by ophthalmologists who do not perform incisional glaucoma surgery increased at an average annual rate of 19.3% (P < .0001), while growth among glaucoma surgeons was more modest (annual growth of 9.2% [P ¼ .0002]). As a consequence, the proportion of laser trabeculoplasty procedures provided by non–glaucoma surgeons increased by 43.0% (Figure 5). Subgroup analyses showed that the percentage of laser trabeculoplasty procedures performed by ophthalmologists who do not perform any incisional ocular surgery more than doubled over the study period, corresponding to a 26.3% average annual increase in the procedure rate within this subgroup (P < .0001; Figure 5). Further, the proportion of laser trabeculoplasty procedures performed by nondiversified cataract surgeons increased by 33.7%, corresponding to an average annual increase in the population procedure rate of 19.4% within this subgroup (P < .0001; Figure 5). In both these subgroups the increased contribution to the provision of laser trabeculoplasty procedures was mediated by the combined effects of increasing numbers of ophthalmologists in the subgroup and the significant growth in the number of procedures done per physician, particularly among high-volume providers (Figures 6 and 7). Specifically, the 95th percentile for laser trabeculoplasty procedure volume increased by 587.0% (from 69 to 474 procedures/year) and 246.5% (from 71 to 246 procedures/year) among ophthalmologists who do not perform incisional ocular surgery and nondiversified cataract surgeons, respectively.
DISCUSSION SUBSPECIALIZATION IS A GROWING REALITY IN MOST
areas of medicine. We have previously shown that incisional glaucoma surgery has increasingly become the purview of high-volume glaucoma subspecialists.10 Nevertheless, our present population-based study found that clinic-based glaucoma care remains dependent on ophthalmologists who do not perform glaucoma surgery. Between 2000 and 2010, surgeons who do not perform incisional glaucoma surgery provided an increasing proportion of consultations and clinic assessments for glaucoma and performed a growing fraction of laser trabeculoplasty procedures. Ophthalmologists who do not perform incisional ocular surgery and nondiversified cataract surgeons showed the greatest increases in the proportion of clinic-based glaucoma care provided. However, despite the recent declines that we have found, glaucoma surgeons continue to provide a significant component of clinic-based glaucoma care. The increased use of laser trabeculoplasty observed across physician categories coincided with the introduction of selective laser trabeculoplasty (SLT), and it is likely that
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FIGURE 1. Percentage of glaucoma consultations provided by ophthalmologist subgroups, 2000-2010. Trend lines indicate percentage of glaucoma consultations performed by glaucoma surgeons, diversified cataract surgeons, nondiversified cataract surgeons, non–glaucoma/non–cataract surgeons, and ophthalmologists who do not perform incisional ocular surgery.
FIGURE 2. Percentage of glaucoma follow-up clinic visits provided by ophthalmologist subgroups, 2000-2010. Trend lines indicate percentage of glaucoma follow-up clinic visits performed by glaucoma surgeons, diversified cataract surgeons, nondiversified cataract surgeons, non–glaucoma/non–cataract surgeons, and ophthalmologists who do not perform incisional ocular surgery.
perceptions regarding the safety and repeatability of SLT underpinned the overall growth in procedure rates. A major strength of our study from a single-payer health care system was the ability to analyze data from all physicians within a large population. Further, our ability to access comprehensive surgical practice data from all 634
ophthalmologists enhanced our analysis by allowing us to stratify ophthalmologists based on their overall surgical practice profile. To the best of our knowledge, this is the first population-based study to track developments in the types of ophthalmologists providing clinic-based glaucoma care. There are limitations to our study that warrant
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FIGURE 3. Distribution of glaucoma consultations provided by nondiversified cataract surgeons. Box plot of glaucoma consultations performed by nondiversified cataract surgeons (2000-2010), with superimposed line graph showing the percentage of ophthalmologists formed by the nondiversified cataract surgeon group. The dividing line in each box indicates the median number of consultations per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
FIGURE 4. Distribution of glaucoma follow-up clinic visits provided by nondiversified cataract surgeons. Box plot of glaucoma follow-up clinic visits performed by nondiversified cataract surgeons (2000-2010), with superimposed line graph showing the percentage of ophthalmologists formed by the nondiversified cataract surgeon group. The dividing line in each box indicates the median number of consultations per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
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FIGURE 5. Percentage of laser trabeculoplasty procedures provided by ophthalmologist subgroups, 2000-2010. Percentage of laser trabeculoplasty procedures performed by glaucoma surgeons, diversified cataract surgeons, nondiversified cataract surgeons, non–glaucoma/non–cataract surgeons, and ophthalmologists who do not perform incisional ocular surgery.
FIGURE 6. Percentage of laser trabeculoplasty procedures provided by nondiversified cataract surgeons. Box plot of laser trabeculoplasty procedures performed by nondiversified cataract surgeons (2000-2010), with superimposed line graph showing the percentage of ophthalmologists formed by the nondiversified cataract surgeon group. The dividing line in each box indicates the median number of procedures per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
highlighting. While the accuracy of the administrative data sources used is excellent, the potential for coding errors exists. Additionally, although Ontario’s population demographics 636
and the technical approach to glaucoma care among the province’s ophthalmologists mirror those in the US, our results may not be generalizable to all jurisdictions.21,22
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FIGURE 7. Distribution of laser trabeculoplasty procedures provided by ophthalmologists who do not perform incisional ocular surgery. Box plot of laser trabeculoplasty procedures performed by ophthalmologists who do not perform incisional ocular surgery (20002010), with superimposed line graph showing the percentage of ophthalmologists formed by ophthalmologists who do not perform incisional ocular surgery. The dividing line in each box indicates the median number of procedures per ophthalmologist per year; boxes, the upper and lower quartiles; and whiskers, the upper 95th and lower 5th percentiles.
Previous survey-based studies of comprehensive (general) ophthalmologists have suggested that most comprehensive ophthalmologists provide glaucoma care.23,24 However, these studies were not able to quantify the overall contributions of different types of ophthalmologists. Previous studies have also documented differences in glaucoma care processes between comprehensive ophthalmologists and glaucoma subspecialists.25–28 Our findings that ophthalmologists who do not perform incisional glaucoma surgery provide a large and growing portion of clinic-based glaucoma care suggest that these differences may have important effects at a population level. However, although evidence suggests that provider specialization improves outcomes in some clinical situations, the magnitude of the effect is highly variable and the relative contributions of the provider vs the provider’s clinical environment remain unclear.29,30 Though limited data suggest that glaucoma surgical success may be affected by surgeon volume and training,31 further research is needed regarding the relationship between glaucoma outcomes and the type of ophthalmologist providing clinic-based aspects of care. Despite increasing surgical subspecialization in glaucoma, the growing contribution of non–glaucoma surgeons to the clinic-based aspects of glaucoma care emphasizes the need for accreditation and certification organizations including the ACGME, ABO, and the RCPSC to ensure VOL. 157, NO. 3
broad-based training in glaucoma in both residency and continuing medical education settings. Further, in combination with our previous work showing that glaucoma surgery has increasingly become a subspecialty field, our current findings suggest that a growing number of patients are referred to a glaucoma subspecialist only at the time of needing surgery. This development emphasizes the importance of systems that support excellent communication among care providers involved in glaucoma treatment. Our finding that ophthalmologists are increasingly limiting their incisional surgical practice to cataract surgery, coupled with the downward trend in the proportion of trainees pursuing glaucoma fellowships, will likely lead to even greater separation between the providers of surgical and nonsurgical glaucoma care in the coming years.32 Further, the rapidly growing need for interventional care for many eye diseases, including cataract and retinal diseases, has commanded a growing proportion of ophthalmologist time in recent years.11,12 This raises concerns regarding the sustainability of access to clinic-based care for chronic diseases such as glaucoma, as competing acute-care demands for ophthalmology resources—human and otherwise—continue to mount.33 In summary, using a population-based approach, we found that ophthalmologists who do not perform incisional glaucoma surgery provide a large and growing portion of clinic-based glaucoma care, and that specific
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subtypes of ophthalmologists have dominated these trends. With increasing focus on integrated care, these findings will have important implications for residency
education programs and their accrediting bodies and will inform decisions of health care policymakers, hospitals, and academic departments.
ALL AUTHORS HAVE COMPLETED AND SUBMITTED THE ICMJE FORM FOR DISCLOSURE OF POTENTIAL CONFLICTS OF INTEREST and none were reported. Dr R.J. Campbell is supported by a Clinician Scientist Award from the Southeastern Ontario Academic Medical Organization, Kingston, Ontario, Canada. Dr Gill is supported by Canadian Institutes of Health Research New Investigator Awards from the Institute of Aging, Ottawa, Ontario, Canada. Dr Bell is supported by a Canadian Institutes of Health Research and Canadian Patient Safety Institute chair in Patient Safety and Continuity of Care, Ottawa, Ontario, Canada. Contributions of authors: design and conduct of the study (R.J.C.); collection, management, analysis, and interpretation of the data (R.J.C., C.M.B., S.S.G., M.W., E. de L.P.C., K.X., S.R.E.); drafting of the manuscript (R.J.C.); critical revision of the manuscript for important intellectual content (R.J.C., C.M.B., S.S.G., M.W., E. de L.P.C., K.X., S.R.E.); statistical analysis (R.J.C., M.W., E. de L.P.C., K.X.); administrative, technical, or material support (M.W., E. de L.P.C.); obtaining funding (R.J.C.); study supervision (R.J.C.). In accordance with the Personal Health Information Protection Act (PHIPA) of Ontario, the raw administrative data used for statistical analyses in this manuscript may only be accessed by agents of the Institute for Clinical Evaluative Sciences (ICES), a prescribed entity under Section 45 of the Act, for the purposes of conducting research that contributes to the effectiveness, quality, equity, and efficiency of health care and health services. Dr R.J. Campbell is an agent of ICES and had full control over the data definitions and analyses used in this manuscript. Dr R.J. Campbell had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The sponsors of this study had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and the decision to submit for publication. This study was supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred.
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22. Campbell RJ, Trope GE, Rachmiel R, Buys YM. Glaucoma laser and surgical procedure rates in Canada: a long-term profile. Can J Ophthalmol 2008;43(4):449–453. 23. Shingleton BJ, Crandall A, Johnstone M, Robin A, Brown R. Medical treatment patterns of ASCRS members for primary open-angle glaucoma—1998 survey. J Cataract Refract Surg 1999;25(1):118–127. 24. Brown RH, Shingleton BJ, Johnstone M, Crandall A, Robin A. Glaucoma laser treatment parameters and practices of ASCRS members—1999 survey. J Cataract Refract Surg 2000;26(5):755–765. 25. Boland MV, Quigley HA, Lehmann HP. The impact of physician subspecialty training, risk calculation, and patient age on treatment recommendations in ocular hypertension. Am J Ophthalmol 2011;152(4):638–645. 26. Hertzog LH, Albrecht KG, LaBree L, Lee PP. Glaucoma care and conformance with preferred practice patterns. Examination of the private, community-based ophthalmologist. Ophthalmology 1996;103(7):1009–1013. 27. Albrecht KG, Lee PP. Conformance with preferred practice patterns in caring for patients with glaucoma. Ophthalmology 1994;101(10):1668–1671.
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Biosketch Dr Robert J. Campbell, MD, MSc, is Deputy Chair of and Associate Professor with the Department of Ophthalmology at Queen’s University, Kingston, Canada. He is also a scientist with the Institute for Clinical Evaluative Sciences, Ontario, Canada, and leads an internationally-recognized health services research program focused on the assessment of eye and vision health care quality, access and safety. Dr Campbell graduated Summa Cum Laude and Valedictorian, and completed ophthalmology training at the University of Ottawa. Dr Campbell undertook fellowship training in glaucoma surgery at the University of Toronto and cornea surgery at Moorfields Eye Hospital.
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Biosketch Dr Sherif El-Defrawy, MD, PhD, is Professor and Chair of the Department of Ophthalmology and Vision Sciences at the University of Toronto and the Ophthalmologist-in-Chief at Kensington Eye Institute. He is also co-Chair of the Eye Health Council of Ontario. He is a Past President of the Canadian Ophthalmological Society and the Association of Canadian University Professors of Ophthalmology. Dr El-Defrawy received his Medical Degree from the University of Calgary in 1989 and residency in Ophthalmology at the University of Ottawa. He joined the University of Ottawa Eye Institute in 1995 and was Residency Program Director there from 1999-2004. He was Professor and Chair of the Department of Ophthalmology at Queen’s University, and Ophthalmologist-in-Chief at the University Hospitals in Kingston from 2004-2012.
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