Depressive Symptoms and Hospital Readmission in Older Adults Jennifer S. Albrecht, PhD,a,b Ann L. Gruber-Baldini, PhD,a Jon M. Hirshon, MD, MPH, PhD,a,c Clayton H. Brown, PhD,a,d Richard Goldberg, PhD,d,e Joseph H. Rosenberg, BS,a Angela C. Comer, MPH,a and Jon P. Furuno, PhDf
OBJECTIVES: To quantify the risk of 30-day unplanned hospital readmission in adults aged 65 and older with depressive symptoms. DESIGN: Prospective cohort study. SETTING: University of Maryland Medical Center. PARTICIPANTS: Individuals aged 65 and older admitted between July 1, 2011, and August 9, 2012, to the general medical and surgical units and followed for 31 days after hospital discharge (N = 750). MEASUREMENTS: Primary exposure was depressive symptoms at admission, defined as a score of 6 or more on the 15-item Geriatric Depression Scale. Primary outcome was unplanned 30-day hospital readmission, defined as an unscheduled overnight stay at any inpatient facility not occurring in the emergency department. RESULTS: Prevalence of depressive symptoms was 19% and incidence of 30-day unplanned hospital readmission was 19%. Depressive symptoms were not significantly associated with hospital readmission (relative risk (RR) = 1.20, 95% confidence interval (CI) = 0.83–1.72). Age, Charlson Comorbidity Index score, and number of hospitalizations within the past 6 months were significant predictors of unplanned 30-day hospital readmission. CONCLUSION: Although not associated with hospital readmission, depressive symptoms were associated with other poor outcomes and may be underdiagnosed in hospitalized older adults. Hospitals interested in reducing From the aDepartment of Epidemiology and Public Health, School of Medicine, University of Maryland, bDepartment of Pharmaceutical Health Services Research, School of Pharmacy, University of Maryland, c Department of Emergency Medicine, School of Medicine, University of Maryland, dVeterans Affairs Capitol Healthcare Network, Mental Illness Research, Education, and Clinical Center, eDepartment of Psychiatry, School of Medicine, University of Maryland, Baltimore, Mayland; and f Department of Pharmacy Practice, College of Pharmacy, Oregon State University/Oregon Health & Science University, Portland, Oregon. Address correspondence to Jennifer S. Albrecht, PhD, Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, 220 Arch Street, 12th floor, Room 01–234, Baltimore, MD 21201. E-mail: [email protected] DOI: 10.1111/jgs.12686
JAGS 62:495–499, 2014 © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society
readmission should focus on older adults with more comorbid illness and recent hospitalizations. J Am Geriatr Soc 62:495–499, 2014.
Key words: hospital readmission; depressive symptoms; older adults
U
nplanned hospital readmission has been targeted for quality improvement initiatives to reduce healthcare costs and improve outcomes. Previous research has suggested that 20% of Medicare beneficiaries are readmitted to the hospital within 30 days of discharge and that 34% are readmitted within 90 days.1 Hospital readmissions are costly as well, accounting for $15 billion in Medicare spending in 2007.2 The Medicare Payment Advisory Commission tied 30-day readmission rates to Medicare reimbursements in 2013 with three diagnoses-related groups initially targeted, but the number of targeted diagnoses groups will expand in 2014.3 Interventions to reduce hospital readmissions have been observed to be effective, but cost efficiency dictates that they be targeted toward individuals at highest risk of readmission.4–6 Risk factors for readmission include older age, male sex, recent previous hospital admission, longer hospital stay, and greater comorbidity,1,7,8 but these characteristics provide few targets for anything other than broad-based interventions. Depression may affect hospital readmissions in Medicare beneficiaries.9–11 Research examining the effect of depressive symptoms on hospital readmission has found a positive association.12–16 Nonetheless, a focus on illnesses such as heart failure, age groups that included much younger individuals (≥18), and variable readmission outcomes limits the generalizability of previous results to an older, more-general population that may be more consistent with current hospital initiatives to reduce readmissions. This article reports results from a prospective cohort study on the association between depressive symptoms at baseline and unplanned 30-day hospital readmission in individuals aged 65 and older. It was hypothesized that
0002-8614/14/$15.00
496
ALBRECHT ET AL.
depressive symptoms would be associated with greater risk of 30-day hospital readmission. If this is the case, screening for and treating depression in this population may provide an additional means of reducing hospital readmission, as well as furnishing a target population for current initiatives.
METHODS Study Design and Study Population This was a prospective cohort study of adults aged 65 and older admitted to the hospital. Study participants were enrolled within 72 hours of admission. After hospital discharge, participants were followed up by telephone at three time points (5, 15, and 31 days) after discharge to ascertain deaths and unplanned readmission events. The study population consisted of community-dwelling adults aged 65 and older admitted to the general medical and surgical services of the University of Maryland Medical Center (UMMC), a 757-bed, tertiary-care hospital in Baltimore, Maryland, between July 1, 2011, and August 9, 2012. Individuals admitted to psychiatric, obstetrical, and intensive care units; residing in a nursing home; unable to speak English; or with a Mini-Mental State Examination (MMSE) score of 15 less or were excluded.17 The institutional review board at the University of Maryland Baltimore approved this study, and all participants provided written informed consent before participating. Admission and discharge data on individuals meeting the inclusion criteria were collected daily from the UMMC Clinical Data Repository (CDR), a relational database including administrative, demographic, and outcome information. Necessary sample size was calculated a priori based upon the assumptions of 13% incidence of hospital readmission, 20% prevalence of depressive symptoms, and 10% loss to follow-up. The 13% incidence rate in adults aged 65 and older was obtained from 5 years of data on 30-day hospital readmission to UMMC from the CDR. Based on these assumptions, a sample size of 750 would allow 80% power to detect twice the risk of 30-day unplanned readmission (relative risk = 2) in study participants with depressive symptoms.
Measures Study participants were administered a baseline questionnaire. Prevalent clinically significant depressive symptoms, the primary exposure, were assessed using the 15-item Geriatric Depression Scale (GDS-15) and defined as a score of 6 or greater.18 This cut-point has been observed to have a sensitivity of 83% and a specificity of 69% to detect depression in elderly inpatients.19 Disabilities in activities of daily living were assessed using the Katz scale (range 0–5, 5 indicating the highest level of disability); cognitive impairment using the 30-item MMSE; and social isolation using the 6-item Lubben Social Network Scale,17,18,20,21 which has been validated as a measure of social isolation risk in community-dwelling adults. A score of
OBJECTIVES: To quantify the risk of 30-day unplanned hospital readmission in adults aged 65 and older with depressive symptoms. DESIGN: Prospective cohort study. SETTING: University of Maryland Medical Center. PARTICIPANTS: Individuals aged 65 and older admitted between July 1, 2011, and August 9, 2012, to the general medical and surgical units and followed for 31 days after hospital discharge (N = 750). MEASUREMENTS: Primary exposure was depressive symptoms at admission, defined as a score of 6 or more on the 15-item Geriatric Depression Scale. Primary outcome was unplanned 30-day hospital readmission, defined as an unscheduled overnight stay at any inpatient facility not occurring in the emergency department. RESULTS: Prevalence of depressive symptoms was 19% and incidence of 30-day unplanned hospital readmission was 19%. Depressive symptoms were not significantly associated with hospital readmission (relative risk (RR) = 1.20, 95% confidence interval (CI) = 0.83–1.72). Age, Charlson Comorbidity Index score, and number of hospitalizations within the past 6 months were significant predictors of unplanned 30-day hospital readmission. CONCLUSION: Although not associated with hospital readmission, depressive symptoms were associated with other poor outcomes and may be underdiagnosed in hospitalized older adults. Hospitals interested in reducing From the aDepartment of Epidemiology and Public Health, School of Medicine, University of Maryland, bDepartment of Pharmaceutical Health Services Research, School of Pharmacy, University of Maryland, c Department of Emergency Medicine, School of Medicine, University of Maryland, dVeterans Affairs Capitol Healthcare Network, Mental Illness Research, Education, and Clinical Center, eDepartment of Psychiatry, School of Medicine, University of Maryland, Baltimore, Mayland; and f Department of Pharmacy Practice, College of Pharmacy, Oregon State University/Oregon Health & Science University, Portland, Oregon. Address correspondence to Jennifer S. Albrecht, PhD, Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, 220 Arch Street, 12th floor, Room 01–234, Baltimore, MD 21201. E-mail: [email protected] DOI: 10.1111/jgs.12686
JAGS 62:495–499, 2014 © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society
readmission should focus on older adults with more comorbid illness and recent hospitalizations. J Am Geriatr Soc 62:495–499, 2014.
Key words: hospital readmission; depressive symptoms; older adults
U
nplanned hospital readmission has been targeted for quality improvement initiatives to reduce healthcare costs and improve outcomes. Previous research has suggested that 20% of Medicare beneficiaries are readmitted to the hospital within 30 days of discharge and that 34% are readmitted within 90 days.1 Hospital readmissions are costly as well, accounting for $15 billion in Medicare spending in 2007.2 The Medicare Payment Advisory Commission tied 30-day readmission rates to Medicare reimbursements in 2013 with three diagnoses-related groups initially targeted, but the number of targeted diagnoses groups will expand in 2014.3 Interventions to reduce hospital readmissions have been observed to be effective, but cost efficiency dictates that they be targeted toward individuals at highest risk of readmission.4–6 Risk factors for readmission include older age, male sex, recent previous hospital admission, longer hospital stay, and greater comorbidity,1,7,8 but these characteristics provide few targets for anything other than broad-based interventions. Depression may affect hospital readmissions in Medicare beneficiaries.9–11 Research examining the effect of depressive symptoms on hospital readmission has found a positive association.12–16 Nonetheless, a focus on illnesses such as heart failure, age groups that included much younger individuals (≥18), and variable readmission outcomes limits the generalizability of previous results to an older, more-general population that may be more consistent with current hospital initiatives to reduce readmissions. This article reports results from a prospective cohort study on the association between depressive symptoms at baseline and unplanned 30-day hospital readmission in individuals aged 65 and older. It was hypothesized that
0002-8614/14/$15.00
496
ALBRECHT ET AL.
depressive symptoms would be associated with greater risk of 30-day hospital readmission. If this is the case, screening for and treating depression in this population may provide an additional means of reducing hospital readmission, as well as furnishing a target population for current initiatives.
METHODS Study Design and Study Population This was a prospective cohort study of adults aged 65 and older admitted to the hospital. Study participants were enrolled within 72 hours of admission. After hospital discharge, participants were followed up by telephone at three time points (5, 15, and 31 days) after discharge to ascertain deaths and unplanned readmission events. The study population consisted of community-dwelling adults aged 65 and older admitted to the general medical and surgical services of the University of Maryland Medical Center (UMMC), a 757-bed, tertiary-care hospital in Baltimore, Maryland, between July 1, 2011, and August 9, 2012. Individuals admitted to psychiatric, obstetrical, and intensive care units; residing in a nursing home; unable to speak English; or with a Mini-Mental State Examination (MMSE) score of 15 less or were excluded.17 The institutional review board at the University of Maryland Baltimore approved this study, and all participants provided written informed consent before participating. Admission and discharge data on individuals meeting the inclusion criteria were collected daily from the UMMC Clinical Data Repository (CDR), a relational database including administrative, demographic, and outcome information. Necessary sample size was calculated a priori based upon the assumptions of 13% incidence of hospital readmission, 20% prevalence of depressive symptoms, and 10% loss to follow-up. The 13% incidence rate in adults aged 65 and older was obtained from 5 years of data on 30-day hospital readmission to UMMC from the CDR. Based on these assumptions, a sample size of 750 would allow 80% power to detect twice the risk of 30-day unplanned readmission (relative risk = 2) in study participants with depressive symptoms.
Measures Study participants were administered a baseline questionnaire. Prevalent clinically significant depressive symptoms, the primary exposure, were assessed using the 15-item Geriatric Depression Scale (GDS-15) and defined as a score of 6 or greater.18 This cut-point has been observed to have a sensitivity of 83% and a specificity of 69% to detect depression in elderly inpatients.19 Disabilities in activities of daily living were assessed using the Katz scale (range 0–5, 5 indicating the highest level of disability); cognitive impairment using the 30-item MMSE; and social isolation using the 6-item Lubben Social Network Scale,17,18,20,21 which has been validated as a measure of social isolation risk in community-dwelling adults. A score of
