BRIEF REPORTS Psychiatric Comorbidity and Greater Hospitalization Risk, Longer Length of Stay, and Higher Hospitalization Costs in Older Adults with Heart Failure Steven L. Sayers, PhD, à w Nancy Hanrahan, PhD, RN, z Ann Kutney, RN, MSN, z Sean P. Clarke, PhD, RN, z Brendali F. Reis, PhD, § and Barbara Riegel, DNSc, RN k # OBJECTIVES: To explore associations between psychi- atric comorbidity and rehospitalization risk, length of hospi- talization, and costs. DESIGN: Cross-sectional study of 1-year hospital admin- istrative data. SETTING: Claims-based study of older adults hospitalized in the United States. PARTICIPANTS: Twenty-one thousand four hundred twenty-nine patients from a 5% national random sample of U.S. Medicare beneficiaries aged 65 and older, with at least one acute care hospitalization in 1999 with a Diag- nostic-Related Group of congestive heart failure. MEASUREMENTS: The number of hospitalizations, mean length of hospital stay, and total hospitalization costs in calendar year 1999. RESULTS: Overall, 15.8% of patients hospitalized for heart failure (HF) had a coded psychiatric comorbidity; the most commonly coded comorbid psychiatric disorder was depression (8.5% of the sample). Most forms of psychiatric comorbidity were associated with greater inpatient utiliza- tion, including risk of additional hospitalizations, days of stay, and hospitalization charges. Additional hospitaliza- tion costs associated with psychiatric comorbidity ranged up to $7,763, and additional days length of stay ranged up to 1.4 days. CONCLUSION: Psychiatric comorbidity appears in a sig- nificant minority of patients hospitalized for HF and may affect their clinical and economic outcomes. The associations between psychiatric comorbidity and use of inpatient care are likely to be an underestimate, because psychiatric illness is known to be underdetected in older adults and in hospitalized medical patients. J Am Geriatr Soc 55:1585–1591, 2007. Key words: heart failure; psychiatric comorbidity; depression; hospitalization costs; economic analysis; Medicare; sex; socioeconomic status; race/ethnicity C urrently, more than 5 million Americans have heart failure (HF), 1 with increasing prevalence in older co- horts of adults, largely because of the aging U.S. population and longer survival of patients with HF. Despite medical advances 2 and the positive effect of HF management programs, 3 the cost of care for HF remains high. HF is responsible for $33.2 billion in healthcare costs in the U.S., approximately 1.5% of total healthcare expendi- tures. 3 Hospitalizations account for 65% of the costs of treating HF. 3 There is significant evidence that comorbid psychiatric disorders contribute to greater risk of hospitalization in patients with HF and higher costs of these hospitalizations. 4 Depression is common in hospitalized older adults with HF 5 and likely leads to higher outpatient utilization and higher healthcare costs, as well as twice the risk of rehos- pitalization and death within 1 year. 6 Few studies have ex- amined the consequences of a broad range of psychiatric disorders for hospitalized older adults with HF (e.g., anx- iety disorders, alcohol abuse), despite evidence of higher rates of these problems in the population with HF. 7 The goal of this study was to examine the effects of identified comorbid psychiatric disorders on healthcare uti- lization and costs in a sample of Medicare beneficiaries hospitalized at least once with a primary diagnosis of HF in 1999. The major hypothesis was that having a psychiatric disorder would be associated with greater rates of hospi- talization, longer length of hospitalizations, and higher hospitalization costs in older adults with HF. Consistent with existing findings, it was hypothesized that identified comorbid psychiatric disorders might vary across groups Address correspondence to Steven L. Sayers, PhD, Philadelphia VA Medical Center, MIRECC 116, 3900 Woodland Avenue, Philadelphia, PA 19104. E-mail: steven.sayers@va.gov DOI: 10.1111/j.1532-5415.2007.01368.x From the à VISN 4 Mental Illness, Research, Education and Clinical Center, Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania; w Department of Psychiatry, z Center for Health Outcomes and Policy Research, k School of Nursing, and # Leonard Davis Institute, University of Pennsylvania, Philadelphia, Pennsylvania; and § Institute for Graduate Clinical Psychology, Widener University, Philadelphia, Pennsylvania. JAGS 55:1585–1591, 2007 r 2007, Copyright the Authors Journal compilation r 2007, The American Geriatrics Society 0002-8614/07/$15.00