Recorded presentation

Ann Bagchi, PhD¹, Usha Sambamoorthi, PhD², James Walkup, PhD², and Stephen Crystal, PhD². (1) Institute for Health, Health Care Policy and Aging Research, Rutgers University, 30 College Avenue, New Brunswick, NJ 08901, (732)932-6949, abagchi@ihhcpar.rutgers.edu, (2) Institute for Health, Health Care Policy, and Aging Research, Rutgers University, 30 College Ave, New Brunswick, NJ 08901

This study examines the correlates of use of and persistence on antidepressant medications among elderly Medicare recipients. We utilized linked Medicare claims and the Medicare Current Beneficiary Survey (MCBS) Cost and Use files from the Centers for Medicare and Medicaid Services (CMS), for the period between 1992 and 1999 to analyze persistence on antidepressants among the elderly diagnosed with depression. Our sample was restricted to community-dwelling Medicare recipients aged 65 and over enrolled for the full year and those without Medicare HMO participation. We identified individuals with major depression based on diagnostic codes conforming to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) and recorded in the Medicare claims files. We included only those with major depression (ICD-9-CM codes of 296.2 and 296.3) because the accepted clinical guidelines pertain only to patients with major depression. Since the depression guidelines suggest at least a 6-week trial phase, we excluded from our sample individuals diagnosed after October 15th for each year in question due to the insufficiency of follow-up time for a study of persistence. We tested for significant bivariate differences in use of antidepressant medications and examined persistence (defined as 4 or more prescription claims for antidepressants) using an extension of the binary probit model known as the ordered (or ordinal) probit model. The ordered probit represents the dependent variable as a recoded version of a continuous variable. Under model assumptions, higher numbers of prescriptions provide greater benefits to the patient than lower numbers. Dependent variables included demographic characteristics, access to care variables, health status variables, provider type and antidepressant class. Bivariate statistical analysis revealed that educational attainment and treatment by a specialist significantly predicted receipt of antidepressant medications among elderly Medicare beneficiaries. Analyses of medication persistence suggested that specialist care significantly improves adherence to antidepressants in this population. The analyses also indicated that metropolitan residents and non-white individuals are less likely to persistently utilize antidepressant treatments when compared with non-metropolitan residents and whites, respectively. The analyses did not find significant improvements in antidepressant persistence with use of SSRIs despite suggestions that the lower incidence of side effects could lead to improved compliance and treatment outcomes. As Medicare represents the largest insurance payer for individuals aged 65 and older understanding elderly Medicare beneficiaries’ use of antidepressant medications can significantly influence depression treatment among a vast majority of American elders.

Learning Objectives:

• Upon completion of this session, participants will be able to identify the factors associated with higher antidepressant adherence among elderly Medicare recipients and recognize the importance of the specialty care sector in the treatment of major depression among the elderly.

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

Recorded presentation