Prescription Drug Use in the Elderly: A Descriptive Analysis

Article excerpt

BACKGROUND

Payment for pharmaceutical therapy in the elderly has become a central policy debate but has been poorly informed by data on actual drug use in this population. The research literature has focused almost exclusively on cost and payment issues, essentially ignoring patterns of demographic and clinical factors that determine differences in utilization and, ultimately, spending. To date, no national comprehensive descriptive data have been made available on the composition of prescription drug use in the elderly in total or in its subgroups. One study provides an overview of utilization of the five most common classes of drugs in the elderly with stratification by age and sex (Waldron and Poisal, 1999). Other studies have been conducted in targeted populations that may not be representative, or are limited by collection methodologies, e.g., one time collection, or have been conducted in very small samples (Schmader et al., 1998; Lassila, Stoehr, and Ganguli, 1996; Chrischilles, Foley, and Wallace, 1992; Stewart et al., 1991; Helling et al., 1987; Darnell et al. 1986). Few studies have examined subgroups of the population.

The elderly, however, are not homogeneous and will be differentially affected by any of the currently proposed prescription drug benefit policies. Analysis of socioeconomic characteristics and health and functional status of beneficiaries to help policymakers understand gaps in coverage and craft options for reform is needed (Davis et al., 1999). One study used data from a pharmacy benefit management (PBM) organization for a population with continuous prescription drug coverage and no annual cap to assess drug use differences by subgroups defined by comorbid conditions (Steinberg et al., 2000). Many studies have examined drug use and adherence in subpopulations with specific diseases. A recent study examined the use of inappropriate medications in the elderly (Zhan et al., 2001). To date, however, no study has surveyed the entire population.

This study provides a comprehensive description of the composition of prescription drug use in the community-dwelling elderly, and health and functional status, subgroups to inform policymakers of the potential impact of benefit designs on them Using a nationally representative sample of Medicare beneficiaries, we describe overall drug utilization for a 1-year period in terms, of the number of broad therapeutic classes and the number of more specific drug subclasses.

STUDY METHODOLOGY

Data Source

The 1996 MCBS Cost and Use Data Files were used for this study. The MCBS is a nationally-representative longitudinal panel survey of Medicare beneficiaries that is intended for use in policy studies. Data collected include use of health services, medical care expenditures, health insurance coverage, sources of payment, health status and functioning, and a variety of demographic and behavioral information, such as income, assets, living arrangements, family supports, and access to medical care. Data are collected from each survey participant or a proxy three times a year using computer assisted personal interviews.

Study Sample

We used the 1996 MCBS data files for the study. There were 11,884 Medicare beneficiaries participating in the MCBS sample in calendar year 1996, representing approximately 39 million persons. While the MCBS includes in its sample the disabled and facility-dwelling elderly, our analysis is focused on the community dwelling elderly only. Data collection methodologies for those who are institutionalized do not support detailed analysis of pharmaceutical use, and the characteristics of the disabled population warrant a separate analysis. Subjects were included who: (1) were community dwelling (i.e., those who spent no time in a long-term care facility during the study year), (2) were at least age 65 or over, and (3) completed the entire survey year to ensure that we had a complete year of prescription drug use. …