Chronic catastrophes: Exploring the concentration and sustained nature of ambulatory prescription drug expenditures in the population of British Columbia, Canada

https://doi.org/10.1016/j.socscimed.2008.12.008Get rights and content

Abstract

Previous research has shown that a small proportion of the population accounts for a substantial proportion of spending on physician and hospital services. Much less is known about the high-cost users of ambulatory prescription medicines. We investigate the concentration and sustained nature of ambulatory prescription drug expenditures among residents of British Columbia, Canada in 2001 and 2004. Linking person-specific administrative data from several sources, we examine the demographics, socio-economic status, and health status of high-cost ambulatory pharmaceutical users and the extent that high-cost pharmaceutical use was sustained, at the individual level, from 2001 to 2004. The top 5% of users were responsible for 48% of ambulatory prescription expenditures in the province. A significant burden of morbidity, as well as sustained high expenditures, characterized these users. They were older, more likely to be female, more likely to be of low income, and more likely to be hospitalized and die within the year of study than other pharmaceutical users and non-users.

Our results suggest that careful consideration should be given to the long-term financial burdens and access barriers created by pharmaceutical insurance policies that rely heavily on private payments by individuals. Our focus is on costs associated with ambulatory prescription drug use, however, had we included information on the cost of prescription drugs used in hospitals, we would likely have detected an even stronger relationship between high-cost pharmaceutical use and poor health status.

Section snippets

Data

This population-based study draws on anonymized data from person-specific administrative data describing prescription drug use, demographics, household income, mortality, and diagnostic information. Different records (e.g., health plan registration, medical, hospital, prescription drug use, and death) have been made linkable, with a linkage rate over 95%. Anonymized data for the calendar years from 2001 and 2004 were extracted with the permission of the B.C. Ministry of Health and the B.C.

Results

A total of 4.045 million individuals met our study inclusion criteria in 2004. A total of 3.849 million individuals met our study inclusion criteria in 2001. There were 3.730 million individuals who were alive and met our study inclusion criteria in both 2001 and 2004. Table 1 lists average 2004 ambulatory drug use and expenditure for this population, stratified into the categories of non-users, low-cost users, medium-cost users, and high-cost users. Approximately 35% of the population did not

Discussion

Results from this study confirm that ambulatory prescription drug expenditures are highly concentrated: in 2004, 20% of the population of B.C. accounted for approximately 80% of all prescription drug expenditures. The highest-cost users (5% of the population) accounted for nearly half (48%) of all expenditures. On average, these high-cost users filled prescriptions for more than nine different types of drug that year. They were also likely to have diagnoses of multiple morbidities in medical

Acknowledgements

This research was funded by the Canadian Institute of Health Research (CIHR). Both authors are also supported by the CIHR and the Michael Smith Foundation for Health Research. Gillian Hanley is also supported by the Western Regional Training Centre. Thanks to the reviewers and the editors for their incredibly helpful comments.

References (21)

  • J. Hurley

    An overview of the normative economics of the health sector

  • A. Wagstaff et al.

    Equity in the finance of health care: some international comparisons

    Journal of Health Economics

    (1992)
  • A. Wagstaff et al.

    Equity in the finance of health care: some further international comparisons

    Journal of Health Economics

    (1999)
  • G. Anderson et al.

    Patterns of expenditures among high utilizers of medical care services: the experience of Medicare beneficiaries from 1974 to 1977

    Medical Care

    (1984)
  • K.J. Arrow

    Uncertainty and the welfare economics of medical care

    Journal of Health Politics Policy and Law

    (2001)
  • S.E. Berki et al.

    High-volume and low-volume users of health services: United States, 1980

    National Medical Care Utilization & Expenditure Survey – Series C

    (1985)
  • P.M. Densen et al.

    Concerning high and low utilizers of service in a medical care plan, and the persistence of utilization levels over a three year period

    Milbank Memorial Fund Quarterly

    (1959)
  • A. Kozyrskyj et al.

    High-cost users of pharmaceuticals: Who are they?

    (2005)
  • G. Mallya et al.

    Medicare Part D: practical and policy implications for family physicians

    American Family Physician

    (2006)
  • NPS, Federal/Provincial/Territorial Ministerial Task Force on the National Pharmaceuticals Strategy

    National pharmaceuticals strategy progress report

    (2006)
There are more references available in the full text version of this article.

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    There was methodological variation in the studies’ exploration of the factors affecting pharmaceutical expenditures. The methods include: analysis of prescription claims [13] and the structural effect approach [14]; decomposition of pharmaceutical spending growth [15]; dynamics of expenditure through time [16]; decomposition of change in real drug spending using a multiplicative growth equation [17]; decomposition of real drug spending into price, quantity and residual [18,19]; prescription drug expenditures [20–22]; decomposing the growth of pharmaceutical expenditures into three components: treatment expansion; treatment substitution; and price effect [23]; a pharmacoepidemiological model based on incidence, treatment discontinuation and drug user mortality [24];decomposition of the increase in real drug expenditures into a price effect, a volume effect, and a product-mix effect [25]; multiplicative factor equations using index numbers [26–29]; and equations describing changes in age/sex-specific expenditures [30]. Other studies included trend analysis [31–36] and fixed effects using regression analysis and the demographic impact method [37].

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