Socioeconomic gradient in use of statins among Danish patients: population-based cross-sectional study

Abstract

Aims: Socioeconomic inequalities in statin use are a public health concern but they may also confound observational studies of statins' effectiveness. We conducted a population-based cross-sectional study in Denmark to examine the association between socioeconomic status (SES) and statin use.

Methods: We obtained data on socioeconomic status of all persons in North Jutland County, Denmark, between 1995 and 1999 from the Prevention Registry at Statistics Denmark. Data on filled statin prescriptions were identified through the County Prescription Database. We compared the 1-year prevalence proportions of statin use for different socioeconomic groups, adjusted for age and urbanization. Separate analyses were done for patients with a history of cardiovascular disease as recorded in the County Hospital Discharge Registry.

Results: Among men with cardiovascular disease, statin use in 1995 was higher in those with the highest socioeconomic status (adjusted relative prevalence proportion (RPP) among top managers 1.86, 95% CI: 1.17-2.96), and lower among retired men (RPP (95% CI) 0.63 [0.43-0.93] in old-age pensioners, and 0.66 [0.45-0.98] in the early retired), when compared with basic-level workers. The socioeconomic differences in statin use among men decreased in magnitude over time but remained throughout the study period. We found no clear social gradient in statin use among women.

Conclusions: Even in a health care system that claims to ensure a high degree of equity in medical care, we found clear indications of a socioeconomic gradient in statin use among men in the years after the launching of these drugs.

Figure 1

Adjusted relative prevalence proportions (RPP) of statin use in selected socioeconomic groups from 1995 to 1999 among men with a previous discharge diagnosis of cardiovascular disease. Basic level salaried employees served as the reference group in each year. Top managers (♦), upper level employees (▪), basic level employees (▴), unemployed (×), old-age pensioners ()

Figure 2

Adjusted relative prevalence proportions (RPP) of statin use in selected socioeconomic groups from 1995 to 1999 among women with a previous discharge diagnosis of cardiovascular disease. Basic-level salaried employees served as the reference group in each year. Top managers (♦), upper level employees (▪), basic level employees (▴), unemployed (×), old-age pensioners ()