Influence of socioeconomic status on the quality of prescribing in the elderly – a population based study

Aims To compare the quantity and quality of prescribing, using prescribing indicators, between the relatively deprived and the relatively affluent patients over 70 years old in primary care. Methods We examined the General Medical Services (GMS) scheme prescribing data for the Eastern region in Ireland for all patients aged 70 years or more ( n = 95 055) during July 2001–December 2002. Prescribing indicators applied to the prescription data to evaluate drugs prescribed to each patient were classified as: (1) descriptive, e.g. number of drug items/patient; (2) indicators assessing potentially harmful prescribing; (3) evidence‐based indicators, e.g. secondary prevention therapy in those with ischaemic heart disease (IHD). Results are expressed as odds ratio (OR) and 95% confidence intervals for comparison of prescribing between the relatively deprived and affluent cohorts, adjusted for age and gender (CI) using logistic regression analysis. Results The relatively deprived cohort was more likely to receive a greater number of drugs (5.2 vs. 4.5, P < 0.0001), more generic products ( P = 0.01) and be exposed to major polypharmacy (≥ five drugs) compared with monotherapy (OR = 1.58; 95% CI = 1.52,1.64, P < 0.0001). They were more likely to receive potentially harmful drugs such as cerebral vasodilators (OR = 1.52; 1.38,1.69), long‐acting sulphonylurea (OR = 1.43; 1.20,1.72), potentially interacting agents such as angiotensin converting enzyme (ACE) inhibitor and potassium sparing diuretic (OR = 1.78; 1.48,2.15). In terms of evidence‐based prescribing, the relatively deprived cohort with IHD was less likely to receive secondary prevention therapies such as statins (OR = 0.82; 0.74, 0.90) and beta blockers (OR = 0.85; 0.77,0.93). Conclusions These results show that suboptimal prescribing is more prevalent among the relatively deprived cohort and suggests the differences observed in the quality of prescribing between these patient groups may be related to their socioeconomic status.