Prevalence of Polypharmacy and Correlations with Sex, Age and Drug Regimen in Insurance Prescription

Abstract Simultaneous use of multiple drugs (Polypharmacy, PP) is associated with adverse drug reactions, medication errors, increased risk of hospitalisation and increased curative costs, specially when the number of drugs exceeds four items. This cross-sectional study was conducted to determine prevalence of PP and its some associated factors. Data were derived from health insurance prescriptions practitioners in Social Security Organization and Employees Services insurance: Rasht 2000-2001(n=4750). Data collection tool was a questionnaire including: drug items, graduation year specially and sex of practitioners and patient. Data analysis was performed by SPSS, NOS-3 softwares and for hypothesis test chi-square and t-test was used and statistically significant difference was determined (α=0/05). Poly pharmacy was observed in 88% of prescriptions, which consisted of 62% minor PP(2-4 Drug) and 26% Major PP (Drug>=5). Drug prescriptions were 60% more prevalent among women than men, but prevalence of PP was 89% in men and 87% in women (non significant). The prevalence of PP was 91% in prescriptions of general practitioners and 83.5% in prescriptions of specialists (non significant). There was a significant difference between general practitioners and specialists in major PP(P<0.01). Cardiologistes had the most of major PP(29.3%). The prevalence of PP was 89% in male practitioners and 82% in female practitioners. PP were seen in prescriptions of practitioners graduated between 1995-2000 and the least of major PP (13%) in prescriptions of 1981- 84 graduates . Drug interaction occurred in 8.5% of prescriptions and 59% of server drug interaction were associated with major PP. The most prescribed drugs were central nervous system medications with 45% and the predominant drug in this group were analgesics (24%) and cardiovascular drugs with 20.5% were the second degree. In conclusion PP is widespread in this sample; not related to prescribers' sex, but related to graduation year. Responsible authorities should make priority in supervising and planning for rational drug use.