Apparent discontinuation rates in patients prescribed lipid-lowering drugs

Abstract

Objective: To evaluate apparent discontinuation rates in patients newly prescribed lipid-lowering drugs.

Design and setting: A prospective survey of 12 months' dispensing data in 138 community pharmacies across metropolitan Sydney.

Patients: 610 adults (49% men) with a mean age of 58 years; 91% of prescriptions were from general practitioners; prescribed drugs were simvastatin (54%), pravastatin (31%) and gemfibrozil (15%).

Main outcome measure: The number of patients failing to collect prescription refills.

Results: 60% of patients (95% confidence interval [CI], 56%-64%) apparently discontinued their medication over 12 months. Half of the apparent discontinuations occurred within three months and a quarter within one month of starting treatment. The predominant reasons for discontinuation were: patient unconvinced about need for treatment (32%), poor efficacy (32%) and adverse events (7%). Only half of those experiencing poor efficacy were switched to another drug. The relative risk (RR) of discontinuation was lower in older patients (age 65+ v. <50 years: RR 0.66; 95% CI 0.47-0.93) and in those using other cardiovascular drugs (RR 0.69; CI 0.56-0.86), but was increased in those showing early evidence of poor compliance (RR 1.77; CI 1.33-2.35). Discontinuation appeared to be unrelated to sex, the source of the prescription (general practitioner or specialist), past use of lipid-lowering drugs or the cost of medication.

Conclusions: High apparent discontinuation rates with lipid-lowering drugs suggest significant wastage of resources in treatments that are initiated but not continued and a lost opportunity for heart disease prevention. Many patients appear to discontinue therapy for illogical reasons and this may be amenable to intervention.