Abstract 3726: Risk Factors for Discontinuation of Statin Medications: Evidence From a Large National Pharmacy Claims Database
Purpose: The discontinuation rate in long-term use of statins is high. It is important to understand the complex reasons for discontinuation so that interventions can be successful. This study aims to assess discontinuation rates by risk factors including demographics, co-payment, co-morbidities and particularly dose.
Methods: Using a retrospective cohort study design with a 6-month baseline period and a 12-month treatment follow-up period, prescription records from September 1, 2004 to December 31, 2006 were obtained from pharmacy claims database in a large national retail pharmacy chain. Inclusion criteria were as follows:
age ≥ 18 years;
continuously refilled medications at the pharmacy stores during the study period;
had no fills of the study drugs in the baseline period but had at least two refills of the study drugs in the follow-up period.
Discontinuation rate is defined as the proportion of patients who discontinued the study medication.
Results: A total of 768,184 subjects were included. The discontinuation rates were 27.87%, 41.37% and 58.73% at 3 month, 6 month and 12 month follow-up time point, respectively. We found that subjects who were on high dose statins, paid high co-payment, or speak Spanish were significantly more likely to discontinue, with odds ratio at 1.040 (95% CI: 1.015–1.065), 1.011 (95% CI: 1.010–1.011) and 2.086 (95% CI: 2.031–2.146), respectively. Subjects who used Internet, had CHD or Hypertension were significantly less likely to discontinue, with odds ratio at 0.709 (95% CI: 0.701–0.717), 0.350 (95% CI: 0.340–0.361) and 0.877 (95% CI: 0.868–0.886).
Conclusion: This very large database of statin prescribers demonstrates that statin discontinuation rates remain high with over half of the patients stopping therapy within 12 months. Risk factors for discontinuation may be associated with increased side effects at high doses and socioeconomic issues with higher co-pays but especially ethnic-language barriers. Targeting these risk factors for discontinuation may improve long-term statin compliance.