Predictors of ceasing or reducing statin medication following a large increase in the consumer co-payment for medications: A retrospective observation study
Seaman, K., Sanfilippo, F., Bulsara, M., Roughead, L., Kemp-Casey, A., Bulsara, C., & Watts, G. (2019). Predictors of ceasing or reducing statin medication following a large increase in the consumer co-payment for medications: A retrospective observation study. Public Health Research and Practice, Online First.
Objectives: Previous Australian research has shown that following the 21% increase in the patient co-payments in 2005, the use of lipid-lowering therapy declined by 5%. This study aimed to determine the demographic and clinical characteristics of individuals who continued, reduced or ceased their use of statin medication in 2005.
Study type: Retrospective observational study using routinely collected administrative data.
Method: Pharmaceutical claims, hospital separations, and mortality records from 2000–2005 were used from the Western Australian (WA) population. The cohort comprised stable users of statin medication in 2004. We identified individuals who i) continued using statins, ii) reduced their use by ≥20%, or iii) ceased therapy for at least the first six months in 2005, based on changes in statin use between 2004 and 2005. Multivariate logistic regression models were used to determine whether the demographic and clinical characteristics of the three groups differed.
Results: There were 205 924 statin users identified in Australia in 2004. After the January 2005 Pharmaceutical Benefits Scheme (PBS) co-payment increase, 3.2% of individuals ceased their regular statin therapy, 12.9% reduced statin use and 83.9% continued statin usage. This was an increase of 2.1% in statin users reducing or ceasing therapy compared to 2004. Predictors of cessation and reduction of statin therapy included younger age, greater socio-economic disadvantage, residing in very remote areas, having general beneficiary status, being a new statin user, having no prior history of ischaemic heart disease, having no prior history of a coronary artery revascularisation procedure, taking no other cardiovascular medication or diabetic medication, taking an increased number of medications and having a lower adherence level to statin medication in 2004.
Conclusion: Compared to 2004, an additional 2.1% of statin users reduced or discontinued medication use in 2005, which may be attributed to an increase in the medication co-payment. Individuals with general beneficiary status, younger and healthier people were at particular risk of cessation or reduction in statin use in 2005.