Gaps and discontinuation of statin treatment in Norway: potential for optimizing management of lipid lowering drugs

AIMS: In clinical practice, many patients do not reach the recommended treatment targets for LDL-cholesterol levels. We aimed to examine treatment patterns and adherence for patients on lipid lowering drugs in Norway to inform future strategies to improve therapies. METHODS AND RESULTS: We obtained information on all dispensed statins, ezetimibe, and proprotein convertase subtilisin/-kexin 9 (PCSK9) inhibitors 2010–2019 from the Norwegian Prescription Database. Treatment gaps were assessed assuming patients take one tablet per day and were defined to occur if a patient did not refill a prescription when the previous one should have been depleted. Treatment was defined as discontinued when the preceding prescription would have been used and no new subsequent prescription was filled. The mean proportion of days covered (PDC) was calculated by aggregating the total number of tablets dispensed during each calendar year and dividing by 365. Patients 80 years were excluded. A considerable proportion of statin users in Norway had long treatment gaps or discontinuation in treatment. The 19.6% of the patients had treatment gaps of 180 days or more, and 10.8% had gaps or greater than 365 days. Similar results were found for patients on antidiabetics and hypertensives. PDC ranged from 84.9% for simvastatin to 72.2% for ezetimibe (2019). The most common lipid lowering drugs in 2019 were atorvastatin, simvastatin, and ezetimibe. CONCLUSION: There is a great potential for improving drug adherence and optimizing lipid lowering therapy by switching to more effective statins in greater doses, and more often add ezetimibe and PCSK9 inhibitors to treatment.