Factors predicting statin prescribing for primary prevention: a historical cohort study

Background Initiation of statins for the primary prevention of cardiovascular disease (CVD) should be based on CVD risk estimates, but their use is suboptimal. Aim To investigate the factors influencing statin prescribing when clinicians code and do not code estimated CVD risk (QRISK2). Design and setting A historical cohort of patients who had lipid tests in a database (IQVIA Medical Research Data) of UK primary care records. Method The cohort comprised 686 560 entries (lipid test results) between 2012 and 2016 from 383 416 statin-naive patients without previous CVD. Coded QRISK2 scores were extracted, with variables used in calculating QRISK2 and factors that might influence statin prescribing. If a QRISK2 score was not coded, it was calculated post hoc. The outcome was initiation of a statin within 60 days of the lipid test result. Results Of the entries, 146 693 (21.4%) had a coded QRISK2 score. Statins were initiated in 6.6% (95% confidence interval [CI] = 6.4% to 6.7%) of those with coded and 4.1% (95% CI = 4.0% to 4.1%) of uncoded QRISK2 ( P< 0.001). Statin initiations were consistent with National Institute for Health and Care Excellence guideline recommendations in 85.0% (95% CI = 84.2% to 85.8%) of coded and 44.2% (95% CI = 43.5% to 44.9%) of uncoded QRISK2 groups ( P< 0.001). When coded, QRISK2 score was the main predictor of statin initiation, but total cholesterol was the main predictor when a QRISK2 score was not coded. Conclusion When a QRISK2 score is coded, prescribing is more consistent with guidelines. With no QRISK2 score, prescribing is mainly based on total cholesterol. Using QRISK2 is associated with statin prescribing that is more likely to benefit patients. Promoting the routine CVD risk estimation is essential to optimise decision making.

Automated summary

The study investigated factors affecting statin prescribing based on coded and uncoded CVD risk estimates. Results showed that prescribing based on coded QRISK2 was more consistent with guidelines, while prescribing without a coded risk estimate was mainly based on total cholesterol levels. Promoting routine use of CVD risk estimation tools is important for optimizing decision making in statin prescribing.