Statin initiations and QRISK2 scoring in UK general practice: a THIN database study

Background Statin prescribing should be based on cardiovascular disease (CVD) risk, but evidence suggests overtreatment of low-risk groups and undertreatment of high-risk groups.

Aim To investigate the relationship between CVD risk scoring in primary care and initiation of statins for the primary prevention of CVD, and the effect of changes to the National Institute for Health and Care Excellence (NICE) guidance in 2014.

Design and setting Historical cohort study using UK electronic primary care records.

Method A cohort was created of statin-naïve patients without CVD between 1 January 2000 and 31 December 2015. CVD risk scores (calculated using QRISK2 available from 2012) and statin initiations were identified. Rates of CVD risk score recording were calculated and relationships between CVD risk category (low-, intermediate-, and high-risk: <10%, 10–19.9%, and ≥20% 10-year CVD risk) and statin initiation were analysed.

Results A total of 1.4 million patients were identified from 248 practices. Of these, 151 788 had a recorded CVD risk score since 2012 (10.67%) and 217 860 were initiated on a statin (15.31%). Among patients initiated on a statin after 2012, 27.1% had a documented QRISK2 score: 2.7% of low-risk, 13.8% of intermediate-risk, and 35.0% of high-risk patients were initiated on statins. Statin initiation rates halved from a peak in 2006. After the 2014 NICE guidelines, statin initiation rates declined in high-risk patients but increased in intermediate-risk patients.

Conclusion Most patients initiated on statins had no QRISK2 score recorded. Most patients at high risk of CVD were not initiated on statins. One in six statin initiations were to low-risk patients indicating significant overtreatment. Initiations of statins in intermediate-risk patients rose after NICE guidelines were updated in 2014.