Reducing liver function tests for statin monitoring: an observational comparison of two clinical commissioning groups.

Background: Current liver function testing for statin monitoring is largely unnecessary and costly. Statins do not cause liver disease. Both reduction in test frequency and use of a single alanine transaminase (ALT) rather than a full seven analyte liver function test (LFT) array would reduce cost and may benefit patients.

Aim: To assess LFT testing in relation to statin use and evaluate an intervention to reduce full-array LFTs ordered by GPs for statin monitoring.

Design And Setting: Two-year cross-sectional time series in two east London clinical commissioning groups (CCGs) with 650 000 patients. One CCG received the intervention; the other did not.

Method: The intervention comprised local guidance on LFTs for statin monitoring and access to a single ALT rather than full LFT array.

Results: Of the total population, 17.6% were on statins, accounting for 43.2% of total LFTs. In the population without liver disease, liver function tests were 3.6 times higher for those on statins compared with those who were not. Following intervention there was a significant reduction in the full LFT array per 1000 people on statins, from 70.3 (95% confidence interval [CI] = 66.3 to 74.6) in the pre-intervention year, to 58.1 (95% CI = 55.5 to 60.7) in the post-intervention year (<0.001). In the final month, March 2016, the rate was 53.2, a 24.3% reduction on the pre-intervention rate.

Conclusion: This simple and generalisable intervention, enabling ordering of a single ALT combined with information recommending prudent rather than periodic testing, reduced full LFT testing by 24.3% in people on statins. This is likely to have patient benefit at reduced cost.