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

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.

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

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.

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

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 (P<0.001). In the final month, March 2016, the rate was 53.2, a 24.3% reduction on the pre-intervention rate.

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.