An electronic algorithm integrated with primary care clinical database systems achieved a modest increase in hepatitis C (HCV) case finding, a UK general practice-based study has found.

Overall 90 practices in Bristol, North Somerset and Gloucestershire were invited to take part in HepCATT (Hepatitis C Assessment Through to Treatment Trial) a pragmatic, cluster randomised controlled trial during April to December 2016.

A total of 45 practices agreed to participate; 22 were randomised to the intervention and 23 to the control arm. In the intervention group, an electronic algorithm and flag system were built onto practice databases to identify patients with HCV risk markers (e.g. history of opioid dependence and previous HCV test with no record of referral to hepatology).

Staff received training in HCV, and practice posters and leaflets were displayed to increase patient awareness.

Flagged patients were invited by letter for an HCV test (with one follow-up) and on-screen pop-ups used to encourage opportunistic testing. The intervention lasted one year. In the control group, opportunistic HCV case finding was carried out as usual.

Baseline HCV testing of patients flagged by the algorithm for the six months before the study commenced was 608/13,097 (4.6%) in intervention practices and 380/11,376 (3.3%) in control practices.

During the study year, 2,071 (16%) of flagged patients in the intervention practices and 1,163 (10%) in control practices were tested for HCV. This provided evidence of a higher rate of antibody testing in the intervention practices; adjusted rate ratio (RR) 1.59 (95% CI: 1.21-2.08; P < 0.001) compared with control practices.

HCV antibodies were detected in 129 patients from intervention practices and 51 patients from control practices; RR 2.24 (95% CI: 1.47-3.42), showing weak evidence of an increase in yield (6.2% vs 4.4%); RR 1.40 (95% CI: 0.99-1.95).

Referral and assessment increased significantly in intervention practices compared with control practices; RR 5.78 (95% CI: 1.6-21.6).

After exclusion of the training, software, and installation costs, the cost of case finding was £4.03 and the average cost per additional patient referred to hepatology for treatment was £3,165. The incremental cost effectiveness ratio was £6,212 per quality adjusted life year (QALY).

HCV infection is a major cause of chronic liver disease and cirrhosis in the UK and is mainly acquired through injecting drug use. Chronic HCV infection can be cured in the vast majority of patients with a short course (typically 8-12 weeks) of direct acting oral antiviral agents. The World Health Organization (WHO) has set targets for reducing the prevalence of HCV by 80% and HCV related mortality by 65% by 2030.

NHS England aims to achieve the WHO goals by 2025. Screening for HCV infection in primary care will contribute to achieving these goals.

Though the size of the effect of the interventions on HCV infection case finding was relatively modest, the interventions were low cost, and this research demonstrates that with the right infrastructure primary care can make a valuable contribution to the elimination of HCV infection in the UK.

The study authors conclude: ‘Our intervention was highly cost effective but increased HCV testing by only a modest amount. The overall findings are strong enough for us to recommend optimisation as part of implementation across primary care in the UK.’

They add: ‘An alternative, and possibly complementary, approach is to conduct birth cohort screening, whereby all patients born between specific years (such as 1945 to 1965 as recommended by the Centers for Disease Control and Prevention in the US) are invited to be screened for HCV.’

Dr Jez Thompson