Background A key aim of the Hepatitis C Action Plan for Scotland was to reduce the undiagnosed population through awareness-raising activities, for general practitioners and those at risk, and the introduction of dried blood spot (DBS) sampling in community drug services to overcome barriers to testing. This study evaluates the impact of these activities on testing and diagnosis.

Methods Data on hepatitis C virus (HCV) testing undertaken between January 1999 and December 2011 in Scotland's four largest health boards were analysed. Segmented regression analysis was used to examine changes in testing following the (1) launch of the Action Plan and (2) introduction of DBS testing.

Results Between the pre-Action Plan and Action Plan periods, increases were observed in the average number of HCV tests (19 058–29 045), positive tests (1993–2405) and new diagnoses (1221–1367). Since July 2009, 26% of new diagnoses were made in drug services. The trend in the number of positive tests was raised during the Action Plan, compared to pre-Action Plan, particularly in drug services (rate ratio (RR)=1.4, p<0.001) and prisons (RR=1.2, p<0.001); no change was observed in general practice. Following introduction of DBS testing, there was a 3-fold increase in testing (RR=3.5, p<0.001) and 12-fold increase in positives (RR=12.1, p<0.001) in drug services.

Conclusions The introduction of DBS sampling in community drug services has made an appreciable contribution to efforts to diagnose the HCV-infected population in Scotland. These findings are important to other countries, with injecting-related HCV epidemics, needing to scale-up testing/case-finding initiatives.