Sustained and cumulative impact of an electronic medical record-based alert on a hepatitis C birth cohort screening programme.

The study aimed to assess the effect of an electronic medical record-embedded best practice alert (BPA) on HCV age cohort screening in primary care clinics. HCV testing by primary care physicians was monitored prior and subsequent to the implantation of the BPA. Four intervals of 9 months duration were analysed in detail, including a pre-BPA baseline analysis and three annual post-BPA assessments. Pre- and post-BPA orders consistently followed a power law distribution, characterized by small groups of physicians placing the majority of test orders. Significant correlations were present between the numbers of tests orders by each physician, suggesting that 'high' and 'low' screening performances tended to be physician-specific. Testing rates increased markedly in response to the BPA, resulting in completion of screening in 56.8% (50,468 of 88,914%) of the entire age cohort within less than 3 years. In conclusion, HCV age cohort testing by primary care physicians follows a power-law distribution, with high-performing physicians contributing disproportionately to the overall effort. A simple BPA resulted in a sufficient increase in testing to allow testing of the entire target population within a reasonable time frame.