Evaluation of the German surveillance system for hepatitis B regarding timeliness, data quality, and simplicity, from 2005 to 2014.

ABSTRACT

OBJECTIVES: Germany has a mandatory surveillance system for acute hepatitis B (AHB) with the Protection against Infection Act as the legal basis in place since 2001. An amendment was introduced in 2013. We aimed at evaluating the surveillance systems' performance regarding timeliness, data quality, and simplicity from 2005 to 2014 and at assessing the effect of the amendment on timeliness of AHB surveillance. STUDY DESIGN: This study is a trend analysis of surveillance data. METHODS: Aspects of simplicity versus complexity of the surveillance system were assessed by describing data flow, levels of reporting, and data management procedures. Data quality, in terms of data completeness, was evaluated by quantitative indicators, and timeliness was measured in days between different levels of the surveillance system, notification delay, and reporting delay. Trends over time in data quality were analyzed by logistic regression, while negative binomial regression was used to test for trend over time regarding mean notification and reporting delay. RESULTS: Between January 2005 and December 2014, a total of 22,549 AHB infections were reported at the national level. The data flow of the German AHB surveillance system showed structural characteristics of a complex system. Over the 10-year period, completeness of reporting sex, age, probable route of transmission, and hepatitis B virus (HBV) vaccination were 99%, 100%, 25%, and 73%, respectively. However, data quality decreased over the evaluation period. Although notification delay improved over time (incident rate ratio [IRR] = 0.95, 95% confidence interval [CI] = 0.95-0.96; P < 0.05), reporting delay improved only since the amendment (IRR = 0.76, 95% CI = 0.70-0.82; P < 0.05). In total, mean notification and reporting delay were 3.0 days and 14.3 days, respectively. CONCLUSIONS: The German AHB surveillance system is operating in a timely manner. Although timeliness improved over the evaluation period and the amendment to the Protection against Infection Act succeeded in reducing reporting time, data quality in terms of completeness of information decreased considerably. As improved data completeness is required to adequately design prevention activities, reasons for this decrease should further be explored.