Record-linkage and capture-recapture analysis to estimate the incidence and completeness of reporting of tuberculosis in England 1999-2002.

In 1999 the Enhanced Tuberculosis Surveillance (ETS) system was introduced in the United Kingdom to strengthen surveillance of tuberculosis (TB). The aim of this study was to assess the use of record-linkage and capture-recapture methodology for estimating the completeness of TB reporting in England between 1999 and 2002. Due to the size of the TB data sources sophisticated record-linkage software was required and the proportion of false-positive cases among unlinked hospital-derived TB records was estimated through a population mixture model. This study showed that record-linkage of TB data sources and cross-validation with additional TB-related datasets improved data quality as well as case ascertainment. Since the introduction of ETS observed completeness of notification in England has increased and the results were consistent with expected levels of under-notification. Completeness of notification estimated by a log-linear capture-recapture model was highly inconsistent with prior estimates and the validity of this methodology was further examined.