Accuracy and completeness of notification of tuberculosis in two high incident communities in Cape Town, South Africa

[摘要] ENGLISH ABSTRACT: Introduction: Tuberculosis (TB) treatment registers and laboratory records are essential recordingand reporting tools in TB control programmes. Reliable data are essential for any TB controlprogramme but under-registration of TB cases has been well documented internationally, due tounder-reporting of patients on treatment or failure to initiate treatment. The accuracy andcompleteness of routinely collected data are seldom monitored.Aim: This study used record linking to assess the accuracy and completeness of TB treatmentregister data and the feasibility of estimating the completeness of bacteriological confirmedpulmonary TB registration in two high incident communities in South Africa with capturerecapturemethods.Methods: All cases of bacteriologically confirmed TB defined as 2 smear-positive results and/or atleast one culture-positive result were included. Record linking was performed between three datasources: (1) TB treatment registers; and (2) all smear and culture results from (a) the nearestcentral laboratory, and (b) the referral hospital laboratory. To estimate the completeness of TBtreatment recording three-source log-linear capture-recapture models were used, with internalvalidity analysis.Results: The TB treatment registers had 435 TB cases recorded of which 204 (47%) werebacteriologically confirmed cases. An additional 39 cases that were recorded as nonbacteriologicalcases in the TB treatment register, were reclassified as bacteriologically confirmed.In addition, there were 63 bacteriologically confirmed cases identified from the laboratorydatabases which were not recorded in the TB treatment register. The final total number ofbacteriologically confirmed TB cases across all 3 databases was 306, an increase of 50% overwhat had initially been recorded in the TB treatment register. The log-linear capture-recapturemodel estimated the number of bacteriologically confirmed TB cases not found in any of the datasources at 20, resulting in a total number of bacteriologically confirmed TB cases of 326 (95% CI 314-355). The completeness of registration of bacteriologically confirmed pulmonary TB caseswas 79% after record linking and 75% after the capture-recapture estimate.Conclusions: The results presented in this thesis highlighted the concern regarding the accuracyand completeness of routinely collected TB recording and reporting data. A high percentage of bacteriologically confirmed cases from both laboratories were not recorded in the TB treatmentregisters. Capture-recapture can be useful, but not essential, for evaluation of TB controlprogrammes, also in resource-limited settings, but methodology and results should be carefullyassessed. The present study estimated the extent of the problem of underreporting of TB in SouthAfrica and identified challenges in the process. Interventions to reduce underreporting of TB areurgently needed.

[发布机构] Stellenbosch University