Skip to main content

Free Content Validation of candidate smear microscopy quality indicators, extracted from tuberculosis laboratory registers

Download Article:
(PDF 121.6826171875 kb)


SETTING: Kinshasa Province, Democratic Republic of Congo.

OBJECTIVE: To identify and validate register-based indicators of acid-fast bacilli (AFB) microscopy quality.

DESIGN: Selection of laboratories based on reliability and variation in routine smear rechecking results. Calculation of relative sensitivity (RS) compared to recheckers and its correlation coefficient (R) with candidate indicators based on a fully probabilistic analysis incorporating vague prior information using WinBUGS.

RESULTS: The proportion of positive follow-up smears correlated well (median R 0.81, 95% credibility interval [CI] 0.58–0.93), and the proportion of first smear-positive cases fairly (median R 0.70, 95% CI 0.38–0.89) with RS. The proportions of both positive suspect and low positive case smears showed poor correlations (median R 0.27 and −0.22, respectively, with ranges including zero).

CONCLUSIONS: The proportion of positives in follow-up smears is the most promising indicator of AFB smear sensitivity, while the proportion of positive suspects may be more indicative of accessibility and suspect selection. Both can be obtained from simple reports, and should be used for internal and external monitoring and as guidance for supervision. As proportion of low positive suspect smears and consistency within case series are more difficult to interpret, they should be used only on-site by laboratory professionals. All indicators require more research to define their optimal range in various settings.

Keywords: AFB microscopy; evaluation; indicators; registration

Document Type: Regular Paper

Affiliations: 1: Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium; International Union Against Tuberculosis and Lung Disease, Paris, France 2: Department of Social and Preventive Medicine, University of Bern, Bern, Switzerland 3: Programme National de Lutte contre la Tuberculose, Lingwala, Democratic Republic of Congo 4: Fondation Damien, Gombe, Kinshasa, Democratic Republic of Congo 5: International Union Against Tuberculosis and Lung Disease, Paris, France

Publication date: 2007-03-01

More about this publication?
  • The International Journal of Tuberculosis and Lung Disease publishes articles on all aspects of lung health, including public health-related issues such as training programmes, cost-benefit analysis, legislation, epidemiology, intervention studies and health systems research. The IJTLD is dedicated to the continuing education of physicians and health personnel and the dissemination of information on tuberculosis and lung health world-wide.

    Certain IJTLD articles are selected for translation into French, Spanish, Chinese or Russian. They are available on the Union website

  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • International Journal of Tuberculosis and Lung Disease
  • Public Health Action
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more