Setting: Designated microscopy centre (DMC) attached to a tertiary care centre in Pondicherry, India.
Objectives: To determine 1) the proportion of diabetes mellitus (DM), 2) the additional yield of newly diagnosed DM cases, and 3) the number needed to screen (NNS) to find a new case of DM among presumed TB patients.
Design: An institution-based cross-sectional study was carried out among 650 presumed TB patients attending the DMC. Capillary blood glucose was measured using fasting blood sugar and/or oral glucose tolerance test, and evaluated according to the World Health Organization criteria.
Results: Of 570 presumed TB patients evaluated for DM, 121 (21.2%) were found to be diabetic. Of these, 69 were previously known to have DM, while 52 were newly diagnosed. The additional yield of diabetes was 43%. The NNS to detect a new case of DM was 11; among those aged >40 years, the NNS was 9.3, and among smear-positive TB patients it was 4.6.
Conclusion: One fifth of the presumed TB patients had diabetes, and nearly half of these patients were newly diagnosed. Opportunity screening of presumed TB patients for DM in routine care will help in early detection of diabetes and pre-diabetes.