Impact of diabetes on diagnostic delay for pulmonary tuberculosis in Beijing

Setting Delays in the diagnosis of pulmonary tuberculosis (PTB) increase the risk of transmission and severity of the disease. Little information is available on PTB patients with diabetes mellitus (DM). Objectives To examine the impact of DM on delays in diagnosing PTB and the effect of diagnostic delay on the clinical presentation of PTB among patients in Beijing, China. Design In a cross-sectional study conducted in two PTB dispensaries of Beijing, all confirmed PTB patients were screened for DM. Data relating to diagnostic delay and clinical presentation of PTB were collected and analysed. Results Of 1126 PTB patients selected, 182 (16.2%) were identified as having DM. The median delay for PTB patients with DM (25 days) was significantly higher than that of PTB patients without DM (6 days). In a subgroup analysis, diagnostic delay was associated with smear positivity among PTB patients with DM (OR 3.10, 95%CI 1.66-5.76) and associated with smear positivity (OR 4.38, 95%CI 3.19-6.04), pulmonary cavities (OR 2.62, 95%CI 1.85-3.71) and more symptoms (OR 1.81, 95%CI 1.20-2.73) among PTB patients without DM. Conclusions DM was associated with longer diagnostic delays, which in turn was associated with more serious clinical presentations of PTB. It is thus necessary to examine risk factors associated with diagnostic delay among PTB patients with and without DM.