Development and validation of the Tuberculosis Diabetes Mellitus-Predictive Tool (TBDM-PT) in primary care

Tuberculosis (TB) is a major public health issue worldwide. Screening patients with diabetes mellitus (DM) for TB incurs the highest cost per TB case discovered. Thus, a more practical and useful screening tool is required, especially at the primary care level. This study sought to develop and validate the Tuberculosis Diabetes Mellitus-Predictive Tool (TBDM-PT) in Kelantan, Malaysia.

This study included 270 patients with DM (with and without TB) from 2019 to 2021 at health clinics in Kelantan. The variables included in the risk score were chosen using logistic regression analysis. Receiver-operating characteristic curves were used to define the cut-off points for scores indicating a low or high risk of developing TB. Nine experts and 20 healthcare workers were involved in the content and face validation processes, respectively.

The risk score was created using eight different variables. The cut-off point selected was 11 out of 21, with sensitivity and specificity of 81% and 90%, respectively. The content validity index of the scale was 0.93, while the face validity index of each component varied from 0.95 to 1.00.

The newly developed TBDM-PT has great potential as a screening tool for TB among patients with DM at the primary care level. External validation and evaluation of this tool in diverse settings and larger populations are required before being applied into standard diabetes care pathways in primary care facilities.