Validation and intra-rater reliability of the CDQ scale for the diagnosis of COPD in Colombia

Background: COPD is highly underdiagnosed, thus applying clinical prediction scales such as the COPD Diagnostic Questionnaire (CDQ) helps to address this problem. Objective: To evaluate the criterion validity and in-tra-rater reproducibility of the questionnaire CDQ in a Colombian population. Materials and methods: A prospective cohort study. The reproducibility was assessed with the Kappa sta-tistic and the intraclass correlation coefficient (ICC). Validity was established with the score obtained from the CDQ questionnaire and the spirometry values (FEV1/ FVC 16.5 and < 19.5, and high probability of CDQ COPD ≥ 19.6. The ACOR was 0.68 (95%CI: 0.647-0.712), a sensitivity of 79% and a specificity of 44% were obtained for a score ≥16.5, with a PPV of 26% and a NPV of 86%. Conclusions: The CDQ questionnaire has a regu-lar performance for the diagnosis of COPD with an ACOR similar to other questionnaires, it can be useful in underdiagnosed patients. The optimal cut-off point for this population was 16.5