Validation of clinical control in COPD as a new tool for optimizing treatment

Abstract

Background: It has recently been proposed that the concept of clinical control in COPD may be useful for deciding treatment in COPD, but the original control criteria (OCC) were considered too restrictive. Objective: Define and subsequently validate “modified” control criteria (MCC) of COPD. Method: Prospective observational study in COPD patients with a 1-year follow-up. Control was defined as the presence of low clinical impact and clinical stability. To evaluate clinical impact, the following clinical parameters were assessed: the degree of dyspnea, use of rescue medication, physical activity, and sputum color. Stability was assessed by clinical changes and exacerbations in the last 3 months. The COPD assessment test score and their changes were also evaluated as alternative control criteria. To define the MCC, adjustment for disease severity using BODEx index (MCC-B) or FEV 1 (MCC-F) was evaluated, and the best cutoff point was established. Time to first combined event (emergency visit, hospitalization, or death) was analyzed to evaluate the predictive capacity of risk of the OCC, MCC-B, and MCC-F. Results: We included 265 patients, 224 (83.9%) men, with a mean age (±SD) of 68±9 years and FEV 1 of 58%±17%. The proportion of controlled patients was higher using clinical MCC-B or MCC-F (61.5% and 59.6%) than OCC (27.5%). Similar percentages were found using COPD assessment test scores. The time to the first combined event was significantly greater in controlled patients using MCC criteria (P<0.001, all cases). The predictive capacity of risk was similar in MCC-B (c-statistic [C]=0.639) and MCC-F (C=0.637) and higher than OCC (C=0.589). Conclusions: The new MCC identified a higher number of controlled COPD patients. These patients have a better quality of life and lower risk of poor outcomes. The concept of control and the new MCC could be a useful tool to optimize therapy.