Variability of symptoms in outpatients with COPD and validation of the Colombian instrument for symptoms variability in COPD (CoVaSy)

Abstract

Introduction: It is considered that the variability of respiratory symptoms in chronic obstructive pulmonary disease (COPD) is low or nonexistent; however, some authors state that there may be fluctuations. Objectives: To describe the variability of symptoms in patients with COPD throughout the day and night during four weeks using a patient diary, and to validate a questionnaire created for such purpose (the Colombian instrument for symptoms variability in COPD - COPD-CoVaSy). Materials and methods: Cohort study conducted in 96 patients with COPD treated between June and December, 2016, at the Centro de Atención Pulmonar - CAP, in Barranquilla, Colombia, who completed the patient diary for four weeks and, after this period, the self-administered COPD-CoVaSy instrument. The independence and comparison of frequencies of categorical and continuous variables were established using the chi-square and the Fisher's exact tests and the Pearson's correlation coefficient, respectively. A MANOVA was performed, using linear regression models, to determine the correlations between the results of the diary and those of the instrument. Results: Participants’ mean age was 73.3±8.3 years and 71.87% were male. According to the analysis of the diaries, the average scores (visual analog scale) for all symptoms and the performance of daily activities ranged between 0.5 and 2.5, being higher in the morning (with average scores between 1.5 and 2.5) than in the afternoon and evening (with average scores between 0.5 and 1.5); however, symptom variability was minimal. These results were similar to those obtained in the COPD-CoVaSy instrument, evidencing a high correlation between both instruments, which allowed confirming that COPD-CoVaSy is useful tool to measure such variability. Conclusions. Based on the findings of the present study, it can be concluded that there is a slight variability in COPD symptoms throughout the day, which should be considered when establishing treatment regimens for this disease. Likewise, it was determined that the COPD-CoVaSy is valid to measure such variability in Colombian patients with COPD.