Predictors of Quality-of-Life Improvement at Different Minimum Clinically Important Difference Values in Patients with Chronic Obstructive Pulmonary Disease after Climatic Rehabilitation Treatment

Background: The minimum clinically important difference (MCID) for the St George’s Respiratory Questionnaire (SGRQ) is debated in chronic obstructive pulmonary disease (COPD) quality-of-life (QoL) assessments. This study aimed to determine whether there is a difference in predictors of clinically significant improvement between the traditional (value of 4) and newly proposed MCID SGRQ (value of 7) after climatic rehabilitation treatment. Climatic rehabilitation treatment consists of two main parts: climatotherapy, which typically involves the controlled exposure of individuals to natural environmental elements, and climatic rehabilitation, which includes other therapeutic factors such as physical activities as well as educating the patient to change their lifestyle. Methods: This study included 90 consecutive patients diagnosed with COPD who underwent structured complex pulmonary rehabilitation in High Tatras, part of the Carpathian Mountains. The examination before and after treatment included spirometry, QoL assessment using the SGRQ, 6 min walk test (6-MWT), and the Borg, Beck and Zung scale. Results: Patients showed statistically significant improvement after the intervention in FEV1, FEV1/FVC, 6-MWT, (p < 0.001), anxiety scores, depression, and improvement in dyspnoea both before and after the 6-MWT (p < 0.001). For both MCID for SGRQ levels 4 and 7, we confirmed the same predictors of clinical improvement for bronchial obstruction grade (spirometry) and exercise capacity (6-MWT), for quality of life in activity score and total score. Conclusion. The results suggest that both the proposed MCID for SGRQ values could be sufficient to assess the clinical significance of the achieved change in health status when assessing the need for pulmonary rehabilitation comprising climatotherapy in patients with COPD.