Is the Leicester Cough Questionnaire useful for nontuberculous mycobacterial lung disease?

BACKGROUND: Although the incidence of nontuberculous mycobacterial lung disease (NTM-LD) is increasing worldwide, there is no established standard of care leading to eradication. Therefore, research on health-related quality of life (HRQOL) is important for patients with NTM-LD. HRQOL is commonly evaluated using the St. George's Respiratory Questionnaire (SGRQ), developed for chronic obstructive pulmonary disease (COPD). However, NTM-LD differs from COPD in that few patients complain of dyspnea or wheezing, and cough and sputum are their main symptoms. The Leicester Cough Questionnaire (LCQ) is an HRQOL questionnaire dedicated to cough, but few studies have used it for NTM-LD. This study evaluated HRQOL in patients with NTM-LD using the SGRQ and LCQ and clarified the usefulness of the LCQ. METHODS: Information on age, height, weight, lung function, percent ideal body weight, laboratory data, radiological scores, exercise capacity, SGRQ, and LCQ were collected from the medical records of 81 patients. Correlations between SGRQ and LCQ domains were assessed using Spearman's rank correlation coefficients. Multivariate analysis was performed with SGRQ and LCQ total scores. RESULTS: Statistically significant correlations were observed between all domains, and the correlation between the total scores was -0.67 (p < 0.01). Multivariate analysis with total scores as the dependent variable showed that the explanatory variables were lung function (p < 0.05) and radiological score (p < 0.05) in the SGRQ, and radiological score (p < 0.05) and C-reactive protein level (p < 0.05) in the LCQ. CONCLUSION: The LCQ, which evaluates an inflammatory response involved in the diagnosis of NTM-LD, may be useful to assess HRQOL in patients with NTM-LD.