[Background]

Because treatment of nontuberculous mycobacteria pulmonary disease (NTM-PD) is complicated and the outcomes is challenging, alternative treatment outcomes are needed. Physical activity (PA), which is significantly associated with prognosis of chronic respiratory diseases, may be a new outcome. However, characteristics of PA in NTM-PD are not clear.?The purpose of this study was to determine PA and its associated factors in NTM-PD.

[Method]

This was a prospective observational study, stable patients with NTM-PD who admitted for management of pharmacotherapy were measured daily step count for 7 consecutive days. We investigated C-reactive protein (CRP), pulmonary function, quadriceps force, incremental shuttle walk distance (ISWD), Leicester Cough Questionnaire (LCQ), modified Medical Research Council (mMRC) dyspnea scale, chronic cough and sputum symptoms (CCS). Daily step count in patients with and without CCS were compared, and association between daily step count and clinical parameters was evaluated.

[Results]

One-hundred-thirty-one patients (female: 109 [83.2%]) were analyzed, and median daily step count was 3968. Patients with CCS had significantly lower daily step count than those without CCS (4567 vs. 3426). The daily step count was significantly correlated with age, mMRC dyspnea scale, CRP, %ISWD, and LCQ. Multiple regression analysis showed that daily step count was significantly associated with %ISWD and CCS.

[Conclusion]

These results suggests that CCS should be considered in the assessment of PA in patients with NTM-PD.