Table 2.

Factors influencing the decision to initiate therapy for NTM-PD

Host factors	Mycobacterial factors	Environmental factors
Severity of respiratory and constitutional symptoms (eg, cough, sputum production, breathlessness, fatigue and malaise)	Virulence/pathogenicity (usually identified from mycobacterial speciation)	Promotion of NTM persistence (eg, through the use of inhaled steroids)
Comorbidities	Drug resistance profile (note: there is usually only limited information available)	Ongoing exposure to mycobacteria
Degree of lung damage (severity and/or extent of disease)

NTM, non-tuberculous mycobacteria; NTM-PD, non-tuberculous mycobacterial pulmonary disease.