Development and validation of the prognostic predictive model in patients with Mycobacterium avium complex pulmonary disease: a multicenter observational study

<bold>Background:</bold> The clinical course of <italic>Mycobacterium avium</italic> complex pulmonary disease (MAC-PD) is highly heterogeneous, making treatment decisions challenging for clinicians. <bold>Aims and objectives:</bold> To identify prognostic factors for MAC-PD and develop a predictive scoring model to identify patients with poor prognosis who should receive treatment. <bold>Methods:</bold> This multicenter retrospective cohort study was conducted at 18 hospitals. Patients newly diagnosed with MAC-PD between 2010 and 2017 were included. Patients aged < 80 years and those with malignancy-related deaths were excluded. Participants were randomly allocated in a 4:1 ratio to derivation and validation groups. Risk factors for mortality were identified in the derivation group, and scores were developed to ensure consistency in the validation group. <bold>Results:</bold> 891 (mean age 66.6 years; 29.6% male) were included in the analysis. 713 and 178 patients were allocated to the derivation and validation groups, respectively. Within 5 years, 553 (62.1%) patients received treatment for MAC-PD, and 72 (8.1%) died. Male sex, albumin (Alb) <3.5 g/dL, and oral corticosteroid (OCS) use were identified as independent risk factors for mortality. The AUC of ROC curve for the score model comprising these factors were 0.812 and 0.741 in the derivation and validation groups, respectively. Patients with scores of ≥ 2 had significantly poorer prognoses than those with scores of ≤ 1. <bold>Conclusions:</bold> The scoring model, comprising male sex, Alb <3.5 mg/dL, and OCS use, effectively predicted mortality of MAC-PD. This model may assist clinicians in making appropriate treatment decisions.