Aerosol components associated with hospital mortality in systemic sclerosis: an analysis from a nationwide Thailand healthcare database

Abstract

Occupational and environmental associations with systemic sclerosis (SSc) have been confirmed; however, the association between aerosol components and mortality is uncertain. The study aimed to define the association between aerosol components and hospital mortality among Thai SSc patients. A study was conducted using a national database of patients covered by the National Health Security Office, hospitalised between 2014 and 2018. Data included all patients over 18 having a primary diagnosis of SSc (ICD-10: M34). Spatial resources used map information based on GPS coordinates of Thailand. Aerosol components—including organic carbon, black carbon, dust particulate matter diameter < 2.5 µm (PM2.5), and sulfate—were assessed using the NASA satellite MERRA-2 Model M2TMNXFLX v5.12.4. Spatial modelling with R Package Integrated Nested Laplace Approximation (R-INLA) was used to analyse the association between the incidence of mortality and the 5-year accumulation of each aerosol component adjusted by age, sex, and comorbid diseases. The study included 2,094 SSc patients with 3,684 admissions. Most (63.8%) were female. During admission, 1,276 cases died. R-INLA analysis indicated an increase of 1 µg/m3 of dust PM2.5 was associated with a respective increase in the risk of overall mortality and death due to pneumonia of 96% and 79%. An increase of 1 µg/m3 of dust PM2.5 resulted in 1.17, 1.18, 1.64, and 2.15 times greater risk of mortality due to pulmonary fibrosis, cardiac involvement, renal involvement, and cancer, respectively. Aerosol components—particularly dust PM2.5 exposures—increased the risk of overall, cardio-pulmonary-renal, and cancer mortality among SSc patients.