Examination of the chronic respiratory disease mortality by occupation in the South African context

The study aimed to examine chronic respiratory disease mortality by occupation in the South African context by providing valuable data and insights that can contribute to the existing knowledge on occupational health and respiratory diseases. An analytical cross-sectional study using secondary national mortality data was conducted from Statistics South Africa (Stats SA) of the nine South African provinces from 2013 to 2019. All registered deaths among individuals aged 18-75 years with known occupation and certified cause of death were included. CRD deaths were identified using ICD-10 codes J30-J99 and coded as a binary outcome (1 = any CRD as the underlying cause of death; 0 = all other causes). Descriptive statistics were used to analyse sociodemographic characteristics and proportions of CRD mortality. Multivariable logistic regression was used to determine the association between occupation and CRD mortality, and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were estimated. Potential confounders were selected a priori based on epidemiological theory and prior literature including age group, sex, education level, marital status, smoking status, province of death, population group, and year of death. These variables were retained in the model to minimise confounding. Model performance was assessed using the Hosmer-Lemeshow test, area under the ROC curve (AUC), and classification accuracy. Statistical significance was assessed at a two-sided alpha level of 0.05. Results: Among 2,373,703 total deaths, 79,840 (3.4%) were due to CRDs (ICD-10 J30-J99) as the underlying cause. Chronic obstructive pulmonary disease (COPD) (J44) was the leading cause, accounting for 40,180 of 79,840 deaths, representing 50.3% of all CRD deaths. <br>Asthma (J45) contributed 15,483/79,840 deaths (19.4%) and other respiratory disorders (J98) 8,335/79,840 deaths (10.4%). Mortality due to CRD was substantially higher among males (3.8%, 51,083/1,348,157) and older adults and higher among Coloured (7.8%, 14,326/184,635) and white (6.9%, 10,905/157,291) individuals compared with Black Africans (2.6%, 43,569/1,698,765). Compared with professional (reference) technicians and associate professionals (aOR 1.16; 95% CI 1.04-1.30; p = 0.011), clerical support workers (aOR 1.42; 95% CI 1.28-1.60; p &lt; 0.001), skilled agricultural and fishery workers (aOR 1.29; 95% CI 1.16-1.44; p &lt; 0.001), craft and related trade workers (aOR 1.38; 95% CI 1.26-1.51; p &lt; 0.001), plant and machine operators and assemblers (aOR 1.24; 95% CI 1.14-1.34; p &lt; 0.001), and elementary occupations (aOR 1.32; 95% CI 1.22-1.42; p &lt; 0.001) had higher adjusted odds of CRD mortality. While managers (aOR 1.04; 95% CI 0.91-1.19; p = 0.522) and service and sales workers (aOR 1.07; 95% CI 0.97-1.19; p = 0.162) did not differ significantly from professionals after adjustment.