Factors Associated with Tuberculosis Among Workers in South Africa: Cross-Sectional Analysis of the National Income Dynamics Study, 2017–2018

Abstract

Background Tuberculosis (TB) is a significant infectious disease that contributes to the worldwide burden of illness. In 2014, the South African government endorsed the End TB initiative, aiming to attain a 90% reduction in TB deaths by 2030. Amid all the strategies in place to reduce TB, it remains an occupational health problem, particularly for individuals who have worked as plant and machine operators. The objective of this study was to describe the socio-demographic characteristics and proportions of tuberculosis among these workers in South African population groups surveyed in 2017. Methods A cross-sectional analysis was conducted using Wave 5 of the National Income Dynamic Study dataset, a nationally representative longitudinal household survey conducted in South Africa in 2017. Stratified, two-stage cluster sampling was used to select households, and data were collected through face-to-face interviews to assess multiple dimensions of well-being and social change over time. The outcome variable (TB) was assessed through self-report, based on responses to the health module questionnaire, asking respondents if they had ever been diagnosed with TB. Data were analyzed using descriptive statistics and reported measures of central tendency for continuous variables and frequencies for categorical variables. Bivariate and multivariable analyses were conducted to determine factors associated with TB among workers using a cross- sectional study design in South Africa. Factors included in the final model were age, marital status, province, occupation, household income, BMI, smoking, and HIV/AIDS. Results The records of 850 participants were analyzed. The following variables were significant factors associated with TB in the adjusted model: age, marital status, province, occupation, household income, BMI, smoking, and HIV. Participants who were aged between 66 – 70 years had 9.6 times higher odds of reported TB compared to participants aged between 15 – 25 years (AOR = 9.6, 95% CI: 1.8 – 50.1). The adjusted odds of reported TB among participants residing in the Eastern Cape were 3.9 times higher than iv | P a g e the odds of reported TB in those living in Gauteng (AOR = 3.9, 95% CI: 2.0–7.3). Participants who worked as plant and machine operators had 3.7 times higher odds of reported TB compared to participants who worked as professionals, and this difference was statistically significant (AOR = 3.7, 95% CI: 1.7–8.3). Additionally, participants who earned much below average income had 3.9 times higher odds of reported TB compared to participants who earned much above average income (AOR = 3.9, 95% CI: 1.2 – 13.0). The odds of reported TB among participants whose BMI was categorized into being obese (AOR = 0.1, 95% CI: 0.1 – 0.3) were 90% times less compared to participants whose BMI was categorized into being underweight. Participants who self-reported having HIV/AIDS had 2.8 times higher odds of reported TB compared to those who self- reported not having HIV/AIDS (AOR = 2.8, 95% CI: 1.7 – 4.9). Conclusion This study found a significant association between age, province, occupation, household income, BMI, HIV/AIDS, and reported TB among study participants. A diagnosis of tuberculosis among workers may adversely affect their work performance, and lead to increased utilization of health care services. This can be addressed by understanding the prevalence of tuberculosis among different occupations, as TB remains an occupational health problem.