Socioeconomic inequalities in diabetes prevalence: the case of South Africa between 2003 and 2016

Abstract

Background: Diabetes is a growing epidemic worldwide and the effect of socioeconomic status (SES) is frequently acknowledged in the literature. This study aims to compare the effect of SES on diabetes prevalence in South Africa between 2003 and 2016. In addition, vulnerable groups regarding diabetes development in 2016 will be identified.

Methods: Using DHS data there were 8,006 participants (59.19% women) in 2003 and 10,292 participants (59.42% women) in 2016. Logistic regression and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for diabetes by age, gender, educational level and place of residence. To identify vulnerable groups with high risk of developing diabetes in 2016, the method of p-value based regression tree analysis was applied using "wealth index" and "weight perception" as additional variables.

Results: There was an increase in diabetes prevalence from 3.86% in 2003 to 4.46% in 2016. Women had more risk of developing diabetes at both time points (27% in 2003 and 24% in 2016 more risk). Increase in age and living in urban areas were associated with more risk of developing diabetes at both time points. There was no specific pattern regarding risk of developing diabetes and educational level in case of women. However, men who completed secondary school or had a higher diploma or above had more risk of developing diabetes in 2016 (OR = 2.24 and 4.67 respectively). Vulnerable groups who have higher risk of developing diabetes in 2016 were participants aged "60 years or older" with a wealth index of "rich" or "richer", followed by participants from the same age group who were "poor" or "poorer" and participants aged "40-59 years" with a wealth index of "rich" or "richer". Subsequently were participants from the age group "15-39 years" with a weight perception of "overweight" or "obese".

Conclusion: Diabetes prevalence increased in South Africa between 2003 and 2016. Main risk factors were age, gender and living in urban areas. Men with high educational level were more at risk of developing diabetes in 2016. Vulnerable groups in 2016 were participants 40 years and older, particularly with high SES. This was followed by younger participants who were obese or overweight.

Keywords: DHS; Diabetes; Educational level; Prevalence; Social inequalities; South Africa.