# Socioeconomic inequalities in the prevalence of chronic non-communicable disease risk factors in the DIMAMO health and demographic surveillance system

## TL;DR

This study shows that in South Africa, poor people face more behavioral health risks while wealthy people have higher rates of diabetes.

## Contribution

The study provides new insights into how wealth disparities drive different types of non-communicable disease risks in a specific South African population.

## Key findings

- Low fruit/vegetable intake and smoking are more common among lower socioeconomic groups.
- Diabetes and alcohol use are more prevalent among wealthier individuals.
- Socioeconomic status explains most of the observed health risk inequalities.

## Abstract

Socioeconomic inequalities play a crucial role in shaping the burden of non-communicable diseases (NCDs) and associated risk factors. This study examined socioeconomic disparities in the prevalence of chronic NCD risk factors among adults in the DIMAMO Health and Demographic Surveillance Site (HDSS) in Limpopo Province, South Africa.

A cross-sectional study was conducted among adults aged 18 years and above. Data on socioeconomic status (SES) and NCD risk factors such as smoking, alcohol consumption, high salt intake, low fruit and vegetable intake, and physical inactivity were collected using an adapted WHO STEPS questionnaire. Socioeconomic status (SES) was assessed through household assets. A wealth index was constructed using principal component analysis to classify participants into SES quintiles. Concentration indices (CIs) and concentration curves were computed to assess the magnitude and direction of SES-related inequalities. Inequality decomposition analysis was performed to quantify the contribution of SES to each risk factor's inequality.

Participants were predominantly female (63%) and younger than 50 years (58%), with the majority unemployed (60.3%) and possessing secondary-level education (63.1%). Low fruit and vegetable intake (88.7%) emerged as the most prevalent NCD risk factor, followed by alcohol consumption (35.2%) and hypertension (22.6%). Diabetes prevalence was significantly higher among individuals in higher SES groups (p = 0.0071), while smoking (CI = −0.149, p = 0.024), physical inactivity (CI = −0.159, p = 0.009), and low fruit and vegetable intake (CI = −0.021, p = 0.047) were more concentrated among the poor. In contrast, diabetes (CI = 0.336, p = 0.001) and alcohol use (CI = 0.090, p = 0.036) were significantly more prevalent among the wealthy. Decomposition analysis showed that socioeconomic status accounted for nearly all observed inequalities, indicating that wealth disparities remain the dominant driver of NCD risk distribution in this population.

The findings of the current study reveal a dual burden of NCD risk factors across socioeconomic groups; behavioral risks are concentrated among the poor, while metabolic conditions such as diabetes are more common among the affluent. Addressing these disparities requires context-specific interventions that target both behavioral and metabolic risk factors across all socioeconomic strata.