Non-communicable diseases and COVID-19 outcomes: insights from the 2021 Iran STEPS survey

The association between non-communicable diseases (NCDs) and COVID-19 has imposed a significant burden on health systems, particularly in middle-income countries. This study aimed to evaluate the association between major NCDs, socioeconomic determinants, and COVID-19 outcomes (infection, hospitalization, and ICU admission) using nationally representative data from Iran.

This secondary analysis utilized data from the 2021 National STEPS Survey, a cross-sectional study comprising 27,874 adults aged ≥ 18 years across all 31 provinces of Iran. The study followed the World Health Organization stepwise approach. COVID-19 history and outcomes were assessed via a dedicated module. Multivariable logistic regression models were employed to estimate Odds Ratios (OR) and 95% Confidence Intervals (CI), adjusted for demographic and socioeconomic confounders.

The analytic sample comprised 27,874 adults, of whom approximately 70% were aged 25-59 years. In multivariable analyses, COVID-19 infection was significantly associated with urban residence (OR = 1.98, 95% CI:1.74-2.26) and the wealthiest socioeconomic status (OR = 1.58, 95% CI:1.34-1.84), whereas current smoking showed an inverse association (OR = 0.83, 95% CI:0.73-0.96). Regarding healthcare utilization, using outpatient service was only associated with supplementary health insurance (OR = 1.28, 95% CI:1.04-1.57). Diabetes (OR = 1.83, 95% CI:1.33-2.54), abnormal Body Mass Index (BMI) (OR = 1.48, 95% CI:1.06-2.07), and age over 60 years (OR = 6.46, 95% CI:2.51-16.63) were associated with higher odds of hospitalization, whereas smoking (OR = 0.60, 95% CI:0.39-0.93) and the highest socioeconomic status (OR = 0.61, 95% CI:0.39-0.96) were associated with lower odds. Hypertension showed no significant association with the risk of infection (p = 0.893) or hospitalization (p = 0.215). Due to the limited number of events and lack of statistical significance in the univariate analysis, Intensive care unit (ICU) admission was not included in the multivariable model.

This study underscores the significant role of specific NCDs as independent predictors of COVID-19 infection and disease severity. Socioeconomic and demographic factors, including older age, urban residency, higher wealth status, and insurance coverage, were key determinants of both infection rates and healthcare utilization. The observed association between tobacco use and COVID-19 outcomes requires cautious interpretation. These findings highlight the necessity of integrating NCD management into pandemic preparedness and ensuring equitable access to healthcare and insurance to mitigate health disparities and enhance population resilience.