Profile and baseline results of non-communicable diseases in Iranian healthcare workers from the PERSIAN SUMS EHCS

The SUMS Employee Health Cohort Study (SUMS EHCS), initiated in 2017 as part of the Prospective Epidemiological Research Studies in Iran (PERSIAN), aims to investigate the burden and determinants of non-communicable diseases (NCDs) among healthcare workers (HCWs). This report presents the cohort profile and baseline findings, describing the methodology, participant characteristics, and prevalence of NCDs and their risk factors. This prospective cohort enrolled employees aged 20–70 from Shiraz University of Medical Sciences from August 9, 2018, to March 20, 2023. Baseline data included interview-administered questionnaires, biological samples, and physical examinations. Multivariable logistic regression was used to investigate factors associated with multimorbidity (≥ 2 of 15 self-reported NCD groups). Among 10,000 invited, 7,091 participants enrolled (70.9% response rate; 43.0% male, mean age 41.1 years). The most prevalent self-reported NCDs were renal stones (18.2%), fatty liver disease (15.9%), thyroid diseases (12.1%), chronic headache (11.4%), clinical depression (6.9%), and known hypertension (6.3%). Clinical assessment showed a higher hypertension prevalence of 23.7% (17.4% undiagnosed). Significant sex differences were observed in NCD prevalence, lifestyle risk factors, and quality of life. Multimorbidity was present in 21.1% of participants. In the fully adjusted model, female sex, older age, longer work experience, alcohol consumption, higher BMI, and lower physical quality of life were independently associated with multimorbidity; and current smoking and greater hip circumference showed inverse associations. A significant age by BMI interaction indicated that the BMI effect weakened with age. The SUMS EHCS baseline showed a lower prevalence of several major NCDs among HCWs compared to the general Iranian population, potentially reflecting a healthy worker effect. However, a substantial hidden disease burden and distinct correlates of multimorbidity were identified. These findings may serve as a resource for longitudinal research and inform occupational health interventions. The SUMS Employee Health Cohort Study (SUMS EHCS) yields a comprehensive baseline profile of non-communicable diseases (NCDs) among Iranian healthcare workers. The prevalence of several major NCDs was lower than in the general population, suggesting a potential "healthy worker effect", yet significant undiagnosed hypertension and clear sex-based disparities were observed. Cross-sectional analyses showed that female sex, older age, longer work experience, higher BMI, and lower physical quality of life were independently associated with having multiple chronic conditions. These findings are expected to establish a reference baseline for this occupational cohort and yield evidence to inform workplace health policies and interventions.