First population-based study on non-communicable diseases and risk factors in northeastern Iran: Sabzevar cohort...

Non-communicable diseases (NCDs) have become the leading cause of mortality globally, with a sharp rise in Iran due to lifestyle changes and urbanisation. Although many NCD risk factors are modifiable, limited understanding of their determinants hinders effective prevention. To address this, the Prospective Epidemiological Research Studies in Iran (PERSIAN) Cohort was established in 2014 to study NCDs nationwide. The Sabzevar PERSIAN Cohort Study (SPECS) is the first in northeastern Iran, aiming to investigate environmental and social factors influencing NCDs in a unique regional context.

SPECS enrolled 5174 adults (aged 35-70 years) in northeastern Iran between January 2018 and January 2019 through a census and an online registration process. The baseline data collection included demographic verification, informed consent, health questionnaires, anthropometric measurements and biological samples (blood, urine, hair, nails). The annual follow-up began in April 2019, with full reassessments every 5 years over a 15-year period. The data is gathered via an active and passive follow-up, supported by trained staff and registry linkages.

Of the 5174 participants, 4241 (81%) remained in the study. Among the cohort, 54.5% were female, with a mean age of 50.5 years. The majority were married (93.5%), and nearly half had at least high-school education (46.5%) and moderate socioeconomic status (49.4%). Drug abuse history (smoking/drugs) was reported by about 15% of the sample. The mean body mass index was 26.9 kg/m², and the average blood pressure was higher in males (118.1/74.0 mm Hg) than in females (111.5/70.2 mm Hg). The common conditions included hypertension (22.8%), kidney stones (22.4%), fatty liver (15.4%) and diabetes (13.8%). Cancer had the highest treatment rate (100%), while fatty liver had the lowest (70.1%). Stroke had the highest mean age of onset (51.2 years), and epilepsy the lowest (23.7 years). All health data were self-reported.

SPECS, part of the national PERSIAN cohort initiative, is the only adult NCD-focused study in Khorasan Razavi. Its 15-year follow-up aims to generate region-specific insights into the incidence of NCDs and their risk factors. The ethnically homogeneous sample enhances statistical power, and the findings may inform culturally tailored health policies. While self-reported data have limitations due to bias, high initial participation and access to free healthcare support long-term engagement, especially among lower-income groups.