**Background:** The global increase in the elderly population presents challenges to health systems. Social participation (SP) is recognized as a key contributor to well-being and active ageing in older adults, with positive effects on mortality, mental health, functional and cognitive skills, and quality of life. Identifying factors that facilitate or inhibit SP—especially in the context of health-oriented activities—is essential for developing effective public health strategies. This study aimed to determine these factors among the elderly in Shiraz, southern Iran.
**Methods:** A descriptive-analytical cross-sectional study was conducted in 2021 across all 11 municipal districts of Shiraz. Using convenience sampling, the largest park in each district was selected as the data collection site. The sample size was calculated at 610 based on a similar study (mean SP 6.71 ± 4.01), type 1 error of 5%, precision of 0.48, and design effect of 2. Ultimately, 612 questionnaires were completed (response rate 92.7%). Inclusion criteria were: living in Shiraz, age ≥ 60, Iranian citizenship, ability to communicate, and informed consent. Data were collected using the Persian-validated Canadian Elderly Survey Project SP questionnaire (21 items: 7 on personal characteristics, 9 on activity frequency scored 0–4 on a Likert scale, and 5 yes/no barrier questions) and a health-related lifestyle questionnaire (20 items across 6 dimensions scored 0–5). Four trained interviewers administered the questionnaires via tablet. Statistical analysis included t-test, ANOVA, Pearson’s correlation, and ANCOVA (SPSS v19.0; significance set at P < 0.05).
**Key Results:** The mean SP score was 24.2 out of 60, below the midpoint. Pearson correlation showed significant positive associations between SP and all health-oriented activity dimensions: mental well-being (r = 0.92, P < 0.001), weight control and diet (r = 0.89, P < 0.001), exercise (r = 0.88, P < 0.001), prevention (r = 0.77, P < 0.001), social well-being (r = 0.75, P < 0.001), and physical well-being (r = 0.63, P < 0.001). In unadjusted analysis, SP was significantly associated with gender, chronic disease, hospitalization, access barriers, cost barriers, physician consultation, age, marital status, income, and education (all P < 0.001). After ANCOVA adjustment, only cost barriers (P < 0.001), physician consultation (P < 0.001), age (P < 0.001), marital status (P < 0.001), income level (P < 0.001), and education level (P < 0.001) remained significant. SP decreased significantly with age (mean 14.75 for > 80 years vs. 25.42 for < 69 years). Single elderly had the highest SP (36.76 ± 5.49). SP increased with income (very high income: 41.08 ± 1.97; very low: 18.00 ± 1.65) and education (collegiate: 41.02 ± 2.02; illiterate: 16.43 ± 2.54). The most common barrier was cost (reported by 391 participants, 63.9%), followed by access barriers (124 participants, 20.3%).
**Clinical Implications:** The low mean SP score (24.2/60) indicates that a substantial proportion of older adults in Shiraz do not participate in social activities, which may negatively impact their physical, mental, and social health. Cost barriers were the strongest inhibitor, suggesting that financial support programs and strengthened social security policies are urgently needed. Access barriers—particularly transportation—highlight the role of urban planning and infrastructure development (e.g., safe sidewalks, ramps, accessible transport) in enabling SP. The strong positive associations between SP and all health-oriented activity dimensions (especially mental well-being, r = 0.92) underscore the bidirectional relationship between social engagement and health. Higher education and income were the strongest facilitators, pointing to the importance of health literacy and economic empowerment. The inverse relationship between age and SP suggests that targeted interventions are needed for the oldest-old (> 80 years). Policymakers should adopt a combination of health promotion strategies, financial support, and infrastructure improvements to increase SP and promote active, healthy ageing in Iran.