Evaluating Social Vulnerability as a Key Social Determinant of Health Index in Iran.

Background: The Social Vulnerability Index (SVI) is a practical metric that operationalizes the social determinants of health. This study aimed to develop a composite SVI for Iran and to measure the social vulnerability status across its provinces. Methods: This ecological study utilized a composite indicator construction method to create a social vulnerability index for the provinces of Iran. Relevant indicators for the social vulnerability index were selected through the Delphi method. Factor analysis was employed to validate the index construction and select appropriate indicators and dimensions. Varimax rotation was used to rotate the indicators, and Principal Component Analysis was conducted for indicator extraction. The data were standardized using the Z-score method and aggregated through a linear aggregation technique. Weighting was performed based on the squared factor loadings, and sensitivity analysis was conducted to assess the robustness of the index. Results: Based on the research findings, the SVI, tailored to the context and structure of Iranian society, comprises 17 indicators categorized into five dimensions. These dimensions include lack of social insurance and low education, household poverty and disability, household structure and population dependency, economic vulnerability, and unemployment and housing vulnerability. The spatial distribution map of social vulnerability across Iran's provinces reveals that Sistan and Baluchistan (2.40) is the most socially vulnerable province, followed by North Khorasan (1.68) and Golestan (1.62). Overall, peripheral and border provinces exhibit higher levels of social vulnerability compared to the central provinces. Among all provinces, Yazd (0.01) demonstrates the lowest level of social vulnerability. Conclusion: The composite social vulnerability index for Iran's provinces can serve as a key tool for evidence-based and equitable policy-making and planning in the health sector. By identifying vulnerable provinces, this index can support prevention efforts and facilitate appropriate responses during disease outbreaks and other health emergencies.