518 Winter 2024. Vol 18. Issue 4 * Corresponding Author: Rajabali Daroudi, Associate Professor. Address: Department of Health Management, Policy and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Tel: +98 (915) 8088846 E-mail: rdaroudi@sina.tums.ac.ir 1. Department of Health Management, Policy and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 2. Department of Epidemiology and Biostatstcs, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 3. Natonal Center for Health Insurance Research, Tehran, Iran. Mahya Razimoghadam 1 , Mehdi Yaseri 2 , Zahra Shahali 3 , Aliakbar Fazaeli 1 , *Rajabali Daroudi 1 Citation Razimoghadam M, Yaseri M, Shahali Z, Fazaeli A, Daroudi. [Age-related and Gender-related Differences in Hospital Admission Rate and Hospital Costs of People Covered by the Iran Health Insurance Organization: A Retrospective Study (Persian)]. Iranian Journal of Ageing. 2024; 18(4):518-535. http://dx.doi.org/10.32598/sija.2023.3523.1 http://dx.doi.org/10.32598/sija.2023.3523.1 Use your device to scan and read the article online Objectves The impact of populaton aging on health expenditure is inevitable. It afects health expenditure by causing changes in people’s health status and the demand for health care services. In this study, we aim to investgate the age-related and gender-related diferences in hospital admission rate, length of stay, and hospital costs of people in Iran. Methods & Materials This is a quanttatve, descriptve-analytcal study with a cross-sectonal design conducted on data of 41 million Iranian people covered by the Iran Health Insurance Organizaton in 2020. Hospital admission rate, length of stay, and hospital costs were dependent variables. Hospital costs included insurance payments, patents’ out-of-pocket spending, and government subsidies. Age and sex of the patents, ownership of the hospital, type of patents’ medical fles were descriptve variables. The Mann-Whitney U test was used to compare hospital costs between elderly (>60 years of age) and non- elderly (<60 years of age) groups and between females and males. Spearman’s correlaton test was used to fnd the correlaton between age and dependent variables. Results During the study period, there were about 3,800,000 hospital admissions. The rate of hospital admission in the elderly was 3.7 tmes higher than that of non-elderly groups. The average length of stay was 1.3 days for the elderly, and 2.2 days for the non-elderly. In the elderly group, men had a higher hospital admission rate than women, while in non-elderly groups, women had a higher admission rate. The average hospital cost was 28 million IRR for the non-elderly and 45 million IRR for the elderly. The average cost of surgery, hospitalizaton, medicine and medical consumables for the elderly was 1.5 tmes more than that of the non-elderly. There was a positve and signifcant relatonship between the hospital admission rate and age of the patents (r=0.879, P<0.001). As the age of the patents increased, the length of stay in the hospital increased signifcantly (r=0.582, P<0.001). The relatonship between patents’ age and the average hospital cost was also positve and signifcant (r=0.582, P=0.006). Conclusion Hospital admission rate, length of stay, and average hospital costs are signifcantly higher for the elderly in Iran. Keywords Health Expenditures, Health Insurance, Aging, Hospital Costs A B S T R A C T Artcle Info: Received: 03 Apr 2023 Accepted: 22 Aug 2023 Available Online: 01 Jan 2024 Research Paper Age-related and Gender-related Diferences in Hospital Admission Rate and Hospital Costs of People Covered by the Iran Health Insurance Organizaton: A Retrospectve Study