The Age and Sex Distribution of Hospital Admissions and Associated Costs with a Focus on the Aging Effect: A Retrospective Analysis of Iran Health Insurance Organization Claims Data

Objectives: The impact of population aging on health expenditure is inevitable. The effects of aging on healthcare costs can be detected through changes in individuals' health as well as changes in the demand for healthcare. In this study, the age and sex distribution of the hospital admission rate and associated costs is determined and analyzed. The spending for 19 groups of hospital services and length of stay for older adults and other age groups are also compared. Materials and methods: This is a quantitative, cross-sectional, descriptive-analytical study conducted on 41 million Iran Health Insurance Organization insured people in 2019. Hospital admission rate, length of stay, and hospital costs are response variables. Costs include insurance payments, patients' out-of-pocket spending, and government subsidies. USD exchange rate in 2020 was 42173.8744 Irian Rial (IRR). Age and sex of the patient, ownership of the hospital, type of hospital registration and services received are descriptive variables. A Mann-Whitney test was used to compare costs between older adults and other age groups, as well as between females and males. Spearman’s test was used to find correlations between age and response variables. Findings: During the study period, there were 3 million and 800 thousand hospital admissions. Older patients over 60 had 3.7 times the hospital admission rate as other age groups. For the older patients, the average length of stay was 1.3 days, and for under 60 patients it was 2.2 days. The number of patients under 60 was 2.3 times that of older patients. However, the average cost for each patient under 60 was 28 million IRR and the average cost for patients over 60 was 45 million IRR. The average cost of surgery, medicine and medical supplies for older patients was more than 1.5 times that of people under 60 years old. There was a positive and significant relationship between the hospital admission rate and the age of the patients (r=0.879, p<0.001). As the age of patients increased, the length of stay in the hospital increased significantly (r=0.582, p<0.001). The relationship between the patient’s age and the average associated hospital costs was positive and significant (r=0.582, p=0.006). Results: Hospital admission rates, length of stay and average hospital costs are significantly higher among older adults.