Is the relationship between individual-and family-levels socioeconomic status with disease different? Analyzing third stage data of IMOS

There are various reporting on the relationship between socio-economic status, SES, and bone density. However, since most of bone fractures occur among low-income social groups, SES appears to be an important factor determining the status of individual bone health. The purpose of this study was to determine the relationship between the individual and household levels of SES with osteoporosis. Data from the third stage of IMOS (Iranian Multi-center Osteoporosis Study) including 2617 subjects aged 20 years and older, from the cities of Sanandaj and Arak was collected in the form of one-stage cluster sampling. To build the individual-and family-levels of SES index, Principal Component Analysis (PCA) model was employed. Individual-and family-levels of SES were addressed as independent variables in univariate and multivariate logistic regression models to investigate their role in the prevalence of osteoporosis as the dependent variable. Both individual and household levels of SES, independently and with controlling the main risk factors showed a significant effect on osteoporosis. At the individual level, the odds ratios and 95% confidence intervals for the SES in "low", "lower-middle", and "upper-middle" levels, compared with "high" level, were: 3.2 (2.96-3.46), 6.08 (5.65-6.55), 4.95 (4.60-5.32), respectively. At the household level, the same valuables were: 1.88(1.80-1.95), 1.38 (1.33-1.44), 1.98 (1.90-2.06), respectively. The results showed that in addition to individual-level of SES, household-level is also important to be considered for intervening and preventing care.