Showing 3 results for Ostovar
K Holakouie Naieni, A Ostovar, A Danesh, S Sadjedinejad, L Ghalichee, Gh Moradi, Ma Mansournia, Ss Hashemi Nazari,
Volume 6, Issue 2 (22 2010)
Abstract
Background and objective: The nested case-control study has become popular as an efficient alternative to the full-cohort design. This study compares the results of a nested case-control analysis approach with the full cohort analysis.
Methods: A cohort of 276 subjects (new cases from a TB registry) was used for this study. Cox Regression model was used for the full cohort analysis. In order to do the nested case-control analysis, for each death, three random controls were selected from those who did not suffer from the outcome at the time of the outcome took place. Case control data was analyzed by the conditional logistic regression model.
Results: Results from both cohort and nested case-control analyses show that treatment group is the only variable that affects on the outcome. Gender, place of residence, and age has no effect on the outcome. For binary exposure variables with trivial effects (e.g. Gender and place of residence), the relative efficiency of nested case-control study design is approximately 75%.
Conclusion: Results of this study show that nested case-control study is not only an easy and cost-effective method for data analysis but also is as robust as cohort analysis in rate ratio and its variance estimation.
P Khashayar, A Keshtkar, A Ostovar, B Larijani, H Johansson, N Harvey, M Lorentzon, U Mc Closkey , J A Kanis,
Volume 16, Issue 4 (Vol.16, No.4 2021)
Abstract
Background and Objectives: The purpose of this study was to adopt and calibrate the fracture risk assessment algorithm FRAX® for the Iranian population and to provide the required guidance on how to apply it in clinical practice.
Methods: The age-specific ten-year probability of major osteoporotic fractures was calculated in women with an average BMI to determine the fracture probability at two potential intervention thresholds. The first threshold was the age-specific fracture probability associated with a femoral neck T-score of -2.5 SD and the other was age-specific fracture probability in women with a history of fracture without BMD. Current Iranian guidelines were used to define these thresholds. The effect of adding BMD values to the assessment of these thresholds was also evaluated separately.
Results: Similar to women with a previous fracture, the 10-year probability of a major osteoporotic fracture increased from 4.9% at the age of 50 years to 17% at the age of 80 years. When using a BMD T-score of ≤−2.5 SD as the intervention threshold, the FRAX probability was twice as high in women aged 50 years as in women of the same age with an average BMD and no risk factor. The FRAX probability increased with age but a T-score of -2.5 SD was actually protective after 80 years or age.
Conclusion: Intervention thresholds based on BMD alone cannot effectively identify high-risk women for fracture, particularly in advanced ages. Using fracture probability based on ‘fracture threshold’ can help to improve the identification of these women.
Fatemeh Hajivalizadeh, Mahnaz Sanjari, Noushin Fahimfar, Kazem Khalagi, Mohammad Javad Mansourzadeh, Elahe Hesari, Bagher Larijani, Hadis Ghajari, Mahboobeh Darman, Afshin Ostovar,
Volume 19, Issue 2 (Vol.19, No.2, Summer 2023)
Abstract
Background and Objectives: In Iran, a substantial number of individuals at risk of osteoporosis lack access to osteoporosis diagnostic services, highlighting a significant gap in the diagnosis and subsequent treatment of osteoporosis. This study aims to investigate the distribution of bone densitometer devices in Iran.
Methods: Bone densitometry devices across the country in 2018 were assessed through a comprehensive census. Information regarding these devices was gathered based on their location (urban or rural), ownership (government or private), adherence to standards, and years of operation. To calculate the inequality index in the distribution of devices among cities within a province, the frequency of devices in the provincial center was compared to those outside the center. To assess the inequality in the distribution of devices among the provinces of the country, the Lorenz curve and concentration index were utilized. All values were calculated per one million people over 50 years of age.
Results: Of the total 492 bone density measurement devices in the country, 399 devices (81.0%) were located in provincial centers. Out of these, 103 (20.9%) devices were in government-owned centers, while 389 (79.0%) devices were in privately-owned centers. For every one million individuals over 50 years old, the total number of devices, standard devices, standard devices with less than 10 years of operation, and devices in government-owned centers were calculated as 33.4, 20.3, 9.9, and 7, respectively. The inequality index in the distribution of devices in the cities was found to be 4.7. Furthermore, the inequality index in the distribution of devices between provinces was estimated as 0.13 (95%CI: 0.005-0.25) (P value=0.05).
Conclusion: There exists a significant disparity in the distribution of bone densitometry devices across the provinces and cities within the country.
