Tehran University of Medical Sciences Health Technology Assessment in Action 2645-3835 6 1 2022 11 06 133 133 Farhad Hosseinzadeh Lotfi Department of Mathematics, Science and Research Branch, Islamic Azad University, Tehran, Iran. Alireza Olyaeemanesh Health Equity ResearchCenter (HERC), TehranUniversity of Medical Sciences, Tehran, Iran. 2.National Institute of HealthResearch, TehranUniversity of Medical Sciences, Tehran, Iran. Efat Mohamadi Health Equity Research Center (HERC), Tehran University of Medical Sciences (TUMS), Tehran, Iran. Reza Majdzadeh Community Based Participatory Research Centre and Knowledge Utilization Research Centre, Tehran University of Medical Sciences and Iran's National Institute of Health Research, Tehran, Iran. Ali Akbari Sari Department of Health Management and Economics, and Knowledge Utilization Research Center, Tehran University of Medical Sciences, Tehran, Iran Iraj Harirchi The Cancer Institute at Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran AliAkbar Haghdoost Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran Hamid Sharafi Department of Mathematics, Science and Research Branch, Islamic Azad University, Tehran, Iran. Haniye Sadat Sajadi National Institute for Health Research, Tehran University of Medical Sciences, Tehran, Iran. Zahra Goodarzi National Institute for Health Research, Tehran University of Medical Sciences, Tehran, Iran. Somayeh Noori Hekmat Research Center for Health Services Management, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran. Mohammad Mehdi Kiani 1.Department of Health Management and Economics, School of Public Health, Tehran, Iran 2.Health Equity Research Center (HERC), Tehran University of Medical Sciences (TUMS), Tehran, Iran. Leila Freidoony 1.Health Equity Research Center (HERC), Tehran University of Medical Sciences (TUMS), Tehran, Iran. 2. Department of Global Health and Public Policy, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Amirhossein Takian 1.Health Equity Research Center (HERC), Tehran University of Medical Sciences, Tehran, Iran. 2.Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 3.Department of Global Health and Public Policy, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 2022 06 12 2022 10 09 Abstract Background: To improve healthcare services’ quality, countries should measure their health systems’ efficiency and performance by robust methods. Objectives: We aimed to develop a national study to measure the efficiency of the health system in Iran. Methods: The literature review identified several methods for measuring efficiency; the most common one was data envelopment analysis (DEA). We adopted DEA, but its findings were simplistic and inaccurate, so we began to modify the method by determining the weight of each indicator. We identified the efficiency measurement indicators, in line with international standards and uniformed units, and then readjusted our input/output indicators according to the study context through four expert panels. We collected data and classified the input/output indicators, followed by determining each indicator’s weight and standard limits. Then we rationalized our previous results by applying the revised model. The initial new results of the refined model were valid, accurate, and consistent with previous studies, as approved by experts. We defined proper modeling to achieve the stated objectives. After investigating various DEA models, we finally designed a new model that was consistent with the existing data and conditions, entitled EDEA (extended DEA), to analyze other subprojects. Conclusions: The conventional DEA methods may not be accurate enough to measure health systems’ efficiency. By modifying modeling process, we propose a modified DEA with a very low error rate. We suggest that others interested in measuring health system efficiency adopt our modified approach to increase accuracy and create more meaningful policy-oriented results. https://htainaction.tums.ac.ir/index.php/hta/article/view/133 https://htainaction.tums.ac.ir/index.php/hta/article/download/133/98