Abstract: Asadi et al. Journal of Pharmaceutical Policy and Practice https://doi.org/10.1186/s40545-023-00511-w (2023) 16:4 Open Access RESEARCH Effectiveness of different treatment regimens on patients with COVID‑19, hospitalized in Sanandaj hospitals: a retrospective cohort study Jalal Asadi1, Mohammad Aziz Rasouli1,2, Ebrahim Ghaderi1,3, Daem Roshani1,3, Behzad Mohsenpour4, Yousef Moradi3 and Ghobad Moradi1,3* Abstract Objectives Different drugs have different effects on the prognosis of patients with COVID-19. This study aimed to evaluate the effect of different drug regimens on patients with COVID-19, hospitalized in Sanandaj city. Methods In this retrospective cohort study, 660 patients with COVID-19, hospitalized in the Tohid, Kowsar and Besat hospitals located Sanandaj (Kurdistan Province, Iran) were studied from February 2020 to February 2021 with clinical symptoms and positive test results. Results The results of multivariate regression analysis showed the days of hospitalization for patients who had received the drug regimen 2 (Interferons (ReciGen/Ziphron) or Interferon Vectra (lopinavir/ritonavir)) was 1.92 times higher than those who had received the drug regimen 1 (hydroxychloroquine group or a combination of chloroquine and azithromycin) while a significant association was observed (OR = 1.92, 95% CI: 1.16–3.16, P = 0.011). Also, the hospitalization in ICU was longer in patients treated by the drug regimen 2 (Interferons (ReciGen/Ziphron) or Interferon Vectra (lopinavir/ritonavir)) (OR = 4.63, 95% CI: 1.80–11.82, P = 0.001), however, drug regimens did not show a significant effect on mortality and use of ventilator in patients (P > 0.05). Conclusion The study results showed the drug regimens 2 and 5 increased the days of hospitalization and hospitalization in ICU, respectively, while the other drug regimens had no significant effect on mortality and use a ventilator in the studied patients and none of the drug regimens had an effect on reducing mortality compared to other ones. Keywords COVID-19, Drug regimen, Treatment, Retrospective cohort, Iran *Correspondence: Ghobad Moradi Moradi_gh@yahoo.com 1 Department of Epidemiology and Biostatistics, School of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran 2 Clinical Research Development Unit, Kowsar Hospital, Kurdistan University of Medical Sciences, Sanandaj, Iran 3 Social Determinants of Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran 4 Department of Infectious Diseases, School of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran Background The first case of COVID-19 was observed in a seafood market in Wuhan, Hubei province, China on December 12, 2019, and the first positive case was diagnosed 21 days later, on January 3 in the United States [1, 2]. The very high outbreak potential led to the announcement of the COVID-19 global pandemic on March 11, 2020 [3]. The full range of COVID-19 disease is from a mild and self-limiting respiratory disease to severe progressive pneumonia, multiple organ failure, and death [4]. © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and..