en Safety پژوهشي Research <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Introduction</b>: Attention to patient safety is one of the essential foundations for promoting health services and it is important to identify the factors contributing to medical errors. This paper aims to develop a questionnaire based on the human factors analysis and classification system (HFACS) for the first time.</span></span><br> <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Materials & Methods</b><b><span style="font-size:11.0pt"><span new="" roman="" style="font-family:" times="">: </span></span></b>A questionnaire was designed based on the HFACS structure. The Likert scale was utilized to score each item. The contribution of the main levels and sublevels in each error and also the correlation coefficients between different levels of HFACS with the lowest level, referred to as &ldquo;Unsafe Acts&rdquo; were determined.<span lang="FA" dir="RTL" style="font-family:"Times New Roman",serif"></span></span></span><br> <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Results</b><b><span style="font-size:11.0pt"><span new="" roman="" style="font-family:" times="">: &nbsp;</span></span></b>The number of medical errors in the emergency department, intensive care unit (ICU), and Cardiac Care Unit (CCU) were higher than in the other departments. Insufficient supervision, management processes, and adverse mental state achieved the highest scores. Pearson&#39;s correlation coefficients show very strong relationships between organizational processes and supervisory violations with routine violations (0.81, and 0.84 respectively).</span></span><br> <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Conclusion</b><b><span style="font-size:11.0pt"><span new="" roman="" style="font-family:" times="">: &nbsp;</span></span></b>Organizational failures are the main cause of decreased patient safety and the mental condition of staff has the greatest impact on reducing medical errors.</span></span><br> &nbsp; Hospital, HFACS, Medical Errors, Patient Safety 25 34 http://jhsp.medilam.ac.ir/browse.php?a_code=A-10-31-2&slc_lang=en&sid=1 Mostafa Mirzaei Aliabadi MAliabadi@gmail.com 1003194753284600278 1003194753284600278 No Center of Excellence for Occupational Health, Occupational Health and Safety Research Center, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran Shiva Souri Ssoury93@gmail.com 1003194753284600279 1003194753284600279 Yes Department of Occupational Health and Safety Engineering, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran Hamed Aghaei 1003194753284600280 1003194753284600280 No Ali Reza Soltanian 1003194753284600281 1003194753284600281 No Mohammad Javad Golhosseini 1003194753284600282 1003194753284600282 No Mohsen Yazdani Aval 1003194753284600283 1003194753284600283 No Sajjad Deyhim 1003194753284600284 1003194753284600284 No