en Nursing Original Article <span style="font-size:12pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:8.0pt">Background:</span></b><span style="font-size:8.0pt"> Arthritis is one of the most common diseases among the elderly, which is affected by adherence to treatment and self-efficacy. The purpose of this study was to determine relationship of adherence to treatment and self-efficacy among the elderly with arthritis.</span></span></span><br> <span style="font-size:12pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:8.0pt">Methods:</span></b><span style="font-size:8.0pt"> This descriptive&ndash;correlational study was conducted in 2019. Based on the convenience sampling method, 200 eligible elderly patients were recruited from three clinics affiliated with Tehran University of Medical Sciences in Tehran, Iran. Data were collected using the Modanloo adherence to treatment questionnaire and the perceived self-efficacy scale. Data were summarized using descriptive statistics (mean, frequency percentage, and standard deviation) and analyzed using inferential statistics (the Pearson correlation coefficient) in SPSS software (version 16).&nbsp; The statistical significance level was set at 0.05.</span></span></span><br> <span style="font-size:12pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:8.0pt">Results:</span></b><span style="font-size:8.0pt"> The mean age of patients was 67.97&plusmn;5.32 years. The mean scores of self-efficacy and adherence to treatment among the elderly with arthritis were 119.8&plusmn;35.3 and 123.88&plusmn;23.04, respectively. There was a statistically significant correlation between adherence to treatment and self-efficacy (r=0.648). The strongest positive correlation (r=0.693) was observed in the subscale of adherence to the treatment, and the weakest positive correlation (r=0.228) was observed in the subscale of indecisiveness for applying treatment with pain.</span></span></span><br> <span style="font-size:12pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:8.0pt">Conclusion:</span></b><span style="font-size:8.0pt"> Because of the direct relationship between treatment adherence and self-efficacy in the elderly with arthritis, healthcare policymakers and planners should develop and implement programs to increase self-efficacy and treatment adherence among the elderly with arthritis and other chronic diseases.</span></span></span> Arthritis, Treatment Adherence, Self-Efficacy, Elderly 34 38 http://nmj.goums.ac.ir/browse.php?a_code=A-10-1316-2&slc_lang=en&sid=1 Ali Afshar afshar55@yahoo.com 100319475328460011519 100319475328460011519 No Department of Community Health and Geriatric Nursing, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran Shahzad Pashaeypoor pashaeypoor.sh@gmail.com 100319475328460011520 100319475328460011520 No Department of Community Health and Geriatric Nursing, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran Shima Hghani shima_haghani@yahoo.com 100319475328460011521 100319475328460011521 No Nursing Care Research Center, Iran University of Medical Science, Tehran, Iran Naeimeh Sarkhani naeimehsarkhani@gmail.com 100319475328460011522 100319475328460011522 No Nursing and Midwifery Care Research Center, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran Nasrin Nikpeyma Nikpeyma@yahoo.com 100319475328460011523 100319475328460011523 Yes Department of Community Health and Geriatric Nursing, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran