Sleep is a universal biological process required by all individuals. People spend approximately one-third of their lives asleep. Sleep is crucial for cognitive, physiological, and psychosocial functioning. Additionally, sleep affects the quality of both personal and professional life. Every individual needs sleep to manage daily stress, prevent fatigue, conserve energy, and restore the body and mind (Berman et al., 2016).

Poor sleep quality is reported to be quite prevalent among nurses. When nurses experience poor sleep quality, it can impact their work performance and efficiency (Alameri et al., 2024; Al-Hammouri & Rababah, 2024; Almhdawi et al., 2021; Park et al., 2018; Zdanowicz et al., 2020; Zhang et al., 2019). It has been reported that nurses working shifts, in particular, often experience sleep problems, that sleep disorders threaten patient safety, and that they increase the tendency to make medical errors (Alameri et al., 2024). In a prospective cohort study by Nilsonn et al. (2025), it was determined that continuous or frequent night shifts or rapid transitions from night shifts to other shifts increase the risk of sleep disorders. In a systematic review by Weaver et al. (2023), night shifts were found to increase sleep deprivation in nurses. Chang (2024) reported that nurses working rotating shifts across three different shifts – day, evening, and night – experienced sleep disorders and that shift work affected cognitive functions. Jung and Kang (2017) also emphasized that sleep disorders were observed more often in nurses working two or three shifts, including night shifts, compared to nurses not working shifts, and that shift work affected cognitive functions.

Medical error has been defined as “the failure of a planned action to be completed as intended or the use of a wrong plan to achieve an aim” (Institute of Medicine, 1999). Medical errors can arise from various causes. Generally, the primary reasons for medical errors can be divided into two categories: human factors and organizational factors. Some of the human-related factors that contribute to medical errors include fatigue, inadequate training, lack of attention, failure to take precautions, carelessness, poor communication, insufficient time, and incorrect decision-making (Ozata, 2009; Özata & Altunkan, 2010). In Türkiye, the exact rates of medical errors are not well known. This situation necessitates identifying the factors associated with medical errors in nurses and taking measures to address them (Ersun et al., 2013; Kıymaz & Koç, 2018).

Sleep deprivation can affect nurses' cognitive performance in areas such as alertness, memory, and attention, which are all essential for effective clinical decision-making, as well as their ability to review plans and make decisions (Arslanian-Engoren & Scott, 2014). Good nursing practice requires a solid clinical decision-making process that is built upon scientific evidence and technological advancements (Benner, 1982). Since nurses are the first to notice changes in a patient's overall condition, this requires them to make quick and effective clinical decisions regarding the patients they care for (Durmaz-Edeer & Sarıkaya, 2015; Jenkins, 1983). Clinical decision-making in nursing refers to the use of professional nursing knowledge and skills. It involves identifying the needs of patients and their families and implementing the most beneficial and acceptable option to address the existing problem (Durmaz-Edeer & Sarıkaya, 2015; Jenkins, 1983).

A review of the literature shows found no studies that examine the relationship between sleep quality in nurses, their clinical decision-making, and their tendency to make medical errors. To the best of the authors' knowledge, this is the first study on the subject. The findings from this study are thus expected to contribute significantly to the development of strategies aimed at enhancing patient and staff safety.