Uncorrected Proof Shiraz E-Med J. In Press(In Press):e106830. Published online 2021 January 16. doi: 10.5812/semj.106830. Research Article The Effects of Environmental Modifications on Improving the Sleep Quality of the Elderly Hospitalized in the Cardiac Care Unit Masoumeh Shohani 1 , Sanaz Azami 1 , Hossein Seidkhani 2 and Zeinab Gholami 3, * 1 Department of Nursing, Faculty of Nursing and Midwifery, Ilam University of Medical Sciences, Ilam, Iran 2 Department of Epidemiology and Biostatics, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran 3 Department of Nursing, Faculty of Nursing and Midwifery, Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran * Corresponding author: Department of Nursing, Faculty of Nursing and Midwifery, Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran. Email: zeinabgholami111@gmail.com Received 2020 July 08; Revised 2020 August 17; Accepted 2020 August 20. Abstract Background: Sleep deprivation is a common problem among the elderly in the cardiac care unit (CCU). Objectives: The present study aimed to determine the effects of environmental modifications on sleep quality improvement in these people. Methods: The study population included 60 elderly patients whose sleep quality was assessed by the Pittsburgh Sleep Quality In- dex with even domains. The environmental factors that can disturb sleep quality were determined via a questionnaire, including 13 questions on a 5-point Likert scale. Descriptive and inferential statistical analyses were performed in SPSS 22 software via indepen- dent sample student t-test and chi-square. Results: After environmental modifications, the total sleep quality scores changed from 11.8 to 5.96, indicating sleep quality im- provement. Before executing the environmental modifications, there were no significant correlations between sleep quality scores and demographic variables (sex, age, marital status, and economic status). However, after the modifications, there was a significant relationship between sleep quality and economic status (P = 0.024). Conclusions: Environmental factors can affect sleep quality in the elderly hospitalized in CCU. Therefore, it is possible to improve sleep quality in these individuals by modulating environmental conditions. Keywords: Sleep Quality, Elderly, Intensive Care Unit, Effective Factors 1. Background Aging is a natural and inevitable biological phe- nomenon. According to the estimates by the United Na- tions, the world’s elderly population will increase up to 1.1 billion in 2025, which can necessitate their regular phys- ical and mental health screening. Sleep is among the most critical circadian circuits and complex biological pro- cesses affecting the physical and mental health of the el- derly. Sleep patterns are influenced by the circadian (84- hour daytime cycle) and homeostatic (equilibrium) pro- cesses, as well as some factors, such as adequate nighttime sleep (sleep quantity), sleep mental quality, and daytime sleepiness (1). Aging is associated with crucial changes in sleep pat- terns and qualities. Poor sleep quality is one of the severe problems among the elderly. Overall, 58% of them experi- ence insomnia at least one night a week. After headache and gastrointestinal disorders, poor sleep is the third most common problem in the elderly (2). Their main complaints are related to either delayed or continuous sleep (3). They are hospitalized three times more frequently than those under the age of 60 years. Also, their hospital stay is 50% longer than other age groups (4). During hospitalization, they are usually deprived of adequate sleep, suffer pain, impaired circadian rhythm, and malnutrition, and have limited physical and cognitive activities due to medica- tions. All of these negative changes can lead to undesirable health outcomes and result in crucial disorders at the be- ginning of the recovery period (5). Sleep disorders among the elderly hospitalized in the intensive care unit (ICU) can be caused by pain, excessive light, delirium, and problems with the artificial ventila- tion instrument (6). These factors are unclear and can have negative impacts on them (7). Also, sleep disturbance is a common problem affected by multifarious environmen- tal and non-environmental factors, such as noise, steroids, pre-hospitalization sleep quality, and gender (4). Annette et al. described noises and inappropriate dark-light cycle Copyright © 2021, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.