1. Objectives
Aging is a natural process and of the stages of human growth. The improvements in living conditions and health care, as well as the longevity and life expectancy, have led to aging in societies [1, 2]. With an increasing elderly population in Iran and the world, paying attention to this group’s biopsychological health is of particular importance [3]. Aging is associated with quantitative and qualitative changes in the sleep pattern. Problems with falling asleep or sleep continuity, waking early in the morning and inability to fall back sleep are prevalent among the elderly [4]. Data are scarce on the negative emotional components in older people and their relation to their sleep quality; thus, this study aimed to compare the negative emotional components in older people with healthy and poor sleep quality.
2. Methods & Materials
This was causal-comparative research. The study population consisted of all elderly residents of Tehran City, Iran, in 2016 (n=200). Of them, 200 samples were selected by visiting recreational, tourism, and sports centers based on the inclusion criteria and using convenience sampling technique. Inclusion criteria were ≥60 years of age, ability to communicate verbally and to read and write, cognitive health, no history of severe biopsychological disorders, no history of substance or alcohol or illegal medications abuse according to the self-reports, and providing informed consent forms to participate in the study. The exclusion criteria were the unwillingness to continue study participation. 

For collecting data, a researcher-made demographic form was used in addition to the Pittsburgh Sleep Quality Index, Ruminative Responses Scale, Pennsylvania State Worry Questionnaire, and Mood and Anxiety Symptoms Questionnaire (Anxious Arousal Scale). If any of the study participants had difficulty with reading or understanding the questions, those were read and explained to them. Based on the cut-off point of 5 for sleep quality, the study participants were divided into two groups of healthy and poor sleep quality. After matching the subjects for demographic factors, 131 subjects participated in the study; 78 were assigned to the poor sleep quality group and 53 to the healthy sleep quality group. The collected data were analyzed in SPSS using descriptive statistics (frequency, mean, standard deviation) and statistical tests, including Chi-squared test, Mann–Whitney U test, ad Independent Samples t-test.
3. Results
Of 131 samples, 55% were male and 45% were female with the Mean±SD age of 68.5±6.78 years. Moreover, (80-90%) of them were married living with the family; (84%) reported moderate economic status; (50%) had a high school diploma and Bachelor’s degree, and (31%) reported elementary education. Chi-squared test results suggested no significant difference between the groups in terms of gender (X2=0.002, P=0.965), living conditions (X2=0.146, P=0.702), and marital status (X2=2.915, P=0.088). Mann–Whitney U test results revealed no significant difference between the groups concerning education (Mann–Whitney U test= 1904.500, Z=-0.792, P=0.429) and health status (Mann–Whitney U test= 1816.000, Z=-1.501, P=0.133).
After matching the groups in terms of demographic characteristics, the study groups were compared with each other in terms of rumination, worry, and anxious arousal. For this purpose, the Independent Samples t-test was used (Table 1). Based on the Levene’s test results, the assumption of equal variances was met for all variables, except for anxious arousal. There was a significant difference between the groups in terms of rumination, worry, and anxious arousal. This finding indicates that older people with poor sleep quality experienced significantly more rumination, worry, and anxious arousal.
4. Conclusion
Rumination, worry, and anxious arousal were significantly different in the elderlies with poor and healthy sleep quality. The obtained data suggested rumination and worry could predict sleep quality, which is consistent with previous studies [5-7]. Negative cognitive activities majorly affect sleep quality and its associated problems. This result was in agreement with those of Harvey [8]. A cognitive model presented by Harvey [9] suggested that sleep-related excessive worry and rumination cause arousal and emotional distress and attentional bias, leading to the development and maintenance of sleep disturbances. We found that rumination, worry, and anxious arousal negatively affected sleep quality. Focusing on these negative emotional components as the risk factors for the onset and continuation of sleep disorders can be useful in designing preventive interventions for sleep problems and reducing mental issues.
Ethical Considerations
Compliance with ethical guidelines
All ethical principles were considered in this article. The participants were informed about the purpose of the research and its implementation stages; they were also assured about the confidentiality of their information; Moreover, They were allowed to leave the study whenever they wish, and if desired, the results of the research would be available to them.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Authors' contributions
All authors contributed in preparing this article.
Conflicts of interest
The authors declared no conflict of interest.