1. Introduction
Iran is one of the countries in the world, whose aging population is rapidly growing [1, 2]. With increasing age, successive changes in physiological systems and organs decline the general health in older adults, thereby affecting their Quality of Life (QOL) [3-6]. Many factors affect the QOL of older people. In other words, QOL is a multidimensional concept with physical, psychological, and social dimensions [7-12]. Living in an inappropriate place, having insufficient income, and lacking proper social communication are effective factors in decreasing the QOL of the elderly. Higher education can also improve the dynamics of older people's lives, promote their social class, increase their economic status, and lead to a better QOL [13-19]. This study aims to evaluate the association of education level and economic status with the QOL of older people living in Mashhad City, Iran.
2. Materials and Methods
This research is a descriptive-analytical study. The study population consists of all older people aged >60 years living in Mashhad, Iran. By cluster sampling method, 270 people aged 65 to 88 years were selected and assigned into two groups; group 1 living in the community (n=135) and group 2 living in nursing homes (n=135). The inclusion criteria included being older than 65 years, being able to follow guidelines, and having no common elderly diseases such as Alzheimer's and Parkinson's. Those who were unwilling to continue participation in the study were excluded from the study.
Informed consent was obtained from the participants before collecting the data. For this study, ethical clearance was obtained from the University of Social Welfare and Rehabilitation Sciences (Code: IR.USWR.REC.1396.162). Firstly, a demographic form surveying age, level of education, and monthly income was completed. We assured the participants of the confidentiality of their information. For measuring the QOL level, we used the Persian version of the 36-Item Short Form (SF-36) health survey questionnaire with acceptable validity and reliability [13, 20]. It has 8 subscales: physical functioning, physical health problems, bodily pain, general health, vitality, social functioning, emotional problems, and mental health. These subscales can be summarized into physical and mental QOL.
We used the Kolmogorov-Smirnov test to test the normality of the data distribution. The results showed no normal distribution. Then, the Mann-Whitney U test was used to compare the means of income and QOL, and the Chi-squared test to compare the educational level with QOL. The effect of some independent factors on mental and physical QOL was investigated using multivariate regression analysis. The data were analyzed in SPSS by considering a significance level of less than 0.05.
3. Results
Of 135 samples in group one, 77 (48.1%) were men, and 58 (43%) were women. Group 2 consisted of 65 (48.1%) men and 70 (51.9%) women. The Independent t-test showed no significant difference between groups in terms of age (P=0.50). Most of the participants were married (84.4%) and illiterate (70%). Group 2 had a lower educational level. The majority of them were suffering from diabetes (38.5%) and hypertension (62.2%) and were smoking cigarettes (23%). The results of the Chi-squared test reported that the income level of the two groups was significantly different (P=0.03). Most of them (about 39%) had an income of less than 5 million IRR. Although some people in group 1 had no income source (about 16%), their income was better than that of the elderly living in nursing homes (group 2). The results of the Chi-squared test after removing the non-income sample group showed that the income level of the two groups was significantly different (P<0.001).
The results of QOL for the elderly in two groups show that both physical and mental dimensions of QOL in group 2 were at a lower level compared to group 1. The overall score of physical QOL was 45.7 in group 1 and 34.2 in group 2, indicating that the participants had a poor QOL in terms of physical functioning. Furthermore, the overall score of mental QOL was 36.3 in group 1 and 29.8 in group 2, indicating that the participants had a worse overall mental state than the physical one. The results of the Mann-Whitney U test showed that the two groups had significant differences in the subscales of physical functioning, physical problems, vitality, mental health, and general health, but in 3 dimensions of emotional problems, social functioning, and bodily pain, the difference was not significant (P>0.05).
The results of multivariate regression analysis showed that only the effect of place of residence (community and nursing homes) had a significant effect on both QOL dimensions. The level of income, education, gender, age, and diseases such as diabetes, hypertension, and smoking had no significant effect. The effect size (Eta coefficient) ranged from 0.001 to 0.035 for the mental QOL response and from 0.001 to 0.154 for the physical QOL response. In both dimensions, the largest effect size was related to the place of residence of the elderly.
4. Conclusion
Sanatorium seniors had a lower educational level, monthly income, and QOL compared to the community seniors. The overall score of physical QOL was 45.7 for the elderly living in community and 34.2 for those living in nursing homes, indicating that the participants had a poor QOL in terms of physical functioning. Furthermore, the overall score of mental QOL was 36.3 for the elderly living in community and 29.8 for those living in nursing homes, indicating that the participants had a worse overall mental state than the physical state. Having enough income is a necessary condition for QOL, though it cannot meet all the basic needs of life. Having higher education can improve the social class and increase the economic status of the elderly. The improved QOL of Iranian seniors can be achieved through treatment, education, and social support programs.
Ethical Considerations
Compliance with ethical guidelines
Prior to the study, informed consent was obtained from the participants and  the ethical approval of the study was obtained from the Research Ethics Committee of the University of Social Welfare and Rehabilitation (Code: IR.USWR.REC.1396.162).
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.
 

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