It was a descriptive-analytical study in 2018. The research population consisted of all older adults living in Qom city. G*Power-3 software was used to calculate the sample size (14). Considering the 95% confidence level, 80% test power, and r = 0.30, 544 were calculated according to the study of Ataollahi et al. (15).To compensate for sample loss and incomplete questionnaires, 20% of the sample size was added to the final samples and the final sample size was calculated 679. The calculated sample size is in accordance with the number of samples proposed for Dyadic analysis (16).
Inclusion criteria for the study included speaking ability, satisfaction to participate in the study, age over 60, lack of cognitive problems such as Alzheimer's. Older adults’ medical records were used to judge these problems as well as older adults patients' records. Exclusion criteria were dissatisfaction with continued cooperation. Data collection was done in one step using a questionnaire consisting of 6 sections by researchers in public places where the target group was referred. The questionnaires were filled out by well-educated older adults under the supervision of questioners and for low-educated or illiterate elders, questionnaires were completed through an organized interview.
Demographic information questionnaire: The questionnaire included age, gender, employment status, marital status, educational level, income source, number of children and housing status.
Life Satisfaction Index-Z (LSI-Z): This questionnaire has 13 questions, designed in 1969 by Wylie, Wood, and Sheafor. Each of the questions is answered in the form of "I do not know", "agree" and "disagree", and the 2-1-0 system is used the scoring the answers.
In this way, “I do not know” is scored zero; in positive questions, “agree” is scored 2 and "disagree" is score 1 and in the case of negative questions, “disagree” is scored 2 and "agree" is score 1. The total score of life satisfaction is estimated0-26. Obviously, a higher score indicates a higher level of life satisfaction. Regarding the interpretation of the LSI-Z score, ≤12 indicate a low level of satisfaction, 13-21 average satisfaction, and 22≤ high satisfaction (17.18).
In Iran, the validity and reliability of this questionnaire are verified in different studies. Taghribi et al. reported the reliability coefficient of the tool through re-test with ICC coefficient as 0.93. Cronbach's alpha coefficient of the present questionnaire was estimated 0.79 (19).
Activities of Daily Living (ADLs): In the present study, the 6-itemversion of Katz was used. This tool includes personal grooming items, eating, dressing, sitting, bathing, and controlling urine and feces. Each item has three options: “dependent” (zero points), “need help” (1 point) and “independent” (2 points).
The overall ADL score is from zero to 12 and each test is ranked "dependent" (0 to 4 points), "need help" (5 to 8 points) and "independent" (9 to 12 points) based on the score it earns. The validity and reliability of this tool have been proven by Katz (20).
WHO (Five) Well-Being Index (1998 version): This scale consists of five questions that assess the mental status of individuals over the past two weeks in a table. These five questions with the Likert technique include 6 options of “at all times” (score 5), “most often” (score 4), “slightly more than half of the times” (score 3), “slightly less than half of the times” (score 2), “sometimes” (score 1) and never (0 score).To compute the points, the numbers in the squares are summed up and multiplied by 4. The resulting number ranges from zero to 100, which points to a greater degree of well-being.
Medical Outcomes Survey (MOS): This scale was created in 1991 by Sherborne and Stewart and provides social support received by the subject. The questionnaire, which is a self-report tool, has 19 sentences, and the subject specifies the amount of disagreement or agreement with each of the expressions bya 5-point Likert scale (1 point for “never” to 5 points for “always”). The lowest score in this test is 19 and the highest score is 95. To get the overall score, all scores are combined.
The high score of the subject on this scale indicates that the subject has favorable social support. To obtain the score for each sub-scale, it is enough to merge the scores for the phrases associated with each sub-scale. The validity and reliability of this scale have been reported desirable. The reliability of this test has been reported using Cronbach's alpha coefficient in the range of 0.74-0.93 (21).
Abbreviated Mental Test (AMT): This questionnaire contains 10 simple and short questions that measure orientation, focus/attention, short-term memory, and long-term memory, and is used to screen for cognitive impairment including dementia and delirium in the elderly. The short form consists of 10 questions with 10 points, which takes only 3 minutes to complete.
This test has been validated in Iran and its scoring is so that the score below 6 is suspected of moderate cognitive disorder, a score of 6 to 8 is suspected of mild disorder, and a score higher than 8 means a lack of cognitive disorder. The intrinsic reliability of the Persian version of AMT is acceptable (Cronbach's alpha coefficient is 0.76), and its external reliability is also desirable (inter-group correlation coefficient is 0.89) (22).
In order to observe ethical considerations in this study, the samples participated in the research project while informing about the goals of the study. Information was also collected without the need to insert personal and in an organized manner.
In this study, data analysis was done using SPSS software version 22 at two descriptive and inferential levels. Descriptive statistics of mean and standard deviation and frequency distribution were used at the descriptive level. Independent T-test, ANOVA, Pearson’s correlation coefficient and multiple regression analysis were used at the inferential level. The significance level of these tests was considered less than 0.05.