Psychometric properties of modified MOS social support survey 5-item (MSSS-5-item) among Iranian older adults

Nowadays, there is a lot of evidence that shows social support has various short- and long-term effects on individuals’ physical and mental health and wellbeing due to its beneficial impacts (either directly or by stress buffer effect). Various studies point out the role of social support in health, wellbeing, and mitigating negative effects of stressful conditions and feeling lonely (loneliness) in older adults [1‐9]. As a vital factor in people’s health, social support highlights the social aspect of humans [10]. Different resources such as friends, family, and society can offer social support whenever the person needs it [11, 12]. Generally, social support has three components: 1) the source of support, 2) satisfaction with the support, and 3) the type of support [12]. It also has four types: emotional support consisting of love, sympathy, care, and understanding; instrumental support, which provides material needs such as food; informational support involving information or suggestions for getting along with difficulties and hardships; appraisal support, which provides information facilitating self-assessment or affirming the person’s appropriateness of behavior or performance [12‐14].

Perceived social support evaluates the individual’s perception of support, regardless of having received the support or not [15]. The perceived social support plays a crucial role in older adults’ lives; as people grow old, its importance increases progressively [16]. So, reasonably, social support has been greatly emphasized in the comprehensive geriatric assessment [11]. On the other hand, the shortage of social support is considered a modifiable risk factor that can be compensated through different interventions [11, 17, 18]. However, precise measurement is necessary before one can intervene in social support status.

Generally, social support is a meta-construct concept that lacks a unique definition and measurement method [18]. Various measuring scales have been designed due to the broad concept of social support, diverse components, and lack of a unique definition [13]. Some of these scales are used for the older adults’ population, including Norbeck Social Support Questionnaire (NSSQ) [19], interview schedule for social interaction [20], Social Support Questionnaire [21], and Multidimensional Scale of Perceived Social Support [22].

The Medical Outcomes Study Social Support Survey (MOS-SSS) is a widely used scale in assessing social support [23]. It is a 20-item scale with four components, developed by Sherbourne and Stewart in 1991, and was first validated and confirmed among 2987 patients with chronic disease [13]. The validity of this questionnaire has been confirmed on both sick [11, 17, 24‐26] and healthy populations in various studies, too [23, 27‐30]. Also, this questionnaire has been translated into other languages (such as Portuguese, Brazilian, Malaysian, Arabic, French, Chinese, Spanish, and Persian), and its psychometric properties have been evaluated in several studies, which have shown its proper characteristics [17, 24‐27, 30, 31]. A review study conducted by Nazari et al. to assess the psychometric properties of the perceived social support scales indicated that the MOS-SSS survey was the finest questionnaire for use among older adults [18]. Another advantage of this questionnaire is having short and comprehensible items [11, 28]. The lack of items with reverse scoring is another positive feature of the MOSS-SSS survey, which reduces the errors in responses of individuals with lower education [28]. Since the original version of this questionnaire may exhaust the examinee due to a large number of items, several studies have applied the abbreviated forms of 8 items [11, 17, 29, 32], 6 items [23], 5 items [33‐39], and 4 items [28] of this questionnaire. The abbreviated forms of this questionnaire also benefit from desirable psychometric features. Also, they are more suitable to be used among older adults because of fewer items, particularly in cases where several scales are to be used in a study [29]. The MSSS-5-item, an abbreviated version of the MOS-SSS, was designed by Ritvo et al. [40]. Ritvo et al. applied the MSSS-5-item in the Multiple Sclerosis Quality of Life Inventory (MSQLI) (α = 0.88) [40]. It also had good reliability in the older adults suffering from Multiple Sclerosis (α = 0.77) [33].

Based on our investigations, psychometric evaluation of the Modified MOS Social Support Survey 5-item has not been conducted so far. This questionnaire is suitable for use in the elderly population due to its briefness and comprehensibility; thus, the current study was developed to evaluate psychometric properties of the MSSS 5-item questionnaire among the Iranian older adults.

The present study results showed that the abbreviated 5-item MOS-SSS questionnaire had a suitable validity and reliability for use in the older adults’ population living in Iran. Other studies have also been developed for psychometric evaluation of the abbreviated versions of this questionnaire; they examine the 4-, 6-, 8-, and 12-item versions in various populations and have obtained similar results [11, 17, 23, 28, 29]. It should be noted that the items vary in the different short forms due to the different approaches of the authors. In the study by Gomez-Campelo et al., Moser et al., and Togari et al., the first four items were selected in two emotional and instrumental components [11, 17, 29]. However, in the current study and the study by Holden et al. and Gjesfeld et al., the items were selected based on the highest level of factor loading and correlation with each component [23, 28].

The MSSS 5-item questionnaire is part of the Multiple sclerosis quality of life inventory survey developed by Ritvo et al. [40]. In the study of Ritvo et al., in order to construct the abbreviated version of social support, items from the MOS-SSS questionnaire that had the highest correlation with the total score of the scales were selected. Five items were selected from all four components of the MOS-SSS questionnaire, and an overall score was considered for it. Although the MSSS-5-item questionnaire created by Ritvo et al. does not have any components, the results from the explanatory factor analysis in this study showed that the scale consisted of two components, which overall explained 67.78% of the total variance. The extracted factors include emotional support (3 items) and instrumental support (2 items). The extracted factors in the present study are similar to the 8-item short forms in Moser et al. and Togari et al. [11, 29]. However, only one component has been reported for the 4- and 6-item versions [23, 28]. Gomez-Campelo et al.’s study used an 8-item form and showed that the explanatory factor analysis results in the two separate populations of men and women showed only one component [17]. This can be considered as the strength of the MSSS-5-item, which despite the small number of items, examines two types of social support. Moreover, another advantage of this questionnaire is the approach used for selecting items, compared to short 8-item versions.

One of the main reasons that makes it difficult to compare the present study results with other abbreviated versions of the MOS-SSS survey is the different populations under study. In the study by Gomez-Campelo et al., the studied population was 18- to 55-year-old Spanish individuals referred to the outpatient centers [17]. Gjesfeld et al.’s study focused on a group of American mothers with children under treatment [28]. The study by Holden et al. has also been done on Australian women of 28–58 years old [23]. Due to the specific population in each study, the results cannot totally be generalized. The study by Togari et al. has investigated 25 to 74 year-old people living in Japan [29]. In their study, explanatory factor analysis was performed on two age groups of below and over 50. Although Togari et al.’s study was conducted on a large number of individuals, what prevents their results from generalization to the elderly population is the age cutoff point (50 years old). According to the definition by the World Health Organization (WHO), the start of the old age is considered 60 and is respectively categorized as follows: young old (60–74), old old (75–84), oldest old (85+) [68]. Since the age range in that study was 25–74 years, it can be concluded that the studied population only included the young old. The study by Moser et al. was the only research showing that the 8-item form of social support survey had the desirable properties of psychometric evaluation in the elderly population over 65 years old [11]. Their study had a limitation by only investigating women. In the current study, however, the psychometric evaluation of the MSSS-5-item was specifically done on the older adults (the age range of 60–93 years old).

Regarding the investigation of the reliability of studies, various methods were used; for example, to reach an internal consistency, both Cronbach’s alpha and McDonald’s Omega were computed. Although Cronbach’s alpha is considered as a common indicator in investigating the internal consistency, McDonald’s Omega is also recommended when explanatory factor analysis is done. This indicator eliminates the shortcomings of the Chi-Square test, such as the number of questions and reverse-scores. The results show that the MSSS-5-item has a proper internal consistency based on both Chi-Square and McDonald’s Omega indicators. The value of Cronbach’s alpha in the present study (alpha = 0.78) matches the results of Dilorenzo et al.’s study, which applied the same questionnaire on the older adults with MS disease (alpha = 0.77) [33]. However, in the abbreviated 8-item questionnaire with similar sample size, Cronbach’s alpha in women and men over 50 years old was reported to be above 0.93 [29]. This contrast may be due to the difference in the number of items in the two questionnaires, as an increase in the number of items usually leads to an increase in the degree of correlation between them, thereby increasing Cronbach’s alpha. In addition to the internal consistency, two more stability and absolute reliability indices were also examined in this study, while only internal consistency is reported in other abbreviated versions [11, 17, 23, 28, 29]. These indices had desirable values in the current study indicative of good reliability of the scale.

The current study showed that the MSSS-5-item well differentiated between the older adults feeling and not feeling lonely. This result shows the suitable discriminant validity of this questionnaire. Also, in the study by Moser et al., the abbreviated 8-item questionnaire indicated a significant difference between women who felt lonely and those who did not [11]. This study showed that there is a negative correlation between instrumental support and health status that is approved with other studies [69, 70]. To summarize, people with deteriorated health gain more instrumental support [29]. Also, a positive correlation between emotional support and health confirmed that having more supporting resources help people to maintain a good health condition [29].

The results of the Mokken scale analysis showed that the present questionnaire was scalable and unidimensional with strong scalability (H > 0.5). According to the results, all items in this questionnaire measure a latent variable and can be a powerful indicator for measuring social support.

The present study was conducted in Tehran as the research setting. As the capital of Iran, Tehran possesses a population with high diversity in ethnicity and socio-economic levels. This study tried to benefit from maximum diversity in sampling by applying the random sampling method and dividing the city into different zones, based on socio-economic status, from underdeveloped to fully developed areas. However, as a research limitation, this questionnaire has been validated in the community-dwelling older adults; so, a reevaluation is needed for use in other populations. Moreover, the results of this study cannot be generalized to the elderly suffering from cognitive disorders.

The results of the current study indicated that the MSSS 5-item has desirable validity and reliability among Iranian community older adults. In addition, the two-factor model has acceptable fit indices. The abbreviated 5-item social support questionnaire also has good scalability. The smaller number of items in this questionnaire minimizes the participants’ burden compared with the original version with 19 items. This is a major benefit of the present scale for use in older adults. The small number of psychometric studies on the abbreviated versions of the MOS-SSS questionnaire indicates the need for designing further studies. In addition, the lack of a unified abbreviated form prevents comparison between different studies, which is a limitation that should be addressed in the future.