Abstract
Background:
The importance of salutogenesis, with the focus of what creates health rather than what causes diseases, has been highlighted for a long time. This has been operationalized by Aaron Antonovsky as the Sense of Coherence (SOC-13) scale. The aim of this study was to further examine the psychometric properties of the SOC-13 in India.
Methods:
The present study was carried out among second-year degree students at three randomly chosen institutions at Mangalore University. Investigators assessed the appropriateness, relevance, comprehensiveness and understandability of the scale. Further, the scale was assessed by five subject experts. The SOC-13 was then pretested by administering it to peers, individuals and a few of the study subjects. Internal consistency was assessed by Cronbach’s alpha and split-half reliability. Test-retest reliability was assessed by administering the instrument to the same study participants after two weeks. Confirmatory factor analysis employing varimax rotation was employed.
Results:
The SOC-13 revealed a Cronbach’s alpha value of 0.76. Split-half reliability and Guttman split-half reliability were found to be 0.71 and 0.70, respectively. Test-retest reliability was found to be 0.71 (p < 0.01). Factor analysis revealed a three-factor solution explaining 40.53% of the variation in SOC.
Conclusions:
SOC-13 was found to be a reliable and valid instrument for measuring SOC in an Indian context. The present study contributes to health promotion in an Indian context, and could be useful even in other developing countries and for further research in India.
Introduction
The traditional focus in the control of diseases has been the search for ‘causes of disease’. Recently, this conventional approach has been supplemented with the search for the ‘origin of health’ (1,2). Focus has shifted to what creates health rather than what causes disease (3,4). This approach has been termed as salutogenesis. Salutogenesis is derived from the words ‘Salus’ meaning ‘health’, and ‘genesis’ meaning ‘origin’ (1,2,5). Salutogenesis deals with the study of health rather than disease and deals with personal resources essential to moving toward and maintaining health. The Sense of Coherence (SOC) reflects the extent to which individuals cope with stressful situations (1,2). The salutogenic theory is here operationalized by using the Sense of Coherence (SOC-13) scale.
In this context, health is viewed as a dynamic construct that extends along an ease/dis-ease continuum (6). Investigators believe that the health status of individuals shifts along this continuum. The salutogenic model of health helps us identify the generalized and specific resistance resources among individuals that are essential resources for moving toward the health (ease) end. Research has identified a global, pervasive and cross-cultural construct that helps people stay healthy, which is reflected by the SOC scale (1,2,5).
SOC is defined as ‘a global orientation that expresses the extent to which one has a pervasive, enduring though dynamic feeling of confidence that (i) the stimuli deriving from one’s internal and external environments in the course of living are structured, predictable, and explicable (comprehensibility); (ii) the resources are available to one to meet the demands posed by these stimuli (manageability); and (iii) these demands are challenges, worthy of investment and engagement (meaningfulness)’ (2).
Studies have shown that the SOC scale is a reliable and valid instrument that can be used to assess how individuals manage stress and stay healthy (7–9). The SOC scale has been tested among healthy individuals (10–12), physically active older individuals (13–15), as well as those with systemic diseases such as cardiac diseases and psychopathology (16–18). Research findings have shown that the SOC was strongly correlated with perceived health (6), especially mental health, and also with quality of life (19). The SOC has a main, moderating or mediating role for explaining health and finally, it predicts health (3). The SOC is shown to have an association with adult oral health knowledge, attitude and behaviors (20–22), adult oral health parameters (23), adolescents’ oral health, oral health-related behaviors and oral health-related quality of life (5,24–26). The SOC may be an important approach for health promotion (3,6,27,28) and might have significant contributions to make toward oral health promotion (29,30).
Suraj and Singh (31) have previously reported findings from a study among Indian graduate students in Chandigarh using the SOC-29 item questionnaire. They have reported an internal consistency of 0.85 with the SOC-29. Tyagi et al. have reported a Cronbach’s alpha value of 0.72 among students pursuing their post-graduation in anesthesiology in India (27). The aim of this study was to assess the psychometric properties, validity and reliability of the SOC-13 scale among Indian university students.
Methods
SOC-13 scale
The SOC-13 scale contains five items for comprehensibility and four each for manageability and meaningfulness domains. Each of the items in the scale is scored on a seven-point semantic differential scale anchored by two phrases. A total of five items in the scale are reverse coded. The total SOC score is obtained by adding the individual responses to 13 items of the scale. The range of the scores is 13–91 points, with higher scores indicating a stronger SOC.
Study population
The present study was carried out among university students in Mangalore, Karnataka, India. The list of all institutions in Mangalore city was obtained from Mangalore University. Three institutions were randomly chosen and a total of 512 individuals were invited to participate in the study. Inclusion criteria included co-education institutions, second-year degree students, familiarity of study participants with the English language and availability during the study period from July 2013 to September 2013. Excluded were institutions not willing to consent, students undergoing orthodontic treatment, students who suffered from health/mental health problems in the last year, students with known systemic illness and students who were currently under treatment for known health/mental health problems.
A total of 452 individuals (response rate of 88.28%) consented to participate in the study. The average age of the participants was 20.17 years (SD = 0.78). The number of respondents who were males was 267 (59.07%) and females was 185 (40.93%). The number of study participants belonging to commerce, science and management streams were 280 (61.95%), 111 (24.56%) and 61 (13.50%), respectively.
Data collection procedure
Validity
Item face validity: Face validity consists of expert opinion on appropriateness, relevance, comprehensiveness and understandability of the scale (32,33). Face validity of the scale was first ascertained, wherein the investigators assessed the aforementioned aspects of the scale. Further, the scale was assessed by five subject experts and, based on their input, modified accordingly. The SOC-13 was administered to the study participants in the English language. A huge majority of the population in India is familiar with the English language. The English as used by the India population, however, is considerably different from the English employed in the Western hemisphere of the world. Moreover, the local vernacular languages that are in use in Mangalore, where the study was conducted, are Kannada, Tulu and Konkani. The dialects that are spoken by people belonging to different castes and classes are different. Some groups of individuals use a dialect of Kannada that is considerably different from that employed by other groups of individuals. Moreover, there are different dialects used in different parts of Mangalore as well.
Keeping all these issues in mind, as the first step in introducing the SOC in India and for issues related to feasibility and practicality, the authors employed the scale in English rather than the local vernacular languages. Subject experts recommended the use of the word ‘that’ in item 9 of the scale. Item 9 of SOC-13 was modified as ‘Does it happen that you have feelings inside
Content validity: Content validity assesses how adequately the items in the scale match concepts being measured (32,33). Content validity of the scale was ascertained by employing inter-item correlations.
Construct validity: Construct validity indicates the extent to which items of the scale are tapping into underlying theory and are applied by using convergent and discriminant validity (32,33). Convergent validity indicates that the items related to a particular domain within a scale should be correlated among themselves and is assessed by Cronbach’s alpha. Discriminant validity indicates that the items related to different domains should not be correlated and is assessed by factor analysis.
Factor analysis
Factor analysis attempts to look at underlying concepts and factors related to the items instead of reporting all the items (32). The SOC-13 was subjected to confirmatory factor analysis with a varimax rotation. We tested for a one-factor and three-factor solution of the SOC scale by confirmatory factor analysis with varimax rotation with Kaiser normalization. The three factors reflected the three components of SOC as propounded by Antonovsky: comprehensibility, manageability and meaningfulness. Varimax criterion for a simple factor solution is to maximize variations for loadings of factors across items, with factor loadings moving toward 0 or 1 (34). A scree plot was employed to ascertain the factor structure of the scale. The number of factors to be extracted was based on the scree plot and the eigenvalues resulting from factor analysis.
Reliability and internal consistency
Internal consistency reliability of the scale was assessed by employing (i) average inter-item correlation, (ii) average item total correlation, (iii) split-half reliability, (iv) Cronbach’s alpha (36) and (v) test-retest reliability (32). The scale was re-administered to study participants after a period of 15 days to assess test-retest reliability.
Ethics
Ethics clearance was obtained from the Institution Ethics Committee, Manipal College of Dental Sciences (MCODS), Mangalore (Protocol Ref No: 11064). Permission to carry out the present study was obtained from the dean, Manipal College of Dental Sciences, Manipal University, Mangalore and also from the principals of educational institutions included in the present study. Informed consent was obtained from the study participants.
Results
Descriptives
The mean SOC-13 was found to be 51.65 (±8.20) and the median value was 52. Table 1 shows the descriptive data related to SOC-13 among the study participants.
Descriptive data: median and standard deviation of items of the SOC-13.
SOC-13: Sense of Coherence 13-item scale.
SD: standard deviation.
Reliability and internal consistency
Reliability analysis of the SOC-13 revealed a Cronbach’s alpha value of 0.76. Split-half reliability and Guttman split-half reliability were found to be 0.71 and 0.70, respectively. Test-retest reliability was found to be 0.71 (p < 0.01). All inter-item correlations were found to be positive ranging from 0.06 to 0.42 (Table 2). Item-total correlations indicate that deleting any of the items in the scale did not increase the Cronbach’s alpha value more than the overall Cronbach’s alpha of 0.76 (Table 3).
Inter-item correlation of items of the SOC-13.
SOC-13: Sense of Coherence 13-item scale.
Item-total correlation of items of the SOC-13.
SOC-13: Sense of Coherence 13-item scale.
Content validity: Inter-item correlations are shown in Table 2. It can be observed that all correlations are positive, with the highest value being 0.42 between items 2 and 3.
Construct validity: Results indicate that the Cronbach’s alpha value of the scale was 0.76. This indicates that the scale had adequate convergent validity when tested in this population.
Factor analysis
A three-factor solution was confirmed with eigenvalues >1.0 and explained variance. Confirmatory factor analysis revealed a three-factor solution explaining 40.53% of the total variance in the SOC (Table 4). The first factor accounted for 13.94% of total variance, while the second and third factors accounted for 13.47% and 13.12% of total variance, respectively. The results of the present study did not support a one-factor solution for the SOC-13. Factor loadings for the SOC items by employing principal component analysis with varimax rotation are shown in Table 5. Scree plots with rotated factor solutions are presented in Figure 1. The scree plot indicates a three-factor solution for SOC-13 and the scale does not follow the one-factor solution as originally proposed by Antonovsky. The scale also does not correspond to the SOC theory as hypothesized by Antonovsky. Factor loadings indicate that the items do not fully correspond with the theoretical dimensions of comprehensibility, manageability and meaningfulness (Tables 5 and 6).
Confirmatory factor analysis of items of the SOC-13.
SOC-13: Sense of Coherence 13-item scale.
Note: Extraction method: principal component analysis.
Factor loading of items of the SOC-13.
SOC-13: Sense of Coherence 13-item scale.

Scree plot.
Factor-wise selection of items of the SOC-13 based on factor loadings.
SOC-13: Sense of Coherence 13-item scale.
Discussion
Salutogenesis has increasingly been applied in different areas all over the world. The important contributions that SOC can make toward public health have now been recognized (36). The present study was undertaken to assess the psychometric properties, validity and reliability of the SOC-13 scale among Indian university students. It is the first investigation to explore the same in an Indian population. Earlier investigations by Suraj and Singh (31), and Tyagi et al. (27) have only partially assessed the internal consistency of the scale by using Cronbach’s alpha. There are no studies that have tested the psychometric properties of the SOC in India. Testing the psychometric properties of the SOC will render measurements that are more reliable and will facilitate comparisons across different populations (37).
Students enrolled in co-education institutions were included in the study. Stressors and salutogenic factors might operate differently among co-education institutions when compared to institutions for only boys or girls. Students in the first year of study might change their courses, while those in their final year might be more engrossed in their studies. Hence, students in their second year of study were included in the present study. Students suffering and/or undergoing treatment for any health/mental health problems or those undergoing orthodontic treatment in the last year were excluded, as the aforementioned health issues might have an impact on their SOC values and render them considerably different from those without these health issues.
The present study was undertaken to introduce the concept of the SOC in India. The scale has also to be tested in other Indian vernacular languages and dialects to further validate the scale in an Indian context.
The SOC-13 was found to be a reliable and valid tool among the study population. Reliability statistics reveal values above 0.70 for the scale. Antonovsky had reported a Cronbach’s alpha in the range of 0.74–0.93 in a review of the SOC scale (7). In their systematic review of 127 studies on SOC-13, Lindstrom and Eriksson have reported a Cronbach’s alpha of 0.70 to 0.92 (8) (Table 7). The findings of the present study are in line with those reported in the aforementioned review. The split-half reliability values of the present study are also in agreement with those reported by Lindström and Eriksson (8) and Naaldenberg et al. (15). The test-retest reliability values of the present study are in agreement with the findings of Lindström and Eriksson (8) and Rohani et al. (11).
Comparison of findings from other validation studies.
SOC: Sense of Coherence
SOC-13: Sense of Coherence 13-item scale.
SOC-29: Sense of Coherence 29-item scale.
The inter-item correlation values in the present study are in agreement with those reported by Naaldenberg et al. (15). However, higher inter-item correlation values were reported by Tang and Dixon (38). All the inter-item correlation values were positive and this indicates that the items were related, but not overlapping. The item-total correlation values in the present study were lower than those reported by Tang and Dixon (38). The Cronbach’s alpha values on deletion of the items were not higher than the overall Cronbach’s alpha value of 0.76. Deletion of any item of the SOC-13 did not lead to any increase in the overall Cronbach’s alpha in the study population.
Analysis of construct validity by means of factor analysis revealed a three-factor structure of the SOC-13 with good explained variance. This is in contrast with the one-factor solution reported by Antonovsky (2). However, Lindström and Eriksson (8) have reported that the SOC seems to be a multidimensional concept. The factor loadings in this study indicate that the items do not fully correspond with the theoretical dimensions of comprehensibility, manageability and meaningfulness. This is in agreement with the findings reported by Sardu et al. (12), Jakobsson (14) and Larsson and Kallenberg (40). Lerdal et al. (41) have highlighted the need for further investigations on dimensions of the SOC. Sandell et al. (34) have reported similar findings among clinical and non-clinical samples. Their analysis did not confirm Antonovsky’s one-factor solution or a theoretical three-factor solution. Antonovsky has pointed out that the SOC scale was designed to assess the individual’s ability to move toward the health end of the health–ease–dis-ease continuum. The scale was not intended to measure separately the components of comprehensibility, manageability and meaningfulness (7). Sandell et al. (34) have, however, reported that it might not be entirely meaningless to look at the components of the SOC scale. They observe that if the scale had to be considered in its entirety, then there was probably no need to propose the domains in the scale in the first place. The factor structure of the SOC is compounded by the fact that the items of the scale do not ‘cleanly’ refer to one or the other domain of the SOC. Hence, further studies on the factor structure of the SOC might be essential to shed more light on the same.
The SOC-13 employs a seven-point Likert scale for its responses. While employing a Likert scale, one has to consider potential biases such as end-aversion bias, positive skew and the halo effect (32). Further studies are needed to shed more light on the influence of these biases.
The results of the present study indicate that the SOC-13 is a reliable and valid tool in an Indian context. The literature indicates that the salutogenic approach has been adopted in different sectors. The present study might open up further vistas for research pertaining to salutogenesis across different sectors in India. This might pave the way for addressing health inequalities in this and other developing countries. Psychometric properties of different versions of the SOC among different age groups (14,42), gender (43), in individuals with different health-related conditions (16–18,44), and in different settings (39,45) are essential. Long-term stability of the SOC (46) should also be investigated in the Indian context. The present study might provide valuable baseline information towards the same.
Conclusions
The present study showed that the SOC-13 is a reliable and valid tool in an Indian context. Results indicate that the SOC-13 has good psychometric properties when tested among students in India. The present study paves the way for further research on salutogenesis and its myriad implications in developing countries like India.
Footnotes
Funding
This research received funding from the Indian Council of Medical Research (ICMR).
Conflict of interest
None declared.
