527188 research-article2014

SJP0010.1177/1403494814527188C. Mattisson et al.Short Title

Scandinavian Journal of Public Health, 2014; 42: 434–445

Original Article

Relationship of SOC with sociodemographic variables, mental disorders and mortality

CECILIA MATTISSON1, VIBEKE HORSTMANN2 & MATS BOGREN1 1Department

of Clinical Sciences in Lund, Division of Psychiatry, The Lundby Study, Lund University Hospital, Sweden and 2Department of Health Sciences, Faculty of Medicine, Lund University, Sweden

Abstract Background: SOC is associated with wellbeing and health. The Lundby Study is a cohort study of an unselected population (n=3563) in whom mental health and personality traits have been assessed since 1947, with follow ups in 1957, 1972, and 1997. Aim: To describe the relationship of Antonovsky’s 29-item sense of coherence scale (SOC) and its three subscales (comprehensibility, manageability, and meaningfulness) to mental health and mortality in an unselected middle-aged and elderly community cohort, controlling for gender, age, marital status, and socioeconomic status. Another aim was to analyse the three-factor structure of the SOC. Methods: Of the 1797 surviving subjects in 1997, 1559 participated in a semistructured diagnostic interview, and 1164 subjects completed the SOC questionnaire. Psychiatrists performed diagnostic evaluations. Collateral information was obtained from case notes and registers. Dates of death from 1997–2011 were obtained from the cause of death register. Results: SOC scores showed no sex differences, but were positively correlated with age. SOC scores were higher in married relative to unmarried participants and in blue-collar workers and self-employed individuals relative to white-collar workers. Total SOC and subscale scores were negatively correlated with depressive, anxiety, organic, and psychotic disorders. Male gender was positively correlated with comprehensibility and female gender was positively correlated with manageability and meaningfulness. Higher comprehensibility scores were correlated with lower mortality. Conclusions: SOC scores increased with age, were higher for blue-collar workers, and were lower for individuals with psychiatric disorders. Higher comprehensibility scores were associated with lower mortality. However, there was only weak evidence for a three-factor structure. Key Words: Epidemiology, mental disorder, mortality, SOC questionnaire

Introduction The World Health Organization has defined health as a state of complete physical, mental, and social wellbeing, not merely the absence of disease or infirmity. In addition to environmental factors, social and personality factors are key determinants of health and wellbeing [1]. More than 30 years ago, Aaron Antonovsky introduced the concept of a person’s sense of coherence (SOC) [2]. His salutogenic theory sought to define factors that promoted health and resilience, rather than seeking mechanisms underlying illness. The

salutogenic model was based on the premise that stress, trauma, and adverse events are integral elements of our existence. In Antonovsky’s view, SOC is a social concept, which is stronger in subjects raised in a stable, positive socioeconomic environment with clearly defined cultural norms, leading to improved health and a better ability to overcome difficult situations. Antonovsky defined SOC as: “a global orientation that expresses the extent to which one has a pervasive, enduring though dynamic feeling of confidence that the stimuli deriving from one’s internal and external

Correspondence: Cecilia Mattisson, Department of Clinical Sciences in Lund, Division of Psychiatry, The Lundby Study, Baravägen 1 G, Lund University Hospital, SE-221 85 Lund, Sweden. E-mail: [email protected] (Accepted 13 February 2014) © 2014 the Nordic Societies of Public Health DOI: 10.1177/1403494814527188

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Relationship of Antonovsky’s sense of coherence   435 environments are structured, predictable, and explicable, the resources are available to one to meet the demands posed by this stimuli; and these demands are challenges, worthy of investment and engagement”. The original 29-items SOC comprises three subscales: (1) Comprehensibility (11 items): The extent to which the social world is interpreted as rational, understandable, structured, ordered, and predictable, a dimension referring to the cognitive controllability of one’s environment. (2) Manageability (10 items): The extent to which individuals consider resources to be personally available to help them cope adequately with demands, stimuli, or problems. (3) Meaningfulness (8 items): The motivational component assesses whether a situation is appraised as challenging and whether it is worth making commitments and investments to cope with it. Antonovsky considered meaningfulness to be the most important subscale because it encompassed motivation, but his intention was to use the SOC total score rather than individual subscale scores. However, researchers commonly analyse subscale scores because the subscales represent dynamically interrelated components of social context. Individuals with strong SOC scores are likely to have high scores on all of the subscales. The SOC has been translated into over 30 languages and has been utilised in the Western world, Asia, and South Africa [3]. A Swedish version of the SOC has been in use since the 1990s [4,5]. The original 29-item SOC questionnaire has good psychometric properties, including high test–retest reliability and internal consistency with a Cronbach’s alpha coefficient ranging from 0.82–0.95 [6]. The 29-item Swedish version has also shown high reliability and has been used to confirm the hierarchical organisation of SOC into three core components of comprehensibility, manageability, and meaningfulness [7]. Confirmatory factor analyses carried out with the 13-item SOC scale have indicated that the SOC scale contained one general second-order SOC factor consisting of three first-order factors of meaningfulness, comprehensibility, and manageability [8,9]. It is unclear how demographic variables such as gender and age are related to SOC scores. A previous publication reported small sex differences with males having a slightly higher SOC than females [1]. However, other studies have found no sex difference [9,10]. Regarding age, one study showed SOC scores to be stable after age 30 [2], another reported that scores increase with age [1], and a third study reported that low SOC was more common among elderly

individuals [9]. Finally, a longitudinal cohort study showed that SOC decreased over time and was only stable for those with initially high SOC scores [11]. Positive social contexts at home and work would be expected to improve SOC. Married participants in a Finnish study had markedly higher SOC scores than unmarried participants [12], consistent with Antonovsky’s hypothesis that marriage may enhance health. SOC encompasses not merely a personality but a psychological state that is determined partly by the individual’s position in the social structure. A positive correlation has been described between SOC and job control, and low socioeconomic status has been found to be associated with lower SOC scores [13]. Several studies have assessed SOC in individuals suffering from diseases and stress, as well as in healthy individuals [10]. Findings from cross-sectional studies support a relationship between perceived good health and a strong sense of coherence [3]. SOC can be regarded as a health-promoting psychological resource, which strengthens a subject’s capacity to deal with stressful events [3]. High negative associations have consistently been observed between SOC and anxiety and depressive symptoms [14] and in subjects diagnosed with major depressive disorder[15]. Researchers have even proposed that a low SOC could indicate anxious and depressive symptoms in adolescent females [16]. Furthermore, strong SOC has been linked to wellbeing among elderly subjects, and high mortality has been associated with weak SOC [17]; participants with strong SOC in the EPIC-Norfolk study had reduced all-cause mortality risk [18]. The Lundby Study is an epidemiological, longitudinal study that has investigated the mental health of an unselected population. Within the framework of the Lundby Study, a study of a subsample of participants that had experienced a childhood with psychiatric risk factors was conducted. Although some participants from the Lundby cohort had experienced psychiatric risk factors during childhood (e.g. abuse or parental death, neglect, alcohol abuse, or criminality), their functioning was satisfactory and SOC scores were comparable to those of middle-class samples [4]. In the latest follow up of the Lundby cohort in 1997, the SOC questionnaire was utilised together with a diagnostic semistructured interview. The first aim of this study was to relate the 29-item SOC questionnaire in the middle-aged and elderly Lundby cohort, to gender, age, marital status, socioeconomic classification, and mental disorders. A second aim was to evaluate the factor structure of the questionnaire and to study how SOC and its subscales were correlated to mortality after controlling for mental disorders.

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436    C. Mattisson et al. Table I.  Socio-demographic description of subjects (n=1164) and prevalence of diagnostic categories. Eleven subjects (8 males, 3 females) were diagnosed with a mental disorder and alcohol use disorder. Characteristic

Males (n=539)

Age (years) Marital state Unmarried Married/cohabitating Divorced Widow/widower Socioeconomic classification Self-employed White-collar Blue-collar Clinical diagnoses Depressive disorders Anxiety disorders Somatoform disorder Organic disorder Psychotic disorder Dementia Anorexia neurosa Alcohol use disorder

60 (51–69)

Females (n=625) 61 (51–69)

Total (n=1164) –

33 (6.1) 438 (81.3) 43 (8.0) 25 (4.6)

29 (4.6) 408 (65.6) 77 (12.3) 111 (17.8)

62 846 120 136

67 (12.4) 208 (38.6) 264 (49.0)

37 (5.9) 263 (42.1) 325 (52.0)

104 471 589

8 (1.5) 19 (3.5) 8 (1.5) 10 (1.9) 9 (1.7) 5 (0.9) 0 56 (10.4)

29 (4.6) 39 (6.2) 17 (2.7) 2 (0.3) 6 (1.0) 2 (0.3) 1 (0.2) 7 (1.1)

37 58 25 12 15 7 1 63

Data are median (interquartile range) or n (%).

The Lundby Study The Lundby Study is an epidemiological study that started in 1947. The population was geographically defined and comprised two parishes in south Sweden, which were rural in the 1940s but have since undergone considerable changes. The original 1947 cohort consisted of 2550 subjects. In 1957, 1013 subjects were added that either had been born into the area or had moved there; no additional subjects have been added since then. All surviving subjects were interviewed in 1957 and were followed up in 1972 and in 1997. During this time, the area developed into a suburban area with subjects of working age commuting to the neighbouring city areas. In 1997, the cohort included 1797 living subjects aged 40–96 years. Sociodemographic descriptions of subjects are given in Table 1.

psychiatric care. The mental health assessment also included alcohol problems. As in earlier field investigations, collateral sources of information such as registers, key informants, and case notes were utilised. In 1997, the SOC questionnaire was given to the participant after the interview with a request for it to be completed later and returned by post. The interviewer was thus not present when the participant completed the questionnaire. In 2011, dates of death for those who had died between 1997 and 2011 were obtained from the cause of Swedish death register [19]. Ethical considerations The ethics committee of Lund University Hospital approved the study, and participants provided informed, written consent. Subjects and attrition

Methods In 1997, as in the earlier field investigations, a semistructured interview was utilised. Before the interview, an introductory letter was sent to the home addresses of the individuals in the Lundby cohort, explaining the background and the purpose of the Lundby Study. Individuals were then contacted by telephone, and appointments were scheduled with those who chose to participate. Clinically experienced psychiatrists did the fieldwork and carried out the interviews, mostly in the subject’s home or workplace. The interview started with questions about the subject’s physical and mental health and contact with healthcare providers, especially for

The Lundby cohort consists of a homogenous group of Nordic people with very few immigrants, especially from countries outside Europe. All subjects of working age or older have been classified according to the Swedish socioeconomic classification system established by Statistics Sweden in 1982 [20]. Subjects were categorised into three socioeconomic levels: (a) blue-collar workers (unskilled, semiskilled, and skilled workers); (b) white-collar workers (assistant nonmanual employees, employed and self-employed professionals, higher civil servants, and executives); and (c) selfemployed workers (other than professionals).

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Relationship of Antonovsky’s sense of coherence   437 In 1997, 1559 out of 1779 (87.6%) participants in the cohort were interviewed and 1164 (65.4%) completed the SOC questionnaire. Those who did not complete the questionnaire were considered dropouts (n=395). The dropouts differed somewhat socio-demographically from participants. Among the dropouts, there were statistically significant more males, unmarried subjects, and blue-collar workers and there were slightly fewer with a diagnosed mental disorder. However, the prevalence of alcohol use disorder was higher in dropouts than in participants (6.8% vs. 5.4%). Diagnostic assessment The participants were diagnostically classified using DSM-IV, as well as the Lundby diagnostic system, which is a simplified diagnostic system adapted to fieldwork. In the present study, diagnoses were grouped into the following categories: depressive, anxiety, somatoform, organic, psychotic, and alcohol use disorders (abuse and dependence as defined in DSM-IV), as well as dementia. Depressive disorders correspond roughly to major depression in DSM-IV, and anxiety disorders include general anxiety disorders and panic disorders. Somatoform disorders include undifferentiated somatoform disorder and pain disorders. Organic disorder includes cognitive deficits such as memory difficulties, slow reactions, and concentration difficulties (e.g. cognitive disorder NOS). Psychotic disorders include schizophrenia and other psychotic disorders. Dementia includes Alzheimer’s disease, multiinfarct dementia, and other varieties of dementia. The Lundby diagnostic system is hierarchical, thus allowing only one diagnosis per episode of mental illness. However, a subject could receive a concurrent diagnosis of alcohol use disorder. During the 1997 follow up, the Lundby Study continued to use the simplified diagnostic system to allow longitudinal comparisons. After gathering all available data, including the semistructured interview and data from outside sources (key informants, case files, and registers), a bestestimate diagnosis was established by consensus by the psychiatrists within the research team. Of particular importance for the 1997 field investigation was the inpatient register (information about all in care in Sweden) [21] and the Dalby-Tierp register of outpatient clinics. In addition to this information, impairment ratings were utilised. In the Lundby cohort, every mental disorder episode from 1947–1997 has been given an impairment rating of mild, medium, or severe, according to Leighton et al. in 1963 [22]. On this continuum, mild impairment typically requires treatment by a psychiatrist, but individuals continue to work although they may be less productive. Medium

impairment is more serious, while severe impairment involves a marked reduction in function and inability to work. Severely impaired individuals require daily assistance or inpatient treatment and may suffer from depression with retardation, delusions, or schizophrenia, for example. For a case to be included in the present analysis, a diagnosis according to the DSM-IV system and a Lundby diagnosis of a mental disorder of at least medium degree of impairment and was required. The SOC scale The Swedish version of the original 29-item SOC scale was used. The questionnaire consists of three subscales: comprehensibility, manageability, and meaningfulness. Every item was scored on a Likert scale from 1–7 points with two anchoring phrases. The possible range of the total SOC score is 29–203, and higher scores indicate stronger SOC. While Antonovsky did not give cut-offs for high or low SOC scores, other studies have presented references for comparison. The possible range of scores for the subscales comprehensibility was 11–77, for manageability 8–56, and for meaningfulness 10–70. Statistics Data are presented as frequencies, percentages, means, and standard deviations. Relationships between demographic variables (gender, marital and socioeconomic status) and SOC total and subscale scores are presented by means and standard deviations. Comparisons between groups were analysed with the Kruskal–Wallis test; furthermore, post-hoc analyses were performed (least significant difference). Spearman correlations between age and SOC total and subscale scores were calculated. Cronbach’s alpha was calculated for the total SOC and the three subscales. Confirmatory factor analysis was carried out in order to confirm the three-factor structure. SOC total and subscale scores in participants with and without mental diagnoses were compared using independent sample t-tests. Linear regression was used to assess the relationship between SOC total and subscale scores and diagnoses of mental disorders, controlling for gender, age, and marital and socioeconomic status. In what we call simple linear regression models, only one mental diagnosis was included at a time besides the confounder variables, whereas in multivariate models, all mental diagnoses were included first and nonsignificant diagnoses were removed one by one in a backward manner while keeping possible confounders in the model. Cox proportional regression analyses were performed to investigate correlation of SOC total and subscale

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438    C. Mattisson et al. Table II.  Relations between demographic variables and SOC total and subscale scores and Spearman correlations for age (n=1164).

Gender Male Female p-value Marital status Unmarried Married/cohabiting Divorced Widow/widower p-value Socioeconomic classification Blue-collar White-collar Self-employed p-values Correlation with age* Males Females All subjects

Total

Comprehensibility

Manageability

Meaningfulness

140.9±22.0 141.7±22.1 0.427

54.6±8.8 53.3±9.2 0.055

47.7±9.5 48.6±8.9 0.042

38.6±7.7 39.8±8.3 0.015

130.6±20.2 141.6±21.4 138.6±24.1 146.8±23.3

Relationship of SOC with sociodemographic variables, mental disorders and mortality.

SOC is associated with wellbeing and health. The Lundby Study is a cohort study of an unselected population (n=3563) in whom mental health and persona...
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