Structural validity and temporal stability of the 13-item sense of coherence scale: prospective evidence from the population-based HeSSup study.

STUDY
OBJECTIVE: To investigate whether the structure of Antonovsky's [Unraveling the Mystery of Health. How People Manage Stress and Stay Well. San Francisco: Jossey-Bass, 1987] 13-item Sense of Coherence (SOC) scale remains invariant across time and across age groups and whether any differences in stability of and mean changes in SOC can be seen between young people and individuals aged 30 or above.
DESIGN: Prospective study with a population-based sample of 18,525 Finns of whom 4,682 were under age 30 and 13,843 over age 30 at both the baseline and 5-year follow-up surveys (the HeSSup study).
RESULTS: Confirmatory factor analysis supported the correlated 3-factor solution for the SOC scale and its equivalent second-order factor structure at both measurement times and in both age groups. According to Structural Equation Modelling (SEM), SOC was more stable among subjects over 30 years (stability coefficient 0.81) than among younger adults (0.70). The mean level of SOC was higher among subjects over age 30 than subjects under age 30 at both times. The level of SOC increased during the follow-up period in both age groups but to a greater extent among the younger than older age group.
CONCLUSIONS: These data suggest relatively high structural validity and high stability for the 13-item SOC measure and support the notion that SOC becomes more stable following maturation. The 13-item SOC measure seems to provide a psychometrically sound survey instrument for testing Antonovsky's theory on life orientation and health.