Self-reported physical and mental health status and quality of life in adolescents: a latent variable mediation model

Abstract

Background: We examined adolescents' differentiation of their self-reported physical and mental health status, the relative importance of these variables and five important life domains (satisfaction with family, friends, living environment, school and self) with respect to adolescents' global quality of life (QOL), and the extent to which the five life domains mediate the relationships between self-reported physical and mental health status and global QOL.

Methods: The data were obtained via a cross-sectional health survey of 8,225 adolescents in 49 schools in British Columbia, Canada. Structural equation modeling was applied to test the implied latent variable mediation model. The Pratt index (d) was used to evaluate variable importance.

Results: Relative to one another, self-reported mental health status was found to be more strongly associated with depressive symptoms, and self-reported physical health status more strongly associated with physical activity. Self-reported physical and mental health status and the five life domains explained 76% of the variance in global QOL. Relatively poorer mental health and physical health were significantly associated with lower satisfaction in each of the life domains. Global QOL was predominantly explained by three of the variables: mental health status (d = 30%), satisfaction with self (d = 42%), and satisfaction with family (d = 20%). Satisfaction with self and family were the predominant mediators of mental health and global QOL (45% total mediation), and of physical health and global QOL (68% total mediation).

Conclusions: This study provides support for the validity and relevance of differentiating self-reported physical and mental health status in adolescent health surveys. Self-reported mental health status and, to a lesser extent, self-reported physical health status were associated with significant differences in the adolescents' satisfaction with their family, friends, living environment, school experiences, self, and their global QOL. Questions about adolescents' self-reported physical and mental health status and their experiences with these life domains require more research attention so as to target appropriate supportive services, particularly for adolescents with mental or physical health challenges.

Figure 1

Structural model of the relationships between self-reported physical and mental health status, domains of life satisfaction, and global QOL. Notes: N = 6,932, WLSMV χ² (178) = 2,083.22 - 2,010.02, RMSEA = .049, CFI = .951. The variances of all latent factors were fixed at 1.0 for model identification. The measurement structures of the latent factors for each of the life domains are identical to those reported by Sawatzky et al. [37] (these are not shown here because of space limitations). All parameter values are standardized. The corresponding unstandardized parameters are provided in Table 4. ¹Self-reported physical and mental health status were modeled as two ordinal variables with a latent factor that accounts for their correlation (not shown here). *p < .05.

Figure 2

Quality of life ladder. Notes: Derived from Cantril's self-anchoring ladder [50]. An error resulted in 8 rungs being presented in the paper-based version whereas 10 rungs were presented in the computer version. To remedy this, we rescaled the QOL-ladder for the computer- and paper-based versions to their common denominator by multiplying the computer-based version of the QOL-ladder by 0.8 and rounding the resulting scores to zero decimals.