How does ageing affect the impact of medically unexplained symptoms and medically explained symptoms on health-related quality of life?

Abstract

Physical symptoms significantly impair health-related quality of life (HRQoL), but age effects and differential effects of medically unexplained symptoms (MUS) and medically explained symptoms (MES) have hardly been examined. Our objective was to determine the effect of age on the impact of MUS and MES on HRQoL. In a population-based cohort (n = 946, aged 28-75 years), MUS and MES were measured using the Composite International Diagnostic Interview and HRQoL using the EuroQol-5 dimensions (EQ-5D). Using multiple linear regression, we regressed MUS, MES and their interaction with age on HRQoL, adjusted for socio-demographic variables and the presence of depressive and anxiety disorders. In case of significant interaction terms, age-stratified results will be presented. In the whole study population, the association between MUS and HRQoL was stronger (β = -0.35; p < 0.001) than between MES and HRQoL (β = -0.26; p < 0.001). Adjusted for depressive and anxiety disorders, differences between these associations decline (MUS: β = -0.28, p < 0.001; MES: β = -0.25, p < 0.001). Age significantly interacted with number of MUS in explaining variance in HRQoL but not with the number of MES. The impact of MUS on HRQoL is much larger in people aged below 65 years (β = -0.39, p < 0.001) versus those aged 65 years and over (β = -0.21, p = 0.002). In the older group, the association between MUS and HRQoL lost significance when adjusted for depressive and anxiety disorders (β = -0.12 p = 0.062). Our results show that age affects the association between MUS and HRQoL, which suggest that older persons cope better with MUS than younger persons.