Socioeconomic inequalities in mobility decline in chronic disease groups (asthma/COPD, heart disease, diabetes mellitus, low back pain): only a minor role for disease severity and comorbidity.

OBJECTIVE This study examined the association between socioeconomic status and mobility decline and whether this could be explained by disease severity and comorbidity in four different chronic disease groups (asthma/COPD, heart disease, diabetes mellitus, and low back pain). It is not clear, whether the adverse course of physical functioning in persons with a low socioeconomic status can be explained by a higher prevalence of more severe disease or comorbidity in these persons. DESIGN Dutch GLOBE study: prospective cohort study. SETTING Region of Eindhoven (south east of the Netherlands). PARTICIPANTS 1384 persons suffering from at least one of the four chronic diseases were selected. The number of respondents in each group was: asthma/COPD 465, heart disease 788, diabetes mellitus 137, and low back pain 707. There were 580 respondents who suffered from more than one condition. MAIN RESULTS Odds ratios of mobility decline between 1991 and 1997, adjusted for age, sex, marital status, and baseline mobility, were significantly higher in low socioeconomic groups in comparison with high socioeconomic groups. Only very little of this association could be explained by the higher disease severity and comorbidity in these patients. Findings were similar in patients with asthma/COPD, heart disease, diabetes mellitus, and chronic low back pain. CONCLUSION These findings indicate that to reduce physical disabilities and particularly the socioeconomic differences therein, it may not be sufficient to solely intervene upon the risks of severe disease and comorbidities.