Do disparities in neighborhood characteristics modify the effectiveness of a walking group intervention to promote physical activity in Detroit?: Implications for reducing health inequities

1) Background:

African Americans and Latinos experience excess risk of cardiovascular disease and disproportionately reside in low-to-moderate income urban communities where they may encounter particular challenges to physical activity. The Walk Your Heart to Health (WYHH) intervention has been demonstrated to increase physical activity and reduce cardiovascular risk (CVR) among residents of such communities.  We examine whether the effectiveness of the WYHH intervention differs by neighborhood percent poverty. 

2) Methods:

Participants (n=603) were randomly assigned into intervention or lagged intervention groups.  They participated in group walks three times/week for 32 weeks.  We use GEE models to test the hypothesis that neighborhood percent poverty modifies the effectiveness of the WYHH intervention in reducing CVR (e.g., blood pressure).

3) Results:

Neighborhood poverty did not significantly modify the effects of participation in WYHH on steps (β=-0.0, p=0.881), nor associations between steps and DBP (β=0.00, p=0.360), total cholesterol (β=-0.1, p=0.247), blood glucose (β=0.00, p=0.917), waist circumference (β=0.00, p=0.456) or high density lipoproteins (β=0.00, p=0.960) at 32 weeks. Neighborhood poverty modified the inverse association between steps and SBP (β=0.01, p=0.009) at 32 weeks.

4) Conclusion/Discussion:

Reductions in most indicators of CVR were not modified by neighborhood percent poverty.  Findings suggest that the WYHH intervention was effective in reducing CVR among residents of neighborhoods where conditions pose challenges for physical activity.  Residents of higher poverty neighborhood realized smaller reductions in SBP, suggesting the need for additional research into other factors (e.g., stress), that may contribute to reduced benefits.