A moderator–mediator analysis of coronary heart disease mortality☆

Abstract 

Objective

The purpose of this study is to better understand how risk factors for coronary heart disease (CHD) mortality may interact.

Methods

We conducted a moderator–mediator analysis of a representative national sample of 5027 and 2902 community-dwelling women and men in the first National Health and Nutrition Examination Survey free of CHD in 1982. The outcome was 10-year CHD mortality.

Results

Two hundred sixty-seven subjects experienced CHD mortality. In the complete sample, gender moderated the effect of depressive symptoms, and among women, race–ethnicity moderated the effect of nonleisure activity on CHD mortality, defining three subgroups for further analysis: men, white women, and black/other women. Among men, baseline differences from median age (55 to 64 years), systolic blood pressure (129 to 158 mmHg), or self-rated general health (“good” to “poor”) were associated with equivalent increases in 10-year CHD mortality from 2.3% to 5.3% [area-under-the-curve effect size (ES)=0.53]. These factors appeared to mediate the effect of education on CHD mortality. Severe depression in men was associated with higher 10-year CHD mortality than less or no depression, 10.0% vs. 2.5% (ES=0.55). Among white women, baseline differences from median age (51 to 65 years) was also associated with 10-year mortality (1.2 to 13.4%, ES=0.56), as was higher blood pressure (125 to 151 mmHg) or worse self-rated health (“very good” to “fair”) to a lesser extent (1.2% to 3.5%, ES=0.51).

Conclusion

Moderators (gender, race–ethnicity) defined possible pathways to CHD mortality characterized by varying factors and interactions between factors, highlighting potential utility for targeted interventions among community-dwelling persons.

Keywords: CHD-related mortality, Depression, Moderator–mediator analysis