Limitations
This study has several limitations. First, appropriate interpre-
tation of the study findings requires consideration of mea-
surement error for self-reported diet data. Further, this study
relied on single measurement of egg and dietary cholesterol
consumption. Exposure misclassification may be of concern,
but results were similar when censoring participants at differ-
ent time points. Second, all cohorts used different dietary as-
sessment tools except 2 Framingham cohorts, which created
heterogeneities for data analyses. This was addressed by the
following: (1) implementing a rigorous methodology to har-
monize diet data; (2) performing cohort-stratified analyses; and
(3) conducting several sensitivity analyses. Third, residual con-
founding was likely, although a number of covariates were ad-
justed. Fourth, data were not available for investigating sub-
types of CHD, stroke, and heart failure, as well asmore detailed
cause-specific mortality such as cancer mortality. Fifth, gen-
eralizing our results to non-US populations requires caution
due to different nutrition and food environments and chronic
disease epidemiology. Sixth, the study findings are observa-
tional and cannot establish causality.