MacDonald et al. Respond to "Search for Preventable Causes of Cardiovascular Disease"

We appreciate the comments by Dr. Cullen (1) on our review of practices in the collection and use of occupational data in population-based cardiovascular studies (2), and we agree with many of his points and recommendations. In this reply, we offer some clarification and respond to Dr. Cullen's remark that occupational cohort studies are a “better solution” to “retrofitting” population-based studies, since our view is that both designs offer complementary advantages to investigating the contribution of workplace social and environmental conditions for the distribution and occurrence of cardiovascular disease (CVD). The idea for our review grew out of broader discussions about 1) how socioeconomic status is used in health research for outcomes with established occupational risks and 2) how to improve surveillance and etiologic research on understudied and hard-to-reach worker populations, such as racial/ethnic minorities and those in nonstandard (e.g., temporary) work arrangements associated with insecure, low-quality jobs (3–5). Population-based cohorts are often larger and more sociodemographically diverse than occupational cohorts and, because participant recruitment and follow-up are not governed by employment type or longevity, these studies overcome barriers associated with the study of hard-to-reach workers; additionally, these studies routinely gather extensive individual risk data and high-quality health measures, and they often conduct long-term follow-up. We noted that occupational data will most likely be from self-reports and/or exposure estimation. Additionally, population-based studies are not well suited to investigations of rare exposures (6). Notwithstanding the practical limitations identified by Dr. Cullen for quantitative exposure assessments, semiquantitative exposure indices may be possible (7, 8). Further, we maintain that the inclusion of self-reports of industry, occupation, and the more prevalent exposures previously linked to CVD provides a scientifically sound and cost-effective way to investigate the contribution of workplace exposures to CVD.