In Reply For analyses of both all-cause and cause-specific mortality in our study,1 follow-up was calculated from date of baseline assessment to date of death (from any cause) or end of follow-up. For analyses of cause-specific mortality, we censored at the age of death from any cause. Consequently, the hazard ratio presented in our study for each cause of death is the relative risk of dying from that cause among the risk set of people who are alive. This approach not only ensured consistency with past studies of coffee drinking and mortality,2,3 but also offered an easily understandable quantity—namely the relative risk of dying from a specific cause among people who are alive. Thus, it is the preferred statistical approach for etiologic research questions as described in detail by Noordzij and colleagues.4 We appreciate that Cox proportional hazards regression assumes independent competing risks and that violations of this assumption could be envisioned; however, no data exist to evaluate whether this assumption holds true. Nevertheless, independence of competing events is not required to obtain valid estimates from a cause-specific approach, such as what was used in our analysis.5
Identify all potential conflicts of interest that might be relevant to your comment.
Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.
Err on the side of full disclosure.
If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.
Not all submitted comments are published. Please see our commenting policy for details.
Loftfield E, Graubard BI, Freedman ND. The Alleged Health-Protective Effects of Coffee—Reply. JAMA Intern Med. 2018;178(12):1726. doi:10.1001/jamainternmed.2018.6545
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: