Intended for healthcare professionals

CCBYNC Open access

Rapid response to:

Research

Estimates of all cause mortality and cause specific mortality associated with proton pump inhibitors among US veterans: cohort study

BMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l1580 (Published 30 May 2019) Cite this as: BMJ 2019;365:l1580

Linked opinion

Investigating the causes of death attributable to use of proton pump inhibitors

Rapid Response:

Re: Estimates of all cause mortality and cause specific mortality associated with proton pump inhibitors among US veterans: cohort study

The paper of Xie et al published in The BMJ (2019 May 29 (1)) interested me so much with its results potentially important in terms of public health but also and especially because of the methodology which made it possible to obtain them.

As a clinician caregiver, I do not have the competence to criticize the analytical techniques used. However, I note that it is possible to involve a new risk factor of cardiovascular disease and cancer from groups probably not comparable at the beginning of the study (cf authors' data from the same cohort in 2017 (2)) and an average follow-up of 10 years, without taking into account important and recognized risk factors: no information was given on the evolution of the consumption of tobacco, alcohol, weight and waist circumference, level of physical inactivity and sedentary lifestyle during the ten years of follow up. These terms are not used in the article, not even in the discussion to explain their absence. There is only mention of differences in smoking between groups at inclusion in Table 1 without comment in the text. No more information on the other risk factors on entrance to the study: This is not because there are no very obvious differences between groups in terms of pathologies at entry (unlike data from 2017) unlike for risk factors! These risk factors are nevertheless argued to be strongly implicated in the pathogenesis of cardiovascular disease and cancer. Being able to draw conclusions after ten years of average follow-through comparisons of selected groups and with high quality methodologies, without any information on these major risk factors, is impressive. I do not have competence to criticize or not the results of Xie et al. I can only express some skepticism. This is not really the subject of this letter but I am questioning the absence of major clinical data for the caregiver.

The announced availability of big data and sophisticated analyzes already available and exponentially in the near future make it possible to dispense with clinical sense. The more complex the data and medical problems analyzed, the more difficult or impossible it will be for the primary caregiver to express doubts or reservations about the results. This is not without posing any ethical questions.

Patrice Couzigou
Emeritus Professor of Medicine
Bordeaux University

1 Xie Y, Bowe B, Yan Y, Xian H, Li T, Al-Aly Z. Estimates of all cause mortality and cause specific mortality associated with proton pump inhibitors among US veterans: cohort study. BMJ. 2019 May 29;365:l1580. doi: 10.1136/bmj.l1580

2 Xie Y, Bowe B, Li T, Xian H, Yan Y, Al-Aly Z. Risk of death among users of proton pump inhibitors: a longitudinal observational cohort study of United States veterans. BMJ Open. 2017 Jul 4;7(6):e015735. doi: 10.1136/bmjopen-2016-015735.

Competing interests: No competing interests

01 July 2019
Patrice Couzigou
Emeritus Professor of Medicine
Bordeaux University