In 34,731 US service members, higher cumulative stress lined up with more days of health care

What the research found

A prospective cohort analysis was published on 12 November 2026. It linked Millennium Cohort Study surveys with Military Health System records. The sample was 34,731 US active-duty service members who completed a baseline survey in 2020. Health care days were counted for up to three years, 2020 to 2023. Mean follow-up was 2.08 years (standard deviation 0.84). 33,252 people (95.8 percent) were young adults aged 17 to 34, so the age tag is under 40. 9,906 (28.5 percent) were female. The abstract does not describe the sample as men only, so the gender tag is all. Mean outpatient days were 17.74 (standard deviation 19.10). Mean inpatient days were 0.61 (standard deviation 4.98). Higher cumulative stress lined up with more total days (incidence rate ratio 1.54, 95 percent CI 1.50 to 1.57), more inpatient days (2.28, 95 percent CI 2.21 to 2.35), and more outpatient days (1.50, 95 percent CI 1.47 to 1.54). Adverse childhood experiences and stressful life events also lined up with more days. This is an association in service members, not a trial of a stress program. DOI 10.1001/jamanetworkopen.2026.43810. Not medical advice.

Evidence level: Human study. A study in people, but an association isn't proof of cause.

Read the original at JAMA Network Open