Schulz · JAMA 1999 · prospective cohort study · n=819

Caregiving as a risk factor for mortality: the Caregiver Health Effects Study.

Cited 3378 times in the scientific literature.

Level 3 - non-randomized controlled study

Prospective cohort study comparing mortality risk across caregiver exposure groups over time.

PubMed 10605972 · doi:10.1001/jama.282.23.2215 · record verified 2026-08-27

What was done

A prospective population-based cohort study (the Caregiver Health Effects Study) followed 392 caregivers and 427 noncaregivers aged 66 to 96 years living with spouses in four US communities from 1993 to 1998 (mean follow-up 4.5 years). All-cause mortality was evaluated across four categories: spouse not disabled (noncaregiving controls), spouse disabled but not helping, spouse disabled and helping without strain, and spouse disabled and helping with reported mental or emotional strain. Multivariable models adjusted for baseline sociodemographics, prevalent clinical disease, and subclinical cardiovascular disease.

What was found

During follow-up, 103 participants (12.6%) died. After adjustment, caregivers reporting mental or emotional strain had a 63% higher mortality risk than noncaregiving controls (relative risk [RR] 1.63, 95% CI 1.00–2.65). Mortality risk was not significantly elevated in caregivers without strain (RR 1.08, 95% CI 0.61–1.90) or in individuals with a disabled spouse who did not provide care (RR 1.37, 95% CI 0.73–2.58) relative to controls.

Why it matters

This study indicates that the psychological and emotional strain of spousal caregiving, rather than the presence of caregiving duties alone, is an independent risk factor for earlier mortality in older adults.

Limits

As an observational study, residual confounding and reverse causation cannot be ruled out. The lower bound of the 95% confidence interval for the primary finding is 1.00, indicating marginal statistical significance. Caregiver strain and clinical covariates were evaluated at baseline, leaving potential changes in caregiving status or disease progression over follow-up unmeasured in the abstract.

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