- Evidence suggested that individuals exposed to general anesthesia may have a modestly elevated risk for dementia.
Why this matters
- Dementia is a major public health burden.
- Data from individual studies on dementia have been mixed.
- Factors such as genetics or comorbidity could influence any relationship.
- For all studies pooled, relative to nonexposed peers, individuals exposed to general anesthesia did not have a significantly elevated risk for dementia, a finding seen in the majority of subgroups evaluated.
- When analysis was restricted to studies that ascertained exposure from medical records, individuals exposed to general anesthesia did have a significantly elevated dementia risk (OR, 1.22).
- A dose-response analysis of 3 studies showed a nonlinear relationship whereby risk rose more sharply with increasing number of exposures (P<.0001).
- A meta-analysis of 19 studies (7 prospective cohort studies, 11 case-control studies, and 1 pooled analysis of 6 case-control studies) among 154,421 individuals.
- Main outcome was incident dementia.
- Funding: National Natural Science Foundation of China; Provincial Natural Science Foundation of Liaoning.
- Findings may have been affected by residual confounding.
- Method of assessing exposure varied.
- Heterogeneity across studies was high.
- All studies were observational in nature.