- Anticholinergic drug use, particularly long-term use, was associated with increased dementia incidence and cognitive decline.
- However, no causal relationship was established, as studies were observational with considerable risk of bias.
Why this matters
- Prescribers should carefully consider the potential benefits and harms when initiating and continuing anticholinergic drugs.
- 26 studies including 621,548 participants met eligibility criteria after a search across electronic databases.
- Funding: Alzheimer’s Society UK.
- The pooled OR for any use of drugs with definite anticholinergic activity and incident dementia was 1.20 (95% CI, 1.09-1.32; I2, 86%).
- Short-term (≥90 days; OR, 1.23; 95% CI, 1.17-1.29) and long-term (≥365 days; OR, 1.50; 95% CI, 1.22-1.85; I2, 90%) anticholinergic use were associated with incident dementia.
- Greater cognitive decline was consistently seen in patients taking anticholinergic drugs (standardised mean difference, 0.15; 95% CI, 0.09-0.21) with no statistically significant difference for mild cognitive impairment (OR, 1.24; 95% CI, 0.97-1.59).
- Heterogeneity among included studies.
- Risk of bias and residual confounding.