Table 2.

Relative risk of types of bias observed in randomised controlled trials reporting the effect of donepezil in mild-to-moderate Alzheimer disease

Independent studies are reported in grey rows.

Risk is assessed as high (+), low (−) or uncertain (?). High or low risk is assigned when methods to avoid bias are inadequate or adequate, respectively. Uncertain risk is assigned when methods to avoid bias are either partially reported or not reported.