Lloret 2009

Methods	Randomised, placebo‐controlled, double‐blind study
Participants	Country: Spain Single centre Diagnosis: probable AD according to NINCDS‐ADRDA Number of participants: 57 patients, 18 healthy controls Age: not stated Inclusion criteria: not stated Exclusion criteria: patients taking antioxidant supplements, patients taking any medication other than cholinesterase inhibitors Severity of patients based on the Geriatric Dementia Scale ‐ mild (N = 25), moderate (N = 26) and severe (N = 6)
Interventions	6‐month intervention 1. Vitamin E (800 IU/day) 2. Placebo daily
Outcomes	1. Clock drawing 2. BDS 3. MMSE 4. Oxidative stress levels
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Patients were randomly assigned to groups using a randomised list of numbers
Allocation concealment (selection bias)	Unclear risk	No reference was made to allocation concealment was ensured
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Though it is a double‐blinded study, and random assignment occurred before the trial, there is no mention of how/if participants and personnel were blinded throughout
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Although it states it is a double‐blinded study, there is no indication to whether the assessors were blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	A total of 24/57 AD participants did not complete the research. "Of the patients who finished the study, 14 had been treated with placebo and 19 with vitamin E." The reason for participant drop‐out was not described
Selective reporting (reporting bias)	Unclear risk	All outcomes reported sufficiently
Other bias	Low risk	No evidence of additional bias