Characteristics of 37 included studies regarding smoking and risk of dementia.

APOE ε4, apolipoprotein E ε4; NA, not available; BMI, body mass index; IGT, impaired glucose tolerance; NINCDS-ADRDA, DSM-III-R, Diagnostic and Statistical Manual of Mental Disorders, third edition Revised; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, fourth edition; NINDS-AIREN, National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences; GMS-AGECAT, Geriatric Mental State-the Automated Geriatric Examination for Computer Assisted Taxonomy; ICD-8, International Classification of Diseases, Eighth Revision; ADDTC core criteria, Alzheimer’s Disease Diagnostic and Treatment Centers core criteria.1 Value refers to mean age of participants at baseline.2 Value is expressed as maximum.3 Dementia was determined by a battery of neuropsychological measures and a standardized neurological examination.4 The term “other” in the “Adjustment factors” column refers to all the confounders except age, sex, education, APOE ε4, BMI, diabetes, alcohol and hypertension.5 Value refers to sample size at baseline.6 The risk estimates were available just for former smoking and the risk of all-cause dementia and AD.Characteristics of 37 included studies regarding smoking and risk of dementia.