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.