Table 1

Characteristics of included studies

Study (first author and year of publication)Study designCountryNumber of participantsMean year of birthMean age at marital status evaluation (years)Baseline marital status of participants (%)Mean/range of follow-up (years)Method of dementia case ascertainmentQuality rating
 MarriedWidowedDivorcedLifelong single
Amieva 201027CohortFrance208919147460.732.52.74.25–15Clinical assessment5
Arai 200428CohortJapan8531929697129 (unmarried)5Clinical assessment3
Bae 201417CohortS Korea35919367270.229.8003.5Clinical assessment3
Bickel 199418CohortGermany33119187442.447.53.86.47–8Clinical assessment5
Fratiglioni 200019CohortSweden136819058227.845.45.920.93Clinical assessment6
Håkansson 200929CohortSweden200019265180.17.84.47.820.9Clinical assessment8
Hatch 201330CohortUSA509219207565.929.94.1N/A12Clinical assessment8
Sundström 201431CohortSweden167719197557.614.25.732.68.6Clinical assessment7
Sundström 201632CohortSweden7 50 12919286964.98.416.010.86Clinical register/death register9
Beard 199215Case-controlUSA48218978028.848.05.417.8N/ASecondary care clinical register3
Seidler 200314Case-controlGermany42419247778.511.13.86.6N/AGeneral practice clinical register2
Correa Ribeiro 201333Cross-sectionalBrazil68319317841.640.87.510.1N/AClinical assessment3
Fan 201534Cross-sectionalTaiwan10 43219367664.231.04.8 (Div/single)N/AClinical assessment4
Guaita 201535Cross-sectionalItaly132119397267.124.62.26.1N/AClinical assessment4
Zhang 200636Cross-sectionalChina34 80719296877.420.81.6 (Div/single)N/AClinical assessment4
  • N/A,Not applicable