Prevalence and determinants of undetected dementia in the community: a systematic literature review and a meta-analysis.
Detection of dementia is essential for improving the lives of patients but the extent of underdetection worldwide and its causes are not known. This study aimed to quantify the prevalence of undetected dementia and to examine its correlates.



A systematic search was conducted until October 2016 for studies reporting the proportion of undetected dementia and/or its determinants in either the community or in residential care settings worldwide. Random-effects models calculated the pooled rate of undetected dementia and subgroup analyses were conducted to identify determinants of the variation.



The outcome measures of interest were the prevalence and determinants of undetected dementia.



23 studies were eligible for inclusion in this review. The pooled rate of undetected dementia was 61.7% (95% CI 55.0% to 68.0%). The rate of underdetection was higher in China and India (vs Europe and North America), in the community setting (vs residential/nursing care), age of <70 years, male gender and diagnosis by general practitioner. However, it was lower in the studies using Mini-Mental State Examination (MMSE) diagnosis criteria.



The prevalence of undetected dementia is high globally. Wide variations in detecting dementia need to be urgently examined, particularly in populations with low socioeconomic status. Efforts are required to reduce diagnostic inequality and to improve early diagnosis in the community.
Faculty of Education, Health and Wellbeing University of Wolverhampton, Wolverhampton, UK.|Post Graduate Academic Institute of Medicine, University of Wolverhampton, Wolverhampton, UK.
Linda
L
Lang
Faculty of Education, Health and Wellbeing University of Wolverhampton, Wolverhampton, UK.
Angela
A
Clifford
Department of Practice and Policy, University College London, London, UK.
Li
L
Wei
School of Health Administration, Anhui Medical University, China.
Dongmei
D
Zhang
New Cross Hospital, The Royal Wolverhampton NHS Trust, UK.
Daryl
D
Leung
Department of Public Health, Wolverhampton City Council, Wolverhampton, UK.
Glenda
G
Augustine
Faculty of Education, Health and Wellbeing University of Wolverhampton, Wolverhampton, UK.
Isaac M
IM
Danat
Faculty of Education, Health and Wellbeing University of Wolverhampton, Wolverhampton, UK.
Weiju
W
Zhou
Department of Psychiatry, University of Liverpool, Liverpool, UK.
John R
JR
Copeland
Dementia Collaborative Research Centre-Early Diagnosis and Prevention, Centre for Research on Ageing, Health and Wellbeing, Research School of Population Health, The Australian National University, Canberra, Australia.
Kaarin J
KJ
Anstey
Faculty of Education, Health and Wellbeing University of Wolverhampton, Wolverhampton, UK.|Post Graduate Academic Institute of Medicine, University of Wolverhampton, Wolverhampton, UK.
Ruoling
R
Chen
D000367:Age Factors; D001208:Asia / Q000453:epidemiology; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology*; D005060:Europe / Q000453:epidemiology; D006801:Humans; D057187:Independent Living / Q000706:statistics & numerical data*; D009656:North America / Q000453:epidemiology; D015995:Prevalence; D012112:Residential Facilities / Q000706:statistics & numerical data*; D012737:Sex Factors
GERIATRIC MEDICINE