Schizophrenia and risk of dementia: a meta-analysis study

Figures & data

Figure 1 Flowchart depicting the literature search and study selection.

Notes: After removal of duplicates, reviews, and quality control, six papers were suitable for analysis.

Table 1 Characteristics of studies included in this meta-analysis

Authors, publication year	Study design	Country/continent	No of participants	No of dementia cases	Sex	Age range or mean (years)	Follow-up duration (years)	Schizophrenia assessment	Dementia ascertainment	Adjustment for confounders
Kørner et al 2009^Citation53	Prospective	Denmark/Europe	20,328	355	M/F	≥40	3	ICD-10 codes	ICD-10 codes	Gender, age, and calendar time
Ku et al 2016^Citation50	Prospective	Korea/Asia	275,510	8,188	M/F	<65, ≥65	5	ICD-10 codes	ICD-10 codes	Charlson Comorbidity Index and underlying comorbidities
Ribe et al 2015^Citation51	Prospective	Denmark/Europe	2,845,440	136,012	M/F	≥50	18	ICD-8 and ICD-10 codes	ICD-8 and ICD-10 codes	Age, sex, and calendar period
Rohde et al 2016^Citation49	Prospective	Denmark/Europe	1,839,006	20,623	M/F	≥50	3–33	ICD-8 and ICD-10 codes	ICD-8 and ICD-10 codes	Diabetes mellitus, myocardial infarction, congestive heart failure, and peripheral vascular disease
Tapiainen et al 2017^Citation48	Retrospective	Finland/Europe	55,896	27,948	M/F	79.7	5	ICD-8, ICD-9, and ICD-10 codes	ICD-8, ICD-9, and ICD-10 codes	Modified Charlson Comorbidity Index
Zilkens et al 2014^Citation52	Retrospective	Australia/Oceania	27,136	13,568	M/F	78.7	20	ICD-9 and ICD-10 codes	ICD-9 and ICD-10 codes	Diabetes, heart disease, cerebrovascular disease, and smoking risk factors

Table 2 Quality scores of included studies

Study	Selection	Comparability	Outcome/exposure	Total
Kørner et al 2009^Citation53	4	1	3	8
Ku et al 2016^Citation50	4	2	3	9
Ribe et al 2015^Citation51	4	2	3	9
Rohde et al 2016^Citation49	4	1	3	8
Tapiainen et al 2017^Citation48	4	2	3	9
Zilkens et al 2014^Citation52	4	2	3	9

Figure 2 Meta-analysis of the association between schizophrenia and dementia incidence. The random-effects model was used. There was a highly significant difference between the two groups (P=0.002).

Note: Weights are from random effects analysis.
Abbreviation: RR, relative risk.

Figure 3 Analyses of subgroups relating schizophrenia to dementia. The random-effects model was applied.

Abbreviation: RR, relative risk.

Figure 4 Sensitivity analyses results when the given named study was omitted.

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RohdeCAgerboENielsenPRSpouse with schizophrenia and risk of dementiaSoc Psychiatry Psychiatr Epidemiol201651121655165827744541

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TapiainenVHartikainenSTaipaleHTiihonenJTolppanenA-MHospital-treated mental and behavioral disorders and risk of Alzheimer’s disease: A nationwide nested case-control studyEur Psychiatry201743929828388490

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