Has dementia research lost its sense of reality? A descriptive analysis of eligibility criteria of Dutch dementia research protocols.
OBJECTIVE
A substantial proportion of dementia patients are excluded from research participation, while for extrapolation of the study findings, it is important that the research population represents the patient population. The aim of this study is to provide an analysis of dementia research and its exclusion criteria in order to get a clearer picture whether the research participants represent the general dementia population.


METHODS
Dementia studies registered at ToetsingOnline.nl between 2006-2015 were analysed. Study characteristics, funding and eligibility criteria were described and analysed using a standardised score sheet.


RESULTS
The search yielded 103 usable study protocols. The number of trials has increased over the years, and 35% of the studies were industry-financed. Alzheimer's disease was the most researched type of dementia (84%). In observational studies the most frequently observed exclusion criterion is a neurological condition, while in drug studies and other intervention studies this is a somatic condition. Of all protocols, 86% had at least one exclusion criterion concerning comorbidity. Most studies focused on mild or moderate dementia (78%).


CONCLUSIONS
Our study has shown that the distribution of dementia research over the different subtypes of dementia does not correspond with the prevalence of these subtypes in clinical practice. The research population in the protocols is not representative of the larger patient population. A greater number of dementia patients could derive benefit from the conducted research if the research agenda were more closely aligned with disease prevalence. A better representation of all dementia patients in research will help to meet the needs of these patients.
Department of Medical Ethics and Philosophy of Medicine, Erasmus Medical Centre, Rotterdam, the Netherlands.
K R
KR
Jongsma
R L
RL
van Bruchem-Visser
S
S
van de Vathorst
F U S
FU
Mattace Raso
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000628:therapy; D035843:Biomedical Research / Q000706:statistics & numerical data*; D002491:Central Nervous System Agents / Q000627:therapeutic use*; D002985:Clinical Protocols; D002986:Clinical Trials as Topic; D060825:Cognitive Dysfunction / Q000628:therapy; D015897:Comorbidity; D003704:Dementia / Q000628:therapy*; D015140:Dementia, Vascular / Q000628:therapy; D004345:Drug Industry; D004608:Eligibility Determination; D005260:Female; D057180:Frontotemporal Dementia / Q000628:therapy; D006801:Humans; D007258:Informed Consent; D020961:Lewy Body Disease / Q000628:therapy; D008297:Male; D016743:Mental Competency; D008875:Middle Aged; D009426:Netherlands; D009735:Nursing Homes; D064887:Observational Studies as Topic; D018579:Patient Selection; D019727:Proxy; D012109:Research Support as Topic; D012111:Residence Characteristics; D012720:Severity of Illness Index; D055815:Young Adult
D002491:Central Nervous System Agents