Measurement tools of resource use andquality of life in clinical trials for dementiaor cognitive impairment interventions:protocol for a scoping review

Background
Dementia and cognitive impairment could severely impact patients’ life and bring heavy burden to patients, caregivers and societies. Some interventions are suggested for the older patients with these conditions to help them live well, but economic evaluation is needed to assess the cost-effectiveness of these interventions. Trial-based economic evaluation is an ideal method; however, little is known about the tools used to collect data of resource use and quality of life alongside the trials. Therefore, the aim of this review is to identify and describe the resource use and quality of life instruments in clinical trials of interventions for older patients with dementia or cognitive impairment.

Methods
We will perform a search in main electronic databases (Ovid MEDLINE, PsycINFO, EMBASE, CINAHL, Cochrane Databases of Systematic Reviews, Web of Science and Scopus) using the key terms or their synonyms: older, dementia, cognitive impairment, cost, quality of life, intervention and tools. After removing duplicates, two independent reviewers will screen each entry for eligibility, initially by title and abstract, then by full-text. A hand search of the references of included articles and general search, e.g. Google Scholar, will also be conducted to identify potential relevant studies. All disagreements will be resolved by discussion or consultation with a third reviewer if necessary. Data analysis will be completed and reported in a narrative review.

Discussion
This review will identify the instruments used in clinical trials to collect resource use and quality of life data for dementia or cognitive impairment interventions. This will help to guide the study design of future trial-based economic evaluation of these interventions.