Development of an Item Pool for a Needs-Based Measure of Quality of Life of Carers of a Family Member with Dementia
Background and Objectives
This paper describes the development of an item pool for a needs-based self-report outcome measure of the impact of caring for a relative, friend or neighbour with dementia on carer quality of life. The aims are to give a detailed account of the steps involved and describe the resulting item pool.
Seven steps were followed: generation of an initial item set drawing on 42 needs-led interviews with carers; a content and face validity check; assessment of psychometric potential; testing of response formats; pre-testing through cognitive interviews with 22 carers; administration rehearsal with two carers; and final review.
An initial set of 99 items was refined to a pool of 70 to be answered using a binary response format. Items were excluded due to overlap with others, ceiling effects, ambiguity, dependency on function of the person with dementia or two-part phrasing. Items retained covered a breadth of areas of impact of caring and were understandable and acceptable to respondents.
The resulting dementia carer-specific item pool reflects the accounts of a diverse sample of those who provide care for a person with dementia, allowing them to define the nature of the impact on their lives and resulting in a valid, acceptable set of items.
We would like to acknowledge the input of our co-investigator colleagues: Dr Zoe Hoare, University of Bangor, Professor Paul Kind, University of Leeds, and Emeritus Professor Alan Tennant, University of Leeds, as well as advice and help with recruitment from Carers Leeds and the Alzheimer’s Society. We would also like to thank all those carers who participated.
All authors contributed to the overall study design and reviewed and approved the paper. MM, EI and SP collected the data and contributed to analysis. JO wrote the paper with help from PW and SP.
Compliance with Ethical Standards
Conflict of interest
Jan Oyebode, Penny Wright, Simon Pini and Mike Horton each declare that this work was supported by the Medical Research Council (MRC) and the National Institute for Health Research (NIHR) (Grant title: “HQLC Dementia Carers Instrument Development: DECIDE” [MR/M025179/1]) and that the grant is registered on the UK Research and Innovation Gateway (http://gtr.ukri.org/projects?ref=MR/M025179/1). They also declare that they have received financial support for travel to meetings for the study, manuscript preparation or other purposes from the grant funder as part of the award only. In addition, Penny Wright declares that she is the principal investigator and was the main applicant for the funding that was received from the MRC and NIHR, and Jan Oyebode declares her position as a co-investigator. Emma Ingleson, Molly Megson, Linda Clare, Hareth Al-Janabi and Carol Brayne have no conflicts of interest to declare.
This work was supported by the Medical Research Council (MRC) and the National Institute for Health Research (NIHR) (Grant title: “HQLC Dementia Carers Instrument Development: DECIDE” [MR/M025179/1]). Jan Oyebode, Penny Wright, Simon Pini and Mike Horton have received financial support for travel to meetings for the study, manuscript preparation or other purposes from the grant funder as part of the award only.
Ethical approval and informed consent
Ethical approval was given in November 2015 by a UK National Health Service ethics committee. Informed consent was obtained from all individual participants included in the study.
Data availability statement
The University of Leeds will make a link to the published study available through the White Rose repository. The datasets generated and/or analysed during the current study are available from https://doi.org/10.5518/375.
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