Development of a new measure of health-related quality of life for people with dementia: DEMQOL

TY - JOUR

T1 - Development of a new measure of health-related quality of life for people with dementia: DEMQOL

AU - Smith, S C

AU - Lamping, D L

AU - Banerjee, S

AU - Harwood, R H

AU - Foley, B

AU - Smith, P

AU - Cook, J C

AU - Murray, J

AU - Prince, M

AU - Levin, E

AU - Mann, A

AU - Knapps, M

PY - 2007/5

Y1 - 2007/5

N2 - Background. We identified the need to develop a scientifically rigorous measure of health-related quality of life (HRQL) in dementia that would be appropriate for use at all stages of dementia severity and would be available in both self- and proxy-report versions. Method. We used standard psychometric methods to eliminate items with poor psychometric properties (item-reduction field test) and to assess the acceptability, reliability and validity of the item-reduced instruments (psychometric evaluation field test). We developed and validated two versions of DEMQOL: a 28-item interviewer-administered questionnaire that is self-reported by the person with dementia (DEMQOL) and a 31-item interviewer-administered questionnaire that is proxy-reported by a caregiver (DEMQOL-Proxy). Results. DEMQOL shows high reliability (internal consistency and test-retest) and moderate validity in people with mild/moderate dementia. DEMQOL-Proxy shows good acceptability and internal consistency and moderate evidence of validity in people with mild/moderate and severe dementia. Test-retest reliability and performance in people with severe dementia need further testing. Conclusions. DEMQOL and DEMQOL-Proxy show psychometric properties that are comparable with the best available dementia-specific measures of HRQL. We recommend that DEMQOL and DEMQOL-Proxy are used together. Reliability and validity need to be confirmed in independent samples and responsiveness needs to be evaluated.

AB - Background. We identified the need to develop a scientifically rigorous measure of health-related quality of life (HRQL) in dementia that would be appropriate for use at all stages of dementia severity and would be available in both self- and proxy-report versions. Method. We used standard psychometric methods to eliminate items with poor psychometric properties (item-reduction field test) and to assess the acceptability, reliability and validity of the item-reduced instruments (psychometric evaluation field test). We developed and validated two versions of DEMQOL: a 28-item interviewer-administered questionnaire that is self-reported by the person with dementia (DEMQOL) and a 31-item interviewer-administered questionnaire that is proxy-reported by a caregiver (DEMQOL-Proxy). Results. DEMQOL shows high reliability (internal consistency and test-retest) and moderate validity in people with mild/moderate dementia. DEMQOL-Proxy shows good acceptability and internal consistency and moderate evidence of validity in people with mild/moderate and severe dementia. Test-retest reliability and performance in people with severe dementia need further testing. Conclusions. DEMQOL and DEMQOL-Proxy show psychometric properties that are comparable with the best available dementia-specific measures of HRQL. We recommend that DEMQOL and DEMQOL-Proxy are used together. Reliability and validity need to be confirmed in independent samples and responsiveness needs to be evaluated.

U2 - 10.1017/S0033291706009469

DO - 10.1017/S0033291706009469

M3 - Article

SN - 1469-8978

VL - 37

SP - 737

EP - 746

JO - Psychological Medicine

JF - Psychological Medicine

IS - 5

ER -