The agreement between proxy and self-completed EQ-5D for care home residents was better for index scores than individual domains.
OBJECTIVE
Proxy measures are an alternative source of data for care home residents who are unable to complete the health utility measure, but the agreement levels between residents and care home staff for the EQ-5D have not been investigated previously. The objective of the present study was to examine the inter-rater agreement levels for the reporting of EQ-5D by care home residents and staff, adjusting for the impact of clustering.


METHODS
The data consist of EQ-5D scores for 565 pairs of care home residents and proxies and quality-adjusted life-years (QALYs) for 248 pairs. Cluster-adjusted agreement was compared for the domains, index scores, and QALYs from the EQ-5D. Factors influencing index score agreement are also described.


RESULTS
The results show poor to fair agreement at the domain level (cluster-adjusted Kappa -0.03 to 0.26) and moderate agreement at the score level (cluster-adjusted intra-class correlation coefficient [ICC] 0.44-0.50) and for QALYs (cluster-adjusted ICC 0.59). A higher likelihood of depression and lower cognitive impairment were both associated with smaller discrepancy between proxy and self-completed scores.


CONCLUSIONS
Proxies appear to be an acceptable source of data for index scores and QALYs but may be less reliable if individual domains are considered.
Department of Health Services Research and Policy, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London, United Kingdom WC1H 9SH. Electronic address: angela.devine@lshtm.ac.uk.
Angela
A
Devine
Queen Mary University of London, 58 Turner Street, London, United Kingdom, E1 2AB.
Stephanie J C
SJ
Taylor
University of Exeter Medical School, Veysey Building, Salmon Pool Lane, Exeter, United Kingdom, EX2 4SN.
Anne
A
Spencer
Department of Health Services Research and Policy, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London, United Kingdom WC1H 9SH.
Karla
K
Diaz-Ordaz
Queen Mary University of London, 58 Turner Street, London, United Kingdom, E1 2AB.
Sandra
S
Eldridge
Warwick Medical School, Coventry, United Kingdom, CV4 7AL.
Martin
M
Underwood
D000369:Aged, 80 and over; D016000:Cluster Analysis; D003625:Data Collection / Q000379:methods*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D009735:Nursing Homes; D010820:Physicians; D019727:Proxy; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D057566:Self Report; D011795:Surveys and Questionnaires
Agreement; Care homes; EQ-5D; Health-related quality of life; Proxy-rated health; Self-rated health