Can care staff accurately assess health-related quality of life of care home residents? A secondary analysis of data from the OPERA trial

Objectives: To compare assessments of healthrelated quality of life outcomes of care home residents reported by residents and care staff acting as proxies. Design: Linear regression and bivariate modelling of paired assessments from care home residents and care staff. Setting: 78 care homes in 2 regions in England. Participants: 556 care home residents aged 65 years or older and care staff. Main outcome measures: EQ-5D utility scores and responses to individual EQ-5D dimensions. Results: The depression status, cognitive function, physical function, activities of daily living, social engagement, pain and dementia diagnosis of care home residents all predicted discrepancies in EQ-5D reporting. For residents with no depressive symptoms, care staff underestimated residents' mean EQ-5D utility score by 0.134 (95% CI 0.097 to 0.171) and for those with severe depressive symptoms they overstated mean utility scores by 0.222 (95% CI 0.104 to 0.339). With increasing levels of pain in residents the care staff progressively estimated EQ-5D utilities above self-reported values; by 0.236 (95% CI 0.003 to 0.469) in those with the second highest pain scores. For those with no cognitive impairment, proxies overstated mean utility scores by 0.097 (95% CI 0.049 to 0.146), while for those with severe cognitive impairment they underestimated mean utility scores by 0.192 (95% CI 0.143 to 0.241). Conclusions: Care home residents and staff appear to differ fundamentally in their assessment of the healthrelated quality of life, as measured by the EQ-5D, of residents with different levels of depression, pain and/or cognitive impairment. This could lead to interventions evaluated using proxy-based quality-adjusted life year estimates being wrongly rejected on cost-effectiveness grounds and may also make it difficult for carers to act as advocates with health and social care professionals for certain groups of residents. A more resident-focussed approach to assessment of health-related quality of life is needed.