Carers’ interpretation of the recall period and perspective-taking when completing the EQ health and wellbeing instrument (EQ-HWB)-9 as proxies for people with dementia: a think-aloud study

Patient-reported outcome measures are often administered with specific recall periods to standardise reporting. However, research on recall periods in proxy reporting is limited. This study sought to explore (1) how informal carers interpret the “last 7 days” recall period of the EQ health and well-being instrument (EQ-HWB)-9 and (2) the perspective they adopt when completing the measure to report on the health and well-being of persons with dementia. A qualitative, descriptive study was conducted. Convenience sampling was used for recruitment. We interviewed informal carers of persons with dementia in Australia using semi-structured cognitive interviews. Participants were asked to think aloud when completing the EQ-HWB-9, and three additional positively-framed questions from the EQ-HWB. Thematic analysis was used, where transcripts were inductively coded to capture new insights and deductively coded as guided by the EQ-HWB-9 questions. Nineteen carers completed interviews. Carers used two main retrieval strategies: supplementing recent observations with key events or self-report occurring slightly outside the recall period, and drawing on the past to contextualise recent behaviours. All participants used their own observations and opinions of the person with dementia (“proxy–proxy perspective”). When questions about the person’s feelings were difficult to answer, carers relied on various observable behaviours as indirect indicators. Nearly half also imagined how the person might answer (“proxy–patient perspective”), even if they sometimes disagreed with the person’s self-assessment. The 7-day recall period for the EQ-HWB-9 was more consistently adhered to for observable aspects of health. Wording changes may be needed to support consistent use, particularly for less observable items. Challenges in perspective-taking and adherence were also identified, suggesting areas to address in instructions. Questionnaires are often used to measure patients’ health and experiences. These questionnaires usually ask people to think about a specific time frame—called a “recall period”. Sometimes, people living with dementia cannot complete these questionnaires themselves, so someone else (“proxies”), like their carer, may be asked to answer on their behalf. We are not sure how proxies think about and use the recall period when answering. This matters because using a time frame helps us collect consistent information, which is important for comparisons between people and tracking health changes over time. If people use different time frames when responding to the same question, it may be hard to interpret the results. In this study, we interviewed carers of people living with dementia about how they used the “last 7 days” recall period in a questionnaire (EQ-HWB-9) about the person’s health and wellbeing. We found that carers sometimes included observations that happened outside the last 7 days if they felt these were important. Carers also compared recent behaviours to how the person acted in the past. All carers based their answers on their own observations of the person living with dementia (“proxy–proxy perspective”), and when it was hard to judge feelings, they looked to behaviours as clues. These findings show that providing clear instructions may be needed for carers to stay within the recall period, and highlights helpful areas to research in the future.