Methods to estimate health-related quality of life for adults with learning disabilities

Description

People with learning disabilities (LD) tend to have worse health than those without. This may be due to delays in diagnosis and treatment, and a higher likelihood of having multiple health problems and poorer outcomes after treatment. In order to address this health inequality we need to be sure that we accurately reflect any benefits that accrue from health care. In the UK, decisions on health care provision are typically subject to being shown to represent value for money (i.e. cost-effective). This is assessed using cost effectiveness analysis, which involves an assessment of the costs and benefits; the latter assessed using a measure of health-related quality of life (HRQoL).

The National Institute for Health and Care Excellence (NICE) recommend using the EQ-5D (EuroQol - Five Dimensions), as the measure of HRQoL for cost-effectiveness analyses. The EQ-5D is a simple, ‘one-for-all’ measure of HRQoL, where the user chooses the statements which best describes their health today. It has been designed for self-completion by participants and can be used in face-to-face interviews, postal surveys and via telephone using a standard set of wording. It was designed to be of little difficulty, taking only a few minutes for someone to complete. For people with LD however, there can be challenges completing the EQ-5D. A recent study, OK-Diabetes, assessed the EQ-5D with adults with mild to moderate LD and found that over half of the group had difficulty completing the measure.

The main difficulty experienced by the study participants was with the wording/language of the statements, and being able to understand what the statements meant. Rephrasing and explanation of terms made completion easier, however this invalidates the questionnaire. Aim: The aim is to adapt the EQ-5D for completion by adults with mild to moderate LD, so that the resulting data accurately reflect the HRQoL of this group. Methods: To inform the development of the adaptation, the research includes a review of existing studies involving people with communication difficulties, cognitive impairment or LD that have developed or used measures of HRQoL as part of the study. The next phase involves individual interviews and two focus groups with people with LD and the carers/supporters of people with LD (e.g. family or staff members who work with people with LD). This phase will be used to explore and understand the key difficulties experienced by people with LD when completing and understanding the EQ-5D.

We will ask participants for their suggestions about the structure and the wording/language of EQ-5D. We will also ask them about aspects of the HRQoL of a person with LD that are, or are not, covered by the EQ-5D. Using the findings from the review, interviews and focus groups we will develop an adapted version of EQ-5D for adults with mild to moderate LD. By using an online survey, we will test if using the adapted EQ-5D would provide similar results as the original EQ-5D in terms of assessing HRQoL. People selected from the general population will be used to assess if the wording/language used in the different versions gives the same values in terms of HRQoL.

This will confirm if the wording/language used in the adapted EQ-5D and the original EQ-5D have the same meaning. The adapted EQ-5D will be tested against the original version to assess whether it is easier to understand and complete by asking people with LD to complete the questionnaire on two different occasions. We will also ask a carer/supporter, if present, to complete the original EQ-5D from the point of view of the person they care for/support. The answers that we receive from the participant with LD and the carer/supporter will be tested using proven statistical methods to assess if the adapted EQ-5D can be used reliably.