Preference-based health-related quality of life in the context of aphasia: a research synthesis

Abstract

Background: Economic considerations are increasingly important in all areas of health care because of the need to determine the value of new and existing treatments. A key component of the current economic evaluation framework is the measurement of health outcomes in a manner that permits comparability across clinical areas-often referred to as "generic" outcome measurement-and incorporates societal preferences. Preference-based health-related quality of life (HRQoL) instruments are widely used to collect such data. Aims: To provide a research synthesis regarding the consideration and/or use of preference-based HRQoL instruments in the context of aphasia. A systematic search was conducted to identify aphasia-related publications that contained any of the leading preference-based instruments; in particular, the 15D, Assessment of Quality of Life (multiple variants), EQ-5D (three-level and five-level), Health Utilities Index (Mark 2 and Mark 3), Quality of Well-Being Scale Self-Administered, and/or SF-6D (SF-36 and SF-12 versions). In addition to providing an overview of how different measures have been used in aphasia research, a focus of the evaluation was to collate evidence for measurement properties and identify knowledge gaps, providing directions for further research. A secondary objective was to explore how preference-based measures have been discussed, broadly, in the aphasia literature. The latter objective originates from a desire to reflect the extent to which aphasia researchers have considered standard approaches to outcome measurement for the purposes of economic evaluation. Main Contribution: Eight publications (from six studies) were identified; the threelevel EQ-5D was used on four occasions, and the 15D and an "accessible" version of the three-level EQ-5D were used once. The key finding is that there have been no psychometric evaluations of preference-based HRQoL instruments in the context of aphasia. One paper explicitly discussed the challenge of using standardised, generic preference-based instruments with individuals with aphasia; researchers devised an accessible version of the EQ-5D, based on pictures rather than text (this remains unvalidated and is not an official EQ-5D instrument). The absence of any supportive evidence regarding the performance of preference-based instruments in the context of *Corresponding author. aphasia hampers the ability to assess the cost-effectiveness of treatments and interventions within the current economic evaluation framework. Conclusions: There is a distinct lack of conceptual or empirical research regarding the appropriateness of current preference-based HRQoL instruments in the context of aphasia. Development and extensive validation of an accessible, generic preferencebased HRQoL instrument appears to be an appropriate research direction.

Behavioural activation therapy for post-stroke depression: the BEADS feasibility RCT

“…This reinforces the view that proxy measures should be avoided when possible, hence the recognised need for accessible preference-based HRQoL measures for participants who are unable to complete the standard EQ-5D questionnaire. 117 Carer QoL was collected marginally less successfully than patient QoL in the BEADS trial. Completion rates were 84.8% at baseline and 63.6% at the 6-month follow-up time point.…”

Developing Accessible, Pictorial Versions of Health-Related Quality-of-Life Instruments Suitable for Economic Evaluation: A Report of Preliminary Studies Conducted in Canada and the United Kingdom

“…The UK and Canadian research groups became aware of their complementary interests while conducting a research synthesis [ 8 ], and a decision was made to form a single, international collaboration. The underlying rationale within both research groups was the same, i.e., current standardized instruments for measuring generic health outcomes for use in economic evaluation were likely to be inaccessible for many individuals living with aphasia.…”

“…In the context of aphasia, recent attention has been paid to the use and suitability of standardized HRQoL instruments that are recommended for use in economic evaluation [ 6 – 8 ]. The US National Institutes of Health defines aphasia as a “neurological disorder caused by damage to the portions of the brain that are responsible for language production or processing” [ 9 ].…”

“…Whitehurst et al [ 8 ] identified the absence of any conceptual or empirical research regarding the appropriateness of current preference-based HRQoL instruments in the context of aphasia. They concluded that, unlike aphasia-specific quality-of-life outcome measures that have been developed in recent years [ 12 – 14 ], current preference-based HRQoL instruments may not be accessible to individuals living with aphasia and proposed that the development and validation of a pictorial variant of an existing generic preference-based instrument was an appropriate research direction.…”

“…A considerable literature exists recommending the use of aphasia-friendly formatting (e.g. pictures, key words, and generous spacing of graphics) as a method of improving comprehension and expression of people with aphasia [ 16 – 19 ], although research that applies such aphasia-friendly formatting to preference-based HRQoL measures is in its infancy [ 6 , 8 ].…”