Producing a preference‐based quality of LIFE measure to quantify the impact of HYPOGLYCAEMIA on people living with diabetes: A mixed‐methods research protocol

Abstract

Background Assessment of patient‐reported outcome measures (PROMs), including quality of life (QoL), is essential in diabetes research and care. However, a recent review concluded that current hypoglycaemia‐specific PROMs have limited evidence of validity, reliability and responsiveness for assessing the impact of hypoglycaemia on QoL in people living with diabetes. None of the PROMs identified could be used directly to inform the cost‐effectiveness of treatments and interventions. There is a need for a new hypoglycaemia‐specific QoL PROM, which can be used directly to inform economic evaluations. Aims This project has three aims: (a) To develop draft PROM content for measuring the impact of hypoglycaemia on QoL in adults with diabetes. (b) To refine the draft content using cognitive debriefing interviews and psychometrics. This will result in a condition‐specific PROM that can be used to quantify the impact of hypoglycaemia upon QoL. (c) To generate a preference‐based measure (PBM) that will enable utility values to be calculated for economic evaluation. Methods A mixed‐methods, three‐stage design is used: (a) Qualitative interviews will inform the draft PROM content. (b) Cognitive debriefing interview data will be used to refine the draft PROM content. The PROM will be administered in a large‐scale survey to enable psychometric validation. Final item selection for the PROM will be informed by psychometric performance, translatability assessment and input from stakeholder groups. (c) A classification system will be generated, comprising a reduced number of items from the PROM. A valuation survey will be conducted to derive a value set for the PBM.

Development of a new health-related quality of life measure for people with diabetes who experience hypoglycaemia: the Hypo-RESOLVE QoL

“…Correlations (Pearson and point-biserial) between the HRQoL measures and background characteristics are shown in Table 4. As hypothesised [12], moderate-to-large correlations were observed between the Hypo-RESOLVE QoL total score and the VAS (4 weeks) (r=0.59), DIDP (r=−0.55) and the EQ-5D-5L (r=0.46), in the expected order of magnitude. Thus, the measure showed preliminary convergent validity.…”

“…The development of the Hypo-RESOLVE QoL is summarised in Fig. 1 and an associated protocol [12]. We used mixed-methods, as follows: concept elicitation interviews (to generate an HRQoL framework and draft PROM content); cognitive debriefing interviews (to validate and refine content); and a large quantitative survey (to assess psychometric performance).…”

“…Survey data were cleaned and subject to a priori defined quality checks [12]. Psychometric analyses were conducted in R (v4.2.2; https:// cran.r-proje ct. org/ bin/ windo ws/ base/ old/4.…”

“…Following final item selection (Stage 2.3), the Hypo-RESOLVE QoL was scored summatively, and Pearson correlations were estimated. This facilitated an initial analysis of the construct validity of the Hypo-RESOLVE QoL based on a priori hypotheses about its associations with other measures [12]. We expected to demonstrate convergent validity by the Hypo-RESOLVE QoL correlating moderately (at r≥0.3) with the VAS, DIDP and EQ-5D-5L, with the size of coefficient larger for more similar constructs (i.e.…”

“…The absence of DIF by gender in the final PROM suggests the measure will function similarly across men and women. The resultant 14-item instrument was designed to help minimise respondent burden while balancing content coverage and psychometric performance, and facilitate subsequent work on producing a preference-based scoring system for use in cost-effectiveness trials for hypoglycaemia [12].…”