A systematic literature review of disability weights measurement studies: evolution of methodological choices

Abstract

Background The disability weight is an essential factor to estimate the healthy time that is lost due to living with a certain state of illness. A 2014 review showed a considerable variation in methods used to derive disability weights. Since then, several sets of disability weights have been developed. This systematic review aimed to provide an updated and comparative overview of the methodological design choices and surveying techniques that have been used in disability weights measurement studies and how they evolved over time. Methods A literature search was conducted in multiple international databases (early-1990 to mid-2021). Records were screened according to pre-defined eligibility criteria. The quality of the included disability weights measurement studies was assessed using the Checklist for Reporting Valuation Studies (CREATE) instrument. Studies were collated by characteristics and methodological design approaches. Data extraction was performed by one reviewer and discussed with a second. Results Forty-six unique disability weights measurement studies met our eligibility criteria. More than half (n = 27; 59%) of the identified studies assessed disability weights for multiple ill-health outcomes. Thirty studies (65%) described the health states using disease-specific descriptions or a combination of a disease-specific descriptions and generic-preference instruments. The percentage of studies obtaining health preferences from a population-based panel increased from 14% (2004–2011) to 32% (2012–2021). None of the disability weight studies published in the past 10 years used the annual profile approach. Most studies performed panel-meetings to obtain disability weights data. Conclusions Our review reveals that a methodological uniformity between national and GBD disability weights studies increased, especially from 2010 onwards. Over years, more studies used disease-specific health state descriptions in line with those of the GBD study, panel from general populations, and data from web-based surveys and/or household surveys. There is, however, a wide variation in valuation techniques that were used to derive disability weights at national-level and that persisted over time.

Burden of infectious disease studies in Europe and the United Kingdom: a review of methodological design choices

“…The shift from the Dutch disability weights [ 50 ] to the European disability weights [ 25 ] for infectious YLD calculations, especially in disease burden studies published after 2015, is another noteworthy finding of this review. This shift can primarily be explained by the fact that the Dutch disability weights [ 50 ] were derived in the 1990s and since then, the methods for deriving disability weights have evolved [ 22 ]. Differences in methodologies to derive disability weights have an impact on the actual value of disability weights, thereby inhibiting comparability with other burden of disease studies, as well as the validity and reproducibility of disability weights.…”

“…Differences in methodologies to derive disability weights have an impact on the actual value of disability weights, thereby inhibiting comparability with other burden of disease studies, as well as the validity and reproducibility of disability weights. Over the years, new sets of disability weights have been derived based on newer techniques, including the set of European disability weights [ 22 , 25 ]. However, there were some variations in disability weights between and within European countries [ 51 ].…”

“…A disability weight reflects the relative severity of a health state with a value anchored between 0 (equivalent to full health) and 1 (equivalent to death). Several sets of disability weights are available, each reflecting different elicitation techniques [ 22 , 23 ]. The GBD study applies the GBD 2013 set of disability weights [ 24 ], the BCoDE study applies the disability weights set for Europe [ 25 ], whereas the WHO/FERG studies used disability weights from the GBD 2010 and/or GBD 2013 studies [ 24 ].…”

An assessment of the impact of developmental dysplasia of the hip on patients’ wellbeing

“… 4 The DALY uses a disability weight (DW) for each disease, which is a measure of the level of disability between 0 (full health with no disability) and 1 (disability level equivalent to death). 5 Murray 6 defined six classes of disability severity according to DW, ranging from class one for disability consisting of limited ability to perform at least one activity in the areas of recreation, education, procreation, or occupation (DW of 0.096) to class six, indicating requirement for assistance with activities of daily living (DW of 0.920). As context-independent DWs are not calculated by reference to local context, in this study, the calculated DW is referred to as ‘global’.…”

Methodological considerations in injury burden of disease studies across Europe: a systematic literature review

“…A third methodological choice relates to the set of disability weights (DWs) that is applied to injury-related health states. Several sets of DWs exist with ranging coverage of injury-related health states [ 13 , 14 ].…”