ReQoL-20

ReQoL-20 in Mental Health Assessment, Trials and Economic Evaluation

The ReQoL-20 is the longer of the two Recovering Quality of Life questionnaires, with twenty scored items where the ReQoL-10 has ten. The longer form takes more time to complete and spreads scores over a wider range, and the developers suggest it for initial assessment, for the end of an intervention and for research, leaving frequent monitoring to the ten-item form. For a health economist the ReQoL-20 matters in two ways. The ReQoL-20 has served as the primary outcome of a mental health trial, and the same form carries the seven items of the ReQoL-UI, so a trial that collects the ReQoL-20 can report a recovery score on a scale of 0 to 80 and a utility for QALYs from one questionnaire, as a Swedish trial of a rehabilitation programme did in 2025 and 2026.

How the twenty items were chosen

The ReQoL-20 was developed together with the ReQoL-10 by Keetharuth and colleagues at the University of Sheffield and published in 2018 in the British Journal of Psychiatry. Item writing used qualitative methods and item reduction used quantitative ones, with data from more than 6,500 service users factor analysed and item response theory models used to inform item selection. The authors set out to provide a measure for people with mental health difficulties after generic measures such as the EQ-5D and SF-6D had been criticised as inappropriate for them.

A companion paper reported the factor analysis in detail. In the first study 2,262 participants completed an initial set of 61 items, and in the second 4,266 participants completed a reduced set of 40 items. A bifactor model with one general factor and two local factors, one for positively and one for negatively worded items, was preferred in both studies, with a root mean square error of approximation of 0.061 and a comparative fit index of 0.954 in the first and 0.066 and 0.971 in the second. The authors concluded that the item sets were sufficiently unidimensional to proceed to item response theory analysis.

The final items cover seven themes, namely activity, hope, belonging and relationships, self-perception, well-being, autonomy and physical health. In the 2018 validation both versions achieved acceptable internal consistency, test and retest reliability above 0.85, known-group differences, convergence with related measures and responsiveness over time.

Structure and scoring of the ReQoL-20

The ReQoL-20 contains twenty mental health items and one physical health item. Respondents describe their thoughts, feelings and activities over the last week, and each mental health item is answered on five levels between none of the time and most or all of the time. The developers' clinician note states that the first ten items of the ReQoL-20 form the ReQoL-10, so a completed ReQoL-20 also yields a ReQoL-10 score.

The University of Sheffield scoring guide lists nine positively worded and eleven negatively worded items. Positively worded items score 0 to 4 and negatively worded items are reversed, and the twenty item scores are summed.

$$S_{20} = \sum_{i \in P} x_i + \sum_{j \in N} (4-x_j)$$

where $S_{20}$ is the ReQoL-20 total, $P$ is the set of nine positively worded items, $N$ is the set of eleven negatively worded items and $x$ is the response coded 0 for none of the time up to 4 for most or all of the time.

The total runs between 0, the poorest quality of life, and 80, the highest. The physical health item, which asks about pain, mobility, difficulties caring for oneself or feeling physically unwell, is excluded from the total because the developers regard physical health as distinct from mental health, although it remains one of the items the ReQoL-UI needs.

Cut-off and reliable change on the 80-point scale

The ReQoL Group's guidance on interpreting scores sets two reference points for the ReQoL-20. A score between 0 and 49 falls within the clinical range and a score of 50 or above within the range of the general population. An increase of 10 points or more denotes reliable improvement, a decrease of 10 points or more denotes reliable deterioration and a smaller change is not counted as reliable.

These values sit in the framework Jacobson and Truax set out in 1991, in which a person's change is clinically significant when the change is statistically reliable and also carries the person into the functional range. The reliable change threshold describes one person's score. A difference in group means between two trial arms is usually judged by its confidence interval, since the 10 point threshold was set for individual change.

Illustrative worked example of a reliable change threshold

All numbers in this example are illustrative and are not the values the ReQoL Group used. The example shows how the standard reliable change calculation turns a scale's spread and reliability into a threshold, and why a longer scale with a wider range needs a larger threshold in points.

$$S_{\text{diff}} = s_1 \sqrt{2(1-r)} \qquad \text{RC} = 1.96 \times S_{\text{diff}}$$

where $S_{\text{diff}}$ is the standard error of the difference between two scores, $s_1$ is the standard deviation of scores at baseline, $r$ is the reliability of the scale and $\text{RC}$ is the smallest change that is statistically reliable at the 95 per cent level.

1. A ReQoL-20 style scale. Suppose the baseline standard deviation is 13 points and the reliability is 0.92. Then 2 × (1 − 0.92) = 0.16, the square root of 0.16 is 0.4 and $S_{\text{diff}}$ is 13 × 0.4 = 5.2. The reliable change threshold is 1.96 × 5.2 = 10.192, or about 10 points.

2. A ReQoL-10 style scale. With half the spread, a standard deviation of 6.5 points, and the same reliability, $S_{\text{diff}}$ is 6.5 × 0.4 = 2.6 and the threshold is 1.96 × 2.6 = 5.096, or about 5 points.

3. Classifying one trial participant. A participant scores 41 on the ReQoL-20 at baseline and 55 at six months. The change of 55 − 41 = 14 points exceeds 10, so the change is a reliable improvement, and because 41 lies in the clinical range and 55 in the general population range the change is also clinically significant in the Jacobson and Truax sense. The participant's ReQoL-10 score, taken from the first ten items of the same forms, would be judged against its own threshold of 5 points.

In the illustration, doubling the spread at the same reliability doubles the threshold, because the reliable change threshold grows in proportion to the standard deviation. A threshold set in one sample is only an approximation in another, since both the spread and the reliability change with the population.

The ReQoL-20 as a trial outcome and in cost-utility analysis

The ReQoL-20 has served as the primary outcome of a randomised trial with an economic evaluation attached. Sjöberg, Liv and Lindström reported in 2025 a pragmatic cluster randomised trial of Everyday Life Rehabilitation in Swedish supported accommodation for people with serious mental illness, run between August 2021 and June 2024. Sixty housing units were randomised 1:1, the intention-to-treat analysis included 161 participants and the ReQoL-20 was the primary outcome. At six months the intervention group's scores had improved more than those of the control group, with a between-group difference of 20.1 points on the 0 to 80 scale (95 per cent confidence interval 15.8 to 24.4).

The same group then reported a cost-utility analysis in 2026 in which QALYs derived from the ReQoL-UI were the primary outcome. The incremental cost-effectiveness ratio was SEK 133,494, about EUR 12,148, per QALY against usual care, and the authors judged the programme to have a high probability of being cost-effective. The trial thus produced a recovery score for the clinical result and utilities for the economic result from one questionnaire, which is possible because the ReQoL-UI items are contained in the ReQoL-20 and the developers state that preference weights can be calculated from either version.

The ReQoL-20 total itself is a non-preference-based score, even though seven of its items can be scored as utilities through the ReQoL-UI, and cannot weight life years in a QALY. For a NICE appraisal, section 4.3.6 of the NICE technology appraisal and highly specialised technologies manual (PMG36) makes the EQ-5D the preferred measure of health-related quality of life in adults, and the interim methods statement PMG51, published on 27 August 2026, names the EQ-5D-5L and the UK EQ-5D-5L value set for adult reference-case analyses, with the PMG36 sections concerned flagged for update. The ReQoL-20 total and the ReQoL-UI are not the reference-case measure. When evidence shows the EQ-5D is not appropriate, figure 4.1 of PMG36 sets an order of preference for other measures, starting with another generic preference-based measure.

Reliability in other languages and settings

Validation outside the original English samples gives a sense of how far the published figures travel. Internal consistency reliability and test-retest reliability both depend on the population and the language version.

Grochtdreis and colleagues validated the German ReQoL measures in 2023 in patients with anxiety, obsessive-compulsive, stress-related, somatoform and personality disorders, drawn from a randomised trial of a stepped care model. Cronbach's alpha was 0.91 for the ReQoL-20 and 0.83 for the ReQoL-10, and the correlation with the Global Severity Index was −0.70. The measures were sensitive to treatment response and to remission of symptoms. In the English validation the developers reported test and retest reliability above 0.85, and a threshold built on reliability in one population is only an approximation in another.

Use in Wales and in services

Health systems have started to build the ReQoL into routine data. The Welsh Government circular on recording mental health outcome measures (WHC/2025/006, May 2025) states that the ReQoL has been recommended for use across adult and older adult mental health services in Wales. The Welsh Information Standards Board approved a data standards change notice in July 2025 (DSCN 2025/15) that sets out the content of the ReQoL-20 as a patient-reported outcome measure within the Value in Health programme.

In England, NHS England guidance names the ReQoL-10 rather than the ReQoL-20 in its recommended suite for community mental health services, which fits the developers' advice to use the shorter form for regular monitoring. A service that uses the ReQoL-20 at assessment and discharge and the ReQoL-10 in between keeps one scale throughout, because the ReQoL-10 items are the first ten of the ReQoL-20. Licences are issued by Oxford University Innovation on behalf of the University of Sheffield, commercially or at no cost to the NHS and not-for-profit organisations.

Choosing between the ReQoL-20 and the ReQoL-10

The two versions measure the same construct and differ mainly in length, precision and intended use. The choice affects respondent burden, the threshold for reliable change and the comparability of results across studies.

Both are patient-reported outcome measures for mental health service users aged 16 and over across diagnoses, unlike a symptom scale such as the PHQ-9 that targets one condition. Neither total is a utility, and both give the same ReQoL-UI utility for the same answers to the seven index items.

Limitations and common misreadings

The longer form removes some problems of the short form and adds others. Several errors recur in trials and service data.

• Validation figures read against the thresholds. The 2018 validation halved ReQoL-20 scores to a range of 0 to 40 for comparison with the ReQoL-10, so ReQoL-20 figures in that paper are not on the 0 to 80 scale and should not be read against the 49 and 50 cut-off or the 10 point threshold.
• Totals compared across versions. A ReQoL-20 total of 40 and a ReQoL-10 total of 20 are both halfway up their scales but are not interchangeable scores, and results from one version cannot be pooled with the other without rescoring the shared items.
• Group differences judged against reliable change. The 10 point threshold applies to one person's change. A trial's mean difference needs its confidence interval and, where available, a minimal clinically important difference established for the population.
• Physical health item added to the total. Including the physical health item changes the range and invalidates the published cut-off and threshold.
• Total treated as a utility. A cost per point on the ReQoL-20 is a cost-effectiveness ratio in natural units with no accepted threshold, and only ReQoL-UI scoring of the item responses yields QALYs.
• Respondent burden ignored. Twenty items take longer to complete than ten, and the developers suggest the ReQoL-10, not the ReQoL-20, for weekly or regular monitoring.

Sources

• Grochtdreis T, König HH, Gallinat J, Konnopka A, Schulz H, Lambert M, Karow A, Dams J. Validation of the Recovering Quality of Life (ReQoL) questionnaires for patients with anxiety, obsessive-compulsive, stress-related, somatoform and personality disorders in Germany. Journal of Psychiatric Research. 2023;157:202-211. doi:10.1016/j.jpsychires.2022.11.032
• Jacobson NS, Truax P. Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology. 1991;59(1):12-19. doi:10.1037/0022-006X.59.1.12
• Keetharuth AD, Brazier J, Connell J, et al. Recovering Quality of Life (ReQoL): a new generic self-reported outcome measure for use with people experiencing mental health difficulties. British Journal of Psychiatry. 2018;212(1):42-49. doi:10.1192/bjp.2017.10. https://pmc.ncbi.nlm.nih.gov/articles/PMC6457165/
• Keetharuth AD, et al. Exploring the item sets of the Recovering Quality of Life (ReQoL) measures using factor analysis. Quality of Life Research. 2019;28(4):1005-1015. https://pubmed.ncbi.nlm.nih.gov/30578454/
• National Institute for Health and Care Excellence. NICE technology appraisal and highly specialised technologies guidance: the manual (PMG36). Published 31 January 2022, last updated 13 October 2026. Section 4.3.6. https://www.nice.org.uk/process/pmg36/chapter/economic-evaluation-2
• National Institute for Health and Care Excellence. Statement on using the EQ-5D-5L value set (PMG51). Published 27 August 2026. https://www.nice.org.uk/process/pmg51/chapter/statement-on-using-the-eq-5d-5l-value-set
• ReQoL Group. Interpreting ReQoL scores. University of Sheffield. https://sheffield.ac.uk/sites/default/files/2022-04/InterpretReQoLscores.pdf
• ReQoL (University of Sheffield). Scoring. Accessed 17 October 2026. https://www.reqol.org.uk/p/scoring.html
• ReQoL (University of Sheffield). ReQoL-UI preference weights. Accessed 17 October 2026. https://www.reqol.org.uk/p/reqol-ui-preference-weights.html
• Sjöberg A, Liv P, Lindström M. Effect of Everyday Life Rehabilitation on recovering quality of life in individuals with serious mental illness in supported accommodation: a pragmatic cluster randomised controlled trial. BMJ Mental Health. 2025;28(1):e301757. doi:10.1136/bmjment-2025-301757
• Sjöberg A, Liv P, Lindholm L, Lindström M. Evaluating the cost-effectiveness of Everyday Life Rehabilitation (ELR) for individuals with serious mental illness in supported accommodation. European Journal of Health Economics. 2026. doi:10.1007/s10198-026-01905-8
• University of Sheffield. ReQoL clinician note. https://sheffield.ac.uk/sites/default/files/2022-04/cliniciannote.pdf
• University of Sheffield. ReQoL-20 scoring guide, version 0.3. https://sheffield.ac.uk/sites/default/files/2022-04/ReQoL20_Scoring_Guide_v0.3.pdf
• University of Sheffield Online Licensing Portal. ReQoL, Recovering Quality of Life. Accessed 17 October 2026. https://licensing.sheffield.ac.uk/product/ReQOL
• Welsh Government. Recording of mental health outcome measures (WHC/2025/006). First published 13 May 2025. https://www.gov.wales/recording-mental-health-outcome-measures-whc2025006-html
• Welsh Information Standards Board. DSCN 2025/15, Recovering Quality of Life (ReQoL-20). Approved 17 July 2025. https://dhcw.nhs.wales/data/information-standards/data-standards/data-standards-files/20250717-dscn-2025-15-recovering-quality-of-life-reqol-20-pdf/