A systematic literature review of patient-reported outcome measures used in gout: an evaluation of their content and measurement properties

Prednisolone Versus Colchicine for Acute Gout in Primary Care (COPAGO): protocol for a two-arm multicentre, pragmatic, prospective, randomized, double-blind, controlled clinical trial of prednisolone and colchicine for non-inferiority with a parallel group design

BACKGROUND

Gout is the most common form of rheumatic disease in which monosodium urate crystals are deposited in the joints followed by acute inflammatory reactions. There are various approved drugs that can be prescribed for pain relief during an acute gout attack. However, to date, no direct comparison of efficacy of colchicine and prednisolone for the treatment of acute gout attacks has been investigated. Furthermore, the majority of previous research studies were not only conducted in tertiary centres but also excluded patients with common comorbidities due to contraindications to naproxen.

METHODS

This pragmatic, prospective, double-blind, double-dummy, parallel-group, randomized, non-inferiority trial investigates whether prednisolone (intervention) is non-inferior to treatment with colchicine (active control) in patients with acute gout. Adult patients presenting with acute gout to their general practitioners in 60 practices across 3 university sites (Greifswald, Göttingen, and Würzburg) are eligible to participate in the study. Participants in the intervention group receive 30 mg prednisolone for 5 days. Those in the control group receive low-dose colchicine (day 1: 1.5 mg; days 2-5: 1 mg). The primary outcome is the absolute level of the most severe pain on day 3 (in the last 24 h) measured with an 11-item numerical rating scale. Day 0 is the day patients take their study medication for the first time. They are then asked to fill out a study diary the same time each day for pain quantification. Pain scores are used for comparison between the two medications. Secondary outcomes are average response to treatment, swelling, tenderness and physical function of the joint, patients' global assessment of treatment success, use of additional pain medication and non-pharmacological pain therapies. For safety reasons, potential side effects and course of systolic blood pressure are assessed.

DISCUSSION

This trial will provide evidence on the effectiveness of pain reduction and side effects of colchicine and prednisolone in acute gout in primary care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05698680 first posted on January 26, 2023 (retrospectively registered). URL of trial registry record: https://clinicaltrials.gov/study/NCT05698680.

Health-related quality of life in gout, psoriatic arthritis, rheumatoid arthritis and ankylosing spondylitis, results from a cross-sectional survey in Western Sweden

OBJECTIVES

Inflammatory joint diseases (IJDs) substantially affect health-related quality of life (HRQoL). We aimed to compare HRQoL between patients with gout, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and ankylosing spondylitis (AS): (i) overall; (ii) stratified by sex; and (iii) between women and men with the same IJD diagnosis.

METHOD

A survey including the RAND36-Item Health Survey for assessing HRQoL was sent to patients with a diagnosis of gout, PsA, RA, or AS, registered at a rheumatology clinic or primary care centre during 2015-2017. HRQoL was compared across IJDs. Because of age differences between diagnoses, age-matched analyses were performed.

RESULTS

In total, 2896/5130 (56.5%) individuals responded to the questionnaire. Of these, 868 had gout, 699 PsA, 742 RA, and 587 AS. Physical component summary (PCS) scores were more affected than mental component summary (MCS) scores for all diagnoses (PCS range: 39.7-41.2; MCS range: 43.7-48.9). Patients with gout reported better PCS scores than patients with PsA, RA, and AS, who reported similar scores in age-matched analysis. MCS scores were close to normative values for the general population and similar across IJDs. When comparing women and men with respective IJDs, women reported worse PCS (range, all IJDs: 34.5-37.4 vs 37.5-42.5) and MCS (PsA: 44.0 vs 46.8; RA: 46.1 vs 48.7) scores.

CONCLUSION

We found that patients with gout reported better PCS scores than patients with other IJDs, for whom the results were similar. Women reported overall worse PCS and MCS scores than men.

ICF Linking and Cognitive Interviewing Are Complementary Methods for Optimizing Content Validity of Outcome Measures: An Integrated Methods Review

Content validity is a fundamental requirement of outcome measures. After reviewing operational needs and existing definitions, content validity we as defined as: the extent to which a measure provides a comprehensive and true assessment of the key relevant elements of a specified construct or attribute across a defined range, clearly and equitably for a stated target audience and context. ICF linkage rules from 2002, 2005, and 2019 have provide increasingly clear processes for describing and evaluating content of outcome measures. ICF Core Sets provide international reference standards of the core constructs of importance for different health conditions. Both are important as reference standards during content validation. To summarize their use as reference standards, the following summary indicators were proposed: (1) Measure to ICF linkage, (2) Measure to (Brief or Comprehensive) Core Set Absolute Linkage, (3) Measure to (Brief or Comprehensive) Core Set Unique Linkage, (4) Core Set Representation, and (5) Core Set Unique Disability Representation. Methods to assess how respondents engage with content are needed to complement ICF-linking. Cognitive interviewing is an ideal method since it used to explore how respondents interpret and calibrate response to individual items on an outcome measure. We proposed a framework for classifying these responses: Clarity/Comprehension, Relevance, Inadequate response definition, Reference Point, Perspective modification, and Calibration Across Items. Our analysis of 24 manuscripts that used ICF linking for content validation since updated linking rules were published found that authors typically used linking to validate existing measures, involved multiple raters, used 2005 linking rules, summarized content at a concept level (e.g., impairment, activity, participation) and/or use core sets as a reference standard. Infrequently, ICF linking was used to create item pools/conceptual frameworks for new measures, applied the full scope of the 2019 linking rules, used summary indicators, or integrated ICF-linking with qualitative methods like cognitive interviews. We conclude that ICF linkage is a powerful tool for content validity during development or validation of PROM. Best practices include use of updated ICF linking rules, triangulation of ICF linking with participant assessments of clarity and relevance preferably obtained using cognitive interview methods, and application of defined summary indicators.

Setting and maintaining standards for patient-reported outcome measures: can we rely on the COSMIN checklists?

As test-developers we have often been troubled by published reviews of patient-reported outcome measures (PROMs). Too often minor issues are judged important while other reviews exclude the best measures available. Perhaps this led several groups to make recommendations for evaluating the quality of PROMs. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist is the latest set of recommendations. While reviewing the COSMIN literature and reviews conducted using their recommendations several concerns became apparent. The checklist is not evidence-based, relying on the opinion of researchers experienced in health-related quality of life. PROMs measuring other types of outcomes are inadequately covered by the checklist. COSMIN choose to focus on Classical Test Theory and the checklists are not appropriate for use with PROMs developed using modern measurement. Such an approach only obstructs progress in the field of outcome measurement. The retrospective nature of the evaluations also penalizes new PROMs. While the checklists imply that composite, ordinal level measurement is acceptable, crucial aspects of instrument development and quality are excluded. Reviews based on the COSMIN checklist produce contradictory conclusions and fail to provide evidence to support the recommendations. These problems suggest that the checklists themselves lack reliability and validity. It is also clear that several reviewers lack the expertise to apply the checklists. Researchers require a good grounding in instrument development and psychometrics to produce quality reviews. The science of modern PROM development is still in an early phase. Few available PROMs have sufficient quality, limiting the need for complex reviews. Standards need to be agreed for high quality outcome measurement. The issue is who should set these standards? Most published reviews merely scratch the surface and lack essential detail. All reviews of PROMs should be treated with caution, irrespective of whether the COSMIN checklist was employed.

Development and Validation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ)

Background and Objective

Chronic insomnia has major consequences for daytime functioning, yet no fully validated patient-reported outcome instrument for once-daily assessments is available to measure these consequences. This study describes the development and psychometric evaluation of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ).

Methods

The Daytime Insomnia Symptom Scale (DISS), an existing 20-item instrument for assessing daytime functioning, was modified to give an 18-item version of the IDSIQ (IDSIQ-18) based on iterative qualitative interviews with 54 subjects with insomnia and expert input. The construct validity and other psychometric properties of the IDSIQ-18 were analyzed based on an interventional study (NCT03056053) in which subjects with insomnia received zolpidem (5 or 10 mg) daily for 2 weeks and an observational study among subjects with no diagnosis of insomnia (good sleepers). Participants in both studies completed the IDSIQ-18 daily for 2 weeks. Exit interviews were conducted with a sample of subjects who completed the interventional study to elicit concepts defining the experience of insomnia, to assess understanding of the response scales, and to determine meaningful change thresholds. Exploratory factor analysis and Rasch analysis were conducted to further assess the structure and latent model for the scoring of the final IDSIQ instrument. Further psychometric evaluation of the final IDSIQ was then conducted.

Results

Subjects in both the interventional study (N = 114) and observational study (N = 103) were predominantly female (65% for subjects with insomnia and 60% for good sleepers). Mean age was 51 years for subjects with insomnia and 45 years for good sleepers. Subjects in the exit interviews (N = 41) demonstrated a good understanding of the IDSIQ-18 response scales. Day 1 mean scores were higher (worse) in subjects with insomnia compared with good sleepers. Based on inter-item correlation, exploratory factor, and Rasch analyses and review of the qualitative data, four items were removed. This yielded the final IDSIQ, with 14 items comprising three domains: Alert/Cognition, Mood, and Sleepiness. The domain structure was determined in a confirmatory factor analysis. Evidence of internal consistency reliability was strong: day 1 Cronbach’s alpha was 0.917 for IDSIQ total score and 0.806–0.918 for the domains. Test-retest reliability, assessed for subjects with insomnia with no change on the Patient Global Assessment of Disease Severity scale between day 1 and day 8, was also good (intra-class correlation coefficient 0.856–0.911). Meaningful change thresholds derived for this sample using anchor-based approaches were 20 for IDSIQ total score, 9 for the Alert/Cognition domain, 4 for the Mood domain, and 4 for the Sleepiness domain.

Conclusions

These studies, which closely followed Food and Drug Administration Guidance for Industry on patient-reported outcome measures, support use of the IDSIQ as a fit-for-purpose measure for deriving valid and reliable endpoints in insomnia clinical research trials and real-world studies.

Electronic supplementary material

The online version of this article (10.1007/s40271-020-00474-z) contains supplementary material, which is available to authorized users.

The experience of a gout flare: a meta-synthesis of qualitative studies

AIMS

Gout flares are an important concern for people with gout and an understanding of patients' experiences with gout flares is central in developing meaningful outcome measures for clinical trials. This study aimed to systematically review and thematically synthesize the qualitative literature reporting the patient experience of gout flares, to inform the development of flare-specific outcome measures.

METHODS

MEDLINE, EMBASE, CINAHL Plus and PsycINFO electronic databases were searched in October 2019 to identify original qualitative research articles reporting on the patient experience of gout flares. Methodological quality of all included papers was assessed using the Critical Appraisal Skills Program (CASP) tool. Following data extraction, coding and synthesis was undertaken using reflexive thematic analysis.

RESULTS

Sixteen papers reporting the patient experience of gout flares were included. The majority of CASP criteria were met by most studies, indicating good methodological quality. Four predominant and overlapping themes were identified from the thematic analysis: gout flare characteristics (pain, swelling, location, duration and frequency); impact on function and activities of daily living (walking, housework and yard work, self-care, exercise and sports, driving, sleep); effects on social and family life (social participation, inability to plan, employment, dependency, relationships, intimacy); and psychological impact (boredom, irritability, fear, shame and embarrassment, isolation, financial worry, depression and anxiety).

CONCLUSIONS

Gout flares impact many aspects of patients' lives, including physical and psychological and social and family life. The patient experience of gout flares goes beyond what is routinely measured in research settings. Measurement and reporting methods that capture these aspects of patients' experiences with gout flares would provide more meaningful outcome measures in clinical trials of flare prevention.