Patient-reported outcomes in chronic gout: a report from OMERACT 10

H. Ralph Schumacher

Dr Schumacher was a force in rheumatology for more than half a century through his multiple roles as a researcher, clinician, mentor, and educator. He is not likely to be soon forgotten by the rheumatology community; however, it is hoped that this chapter can provide a faithful recollection that will help bring his memory to life for some and that rings true to those who knew him and learned from him.

The Relationship Between Psychosocial Behavior and the Quality of Life of Male Gout Patients in Southwest China: A Cross-Sectional Study Based on an Information-Motivation-Behavioral Skills Model

Purpose

Gout is more severe in men, leading to a poor quality of life. Previous studies did not sufficiently pay attention to the quality of life and related factors in gout patients in Southwest China. This study aimed to investigate the quality of life of men with gout in Southwest China and explore the relationship between psychosocial factors and health-related quality of life from the perspective of an information-motivation-behavioral skill model.

Patients and Methods

This was a cross-sectional study conducted in the West China Hospital of Sichuan University located in Southwest China. In total, 230 male patients with gout were enrolled. The health-related quality of life of patients was assessed using the gout impact scale. The gout knowledge questionnaire was used to assess patients' information. The positive psycap questionnaire was used to assess motivation. The gout patients' self-management assessment scale was used to assess behavioral skills. Multiple linear regression was used to identify the factors associated with the health-related quality of life of patients.

Results

The overall mean gout impact scale score was 52.7±15.3 (maximum possible = 100). Factors associated with the total gout impact scale score were tophi (β=0.138, P=0.050), pain (β=0.255, P<0.001), and resiliency (β=-0.282, P<0.001). In addition, demographic characteristics (educational level, smoking and marital status), clinical characteristics (tophi, pain, number of attacks over half a year, and number of affected joints) and psychosocial behavior variables (resiliency, hope, disease treatment management, diet management) were associated with several dimensions of the gout impact scale.

Conclusion

The health-related quality of life of male patients with gout in Southwest China was at a medium level. We found that demographic characteristics, clinical characteristics, and psychosocial factors were associated with health-related quality of life of patients with gout. These findings can be used as a reference to improve health-related quality of life of patients with gout.

Course and predictors of work productivity in gout - results from the NOR-Gout longitudinal 2-year treat-to-target study

OBJECTIVES

In patients with gout there is a lack of longitudinal studies on the course of work productivity. We explored longitudinal changes in and predictors of work productivity over 2 years.

METHODS

Patients in the NOR-Gout observational study with a recent gout flare and serum urate (sUA) >360 µmol/l attended tight-control visits during escalating urate lowering therapy according to a treat-to-target strategy. From the Work Productivity and Activity Impairment (WPAI) questionnaire, scores for work productivity and activity impairment were assessed over 2 years together with the Beliefs about Medicines Questionnaire and a variety of demographic and clinical variables.

RESULTS

At baseline patients had a mean age of 56.4 years and 95% were males. WPAI scores at baseline were 5.0% work missed (absenteeism), 19.1% work impairment (presenteeism), 21.4% overall work impairment and 32.1% activity impairment. Work productivity and activity impairment improved during the first months, and remained stable at 1 and 2 years. Comorbidities were not cross-sectionally associated with WPAI scores at baseline, but predicted worse work impairment and activity impairment at year 1. The Beliefs about Medicines Questionnaire subscale with concerns about medicines at baseline independently predicted worse overall work impairment and worse activity impairment at year 1.

CONCLUSIONS

In patients with gout who were intensively treated to the sUA target, work productivity and activity impairment were largely unchanged and at 1 year predicted by comorbidities and patient concerns about medication.

Beliefs about medicines in gout patients: results from the NOR-Gout 2-year study

OBJECTIVE

Adherence to urate-lowering therapy (ULT) in gout is challenging. This longitudinal study aimed to determine 2 year changes in beliefs about medicines during intervention with ULT.

METHOD

Patients with a recent gout flare and increased serum urate received a nurse-led ULT intervention with tight control visits and a treatment target. Frequent visits at baseline and 1, 2, 3, 6, 9, 12, and 24 months included the Beliefs about Medicines Questionnaire (BMQ), and demographic and clinical variables. The BMQ subscales on necessity, concerns, overuse, harm, and the necessity-concerns differential were calculated as a measure of whether the patient perceived that necessity outweighed concerns.

RESULTS

The mean serum urate reduced from 500 mmol/L at baseline to 324 mmol/L at year 2. At years 1 and 2, 85.5% and 78.6% of patients, respectively, were at treatment target. The 2 year mean ± sd BMQ scores increased for the necessity subscale from 17.0 ± 4.4 to 18.9 ± 3.6 (p < 0.001) and decreased for the concerns subscale from 13.4 ± 4.9 to 12.5 ± 2.7 (p = 0.001). The necessity-concerns differential increased from 3.52 to 6.58 (p < 0.001), with a positive change independent of patients achieving treatment targets at 1 or 2 years. BMQ scores were not significantly related to treatment outcomes 1 or 2 years later, and achieving treatment targets did not lead to higher BMQ scores.

CONCLUSION

Patient beliefs about medicines improved gradually over 2 years, with increased beliefs in the necessity of medication and reduced concerns, but this improvement was unrelated to better outcomes.

TRIAL REGISTRATION

ACTRN12618001372279.

Reliability and Validity of the Korean Version of the Gout Impact Scale

BACKGROUND

The Gout Impact Scale (GIS), part of the Gout Assessment Questionnaire 2.0, measures gout-specific health-related quality of life (HRQOL). This study aimed to translate the GIS into Korean and validate the Korean version (K-GIS) using generic HRQOL measures.

METHODS

The GIS was translated into Korean and back-translated into English. We asked patients aged 18 years or older who met the 2015 gout classification criteria to fill out the questionnaires (from January 2022 to June 2022); the K-GIS (5 scales [0-100 scores each]), along with the Korean version of Health Assessment Questionnaire (HAQ) and EuroQol-5 dimension (EQ-5D). We investigated the internal consistency, construct validity, and discriminative validity for gout characteristics of K-GIS. The K-GIS form was administrated to patients 4 weeks later to assess the test-retest reliability using the intraclass correlation coefficient (ICC).

RESULTS

One hundred patients completed the questionnaire. The mean ± standard deviation age of the patients was 53.0 ± 15.1 years, and 99.0% of the patients were men. All scales had high degree of internal consistency (Cronbach's α = 0.59 to 0.96) and test-retest reliability (n = 18, ICC = 0.83 to 0.94, all P < 0.001), except for unmet gout treatment needs. Weak-to-moderate correlations were observed between the K-GIS scales and HAQ or EQ-5D (r = 0.21 to 0.46). The K-GIS scores were significantly higher in the presence of bone erosion, absence of urate-lowering therapy, serum urate levels > 6 mg/dL, frequent gout flares in the past year, and fewer comorbidities. In contrast, neither the HAQ nor the EQ-5D could discern these subsets of patients.

CONCLUSION

The K-GIS is a reliable and valid HRQOL measure for patients with gout. Higher K-GIS scores were associated with clinical characteristics leading to unfavorable outcomes, which were not demonstrated by the HAQ and EQ-5D.

Factors associated with change in health-related quality of life in people with gout: a 3-year prospective cohort study in primary care

OBJECTIVE

To describe factors associated with change in health-related quality of life (HRQOL) in people living with gout in primary care.

METHODS

In a UK prospective cohort study, adults with a diagnosis of gout registered with 20 general practices completed the Gout Impact Scale (GIS; scale 0-100), 36-item Short Form Physical Function subscale (PF-10; 0-100) and HAQ Disability Index (HAQ-DI; 0-3) via postal questionnaires at baseline and 6, 12, 24 and 36 months. Linear mixed modelling was used to investigate factors associated with changes in HRQOL over 3 years.

RESULTS

A total of 1184 participants responded at baseline (adjusted response 65.6%); 990 (83.6%) were male, with a mean age of 65.6 years (s.d. 12.5). A total of 818, 721, 696 and 605 responded at 6, 12, 24 and 36 months, respectively. Factors associated with worse disease-specific and generic HRQOL over 3 years were flare frequency (five or more flares; GIS subscales, PF-10), oligo/polyarticular flares (GIS subscales, PF-10, HAQ-DI), worse pain (GIS subscales, PF-10, HAQ-DI), body pain (GIS subscales, PF-10, HAQ-DI) and more severe depression (GIS subscales, PF-10, HAQ-DI) (P ≤ 0.05). More severe anxiety was associated with worse disease-specific HRQOL only (GIS subscales). Older age (PF-10), being female (PF-10, HAQ-DI) and BMI (HAQ-DI) were associated with worse generic HRQOL (P ≤ 0.05).

CONCLUSION

Gout-specific, comorbid and sociodemographic factors were associated with change in HRQOL over a 3-year period, highlighting people at risk of worse outcomes who could be targeted for interventions.

Gout Remission as a Goal of Urate-Lowering Therapy: A Critical Review

Urate-lowering therapies for the management of gout lead to a reduction in serum urate levels, monosodium urate crystal deposition, and the clinical features of gout, including painful and disabling gout flares, chronic gouty arthritis, and tophi. Thus, disease remission is a potential goal of urate-lowering therapy. In 2016, preliminary gout remission criteria were developed by a large group of rheumatologists and researchers with expertise in gout. The preliminary gout remission criteria were defined as: serum urate < 0.36 mmol/L (6 mg/dL); an absence of gout flares; an absence of tophi; pain due to gout < 2 on a 0-10 scale; and a patient global assessment < 2 on a 0-10 scale over a 12-month period. In this critical review, we describe the development of the preliminary gout remission criteria, the properties of the preliminary gout remission criteria, and clinical studies of gout remission in people taking urate-lowering therapy. We also describe a future research agenda for gout remission.

Outcome reporting in randomized trials in gout: A systematic scoping review from the OMERACT gout working group assessing the uptake of the core outcome set

OBJECTIVE

The selection and reporting of core outcome measures in clinical trials is essential for patients, researchers, and healthcare providers for clinical research to have an impact on healthcare. In this systematic scoping review, we aimed to quantify the extent to which gout clinical trials are collecting and reporting data in accordance with the core outcome domains from Outcome Measures in Rheumatology (OMERACT) published in 2009 applicable for both acute and chronic trials and evaluate the reporting according to the core domains before and after the 2009 OMERACT endorsement.

METHODS

We searched multiple databases PubMed, EMBASE, the Cochrane Library including the Cochrane Central Register of Controlled Trials (CENTRAL), and Cochrane Database of Systematic Reviews (CDSR) and www.

CLINICALTRIALS

gov for randomized controlled trials (RCTs) allocating people with gout versus an active pharmacological gout treatment or a control comparator (no date limitation). We extracted the data in accordance with the core outcome sets, focusing individually on core outcome domains and the core outcome measurements for acute and chronic trials, respectively. In this study 'Acute trials' reflect studies that describe interventions for short term management of gout flares, and 'chronic trials' describe interventions for long-term urate lowering therapy in the management of gout.

RESULTS

From 8,522 records identified in the database search, 134 full text papers were reviewed, and 71 trials were included, of which 36 were acute and 35 were chronic. Only 3 of 36 (8%) acute trials reported all five core domains and none of the 35 included chronic trials reported all 7 core domains. In the acute trials, twenty-seven unique measurement instruments across the 5 core domains were identified. For chronic trials there were 31 unique measurement instruments used across the 7 core domains. Serum urate was reported in 100% of the chronic trials and gout flares in 80%. However, other core domains were reported in <30% of chronic trials. In particular the patient-important domains such as HR-QOL, patient global assessment and activity limitations were rarely reported. A broad variety of different measurement instruments were used to assess each endorsed core domain, a minority of trials used the OMERACT endorsed instruments. For acute trials, the number reporting on all core domains was consistently low and no change was detected before and after the endorsement of the core domains in 2009. None of the included chronic trials reported on all 7 endorsed core domains at any time.

CONCLUSION

In this study we found a low adherence with the intended endorsed (i.e., core) outcome domains for acute and chronic gout studies which represents a poor uptake of the global OMERACT efforts for the minimum of what should be measured in clinical trials. In addition, there is a significant variation in how the OMERACT endorsed outcome domains have been measured. This systematic review demonstrates the need for continuous encouragement among gout researchers to adhere to OMERACT core domains as well as further guidance on outcome measurements reporting.

REGISTRATION

Prospero: CRD42019151316.

Living with gout. Experiences, impact and challenges of the disease. Qualitative study through focus groups

OBJECTIVE

To delve into the experiences of people living with gout regarding its causes and triggers, recommended treatments and therapeutic measures, and the impact of living with this problem.

SUBJECTS AND METHODS

Descriptive qualitative study. Opinion sampling, looking for discursive variability according to sex, age, socioeconomic position and treatments. Three focus groups were made with 11, 6 and 7 people, following a pre-established script of topics. Analysis following thematic content analysis procedures.

RESULTS

Participants were 19 men and 5 women, of different ages, socioeconomic status and treatments. Frequent comorbidities: hypertension and hypercholesterolemia. Genetics and the lack of renal elimination of urate were mentioned as causes of gout. They reported little knowledge of the causes and need more explanations about them. As triggers of the attack they identified: excess food and/or alcohol, trauma, stress or not following the treatment. Various drug treatment and expressed concern about their possible adverse effects were listed. Difficulties in adherence to the recommendations were also described. Non-pharmacological measures: rest, cold, proper footwear, walking, drinking water, and diet were also described. Chronic gout has an important impact on the daily life of patients and their families. Pain invalidates and leads to difficulties in performing daily activities. Irritations and mood swings were reported, which affect their family relationships.

CONCLUSIONS

These findings provide proposals to improve the care of people with gout. Information on its causes, the triggers of the crisis, dietary recommendations and exercise should be improved. The variability of treatments and recommendations on lifestyle should be analysed in depth.

Using Data-Driven Approaches to Classify and Predict Health Care Spending in Patients With Gout Using Urate-Lowering Therapy

OBJECTIVE

Despite increasing overall health care spending over the past several decades, little is known about long-term patterns of spending among US patients with gout. Current approaches to assessing spending typically focus on composite measures or patients agnostic to disease state; in contrast, examining spending using longitudinal measures may better discriminate patients and target interventions to those in need. We used a data-driven approach to classify and predict spending patterns in patients with gout.

METHODS

Using insurance claims data from 2017-2019, we used group-based trajectory modeling to classify patients ages 40 years or older diagnosed with gout and treated with urate-lowering therapy (ULT) by their total health care spending over 2 years. We assessed the ability to predict membership in each spending group using logistic and generalized boosted regression with split-sample validation. Models were estimated using different sets of predictors and evaluated using C statistics.

RESULTS

In 57,980 patients, the mean ± SD age was 71.0 ± 10.5 years, and 17,194 patients (29.7%) were female. The best-fitting model included the following groups: minimal spending (13.2%), moderate spending (37.4%), and high spending (49.4%). The ability to predict groups was high overall (e.g., boosted C statistics with all predictors: minimal spending [0.89], moderate spending [0.78], and high spending [0.90]). Although average adherence was relatively high in the population, for the high-spending group, the most influential predictors were greater gout medication adherence and diabetes melllitus diagnosis.

CONCLUSION

We identified distinct long-term health care spending patterns in patients with gout using ULT with high accuracy. Several clinical predictors could be key areas for intervention, such as gout medication use or diabetes melllitus.

Change in serum urate level with urate-lowering therapy initiation associates in the immediate term with patient-reported outcomes in people with gout

OBJECTIVE

To examine the associations of changes in serum urate (SU) with health-related quality of life (HRQOL) in gout.

METHODS

We used the first 6-months of data from four interventional trials and one observational, open-label study of urate-lowering therapy (ULT) use. HRQOL were assessed at baseline and every 3-months, and SU was measured monthly. Primary outcome measures were Short-form 36 physical and mental component summary scores, Health Assessment Questionnaire Disability Index (HAQ-DI), Sheehan Disability Scale (SDS), Patient Global Assessment, and pain scores in the last week. Linear mixed models for each outcome were adjusted as appropriate for current SU, change in urate in the last month, number of flare-affected days in the last month, baseline BMI, age, comorbidities, sex, ethnicity, trial/study and treatment combination, and tophi status (fixed effects); subject, and the trial/study month were random effects.

RESULTS

Higher current SU correlated with reduced physical and mental HRQOL, and increased SDS and pain but not with HAQ-DI score. In the first 6-months of new/escalating ULT use, absolute change in SU levels associated with poorer outcomes on the HAQ-DI scale (β (95% CI) = 0.013 (0.007-0.019)) and poorer outcomes on SDS, SF-36 MCS, patient global and pain scales. Reduction of SU associated with poorer outcomes in all six measures.

CONCLUSION

High SU levels were associated with poorer HRQOL, pain and Sheehan disability score. Recent SU level fluctuations are associated with poorer outcomes, primarily driven by a reduction in SU. Clinical emphasis on slow rather than fast SU reduction and the routine use of effective, anti-inflammatory medications at ULT initiation/escalation may avoid short-term poor outcomes.

Remission in Gout: Concepts From a Patient Perspective

Any human who has ever experienced an acute gout flare understands how painful and debilitating this condition is. Unfortunately, due to the episodic nature of these acute flares that occur randomly due to transient fluctuations in urate levels, patients often underreport these attacks.

The challenge of gout flare measurement

Gout flares are central to the patient experience of gout and are included in the Outcome Measures in Rheumatology (OMERACT) core outcome domain set for long-term gout studies. Although a valid definition for gout flare has been developed, there is no consensus around how flare outcomes are measured and reported in long-term clinical studies. Current methods of flare measurement, which are centered on measuring flares as a binary outcome (i.e., present vs absent), do not reflect the variable pattern of flares over time, nor the multidimensional patient experience of gout flares which include factors related to pain severity, functional disability, impact on family and social life, and psychological wellbeing. This review will discuss the importance and challenges of gout flare measurement.

Colchicine for acute gout

BACKGROUND

This is an updated Cochrane Review, first published in 2006 and updated in 2014. Gout is one of the most common rheumatic diseases worldwide. Despite the use of colchicine as one of the first-line therapies for the treatment of acute gout, evidence for its benefits and harms is relatively limited.

OBJECTIVES

To update the available evidence of the benefits and harms of colchicine for the treatment of acute gout.

SEARCH METHODS

We updated the search of CENTRAL, MEDLINE, Embase, Clinicaltrials.gov and WHO ICTRP registries to 28 August 2020. We did not impose any date or language restrictions in the search.

SELECTION CRITERIA

We considered published randomised controlled trials (RCTs) and quasi-randomised controlled trials (quasi-RCTs) evaluating colchicine therapy compared with another therapy (placebo or active) in acute gout; low-dose colchicine at clinically relevant doses compared with placebo was the primary comparison. The major outcomes were pain, participant global assessment of treatment success (proportion with 50% or greater decrease in pain from baseline up to 32 to 36 hours), reduction of inflammation, function of target joint, serious adverse events, total adverse events and withdrawals due to adverse events.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane in this review update.

MAIN RESULTS

We included four trials (803 randomised participants), including two new trials, in this updated review. One three-arm trial compared high-dose colchicine (52 participants), low-dose colchicine (74 participants) and placebo (59 participants); one trial compared high-dose colchicine with placebo (43 participants); one trial compared low-dose colchicine with non-steroidal anti-inflammatory drugs (NSAIDs) (399 participants); and one trial compared low-dose colchicine with Chuanhu anti-gout mixture (traditional Chinese Medicine compound) (176 participants). We did not identify any trials comparing colchicine to glucocorticoids (by any route). The mean age of participants ranged from 51.2 to 70 years, and trial duration from 48 hours to 12 weeks. Two trials were at low risk of bias, one was possibly susceptible to selection bias (random sequence generation), reporting bias and other bias, and one open-label trial was at high risk of performance and detection bias. For the primary comparison, low-quality evidence from one trial (103 participants, downgraded for imprecision and bias) suggests low-dose colchicine may improve treatment outcome compared to placebo with little or no increased risk of adverse events. The number of people who reported treatment success (50% or greater pain reduction) at 32 to 36 hours was slightly larger with low-dose colchicine (418 per 1000) compared with placebo (172 per 1000; risk ratio (RR) 2.43, 95% confidence interval (CI) 1.05 to 5.64; absolute improvement 25% more reported success (7% more to 42% more, the 95% CIs include both a clinically important and unimportant benefit); relative change of 143% more people reported treatment success (5% more to 464% more). The incidence of total adverse events was 364 per 1000 with low-dose colchicine compared with 276 per 1000 with placebo: RR 1.32, 95% CI 0.68 to 2.56; absolute difference 9% more events with low-dose colchicine (9% fewer to 43% more, the 95% CIs include both a clinically important effect and no effect); relative change of 32% more events (32% fewer to 156% more). No participants withdrew due to adverse events or reported any serious adverse events. Pain, inflammation and function were not reported. Low-quality evidence (downgraded for imprecision and bias) from two trials (124 participants) suggests that high-dose colchicine compared to placebo may improve symptoms, but with increased risk of harms. More participants reported treatment success at 32 to 36 hours with high-dose colchicine (518 per 1000) compared with placebo (240 per 1000): RR 2.16, 95% CI 1.28 to 3.65, absolute improvement 28% (8% more to 46% more); more also had reduced inflammation at this time point with high-dose colchicine (504 per 1000) compared with placebo (48 per 1000): RR 10.50, 95% CI 1.48 to 74.38; absolute improvement 45% greater (22% greater to 68% greater); but more adverse events were reported with high-dose colchicine (829 per 1000 compared with 260 per 1000): RR 3.21, 95% CI 2.01 to 5.11, absolute difference 57% (26% more to 74% more). Pain and function were not reported. Low-quality evidence from a single trial comparing high-dose to low-dose colchicine indicates there may be little or no difference in benefit in terms of treatment success at 32 to 36 hours but more adverse events associated with the higher dose. Similarly, low-quality evidence from a single trial indicates there may also be little or no benefit of low-dose colchicine over NSAIDs in terms of treatment success and pain reduction at seven days, with a similar number of adverse events reported at four weeks follow-up. Reduction of inflammation, function of target joint and withdrawals due to adverse events were not reported in either of these trials, and pain was not reported in the high-dose versus low-dose colchicine trial. We were unable to estimate the risk of serious adverse events for most comparisons as there were few events reported in the trials. One trial (399 participants) reported three serious adverse (one in a participant receiving low-dose colchicine and two in participants receiving NSAIDs), due to reasons unrelated to the trial (low-quality evidence downgraded for bias and imprecision).

AUTHORS' CONCLUSIONS

We found low-quality evidence that low-dose colchicine may be an effective treatment for acute gout when compared to placebo and low-quality evidence that its benefits may be similar to NSAIDs. We downgraded the evidence for bias and imprecision. While both high- and low-dose colchicine improve pain when compared to placebo, low-quality evidence suggests that high-dose (but not low-dose) colchicine may increase the number of adverse events compared to placebo, while low-quality evidence indicates that the number of adverse events may be similar with low-dose colchicine and NSAIDs. Further trials comparing colchicine to placebo or other treatment will likely have an important impact on our confidence in the effect estimates and may change the conclusions of this review. There are no trials reporting the effect of colchicine in populations with comorbidities or in comparison with other commonly used treatments, such as glucocorticoids.

Electronic patient-reported outcome measures using mobile health technology in rheumatology: A scoping review

OBJECTIVE

This scoping review aims to characterize the current literature on electronic patient-reported outcome measures (ePROMs) in rheumatology and assess the feasibility and utility of ePROMs and mobile health technology in the management of rheumatic disease.

INTRODUCTION

Patient-reported outcome measures (PROMs) are commonly used in rheumatology as they are important markers of disease activity and overall function, encourage shared decision-making, and are associated with high rates of patient satisfaction. With the widespread use of mobile devices, there is increasing interest in the use of mobile health technology to collect electronic PROMs (ePROM).

INCLUSION CRITERIA

All primary studies that involve the collection of ePROMs using mobile devices by individuals with a rheumatic disease were included. Articles were excluded if ePROMs were measured during clinic appointments.

METHODS

A scoping review was performed using Medline, Embase, PsycINFO, and CINAHL with index terms and key words related to "patient-reported outcome measures", "rheumatic diseases", and "mobile health technology".

RESULTS

A total of 462 records were identified after duplicates were removed. Of the 70 studies selected for review, 43% were conference proceedings and 57% were journal articles, with the majority published in 2016 or later. Inflammatory arthritis was the most common rheumatic disease studied. Generic ePROMs were used over three times more often than disease-specific ePROMs. A total of 39 (56%) studies directly evaluated the feasibility of ePROMs in clinical practice, 19 (27%) were clinical trials that used ePROMs as study endpoints, 9 (13%) were focus groups or surveys on smartphone application development, and 3 (4%) did not fit into one defined category.

CONCLUSION

The use of ePROMs in rheumatology is a growing area of research and shows significant utility in clinical practice, particularly in inflammatory arthritis. Further research is needed to better characterize the feasibility of ePROMs in rheumatology and their impact on patient outcomes.

Sonographic estimation of monosodium urate burden predicts the fulfillment of the 2016 remission criteria for gout: a 12-month study

Objective

To investigate whether baseline monosodium urate (MSU) burden estimated by ultrasound (US) predicts the achievement of the 2016 remission criteria for gout after 12 months.

Methods

In this 12-month prospective, observational and single-center study, patients with gout fulfilling all the domains of the 2016 preliminary remission criteria for gout at baseline and on urate-lowering therapy (ULT) for at least the preceding 6 months were consecutively enrolled.

The US findings indicative of MSU deposits [aggregates, double contour (DC) sign, and/or tophi] were identified according to the Outcome Measure in Rheumatology US Working Group definitions.

The US MSU burden was estimated by evaluating elbows, wrists, 2nd metacarpophalangeal joints, knees, ankles, and 1st metatarsophalangeal joints.

Results

Remission criteria were fulfilled in 21 (42.0%) out of 50 patients at 12 months. The baseline US MSU burden was significantly lower in patients who achieved remission than in those who did not fulfill the remission criteria at 12 months (1.9±1.8 vs 5.1±3.1, p<0.01).

US scores and ongoing flare prophylaxis were the only significant predictors of remission with an odds ratio of 10.83 [(95%CI=1.14–102.59), p=0.04] for the absence of MSU deposits, 5.53 [(95%CI=1.34–22.76), p<0.01] for the absence of aggregates, 7.33 [(95%CI=1.71–31.44), p<0.01] for the absence of DC sign, 3.88 [(95%CI=1.08–13.92), p=0.04] for the absence of tophi, and 0.23 [(95%CI=0.07–0.75), p=0.02] for ongoing flare prophylaxis.

Conclusion

In gout, baseline US estimation of MSU burden is an independent predictor of the achievement of the remission criteria at 12 months.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02568-x.

Patient-Centered Outcomes and Key Study Procedure Finalization in the Pilot Feasibility Gout Randomized Trial: Comparative Feasibility Study in GOUt, CHerry Extract Versus Diet Modification (Mini-GOUCH)

OBJECTIVE

The aim of this study was to report patient-centered outcomes and finalization of key study procedures from a 9-month pilot internet randomized controlled trial of cherry extract versus diet modification.

METHODS

We randomized 84 people with physician-confirmed gout in an internet study to cherry extract (n = 41) or dietitian-assisted diet modification for gout (n = 43). All study outcomes were collected via internet and phone calls. We finalized key study procedures. We assessed acceptability and feasibility of the intervention and satisfaction with study website.

RESULTS

Study participant satisfaction with the intervention was high. The intervention was perceived as easy, enjoyable, understandable, and helpful (scores 65-88 for all; higher = better). The amount of time spent for the study was acceptable. Participant satisfaction with website interaction and content was very high; 85% or more were moderately to extremely satisfied. Significantly lower total calories, total carbohydrate, and saturated fat intake were noted at 6 months in the diet modification versus cherry extract group; differences were insignificant at 9 months. Six of the 8 Health Assessment Questionnaire sections/domains improved significantly from baseline to 9 months in cherry extract versus 2 Health Assessment Questionnaire sections/domains in the diet modification group. Key study procedures were finalized for a future trial, including an internet diet assessment tool, gout flare assessment, provider confirmation of gout diagnosis, patient reporting of classification criteria, and centralized laboratory-assisted serum urate testing.

CONCLUSIONS

High patient acceptability and feasibility of study/intervention and finalization of key study procedures indicate that hypothesis-testing internet gout trials of cherry extract and/or diet modification can be conducted in the future.

Use of the Gout Impact Scale to Evaluate Quality of Life in Chinese Subjects with Gout: A Cross-Sectional Study

BACKGROUND To use a gout-specific quality of life (QoL) tool, the Gout Impact Scale (GIS), to evaluate characteristics of gout affecting QoL in subjects with gout. MATERIAL AND METHODS In this cross-sectional study, 169 individuals with gout completed the 24-item GIS and a general questionnaire regarding gout characteristics. The reliability and validity of the GIS were verified by Cronbach's a and exploratory factor analysis, respectively. The impact of gout characteristics on the QoL of subjects with gout was assessed by stepwise multiple regression analysis. RESULTS The 169 subjects with gout included 149 (88.2%) men and 20 (11.8%) women, of median age 43 years. The reliability of the GIS was appropriate (0.84-0.90), except for Gout Medication Side Effects (0.69) and Unmet Gout Treatment Need (0.59). Exploratory factor analysis showed that construct validity was acceptable, with a cumulative variance contribution rate of 5 common factors of 70.09% and factor loading >0.5 between each pair of items of the GIS. Univariate analysis showed that male sex was positively correlated with Well-being During Attack (p<0.05), and that source of medical expenses, current cigarette use and drinking were significantly correlated with Unmet Gout Treatment Need (p<0.05 each). A family history of gout, gout flares, and attack frequency were significantly correlated with total GIS, Well-being During Attack, and Gout Concern during Attack (p<0.05 each). Multivariate analysis suggested that history of gouty arthritis, acute attack and attack frequency had a considerable impact on QoL (p<0.05 each). CONCLUSIONS The GIS showed acceptable reliability and validity in identifying associations between poor QoL and gout characteristics.

Development of a multivariable improvement measure for gout

Background

Gout is a heterogeneous inflammatory disease with numerous clinical manifestations. A composite means to assess the impact of therapy on numerous aspects of gout could be useful.

Methods

Results from patients treated with pegloticase or placebo in two randomized clinical trials and their open-label extension were assessed using a novel evidence-based Gout Multivariable Improvement Measure (GMIM) derived from previously reported criteria for remission and complete response. Improvement was defined as serum urate (sU) < 6 mg/dL and absence of flares during the preceding 3 months plus 20, 50, and 70% improvement in tophus size, patient global assessment, pain, and swollen and tender joints.

Results

Patients treated with pegloticase manifested a significantly greater GMIM20, 50, and 70 response vs those treated with placebo (GMIM20 at 6 months 37.1% vs 0%, respectively). Higher response rates were significantly more frequent in subjects with persistent urate lowering (GMIM 58.1% at 6 months) in response to pegloticase versus those with only transient urate lowering (GMIM 7.1% at 6 months). However, when the requirement for a decrease in sU to < 6 mg/dL was omitted, a substantial percentage of subjects with transient urate lowering met the GMIM clinical criteria. A sensitivity analysis indicated that gout flares contributed minimally to the model. The response measured by GMIM persisted into the open-level extension for as long as 2 years. Finally, subjects who received placebo in the randomized control trials, but pegloticase in the open-label extension, manifested GMIM responses comparable to that noted with pegloticase-treated subjects in the randomized controlled trials.

Conclusions

GMIM captures changes in disease activity in response to treatment with pegloticase and may serve as an evidence-based tool for assessment of responses to other urate-lowering therapies in gout patients.

A Randomized Internet-Based Pilot Feasibility and Planning Study of Cherry Extract and Diet Modification in Gout

OBJECTIVE

The aim of this study was to conduct a 9-month pilot Internet randomized controlled trial (RCT) of cherry extract and diet modification in gout to assess the feasibility of an Internet study and obtain effect estimates.

METHODS

After providing online informed consent in response to Internet advertisements and social media or clinic flyers, 84 people with physician-confirmed gout were randomized to either cherry extract 3,600 mg/d (n = 41) or dietitian-assisted diet modification for gout (n = 43). All study outcomes were collected via Internet and phone calls. The primary objective was the feasibility of an Internet study, and secondary objectives were to obtain effect estimates for gout flares, functional ability assessed with the Health Assessment Questionnaire (HAQ), and adverse events (AEs) for future trials.

RESULTS

Of the 84 people randomized, overall completion rates were more than 80% for most study procedures up to 6 months and similar for the 2 active comparators. Improvements were seen in gout flares and HAQ scores in cherry extract and diet modification groups at 9 months compared with baseline: gout flares per month, 0.22 versus 0.36 (p = 0.049) and 0.28 versus 0.31 (p = 0.76); proportion with any gout flare, 56% versus 98% (p < 0.0001) and 65% versus 98% (p = 0.0002); and mean ± standard deviation HAQ score, 0.28 ± 0.54 versus 0.55 ± 0.68 (p = 0.001) and 0.23 ± 0.40 versus 0.48 ± 0.61 (p = 0.06), respectively. Any AEs and gastrointestinal symptoms/AEs at 9 months in cherry extract and diet modification groups were 3% versus 0% and 28% versus 27%, respectively.

CONCLUSIONS

An Internet gout RCT is feasible for nonpharmacological gout treatments. A hypothesis-testing, large Internet RCT of cherry extract versus placebo is needed.

The challenges of gout flare reporting: mapping flares during a randomized controlled trial

Background

Methods of gout flare reporting in research settings are inconsistent and poorly defined. The aim of this study was to describe patterns of gout flare and assess the concurrent validity of different methods of flare reporting in a gout clinical trial.

Methods

Daily flare diary entries including self-report of flare and pain scale from a randomised controlled trial of 120 patients with gout were analysed. Detailed pain-by-time plots for each participant were inspected and analysed for different methods of flare reporting for both self-report and the classification tree (CART)-defined flare developed by Gaffo in 2012. Concurrent validity for different methods of flare reporting were analysed.

Results

Although the single gout flare had a 'typical' average pattern (peak on day 1 and resolution over 14 days), individual pain-by-time plots showed wide variation in pain intensity, duration and frequency of flares. Over the four-month study period, there were 84/120 (70%) participants who experienced at least one self-reported flare that was not a 'typical' flare. The time to first self-reported flare correlated poorly with other measures of gout activity and other methods of flare reporting. The number of days with flare (either self-reported or Gaffo-defined) and the area under the pain-by-time curve correlated most strongly with other measures of disease severity.

Conclusion

There is wide variation in the patterns of flare over time in individuals with gout, leading to challenges for flare reporting in clinical trials. Time-dependent reporting strategies such as number of days with flare or area under the pain-by-time curve correlate well with other measures of gout disease severity and may provide a more accurate measure of flare burden.

Trial registration

Clinical trial number: ACTRN12609000479202, registered 17/06/2009.

Concurrent validity of provisional remission criteria for gout: a dual-energy CT study

Background

Provisional gout remission criteria including five domains (serum urate, tophus, flares, pain due to gout, and patient global assessment) have been proposed. The aim of this study was to test the concurrent validity of the provisional gout remission criteria by comparing the criteria with dual-energy CT (DECT) findings.

Methods

Patients with gout on allopurinol ≥ 300 mg daily were prospectively recruited into a multicenter DECT study. Participants attended a standardized study visit which recorded gout flare frequency in the preceding 12 months, physical examination for tophus, serum urate, and patient questionnaires. DECT scans of both hands/wrists, feet/ankles/Achilles, and knees were analyzed by two DECT radiologists. The relationship between the DECT urate crystal volume and deposition with individual domains as well as the provisional remission criteria set was analyzed.

Results

The provisional remission criteria were fulfilled in 23 (15.1%) participants. DECT urate crystal deposition was observed less frequently in those fulfilling the provisional remission criteria (44%), compared with those not fulfilling the criteria (73.6%, odds ratio 0.28, P = 0.004). The median (range) DECT urate crystal volume was 0.00 (0.00–0.46) cm³ for those fulfilling the remission criteria, compared with 0.08 (0.00–19.53) cm³ for those not fulfilling the criteria (P = 0.002). In multivariate regression analysis, the serum urate and tophus domains were most strongly associated with DECT urate crystal deposition.

Conclusions

In people with gout established on allopurinol, a state of remission as defined by the provisional remission criteria is associated with less DECT urate crystal deposition. While this study provides support for the validity of the provisional gout remission criteria, it also demonstrates that some crystal deposition may be present in people achieving these criteria.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1941-8) contains supplementary material, which is available to authorized users.

Validity and reliability of the Gout Impact Scale in a multi-ethnic Asian population

OBJECTIVES

The emphasis on capturing patient-reported outcomes (PRO) is increasing, but gout-specific PRO are lacking. We evaluated the reliability and validity of the 24-item Gout Impact Scale (GIS) of the Gout Assessment Questionnaire 2.0 (GAQ2.0) in a multi-ethnic Asian population.

METHODS

Participants with gout in an academic medical center in Singapore completed the GIS which comprises five scales. Confirmatory factor analyses (CFA) were performed. Known-groups validity, divergent validity and internal consistency were evaluated.

RESULTS

We analyzed data of 267 participants (mean [SD] age 52.2 [16.08] years, 92.1% men and 76.0% Chinese). CFA based on the original GIS factor structure had good model fit based on Tucker-Lewis Index (TLI) of 0.946 but not when based on Root Mean Square Error Of Approximation (RMSEA), which was 0.123 (90% CI: 0.116-0.130). Internal consistency of GIS exceeded 0.7 in all except one scale, consistent with previous studies. Hypotheses related to known-groups validity were largely supported. Scores were significantly higher (ie greater impact) for participants reporting at least some problem on the EQ-5D-3L anxiety/ depression item across all GIS scales. Correlations between RAND-36 Physical Functioning (PF) scale and all five scales in the GIS were poor (Spearman rank correlation coefficients: -0.2355 to 0.0426), implying that GIS does not measure impact of gout on physical health.

CONCLUSION

The GIS is valid and reliable for assessing gout-specific psychosocial functioning in a multi-ethnic Asian population.

Effects of a footwear intervention on foot pain and disability in people with gout: a randomised controlled trial

BACKGROUND

There is limited evidence supporting the long-term effect of a foot care package that includes footwear for people with gout. The aim of this study was to investigate the effectiveness of a footwear intervention on foot pain and disability in people with gout over 6 months.

METHODS

Participants with gout (n = 94) were randomly allocated to either a control group (podiatric care and gout education) or footwear intervention group (podiatric care and gout education plus a commercially available athletic shoe). Measurements were undertaken at baseline and 2, 4, and 6 months. Primary outcome was foot pain severity. Secondary outcomes were overall pain, foot impairment/disability, footwear comfort, fit, ease and weight. Data were analysed using repeated measures models.

RESULTS

Baseline foot pain scores were low, and no differences in foot pain scores were observed between groups over 6 months (adjusted effect estimate: - 6.7, 95% CI - 16.4 to 2.9, P = 0.17). Improvements between groups in overall pain scores (adjusted effect estimate: - 13.2, 95% CI - 22.2 to - 4.3, P < 0.01) and foot impairment/disability scores (- 4.7, 95% CI - 9.1 to - 0.3, P = 0.04) favouring the footwear intervention were observed at 2 months, but not at 4 or 6 months. Improvements between groups in footwear fit (adjusted effect estimate: - 11.1, 95% CI - 21.1 to - 1.0, P = 0.03), ease (- 13.2, 95% CI - 23.8 to - 2.7, P = 0.01) and weight (- 10.3, 95% CI - 19.8 to - 0.8, P = 0.03) favouring the footwear intervention were also observed over 6 months. Similar improvements were observed for footwear comfort at 2 and 4 months. No other differences in secondary outcomes measured were observed at 6 months (P > 0.05).

CONCLUSIONS

Addition of footwear to a foot care package did not improve foot pain in people with gout. Short-term improvements in overall pain and foot impairment/disability and more durable improvements in footwear comfort and fit were observed with the footwear intervention.

TRIAL REGISTRATION

ACTRN12614000209695. Registered 27 February 2014, http://www.anzctr.org.au/TrialSearch.aspx?searchTxt=ACTRN12614000209695&isBasic=True.

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

Background

Gout is a common, monosodium urate crystal-driven inflammatory arthritis. Besides its clinical manifestations, patients often also suffer from pain, physical impairment, emotional distress and work productivity loss, as a result of the disease. Patient-reported outcome measures (PROMs) are commonly used to assess these consequences of the disease. However, current instrument endorsements for measuring such outcomes in acute and chronic gout clinical settings are based on limited psychometric evidence. The objective of this systematic literature review was to identify currently available PROMs for gout, and to critically evaluate their content and psychometric properties, in order to evaluate the current status regarding PROMs for use in gout patients.

Methods

Systematic literature searches were performed in the PubMed and EMBASE databases. The methodological quality of included papers was appraised using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist, and evaluation of measurement properties (reliability, responsiveness, construct validity, floor and ceiling effects) was done in accordance with published quality criteria. Item content was appraised by linking health concepts to the International Classification of Functioning Disability and Health (ICF) framework.

Results

In total, 13 PROMs were identified, of which three were targeted specifically at gout patients. The majority of the PROMs were rated positively for content validity. For most instruments, limited evidence was available for construct validity and reliability. Instruments to assess pain scored well on responsiveness and floor and ceiling effects, but not much is known about their reliability in gout.

Conclusions

The physical functioning subscale of the SF-36v2 (Short Form-36 item version 2) is the only PROM that had sufficient supporting evidence for all its psychometric properties. Many of the commonly used PROMs in gout are currently not yet well supported and more studies on their measurement properties are needed among both acute and chronic gout populations.

Electronic supplementary material

The online version of this article (10.1186/s12955-019-1125-x) contains supplementary material, which is available to authorized users.

Clinical characteristics of infectious ulceration over tophi in patients with gout

Objective The aim of this study was to investigate the clinical characteristics of infectious ulceration over tophi in patients with gout. Methods Participants were recruited from the First Affiliated Hospital of Wenzhou Medical University. The clinical characteristics of the patients and wound characteristics were recorded. Results Of the 38 enrolled patients, 18 were found to have infectious ulceration over tophi. Staphylococcus aureus was the most common pathogen and was identified in nine patients. Patients with infection were significantly older (69.6 vs. 60.1 years) and had a worse quality of life than those without infection. Patients with infection also had a significantly longer ulcer duration (125.6 vs. 54.2 days), larger ulcer size (2.47 vs. 1.99 cm²), a higher rate of tissue necrosis in the ulcer bed (55.6% vs. 20.0%), a lower rate of callus at the edge (27.8% vs. 70.0%), and a higher moisture level than did patients without infection. Additionally, patients with infection had significantly delayed wound healing (35.3 vs. 20.3 days) compared with patients without infection. Conclusions Older patients with a long ulcer duration and larger ulcer size are more susceptible to infection. Infection can lower patients' quality of life and delay wound healing.

How Can We Improve Disease Education in People with Gout?

PURPOSE OF REVIEW

Gout management is currently suboptimal despite excellent available therapy. Gout patient education has been shown to enhance medication adherence and self-management, but needs improvement. We explored the literature on gout patient education including gaps in gout patient knowledge; use of written materials; in-person individual and group sessions; education via nurses, pharmacists, or multi-disciplinary groups; and use of phone, web-based, mobile health app, and text messaging educational efforts.

RECENT FINDINGS

Nurse-led interventions have shown significant improvement in reaching urate goals. Pharmacist-led programs have likewise succeeded, but to a lesser degree. A multi-disciplinary approach has shown feasibility. Needs-assessments, patient questionnaires, and psychosocial evaluations can enhance targeted education. An interactive and patient-centered approach can enhance gout educational interventions. Optimal programs will assess for and address educational needs related to knowledge gaps, health literacy, race, gender, socio-economic status, and level of social support.

Health-related quality of life in gout in primary care: Baseline findings from a cohort study

Objectives

To examine gout-related, comorbid, and sociodemographic characteristics associated with generic and disease-specific health-related quality of life (HRQOL) in gout.

Methods

Adults with gout from 20 general practices were mailed a questionnaire containing the Health Assessment Questionnaire-Disability Index (HAQ-DI), Short-Form-36 Physical Function subscale (PF-10), Gout Impact Scale (GIS), and questions about gout-specific, comorbid and sociodemographic characteristics. Variables associated with HRQOL were examined using multivariable linear regression models.

Results

A total of 1184 completed questionnaires were received (response 65.9%). Worse generic and gout-specific HRQOL was associated with frequent gout attacks (≥5 attacks PF-10 β = −4.90, HAQ-DI β = 0.14, GIS subscales β = 8.94, 33.26), current attack (HAQ-DI β = 0.15, GIS β = −1.94, 18.89), oligo/polyarticular attacks (HAQ-DI β = 0.11, GIS β = 0.78, 7.86), body pain (PF-10 β = −10.68, HAQ-DI β = 0.29, GIS β = 2.61, 11.89), anxiety (PF-10 β = −1.81, HAQ-DI β = 0.06, GIS β = 0.38, 1.70), depression (PF-10 β = −1.98, HAQ-DI β = 0.06, GIS 0.42, 1.47) and alcohol non-consumption (PF-10 β = −16.10, HAQ-DI β = 0.45). Gout-specific HRQOL was better in Caucasians than non-Caucasians (GIS β = −13.05, −13.48). Poorer generic HRQOL was associated with diabetes mellitus (PF-10 β = −4.33, HAQ-DI β = 0.14), stroke (PF-10 β = −12.21, HAQ-DI β = 0.37), renal failure (PF-10 β = −9.43, HAQ-DI β = 0.21), myocardial infarction (HAQ-DI β = 0.17), female gender (PF-10 β = −17.26, HAQ-DI β = 0.43), deprivation (PF-10 β = −7.80, HAQ-DI β = 0.19), and body mass index ≥35 kg/m² (PF-10 β = −6.10, HAQ-DI β = 0.21).

Conclusions

HRQOL in gout is impaired by gout-specific, comorbid, and sociodemographic characteristics, highlighting the importance of comorbidity screening and early urate-lowering therapy. Both gout-specific and generic questionnaires identify the impact of disease-specific features on HRQOL but studies focusing on comorbidity should include generic instruments.

What Outcomes are Important for Gout Patients? In-Depth Qualitative Research into the Gout Patient Experience to Determine Optimal Endpoints for Evaluating Therapeutic Interventions

Background and Objectives

Characterized by sudden onset of severe joint pain, swelling, redness, and tenderness to touch, gout ‘flare ups’ have a substantial impact on quality of life (QoL). This research employed a patient-centered approach to explore the symptoms and impacts of gout, and assess the content validity of existing patient-reported outcomes (PROs).

Methods

Qualitative interviews were conducted with 30 US gout patients (non-tophaceous: n = 20, tophaceous: n = 10) and five expert rheumatologists. Each interview included both concept elicitation (CE) questioning to learn about the patient experience and cognitive debriefing to assess the content validity of three PRO instruments (HAQ-DI, GAQ, and TIQ-20). Nine of the patients provided further real-time qualitative data through a smart phone application. All qualitative data were subject to thematic analysis using Atlas.ti. Two patient advisors and three expert clinicians were engaged as advisors at key stages throughout the research.

Results

Interview and real-time data identified the same core symptoms and proximal impact concepts. Severe pain (typically in joints of extremities) was described as the cardinal symptom, often accompanied by swelling, redness, heat, sensitivity to touch, and stiffness. Domains of QoL impacted included physical functioning, sleep, daily activities, and work. The PRO instruments were generally well-understood by patients, but each included items with questionable relevance to at least some of the sample, dependent on the specific joints affected.

Conclusions

Gout patients experience severe pain in affected joints, resulting in substantial limitations in physical functioning. Both the HAQ-DI and the TIQ-20 are useful for specific research purposes in the gout population, although modifications are recommended.

Electronic supplementary material

The online version of this article (doi:10.1007/s40271-016-0184-x) contains supplementary material, which is available to authorized users.

Associated factors with functional disability and health-related quality of life in Chinese patients with gout: a case-control study

Background

Gout is a painful, inflammatory disease that may cause decreased function and health-related quality of life (HRQoL). Limited study did not take the influence of gout characteristics and anxiety on HRQoL into consideration and there are no studies associated with functional disability in individuals with gout from China. This study aims to investigate the related factors of functional disability and HRQoL in gout patients recruited from China.

Methods

A total of 226 consecutive gout patients and 232 age- and gender-matched healthy individuals were involved in the study. A series of questionnaires (the Short Form 36 health survey, the Patient Health Questionnaire, the Generalized Anxiety Disorder questionnaire, the 10 cm Visual Analog Scale, and the Health Assessment Questionnaire-Disability Index) were applied. Blood samples were taken to examine the level of serum uric acid. Independent samples t-tests, Chi square tests, U test, Spearman rank correlation, logistic regression modeling, and linear regression were used to analyze the data.

Results

After adjusted demographic variables, individuals with gout have poorer HRQoL compared to healthy controls. Univariate tests presented that patients with functional disability had longer disease duration, more frequent flares/last year, more severe total pain, more number of tophi, higher degree of depression and anxiety, with a trend toward diabetes, the treatment of colchicine and corticosteroids use, compared to patients without functional disability. Meanwhile, place of residence, hypertension, DM, disease duration, cardiovascular disease, number of flares/last year, total pain, more number of tophi, presence of tender joints, depression, anxiety, currently using colchicine and corticosteroids were correlated significantly with HRQoL. Additionally, multiple regression analysis identified severe pain, depression, and colchicine use as predictors of functional disability. Cardiovascular disease, total pain, number of flares/last year, presence of tender joints, depression, anxiety, colchicine and corticosteroids use contributed to low HRQoL.

Conclusions

After adjusted demographic variables, gout subjects have poorer HRQoL compared to healthy controls. Chinese gout population experiencing poor HRQoL and functional disability were likely to suffer from gout-related features and psychological problems. The results underscore the need of effective interventions including psychological nursing and appropriate treatment approaches to reduce their functional disability and improve their HRQoL.

Weight loss for overweight and obese individuals with gout: a systematic review of longitudinal studies

OBJECTIVES

Weight loss is commonly recommended for gout, but the magnitude of the effect has not been evaluated in a systematic review. The aim of this systematic review was to determine benefits and harms associated with weight loss in overweight and obese patients with gout.

METHODS

We searched six databases for longitudinal studies, reporting the effect of weight loss in overweight/obese gout patients. Risk of bias was assessed using the tool Risk of Bias in Non-Randomised Studies of Interventions. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

From 3991 potentially eligible studies, 10 were included (including one randomised trial). Interventions included diet with/without physical activity, bariatric surgery, diuretics, metformin or no intervention. Mean weight losses ranged from 3 kg to 34 kg. Clinical heterogeneity in study characteristics precluded meta-analysis. The effect on serum uric acid (sUA) ranged from -168 to 30 μmol/L, and 0%-60% patients achieving sUA target (<360 μmol/L). Six out of eight studies (75%) showed beneficial effects on gout attacks. Two studies indicated dose-response relationship for sUA, achieving sUA target and gout attacks. At short term, temporary increased sUA and gout attacks tended to occur after bariatric surgery.

CONCLUSIONS

The available evidence is in favour of weight loss for overweight/obese gout patients, with low, moderate and low quality of evidence for effects on sUA, achieving sUA target and gout attacks, respectively. At short term, unfavourable effects may occur. Since the current evidence consists of a few studies (mostly observational) of low methodological quality, there is an urgent need to initiate rigorous prospective studies (preferably randomised controlled trials).

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42016037937.

Development of Preliminary Remission Criteria for Gout Using Delphi and 1000Minds Consensus Exercises

OBJECTIVE

To establish consensus for potential remission criteria to use in clinical trials of gout.

METHODS

Experts (n = 88) in gout from multiple countries were invited to participate in a web-based questionnaire study. Three rounds of Delphi consensus exercises were conducted using SurveyMonkey, followed by a discrete-choice experiment using 1000Minds software. The exercises focused on identifying domains, definitions for each domain, and the timeframe over which remission should be defined.

RESULTS

There were 49 respondents (56% response) to the initial survey, with subsequent response rates ranging from 57% to 90%. Consensus was reached for the inclusion of serum urate (98% agreement), flares (96%), tophi (92%), pain (83%), and patient global assessment of disease activity (93%) as measurement domains in remission criteria. Consensus was also reached for domain definitions, including serum urate (<0.36 mm), pain (<2 on a 10-point scale), and patient global assessment (<2 on a 10-point scale), all of which should be measured at least twice over a set time interval. Consensus was not achieved in the Delphi exercise for the timeframe for remission, with equal responses for 6 months (51%) and 1 year (49%). In the discrete-choice experiment, there was a preference towards 12 months as a timeframe for remission.

CONCLUSION

These consensus exercises have identified domains and provisional definitions for gout remission criteria. Based on the results of these exercises, preliminary remission criteria are proposed with domains of serum urate, acute flares, tophus, pain, and patient global assessment. These preliminary criteria now require testing in clinical data sets.

Clinically-evident tophi are associated with reduced muscle force in the foot and ankle in people with gout: a cross-sectional study

Background

The foot and ankle represent a common site for tophi in people with gout, yet it is unclear whether the presence of tophi is related to impaired muscle function. This study aimed to determine the association between foot and ankle tophi and muscle force in people with gout.

Methods

Participants with gout were stratified into two groups based on the presence of clinically-evident tophi affecting the foot or ankle on physical examination. Isometric muscle force for plantarflexion, dorsiflexion, inversion and eversion was measured using static dynamometry. Mixed-models regression was used to determine the difference in muscle force between the two groups while adjusting for age, disease duration and foot pain. This model was also used to determine the difference in muscle force between presence and absence of tophi at specific locations within the foot and ankle. In addition, Pearson’s correlations were used to determine the association between total foot tophus count and muscle force.

Results

Fifty-seven participants were included (22 with foot or ankle tophi and 35 without foot or ankle tophi). Foot and ankle tophi were most often seen at the Achilles tendon. After adjusting for age, disease duration and foot pain, participants with tophi had significantly reduced muscle force during plantarflexion (P < 0.001), dorsiflexion (P = 0.003), inversion (P = 0.003) and eversion (P = 0.001) when compared to participants without tophi. Those with Achilles tophi had significantly reduced force during plantarflexion (P < 0.001), inversion (P = 0.008) and eversion (P = 0.001). No significant differences in muscle force were observed between the presence and absence of tophi at other foot or ankle locations. There were also no significant correlations between total foot tophus count and muscle force (all P > 0.05).

Conclusion

In people with gout, clinically-evident foot or ankle tophi are associated with muscle force deficits during foot plantarflexion, dorsiflexion, inversion and eversion, which persist despite adjusting for age, disease duration and foot pain. Tophi at the Achilles tendon, which associate with force deficits, may contribute to reduced muscular activation and consequent disuse muscle atrophy.

Consensus on draft OMERACT core domains for clinical trials of Total Joint Replacement outcome by orthopaedic surgeons: a report from the International consensus on outcome measures in TJR trials (I-COMiTT) group

BACKGROUND

There are no core outcome domain or measurement sets for Total Joint Replacement (TJR) clinical trials. Our objective was to achieve an International consensus by orthopaedic surgeons on the OMERACT core domain/area set for TJR clinical trials.

METHODS

We conducted surveys of two orthopaedic surgeon cohorts, which included (1) the leadership of international orthopaedic societies and surgeons (IOS; cohort 1), and (2) the members of the American Academy of Orthopaedic Surgeons' Outcome Special Interest Group (AAOS-Outcome SIG), and/or the Outcome Research Interest Group of the Orthopaedic Research Society (ORS; cohort 2). Participants rated OMERACT-endorsed preliminary core area set for TJR clinical trials on a 1 to 9 scale, indicating 1-3 as domain of limited importance, 4-6 being important, but not critical, and 7-9 being critical.

RESULTS

Eighteen survey participants from the IOS group and 69 participants from the AAOS-Outcome SIG/ORS groups completed the survey questionnaire. The median (interquartile range [IQR]) scores were seven or higher for all six proposed preliminary core areas/domains across both groups, IOS and AAOS-Outcome SIG/ORS, respectively: pain, 8 [8, 9] and 8 [7, 9]; function, 8 [8, 8] and 8 [7, 9]; patient satisfaction, 8 [7, 9] and 8 [7, 8]; revision surgery, 7 [6, 9] and 8 [6, 8]; adverse events, 7 [5, 8] and 7 [6, 9]; and death, 7 [7, 9] and 8 [5, 9]. Respective median scores were lower for two additional optional domains: patient participation, 6.5 [5, 7] and 6 [5, 8]; and cost, 6 [5, 7] and 6 [5, 7].

CONCLUSIONS

This study showed that two independent surveys dervied from three groups of orthopaedic surgeons with international representation endorsed a preliminary/draft OMERACT core domain/area set for Joint Replacement clinical trials.

Racial differences in health-related quality of life and functional ability in patients with gout

OBJECTIVE

To compare the health-related quality of life (HRQOL) and the functional ability by race in patients with gout.

METHODS

In a 9-month prospective cohort multicentre study, patients with gout self-reported race, dichotomized as Caucasian or African American (others excluded). We calculated HRQOL/function scores adjusted for age, study site and college education for Short Form-36 (SF-36; generic HRQOL), Gout Impact Scale (GIS; disease-specific HRQOL) and HAQ-disability index (HAQ-DI; functional ability). Longitudinally adjusted scores were computed using multivariable mixed-effect regression models with a random patient effect and fixed sequential visit effect (3-monthly visits).

RESULTS

Compared with Caucasians (n = 107), African Americans (n = 60) with gout were younger (61.1 vs 67.3 years) and had higher median baseline serum urate (9.0 vs 7.9 mg/dl) (P < 0.01). African Americans with gout had worse HRQOL scores on three SF-36 domains, the mental component summary (MCS) and two of the five GIS scales than Caucasians [mean (se); P ⩽ 0.02 for all]: SF-36 mental health, 39.7 (1.1) vs 45.2 (0.9); SF-36 role emotional, 42.1 (4.2) vs 51.4 (4.2); SF-36 social functioning, 36.0 (1.1) vs 40.0 (0.9) (P = 0.04); SF-36 MCS, 43.2 (3.1) vs 50.0 (3.2); GIS unmet treatment need, 37.6 (1.6) vs 31.5 (1.4); and GIS concern during attacks, 53.3 (3.7) vs 47.4 (3.7). Differences between the respective HAQ-DI total scores were not statistically significant; 0.98 (0.1) vs 0.80 (1.0) (P = 0.11). Racial differences in SF-36 mental health, role emotional and MCS scales exceeded, and for HAQ-DI approached, the minimal clinically important difference thresholds.

CONCLUSIONS

African Americans with gout have significantly worse HRQOL compared with Caucasians. Further research is necessary in the form of studies targeted at African Americans on how best to improve these outcomes.

Treat-to-target (T2T) recommendations for gout

OBJECTIVES

The treat-to-target (T2T) concept has been applied successfully in several inflammatory rheumatic diseases. Gout is a chronic disease with a high burden of pain and inflammation. Because the pathogenesis of gout is strongly related to serum urate levels, gout may be an ideal disease in which to apply a T2T approach. Our aim was to develop international T2T recommendations for patients with gout.

METHODS

A committee of experts with experience in gout agreed upon potential targets and outcomes, which was the basis for the systematic literature search. Eleven rheumatologists, one cardiologist, one nephrologist, one general practitioner and one patient met in October 2015 to develop T2T recommendations based on the available scientific evidence. Levels of evidence, strength of recommendations and levels of agreement were derived.

RESULTS

Although no randomised trial was identified in which a comparison with standard treatment or an evaluation of a T2T approach had been performed in patients with gout, indirect evidence was provided to focus on targets such as normalisation of serum urate levels. The expert group developed four overarching principles and nine T2T recommendations. They considered dissolution of crystals and prevention of flares to be fundamental; patient education, ensuring adherence to medications and monitoring of serum urate levels were also considered to be of major importance.

CONCLUSIONS

This is the first application of the T2T approach developed for gout. Since no publication reports a trial comparing treatment strategies for gout, highly credible overarching principles and level D expert recommendations were created and agreed upon.

Development and First Validation of a Disease Activity Score for Gout

Objective

To develop a new composite disease activity score for gout and provide its first validation.

Methods

Disease activity has been defined as the ongoing presence of urate deposits that lead to acute arthritis and joint damage. Every measure for each Outcome Measures in Rheumatology core domain was considered. A 3‐step approach (factor analysis, linear discriminant analysis, and linear regression) was applied to derive the Gout Activity Score (GAS). Decision to change treatment or 6‐month flare count were used as the surrogate criteria of high disease activity. Baseline and 12‐month followup data of 446 patients included in the Kick‐Off of the Italian Network for Gout cohort were used. Construct‐ and criterion‐related validity were tested. External validation on an independent sample is reported.

Results

Factor analysis identified 5 factors: patient‐reported outcomes, joint examination, flares, tophi, and serum uric acid (sUA). Discriminant function analysis resulted in a correct classification of 79%. Linear regression analysis identified a first candidate GAS including 12‐month flare count, sUA, visual analog scale (VAS) of pain, VAS global activity assessment, swollen and tender joint counts, and a cumulative measure of tophi. Alternative scores were also developed. The developed GAS demonstrated a good correlation with functional disability (criterion validity) and discrimination between patient‐ and physician‐reported measures of active disease (construct validity). The results were reproduced in the external sample.

Conclusion

This study developed and validated a composite measure of disease activity in gout. Further testing is required to confirm its generalizability, responsiveness, and usefulness in assisting with clinical decisions.

Discrepancies in how the impact of gout is assessed in outcomes research compared to how health professionals view the impact of gout, using the lens of the International Classification of Functioning, Health and Disability (ICF)

The International Classification of Functioning, Disability and Health (ICF) provides a common language to understand what health means. An ICF core set, a list of ICF categories affected by a certain disease, is useful to objectify the content validity of a health status measurement. This study aims to identify the potential items of a gout specific 'ICF core set'. A three-round Delphi exercise was conducted, using web-based questionnaires. Health professionals, specialized in gout, nominated and subsequently rated the relevance of life areas divided into ICF categories. Agreement was determined by using the UCLA/RAND criteria. Simultaneously, a systematic review of gout measure outcomes was conducted. The results of these studies were compared using the second level of the ICF categories. In the Delphi study, consensus was found for 136 relevant ICF categories. The literature study extracted 134 different ICF categories in 149 articles. Three hundred and ten were non-defined outcomes. A large number of ICF categories were deemed to be relevant for people with gout. Only 29.7 % (19/64) of the level 2 categories, deemed to be relevant by health professionals, had been assessed as relevant in at least 5 % of gout outcome studies. Conversely, 70 % (19/27) of level 2 ICF categories assessed in at least 5 % of outcome studies were deemed relevant by health professionals. These ICF codes, which are found relevant in both studies, should be considered as mandatory in further research to a validated and practical core set of ICF categories. Published gout outcomes research fails to evaluate many life areas that are thought relevant by health professionals.

Surgical Management of Gout in the Foot and Ankle A Systematic Review

BACKGROUND

The surgical management of tophaceous gout has been well documented in the literature, including its effect on foot pain and disability. To date, there have been no systematic reviews assessing the quality of the literature relating to the operative management of tophaceous gout and the outcomes in the foot and ankle.

METHODS

The following electronic databases were searched (1980-2014): Allied and Complementary Medicine, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, Scopus, and the Cochrane Library. The articles identified were published in English and included adult participants (age ≥18 years) with diagnosed gout and surgical intervention to the foot and ankle. The Downs and Black Quality Index was modified to assess the quality of the articles being reviewed.

RESULTS

Six articles were reviewed and were of moderate quality (mean quality score of 71%). Surgical management was conducted on men (88%) with a mean age of 52 years. There was wide variation in the types of surgical procedures performed, with 28% of studies reporting surgery to the first metatarsophalangeal joint. Most studies were retrospective. A wide range of outcome measures were reported: foot pain, function, preoperative and postoperative activity levels, monitoring of uric acid levels, and patient satisfaction after surgery.

CONCLUSIONS

The review demonstrated a limited number of good-quality studies. Several surgical procedures for the foot and ankle in people with chronic tophaceous gout were reported. Future studies should include prospective observational studies using validated and reliable patient-reported outcome measures.

Clinical characteristics of foot ulceration in people with chronic gout

Gout is the most common form of inflammatory arthritis and it has an affliction to the foot. Foot involvement in gout has been linked to foot pain, impairment and disability. There has been limited research on the effect of ulceration on foot pain, impairment, disability and health-related quality of life in patients already living with gout. The aim of the study was to describe the wound characteristics and the effect on foot pain, disability and health-related quality of life in patients with foot ulceration associated with gout. Participants were recruited from rheumatology clinics in Auckland, New Zealand. All the current foot ulceration sites and wound characteristics were recorded using the TIME wound assessment tool. The outcome measures included general pain, patient global assessment scale, foot pain, disability and impairment. Participants completed the Cardiff Wound Impact Schedule to assess the effect of ulcers on health-related quality of life. Sensory loss, vibrational thresholds and ankle brachial pressure index were collated to assess for lower limb arterial disease. Six participants were predominantly older men with a long duration of gout, high rates of obesity and co-morbidities such as hypertension, hyperlipidaemia, diabetes and cardiovascular disease. The mean (SD) duration of the foot ulcers was 4 (2) months. The majority of foot ulcers observed were 0·5 cm(2) or smaller superficial thickness with surrounding callus. Partial thickness and full-thickness ulcers were also observed. Two patients presented with ulcers on multiple sites. There was only one case of infection. Gouty tophi were evident in most of the wounds. The dorsal aspect of the third toe was found to ulcerate in most cases. Moderate scores of foot pain, disability, impairment and health-related quality of life were observed. Most participants wore shoes deemed as poor. Foot ulceration in gout is chronic and multiple ulcers can occur with the potential of leading to delayed wound healing, infection and a reduced quality of life. Poor footwear may contribute to the development and delayed healing of ulceration in people with gout.

Performance of Gout Impact Scale in a longitudinal observational study of patients with gout

OBJECTIVE

The aim was to evaluate the reliability, validity and responsiveness to change of the Gout Impact Scale (GIS), a disease-specific measure of patient-reported outcomes, in a multicentre longitudinal prospective cohort of gout patients.

METHODS

Subjects completed the GIS, a 24-item instrument with five scales: Concern Overall, Medication Side Effects, Unmet Treatment Need, Well-Being during Attack, and Concern Over Attack. The total GIS score was calculated by averaging the GIS scale scores. HAQ-Disability Index (HAQ-DI), Short Form (SF)-36 physical and mental component summaries (PCS and MCS) and physician and patient gout severity assessments were also completed. Reliability was assessed with Cronbach's α. Baseline GIS scores were compared in subjects with and without gout attacks in the past 3 months using Wilcoxon rank sum tests. Multivariate linear regression was used to evaluate predictors of total GIS. Pearson's correlation coefficients 0.24-0.36 were considered moderate and >0.37 considered large. The effect size for responsiveness to change was interpreted as follows: 0.20-0.49 small, 0.50-0.79 medium and >0.79 large.

RESULTS

In 147 subjects, reliability was acceptable for total GIS (0.93) and all GIS scales (0.82-0.94) except Medication Side Effects and Unmet Treatment Need. Total GIS and all scales except Medication Side Effects discriminated between subjects with and without recent gout attacks (P < 0.05). Total GIS showed moderate-to-large correlations with HAQ-DI, SF-36 PCS and MCS (0.33-0.46). Improvement in total GIS tracked with improved physician and patient severity scores. Worsening physician severity score and recent gout attack predicted worsening total GIS.

CONCLUSION

Total GIS score is reliable, valid and responsive to change in patients with gout, and differentiates between subjects with and without recent gout attacks.

Computational Lexical Analysis of the Language Commonly Used to Describe Gout

OBJECTIVE

To characterize the current language that is used in describing and defining gout, its symptoms, and its treatment by reviewing recent publications in rheumatology and determining how word choice may, or may not, be reflective of recent scientific developments in gout specifically.

METHODS

This was a computational linguistics study, using collocations analyses and concordance analyses on a database of scientific literature related to gout. The final data set for analysis included 2,590 articles, all relating to gout and published between May 2003 and May 2013 and amounting to 12,101,036 tokens (sentence segments). Analysis was conducted by a team of linguists and social scientists.

RESULTS

Our primary finding is that current disease language in gout is marked by ambiguity and imprecision, as evidenced by numerous terms that have similar but distinct meanings, but are nevertheless used interchangeably, therefore blending the slight but significant distinctions between these words. Whereas treatment language is characterized by a multitude of terms to describe a therapeutic mechanism of action, there is a relative void of terms and phrases used to describe success (treating to target) in gout.

CONCLUSION

The data suggest that the language used to describe gout could be improved and updated. A transformation from an antiquated and insufficiently descript terminological set to one that reflects the recent scientific and clinical advancements made in the category would maximize opportunities for patient and physician understanding.

Patient-reported outcomes in core domain sets for rheumatic diseases

Patient-reported outcomes (PROs) are abundant in rheumatology and their numbers continue to increase. But which of the available measures are most important? Core outcome sets-including groups of domains and instruments for measuring them-have been defined for many rheumatic diseases, with the aim that all these outcomes should be measured in every clinical trial. The subgroup of PROs included in these core sets is, therefore, undoubtedly important. This Review summarizes the PROs included in core outcome sets developed for use in clinical trials across a wide range of rheumatic diseases. Three PROs are commonly utilized across the majority of rheumatic conditions: pain, physical functioning and the patient global assessment of disease activity. However, additional research is needed to fully understand the role of the patient global assessment of disease activity, to distinguish specific domains within the broad concept of health-related quality of life, and to work towards consensus on the choice between generic and disease-specific instruments in various contexts.

Experiences of gout-related disability from the patients' perspective: a mixed methods study

Disability is a common problem in patients with gout. Recently, the Health Assessment Questionnaire Disability Index (HAQ-DI) was recommended for assessing patient reported activity limitations in gout. However, few studies have explored experiences and issues of disability from the perspective of gout patients themselves. The objectives of this study were to explore disability issues in patients with gout and to examine the content validity of the HAQ-DI in this patient group. Two studies were performed: a semi-structured interview study with seven male gout patients and a cross-sectional survey study among 34 other patients with gout. In both studies, specific examples of activity limitations were elicited using open-ended methods. The survey study additionally aimed to quantify the relevance of the activities listed in the HAQ-DI. Most patients experienced several gout attacks in the previous year. Limitations were reported to occur during a flare, but patients were generally not limited between attacks. During an attack, patients mainly experienced limitations related to mobility, especially walking and climbing stairs. Patients also mentioned limitations in activities related to domestic life, such as gardening and doing housework. Limitations related to self-care or activities requiring the use of the upper extremities were rarely mentioned. Corresponding HAQ-DI items were skewed towards very low disability scores over the past week. Assessments of gout-related disability should particularly focus on mobility and lower extremity functioning and should consider the intermittent nature of the disease. The HAQ-DI may not adequately meet these requirements, suggesting the need to explore other measures of gout-related disability

Health-related quality of life and treatment satisfaction in patients with gout: results from a cross-sectional study in a managed care setting

BACKGROUND

Patient satisfaction with treatment directly impacts adherence to medication.

OBJECTIVE

The objective was to assess and compare treatment satisfaction with the Treatment Satisfaction Questionnaire for Medication (TSQM), gout-specific health-related quality of life (HRQoL) with the Gout Impact Scale (GIS), and generic HRQoL with the SF-12v2(®) Health Survey (SF-12) in patients with gout in a real-world practice setting.

METHODS

This cross-sectional mail survey included gout patients enrolled in a large commercial health plan in the US. Patients were ≥18 years with self-reported gout diagnosis, who filled ≥1 prescription for febuxostat during April 26, 2012 to July 26, 2012 and were not taking any other urate-lowering therapies. The survey included the TSQM version II (TSQM vII, score 0-100, higher scores indicate better satisfaction), GIS (score 0-100, higher scores indicate worse condition), and SF-12 (physical component summary and mental component summary). Patients were stratified by self-report of currently experiencing a gout attack or not to assess the discriminant ability of the questionnaires.

RESULTS

A total of 257 patients were included in the analysis (mean age, 54.9 years; 87% male). Patients with current gout attack (n=29, 11%) had worse scores than those without gout attack on most instrument scales. Mean differences between current attack and no current attack for the TSQM domains were: -20.6, effectiveness; -10.6, side effects; -12.1, global satisfaction (all P<0.05); and -6.1, convenience (NS). For the GIS, mean differences were: 30.5, gout overall concern; 14.6, gout medication side effects; 22.7, unmet gout treatment needs; 11.5, gout concern during attack (all P<0.05); and 7.9, well-being during attack (NS). Mean difference in SF-12 was -6.6 for physical component summary (P<0.05) and -2.9 for mental component summary (NS). Correlations between several TSQM and GIS scales were moderate.

CONCLUSION

The TSQM and GIS were complementary in evaluating the impact of gout flare on treatment satisfaction and HRQoL. Correlations between the two instruments supported the relationship between treatment satisfaction and HRQoL.

Uricosuric medications for chronic gout

BACKGROUND

Uricosuric agents have long been used in the treatment of gout but there is little evidence regarding their benefit and safety in this condition.

OBJECTIVES

To assess the benefits and harms of uricosuric medications in the treatment of chronic gout.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 4, 2013), Ovid MEDLINE and Ovid EMBASE for studies to the 13 May 2013. We also searched the World Health Organization Clinical Trials Registry, ClinicalTrials.gov and the 2011 to 2012 American College of Rheumatology and European League against Rheumatism abstracts. WE considered black box warnings and searched drug safety databases to identify and describe rare adverse events.

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) or quasi-randomised controlled trials (controlled clinical trials (CCTs)) that compared uricosuric medications (benzbromarone, probenecid or sulphinpyrazone) alone or in combination with another therapy (placebo or other active uric acid-lowering medication, or non-pharmacological treatment) in adults with chronic gout for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted data and performed a risk of bias assessment. Main outcomes were frequency of acute gout attacks, serum urate normalisation, study participant withdrawal due to adverse events, total adverse events, pain reduction, function and tophus regression.

MAIN RESULTS

The search identified four RCTs and one CCT that evaluated the benefit and safety of uricosurics for gout. One study (65 participants) compared benzbromarone with allopurinol for a duration of four months; one compared benzbromarone with allopurinol (36 participants) for a duration of nine to 24 months; one study (62 participants) compared benzbromarone with probenecid for two months and one study (74 participants) compared benzbromarone with probenecid. One study (37 participants) compared allopurinol with probenecid. No study was completely free from bias.Low-quality evidence from one study (55 participants) comparing benzbromarone with allopurinol indicated uncertain effects in terms of frequency of acute gout attacks (4% with benzbromarone versus 0% with allopurinol; risk ratio (RR) 3.58, 95% confidence interval (CI) 0.15 to 84.13), while moderate-quality evidence from two studies (101 participants; treated for four to nine months) indicated similar proportions of participants achieving serum urate normalisation (73.9% with benzbromarone versus 60% with allopurinol; pooled RR 1.27, 95% CI 0.90 to 1.79). Low-quality evidence indicated uncertain differences in withdrawals due to adverse events (7.1% with benzbromarone versus 6.1% with allopurinol; pooled RR 1.25, 95% CI 0.28 to 5.62), and total adverse events (20% with benzbromarone versus 6.7% with allopurinol; RR 3.00, 95% CI 0.64 to 14.16). The study did not measure pain reduction, function and tophus regression.When comparing benzbromarone with probenecid, there was moderate-quality evidence based on one study (62 participants) that participants taking benzbromarone were more likely to achieve serum urate normalisation after two months (81.5% with benzbromarone versus 57.1% with probenecid; RR 1.43, 95% CI 1.02 to 2.00). This indicated that when compared with probenecid, five participants needed to be treated with benzbromarone in order to have one additional person achieve serum urate normalisation (number needed to treat for an additional beneficial outcome (NNTB) 5). However, the second study reported no difference in the absolute decrease in serum urate between these groups after 12 weeks. Low-quality evidence from two studies (129 participants) indicated uncertain differences between treatments in the frequency of acute gout attacks (6.3% with benzbromarone versus 10.6% with probenecid; pooled RR 0.73, 95% CI 0.09 to 5.83); fewer withdrawals due to adverse events with benzbromarone (2% with benzbromarone versus 17% with probenecid; pooled RR 0.15, 95% CI 0.03 to 0.79, NNTB 7) and fewer total adverse events (21% with benzbromarone versus 47% with probenecid; pooled RR 0.43, 95% CI 0.25 to 0.74; NNTB 4). The studies did not measure pain reduction, function and tophus regression.Low-quality evidence based on one small CCT (37 participants) indicated uncertainty around the difference in the incidence of acute gout attacks between probenecid and allopurinol after 18 to 20 months' treatment (53% with probenecid versus 55% with allopurinol; RR 0.96, 95% CI 0.53 to 1.75). The study did not measure or report the proportion achieving serum urate normalisation, pain reduction, function, tophus regression, withdrawal due to adverse events and total adverse events.

AUTHORS' CONCLUSIONS

There was moderate-quality evidence that there is probably no important difference between benzbromarone and allopurinol at achieving serum urate normalisation, but that benzbromarone is probably more successful than probenecid at achieving serum urate normalisation in people with gout. There is some uncertainty around the effect estimates, based on low-quality evidence from only one or two trials, on the number of acute gout attacks, the number of withdrawals due to adverse events or the total number of participants experiencing adverse events when comparing benzbromarone with allopurinol. However, when compared with probenecid, benzbromarone resulted in fewer withdrawals due to adverse events and fewer participants experiencing adverse events. Low-quality evidence from one small study indicated uncertain effects in the incidence of acute gout attacks when comparing probenecid with allopurinol therapy. We downgraded the evidence because of a possible risk of performance and other biases and imprecision.