Allopurinol and cardiovascular outcomes in patients with ischaemic heart disease: the ALL-HEART RCT and economic evaluation

Background

Allopurinol is a xanthine oxidase inhibitor that lowers serum uric acid and is used to prevent acute gout flares in patients with gout. Observational and small interventional studies have suggested beneficial cardiovascular effects of allopurinol.

Objective

To determine whether allopurinol improves major cardiovascular outcomes in patients with ischaemic heart disease.

Design

Prospective, randomised, open-label, blinded endpoint multicentre clinical trial.

Setting

Four hundred and twenty-four UK primary care practices.

Participants

Aged 60 years and over with ischaemic heart disease but no gout.

Interventions

Participants were randomised (1 : 1) using a central web-based randomisation system to receive allopurinol up to 600 mg daily that was added to usual care or to continue usual care.

Main outcome measures

The primary outcome was the composite of non-fatal myocardial infarction, non-fatal stroke or cardiovascular death. Secondary outcomes were non-fatal myocardial infarction, non-fatal stroke, cardiovascular death, all-cause mortality, hospitalisation for heart failure, hospitalisation for acute coronary syndrome, coronary revascularisation, hospitalisation for acute coronary syndrome or coronary revascularisation, all cardiovascular hospitalisations, quality of life and cost-effectiveness. The hazard ratio (allopurinol vs. usual care) in a Cox proportional hazards model was assessed for superiority in a modified intention-to-treat analysis.

Results

From 7 February 2014 to 2 October 2017, 5937 participants were enrolled and randomised to the allopurinol arm (n = 2979) or the usual care arm (n = 2958). A total of 5721 randomised participants (2853 allopurinol; 2868 usual care) were included in the modified intention-to-treat analysis population (mean age 72.0 years; 75.5% male). There was no difference between the allopurinol and usual care arms in the primary endpoint, 314 (11.0%) participants in the allopurinol arm (2.47 events per 100 patient-years) and 325 (11.3%) in the usual care arm (2.37 events per 100 patient-years), hazard ratio 1.04 (95% confidence interval 0.89 to 1.21); p = 0.65. Two hundred and eighty-eight (10.1%) participants in the allopurinol arm and 303 (10.6%) participants in the usual care arm died, hazard ratio 1.02 (95% confidence interval 0.87 to 1.20); p = 0.77. The pre-specified health economic analysis plan was to perform a 'within trial' cost-utility analysis if there was no statistically significant difference in the primary endpoint, so NHS costs and quality-adjusted life-years were estimated over a 5-year period. The difference in costs between treatment arms was +£115 higher for allopurinol (95% confidence interval £17 to £210) with no difference in quality-adjusted life-years (95% confidence interval -0.061 to +0.060). We conclude that there is no evidence that allopurinol used in line with the study protocol is cost-effective.

Limitations

The results may not be generalisable to younger populations, other ethnic groups or patients with more acute ischaemic heart disease. One thousand six hundred and thirty-seven participants (57.4%) in the allopurinol arm withdrew from randomised treatment, but an on-treatment analysis gave similar results to the main analysis.

Conclusions

The ALL-HEART study showed that treatment with allopurinol 600 mg daily did not improve cardiovascular outcomes compared to usual care in patients with ischaemic heart disease. We conclude that allopurinol should not be recommended for the secondary prevention of cardiovascular events in patients with ischaemic heart disease but no gout.

Future work

The effects of allopurinol on cardiovascular outcomes in patients with ischaemic heart disease and co-existing hyperuricaemia or clinical gout could be explored in future studies.

Trial registration

This trial is registered as EU Clinical Trials Register (EudraCT 2013-003559-39) and ISRCTN (ISRCTN 32017426).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 11/36/41) and is published in full in Health Technology Assessment; Vol. 28, No. 18. See the NIHR Funding and Awards website for further award information.

Relationship between Gout and Diabetes Mellitus after Acute Pancreatitis: A Nationwide Cohort Study

OBJECTIVE

After acute pancreatitis, individuals often have low-grade inflammation, and subsequently develop metabolic sequelae such as post-pancreatitis diabetes mellitus (PPDM). Although numerous studies have investigated the relationship between gout and type 2 diabetes, little is known about the relationship between gout and PPDM. The aim was to investigate the associations between gout and PPDM.

METHODS

Using nationwide pharmaceutical dispensing data linked to hospital discharge data in New Zealand, gout and PPDM were identified among individuals after first episode of acute pancreatitis between January 1, 2007, and December 31, 2015. Multivariable Cox regression analyses were conducted, adjusting for age, sex, ethnicity, social deprivation index, alcohol consumption, tobacco smoking, comorbidities, medications (glucocorticoids, statins, and estrogens), and characteristics of acute pancreatitis.

RESULTS

A total of 10,117 individuals were included in the analysis of risk for gout and 9471 in the analysis of risk for PPDM. PPDM was significantly associated with a higher risk of gout in the overall cohort (adjusted HR 1.88, 95% CI 1.15-3.06) and women (2.72, 95% CI 1.31-5.65), but not in men (1.42, 95% CI 0.73-2.78). Preexisting gout was significantly associated with a higher risk of PPDM in the overall cohort (adjusted HR 1.58, 95% CI 1.04-2.41) and women (2.66, 95% CI 1.29-5.49), but not in men (1.31, 95% CI 0.78-2.20).

CONCLUSION

The relationship between gout and PPDM is bidirectional in the post-pancreatitis setting. A history of gout is a risk factor of PPDM, particularly in women.

Factors Influencing the Effectiveness of Allopurinol in Achieving and Sustaining Target Serum Urate in a US Veterans Affairs Gout Cohort

OBJECTIVE

To assess factors associated with the ability to achieve and maintain target serum urate (SU) with allopurinol in patients with gout.

METHODS

We used US Veterans Affairs (VA) databases from 2002-2012. Eligible patients had ≥ 1 inpatient or ≥ 2 outpatient visits with a diagnostic code for gout, filled a new index allopurinol prescription, had at least 1 posttreatment SU level measured, and met the 12-month observability rule. Treatment successes were defined as the achievement of postindex SU < 6 mg/dl (success 1) and postindex SU < 6 mg/dl that was sustained (success 2).

RESULTS

Of the 198,839 unique patients with allopurinol use, 41,153 unique patients (with 47,072 episodes) and 17,402 unique patients (with 18,323 episodes) were eligible for analyses for success 1 and success 2; 42% each achieved (success 1) or achieved and maintained postindex SU < 6 mg/dl (success 2). In multivariable-adjusted models, factors associated with significantly higher odds of both outcomes were older age, normal body mass index, Deyo-Charlson index score of 0, rheumatologist as the main provider rather than non-rheumatologist, midwestern US location for the healthcare facility, a lower hospital bed size, military service connection for medical conditions of 50% or more (a measure of healthcare access priority), longer distance to the nearest VA facility, and lower preindex SU.

CONCLUSION

We identified novel factors associated with maintaining SU < 6 mg/dl based on a theoretical model. Several potentially modifiable factors can be targeted by individual/provider/systems interventions for improving successful achievement and maintenance of target SU in patients with gout.

Changes in the Presentation of Incident Gout and the Risk of Subsequent Flares: A Population-based Study over 20 Years

OBJECTIVE

To examine whether a change in the presentation of incident gout happened over the last 20 years and to determine the risk of subsequent gout flares after an initial gout attack.

METHODS

All incident cases of gout were identified among residents of Olmsted County, Minnesota, diagnosed in 1989-1992 and 2009-2010 according to the earliest date fulfilling the 1977 American Rheumatism Association preliminary criteria, or the New York or Rome criteria for gout. Patients in both cohorts were then followed for up to 5 years. Cumulative incidence and person-year methods were used to compare flare rates, and conditional frailty models were used to examine predictors.

RESULTS

A total of 429 patients with incident gout (158 patients in 1989-1992 and 271 patients in 2009-2010) were identified and followed for a mean of 4.2 years. The majority of patients were male (73%) and the mean age (SD) at gout onset was 59.7 (17.3) years. Classic podagra decreased significantly from 74% to 59% (p < 0.001). Cumulative incidence of first flare was similar in both cohorts (62% vs 60% by 5 yrs in 1989-1992 and 2009-2010, respectively; p = 0.70), but overall flare rate was marginally higher in 2009-2010 compared to 1989-1992 (rate ratio: 1.24). Hyperuricemia (HR 1.59) and kidney disease (HR 1.34) were significant predictors of future flares.

CONCLUSION

Gout flares were common in both time periods. Hyperuricemia and kidney disease were predictors of future flares in patients with gout. Podagra as a presentation of gout has become relatively less frequent in recent years.

Dissociation Between Clinical Benefit and Persistent Urate Lowering in Patients with Chronic Refractory Gout Treated with Pegloticase

OBJECTIVE

To assess clinical benefit in patients with chronic refractory gout who did not meet the protocol-defined criteria of responders to pegloticase.

METHODS

This analysis used results from 2 randomized controlled trials (ClinicalTrials.gov: NCT00325195, NCT01356498) to assess the clinical efficacy in responders and nonresponders to treatment (8 mg of pegloticase every 2 weeks). Serum urate was measured before each infusion and the following were recorded: assessment of gout flares, tophus reduction, patient's global assessment (PtGA), tender and swollen joints (TJC and SJC), pain using a 100-mm visual analog scale, and a variety of patient-reported outcomes [Medical Outcomes Study Short Form-36 questionnaire physical component summary score and arthritis-specific health index (ASHI) score].

RESULTS

The analysis included 36 persistent urate responders, 49 nonresponders, and 43 patients who received placebo. Results for both responders and nonresponders indicated significant reduction in tophi and improvements from baseline in PtGA, TJC, SJC, pain, and ASHI. No significant improvements were observed in the patients who received placebo.

CONCLUSION

Chronic refractory gout patients not achieving protocol-defined persistent urate lowering still achieve significant clinical benefits with pegloticase treatment, suggesting that transient reduction in serum urate may result in sustained clinical benefit.

Are Target Urate and Remission Possible in Severe Gout? A Five-year Cohort Study

OBJECTIVE

Determine the proportion of patients achieving target serum urate (SU), defined as < 6 mg/dl for patients with non-severe gout and < 5 mg/dl for patients with severe gout, as well as the proportion of patients achieving remission after 5 years of followup.

METHODS

Patients from the Gout Study Group (GRESGO) cohort were evaluated at 6-month intervals. Demographic and clinical data were obtained at baseline. Visits included assessments of serum urate, flares, tophus burden, health-related quality of life using the EQ-5D, activity limitations using the Health Assessment Questionnaire adapted for gout, and pain level and patient's global assessment using visual analog scales. Treatment for gout and associated diseases was prescribed according to guidelines and available drugs.

RESULTS

Of 500 patients studied, 221 had severe gout (44%) and 279 had non-severe gout (56%) at baseline. No significant differences were observed across the study in percentages of severe gout versus non-severe gout patients achieving SU 6 mg/dl or 5 mg/dl. The highest proportion of patients achieving target SU (50-70%) and remission (39%) were found after 3-4 years of followup. In the fifth year, these proportions decreased and 28% of the patients were in remission, but only 40 patients remained in the study. None of the patients with severe gout achieved remission.

CONCLUSION

In patients with severe gout, target SU was hard to achieve and remission was not possible. The main obstacles for target SU and gout remission include poor medication adherence, persistent tophi, and loss to followup.

The Validity of Gout Diagnosis in Primary Care: Results from a Patient Survey

OBJECTIVE

Validate primary care diagnosis of gout by the Mexico and the Netherlands classification criteria.

METHODS

Questionnaires on gout characteristics were sent to all individuals aged ≥ 18 with ≥ 1 International Classification of Diseases, 10th ed. diagnosis of gout at 12 primary care centers.

RESULTS

Positive predictive values for gout diagnosis ranged from 71% for the Netherlands criteria to 80% for the Mexico criteria. Maximum inflammation within 24 h was the most common reported symptom (86%).

CONCLUSION

The vast majority of gout cases in primary care fulfill classification criteria and are valid for research purposes.

Precipitation of Soluble Uric Acid Is Necessary for In Vitro Activation of the NLRP3 Inflammasome in Primary Human Monocytes

OBJECTIVE

To investigate the effects of soluble uric acid (UA) on expression and activation of the NOD-like receptor (NLR) pyrin domain containing protein 3 (NLRP3) inflammasome in human monocytes to elucidate the role of hyperuricemia in the pathogenesis of gout.

METHODS

Primary human monocytes and the THP-1 human monocyte cell line were used to determine the effects of short- and longterm exposure to UA on activation of the NLRP3 inflammasome and subsequent interleukin 1β (IL-1β) secretion by ELISA and cell-based assays. Expression of key NLRP3 components in monocytes from patients with a history of gout were analyzed by quantitative PCR.

RESULTS

Precipitation of UA was required for activation of the NLRP3 inflammasome and subsequent release of IL-1β in human monocytes. Neither monosodium urate (MSU) crystals nor soluble UA had any effect on activation of the transcription factor, nuclear factor-κB. Prolonged exposure of monocytes to soluble UA did not alter these responses. However, both MSU crystals and soluble UA did result in a 2-fold increase in reactive oxygen species. Patients with gout (n = 15) had significantly elevated serum UA concentrations compared to healthy individuals (n = 16), yet secretion of IL-1β and expression of NLRP3 inflammasome components in monocytes isolated from these patients were not different from those of healthy controls.

CONCLUSION

Despite reports indicating that soluble UA can prime and activate the NLRP3 inflammasome in human peripheral blood mononuclear cells, precipitation of soluble UA into MSU crystals is essential for in vitro NLRP3 signaling in primary human monocytes.

Use of Anakinra in Hospitalized Patients with Crystal-associated Arthritis

OBJECTIVE

In this retrospective observational study, we assess the efficacy and safety of the interleukin 1 receptor antagonist anakinra in medically complex, hospitalized patients with acute gout and calcium pyrophosphate crystal arthritis.

METHODS

Adult inpatients treated with anakinra from 2014 to 2017 were identified for inclusion. Charts were reviewed for demographics, comorbidities, laboratory data, pain scores, joint involvement, prior treatment, dosing and response to anakinra, concurrent infections, and surgical interventions. Response to anakinra treatment was determined from review of provider documentation, as well as recorded pain scores on a numeric scale.

RESULTS

We identified 100 individuals accounting for 115 episodes of arthritis. This population was 82% male, with an average age of 60 years. Comorbidities included renal disease (45%) and history of organ transplantation (14%). Twenty-nine episodes of arthritis occurred in the perioperative setting. Concurrent infection was present in 34 episodes. Eighty-six episodes of arthritis had partial or complete response to anakinra within 4 days of treatment initiation; 66 episodes had partial or complete response within 1 day of anakinra administration. Anakinra was well tolerated.

CONCLUSION

To our knowledge, this is the largest observational study of anakinra use in the inpatient setting for the acute treatment of crystal-associated arthritis. We observed a rapid response to anakinra, with 75% of episodes significantly improving or completely resolving within 4 days of the first dose. Our data also support the use of this biologic agent in individuals with infections, as well as perioperative individuals and immunosuppressed transplant recipients.

Utility of Anakinra in Acute Crystalline Diseases: A Retrospective Study Comparing a University Hospital with a Veterans Affairs Medical Center

OBJECTIVE

To evaluate the efficacy and safety of anakinra in inpatient management of acute gout and pseudogout.

METHODS

Hospitalized patients with acute gout (n = 77) or pseudogout (n = 11) or both (n = 3) were analyzed for response to anakinra and adverse effects.

RESULTS

Half of all patients had comorbidities limiting the treatment choice. Anakinra was well tolerated, and 92% of gout flares and 79% of pseudogout flares responded to treatment.

CONCLUSION

Anakinra is an effective and safe treatment for acute gout and pseudogout in hospitalized patients, particularly in those with comorbidities.

Hospitalization Increases the Risk of Acute Arthritic Flares in Gout: A Population-based Study over 2 Decades

OBJECTIVE

To assess in-hospital gout flares in patients with gout.

METHODS

Hospitalizations were evaluated for gout flares in a cohort of Olmsted County, Minnesota, residents with incident gout in 1989-1992 or 2009-2010.

RESULTS

There were 429 patients followed up to 5 years. Of these, 169 patients experienced 454 hospitalizations. Hospitalization rates increased without reaching statistical significance from 1989-1992 to 2009-2010 [rate ratio (RR) 1.19, 95% CI 0.98-1.45]. The gout flare rate increased significantly during hospitalization (RR 10.2, 95% CI 6.8-14.5). In-hospital gout flare increased the average hospital stay by 1.8 days (p < 0.001).

CONCLUSION

Hospitalization increased the risk of gout flares 10-fold. In-hospital gout flares were associated with longer hospitalization.

The Rising Incidence of Gout and the Increasing Burden of Comorbidities: A Population-based Study over 20 Years

OBJECTIVE

To examine the incidence of gout over the last 20 years and to evaluate possible changes in associated comorbid conditions.

METHODS

The medical records were reviewed of all adults with a diagnosis of incident gout in Olmsted County, Minnesota, USA, during 2 time periods (January 1, 1989-December 31, 1992, and January 1, 2009-December 31, 2010). Incident cases had to fulfill at least 1 of 3 criteria: the American Rheumatism Association 1977 preliminary criteria for gout, the Rome criteria, or the New York criteria.

RESULTS

A total of 158 patients with new-onset gout were identified during 1989-1992 and 271 patients during 2009-2010, yielding age- and sex-adjusted incidence rates of 66.6/100,000 (95% CI 55.9-77.4) in 1989-1992 and 136.7/100,000 (95% CI 120.4-153.1) in 2009-2010. The incidence rate ratio was 2.62 (95% CI 1.80-3.83). At the time of their first gout flare, patients diagnosed with gout in 2009-2010 had higher prevalence of comorbid conditions compared with 1989-1992, including hypertension (69% vs 54%), diabetes mellitus (25% vs 6%), renal disease (28% vs 11%), hyperlipidemia (61% vs 21%), and morbid obesity (body mass index ≥ 35 kg/m²; 29% vs 10%).

CONCLUSION

The incidence of gout has more than doubled over the recent 20 years. This increase together with the more frequent occurrence of comorbid conditions and cardiovascular risk factors represents a significant public health challenge.

Ultrasound Characteristics of the Achilles Tendon in Tophaceous Gout: A Comparison with Age- and Sex-matched Controls

OBJECTIVE

To investigate the frequency and distribution of characteristics of the Achilles tendon (AT) in people with tophaceous gout using musculoskeletal ultrasound (US).

METHODS

Twenty-four participants with tophaceous gout and 24 age- and sex-matched controls without gout or other arthritis were recruited. All participants underwent a greyscale and power Doppler US examination. The AT was divided into 3 anatomical zones (insertion, pre-insertional, and proximal to the mid-section). The following US characteristics were assessed: tophus, tendon echogenicity, tendon vascularity, tendon morphology, entheseal characteristics, bursal morphology, and calcaneal bone profile.

RESULTS

The majority of the participants with tophaceous gout were middle-aged men (n = 22, 92%) predominately of European ethnicity (n = 14, 58%). Tophus deposition was observed in 73% (n = 35) of tendons in those with gout and in none of the controls (p < 0.01). Intratendinous hyperechoic spots (p < 0.01) and intratendinous power Doppler signal (p < 0.01) were more frequent in participants with gout compared to controls. High prevalence of entheseal calcifications, calcaneal bone cortex irregularities, and calcaneal enthesophytes were observed in both gout participants and controls, without differences between groups. Intratendinous structural damage was rare. Hyperechoic spots were significantly more common at the insertion compared to the zone proximal to the mid-section (p < 0.01), but between-zone differences were not observed for other features.

CONCLUSION

US features of urate deposition, tophus, and vascularization are present throughout the AT in patients with tophaceous gout. Despite crystal deposition, intratendinous structural changes are infrequent. Many characteristics observed in the AT in people with tophaceous gout, particularly at the calcaneal enthesis, are not disease-specific.

Management of Gout in a Hospital Setting: A Lost Opportunity

OBJECTIVE

Management of gout is frequently suboptimal. The aim of this study was to determine the proportion of patients presenting to Christchurch Hospital for a gout flare and to determine whether management for both acute flares and urate lowering was in accordance with international recommendations.

METHODS

A retrospective audit was undertaken of all admissions to Christchurch Hospital from June 1, 2013, to May 31, 2014, in which gout was coded as a primary or secondary discharge diagnosis. Information including demographics, comorbidities, concomitant medications, treatment of acute gout, and urate lowering was collected.

RESULTS

A total of 235 acute admissions for gout in 216 individuals were identified. Eleven individuals had 2 admissions and 4 individuals had 3 admissions. In 95/235 admissions (40.4%), gout was the primary diagnosis. Gout accounted for 95/77,321 (0.12%) of acute admissions. The treatment of acute gout was prednisone monotherapy in 170/235 (72.3%) of admissions. Serum urate was measured at some point during 123/235 (52.3%) of admissions, with only 19/123 (15.4%) at target urate level (< 0.36 mmol/l). At 60 of the 235 admissions, urate-lowering therapy was already being prescribed. Nine out of 175 patients (5.1%) not treated with urate-lowering therapy at admission commenced allopurinol and 32/174 (18.4%) had commencement of urate-lowering therapy recommended in the discharge plan.

CONCLUSION

Rates of admission for gout are similar to that observed in other studies. Failure to initiate, change, or recommend alterations in urate-lowering therapy to achieve target urate in people with gout admitted to hospital represents a significant lost opportunity to improve longterm gout management.

Gout and the Risk of Non-vertebral Fracture

Prior studies suggest an association between osteoporosis, systemic inflammation, and pro-inflammatory cytokines such as interleukin (IL)-1 and IL-6. Conflicting findings exist on the association between hyperuricemia and osteoporosis. Furthermore, it remains unknown whether gout, a common inflammatory arthritis, affects fracture risk. Using data from a US commercial health plan (2004-2013), we evaluated the risk of non-vertebral fracture (ie, forearm, wrist, hip, and pelvis) in patients with gout versus those without. Gout patients were identified with ≥2 diagnosis codes and ≥1 dispensing for a gout-related drug. Non-gout patients, identified with ≥2 visits coded for any diagnosis and ≥1 dispensing for any prescription drugs, were free of gout diagnosis and received no gout-related drugs. Hip fracture was the secondary outcome. Fractures were identified with a combination of diagnosis and procedure codes. Cox proportional hazards models compared the risk of non-vertebral fracture in gout patients versus non-gout, adjusting for more than 40 risk factors for osteoporotic fracture. Among gout patients with baseline serum uric acid (sUA) measurements available, we assessed the risk of non-vertebral fracture associated with sUA. We identified 73,202 gout and 219,606 non-gout patients, matched on age, sex, and the date of study entry. The mean age was 60 years and 82% were men. Over the mean 2-year follow-up, the incidence rate of non-vertebral fracture per 1,000 person-years was 2.92 in gout and 2.66 in non-gout. The adjusted hazard ratio (HR) was 0.98 (95% confidence interval [CI] 0.85-1.12) for non-vertebral fracture and 0.83 (95% CI 0.65-1.07) for hip fracture in gout versus non-gout. Subgroup analysis (n = 15,079) showed no association between baseline sUA and non-vertebral fracture (HR = 1.03, 95% CI 0.93-1.15), adjusted for age, sex, comorbidity score, and number of any prescription drugs. Gout was not associated with a risk of non-vertebral fracture. Among patients with gout, sUA was not associated with the risk of non-vertebral fracture. © 2016 American Society for Bone and Mineral Research.

Serum Uric Acid and the Risk of Incident and Recurrent Gout: A Systematic Review

OBJECTIVE

Lowering serum uric acid (SUA) levels can essentially cure gout; however, this is not widely practiced. To summarize epidemiologic evidence related to this causal link, we conducted a systematic review of the published literature reporting the association between SUA level and incident and recurrent gout (i.e., gout flares).

METHODS

We systematically searched Medline, EMBASE, and the Cochrane Database of Systematic Reviews using separate search strategies for incident gout and recurrent gout. We screened 646 abstracts to identify 8 eligible articles reporting gout incidence and 913 abstracts to identify 18 articles reporting recurrent gout.

RESULTS

For both gout incidence and recurrence, a graded trend was observed where the risk was increased with higher SUA levels. Gout incidence rates per 1000 person-years from population-based studies ranged from 0.8 (SUA ≤ 6 mg/dl) to 70.2 cases (SUA ≥ 10 mg/dl). Recurrent gout risk in clinical cohorts ranged from 12% (SUA ≤ 6 mg/dl) to 61% (SUA ≥ 9 mg/dl) among those receiving urate-lowering therapy (ULT), and 3.7% (SUA 6-7 mg/dl) to 61% (SUA > 9.3 mg/dl) after successful ULT. Retrospective database studies also showed a graded relationship, although the strength of the association was weaker. Studies reporting mean flares or time-to-flare according to SUA showed similar findings.

CONCLUSION

This systematic review confirms that higher SUA levels are associated with increased risk of incident and recurrent gout in a graded manner. Although few prospective cohorts have evaluated incident and recurrent gout according to SUA, the existing evidence underscores the need to treat to SUA targets, as recommended by the American College of Rheumatology and the European League Against Rheumatism.

Predictors of Mortality in People with Recent-onset Gout: A Prospective Observational Study

OBJECTIVE

To determine mortality rates and predictors of death at baseline in people with a recent onset of gout.

METHODS

People with gout disease duration < 10 years were recruited from primary and secondary care settings. Comprehensive clinical assessment was completed at baseline. Participants were prospectively followed for at least 1 year. Information about death was systematically collected from primary and secondary health records. Standardized mortality ratios (SMR) were calculated and risk factors for mortality were analyzed using Cox proportional hazard regression models.

RESULTS

The mean (SD) followup duration was 5.1 (1.6) years (a total 1511 patient-yrs accrued). Of the 295 participants, 43 (14.6%) had died at the time of censorship (SMR 1.96, 95% CI 1.44-2.62). In the reduced Cox proportional hazards model, these factors were independently associated with an increased risk of death from all causes: older age (70-80 yrs: HR 9.96, 95% CI 3.30-30.03; 80-91 yrs: HR 9.39, 95% CI 2.68-32.89), Māori or Pacific ethnicity (HR 2.48, 95% CI 1.17-5.29), loop diuretic use (HR 3.99, 95% CI 2.15-7.40), serum creatinine (per 10 µmol/l change; HR 1.04, 95% CI 1.00-1.07), and the presence of subcutaneous tophi (HR 2.85, 95% CI 1.49-5.44). The presence of subcutaneous tophi was the only baseline variable independently associated with both cardiovascular (CV) cause of death (HR 3.13, 95% CI 1.38-7.10) and non-CV cause of death (HR 3.48, 95% CI 1.25-9.63).

CONCLUSION

People with gout disease duration < 10 years have an increased risk of death. The presence of subcutaneous tophi at baseline is an independent predictor of mortality, from both CV and non-CV causes.

Construct Validity of Radiographs of the Feet to Assess Joint Damage in Patients with Gout

OBJECTIVE

To investigate construct validity of radiographic damage of the feet in gout.

METHODS

Radiographs of the feet were scored using the Sharp/van der Heijde method. Factors associated with damage were investigated by a negative binomial model, and contribution of damage to health by linear regressions.

RESULTS

Age, disease duration, serum uric acid, and tophi were associated with being erosive and erosion score. Tophi were associated with joint space narrowing. Erosions were associated (β 0.47, 95% CI 0.09-0.84) with physical function, but damage was not associated with overall physical health.

CONCLUSION

Our results support construct validity for radiographs of the feet when assessing joint damage in gout.

Using serum urate as a validated surrogate end point for flares in patients with gout: protocol for a systematic review and meta-regression analysis

INTRODUCTION

Gout is the most common inflammatory arthritis in men over 40 years of age. Long-term urate-lowering therapy is considered a key strategy for effective gout management. The primary outcome measure for efficacy in clinical trials of urate-lowering therapy is serum urate levels, effectively acting as a surrogate for patient-centred outcomes such as frequency of gout attacks or pain. Yet it is not clearly demonstrated that the strength of the relationship between serum urate and clinically relevant outcomes is sufficiently strong for serum urate to be considered an adequate surrogate. Our objective is to investigate the strength of the relationship between changes in serum urate in randomised controlled trials and changes in clinically relevant outcomes according to the 'Biomarker-Surrogacy Evaluation Schema version 3' (BSES3), documenting the validity of selected instruments by applying the 'OMERACT Filter 2.0'.

METHODS AND ANALYSIS

A systematic review described in terms of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines will identify all relevant studies. Standardised data elements will be extracted from each study by 2 independent reviewers and disagreements are resolved by discussion. The data will be analysed by meta-regression of the between-arm differences in the change in serum urate level (independent variable) from baseline to 3 months (or 6 and 12 months if 3-month values are not available) against flare rate, tophus size and number and pain at the final study visit (dependent variables).

ETHICS AND DISSEMINATION

This study will not require specific ethics approval since it is based on analysis of published (aggregated) data. The intended audience will include healthcare researchers, policymakers and clinicians. Results of the study will be disseminated by peer-reviewed publications.

TRIAL REGISTRATION NUMBER

CRD42016026991.

Trends in Emergency Department Visits and Charges for Gout in the United States between 2006 and 2012

OBJECTIVE

To examine temporal trends in the rate of gout emergency department (ED) visits and charges in the United States between 2006 and 2012.

METHODS

A serial cross-sectional analysis of the Nationwide Emergency Department Sample.

RESULTS

The rate of ED visits for gout in adults overall increased from 75.0 to 85.4 per 100,000 persons over the study period (14% increase, p < 0.001), and increased 29% for those aged 45-54 years. Nationwide ED charges increased from $156 million to $281 million (80% increase, p < 0.001).

CONCLUSION

Between 2006 and 2012, the rate of gout ED visits increased among US adults, most notably in those aged 45-54 years.

Time Trends, Predictors, and Outcome of Emergency Department Use for Gout: A Nationwide US Study

OBJECTIVE

To assess gout-related emergency department (ED) use/charges and discharge disposition.

METHODS

We used the US National ED Sample (NEDS) data to examine the time trends in total ED visits and charges and ED-related hospitalizations with gout as the primary diagnosis. We assessed multivariable-adjusted predictors of ED charges and hospitalization for gout-related visits using the 2012 NEDS data.

RESULTS

There were 180,789, 201,044, and 205,152 ED visits in 2009, 2010, and 2012 with gout as the primary diagnosis, with total ED charges of $195 million, $239 million, and $287 million, respectively; these accounted for 0.14%-0.16% of all ED visits. Mean/median 2012 ED charges/visit were $1398/$956. Of all gout-related ED visits, 7.7% were admitted to the hospital in 2012. Mean/median length of hospital stay was 3.9/2.6 days and mean/median inpatient charge/admission with gout as the primary diagnosis was $22,066/$15,912 in 2012. In multivariable-adjusted analyses, these factors were associated with higher ED charges: older age, female sex, highest income quartile, being uninsured, metropolitan residence, Western United States hospital location, heart disease, renal failure, heart failure, hypertension (HTN), diabetes, osteoarthritis (OA), and chronic obstructive pulmonary disease (COPD). These factors were associated with higher odds of hospitalization: older age, Northeast location, metropolitan teaching hospital, higher income quartile, heart disease, renal failure, heart failure, hyperlipidemia, HTN, diabetes, COPD, and OA, whereas self-pay insurance status was associated with lower odds of hospitalization, following an ED visit for gout.

CONCLUSION

Absolute ED use and charges for gout increased over time, but relative use remained stable. Modifiable comorbidity factors associated with higher gout-related use should be targeted to reduce morbidity and healthcare use.

Patients with Gout Treated with Conventional Urate-lowering Therapy: Association with Disease Control, Health-related Quality of Life, and Work Productivity

OBJECTIVE

Implications of inadequate gout control were assessed through health-related quality of life (HRQOL) and work productivity of patients with gout adequately controlled while taking conventional urate-lowering therapy (ULT) for ≥ 3 months vs those whose gout was inadequately controlled.

METHODS

Retrospective data were drawn from the Adelphi Disease Specific Programme (DSP), a cross-sectional survey of patients with gout in France, Germany, the United Kingdom, and the United States. Patients completed these questionnaires: EQ-5D (3L), Patient Reported Outcomes Measurement Information System (PROMIS) Health Assessment Questionnaire (HAQ), and Work Productivity and Activity Impairment. Inadequate control was defined as the most recent serum uric acid (SUA) level > 6 mg/dl (> 360 µmol/l) or ≥ 2 flares in the last 12 months; adequate control as SUA level ≤ 6 mg/dl (≤ 360 µmol/l) and 0 flares. Appropriate statistical tests were used to assess differences between groups.

RESULTS

There were 836 (69%) inadequately and 368 (31%) adequately controlled gout cases. Mean age was 61 and 63 years and duration of current ULT was 32 and 57 months, respectively. Patients experiencing inadequate control reported significantly worse functioning and HRQOL, as measured by the EQ-5D (0.790 vs 0.877; difference: -0.087; p < 0.001) and PROMIS HAQ (13.21 vs 6.91; difference: 6.30; p < 0.001) scales. Productivity was also more impaired (work time missed: 4.5% vs 1.3%; impairment while working: 19.1% vs 5.2%; overall work impairment: 20.4% vs 5.6%; activity impairment: 20.3% vs 5.3%; all p < 0.001).

CONCLUSION

Less than one-third of patients had gout that was adequately controlled. Those experiencing inadequately controlled gout reported significantly worse functioning, quality of life, and work productivity. Gout treatment strategies to improve disease control may lead to improvements in HRQOL and productivity.

Gout Prophylaxis Evaluated According to the 2012 American College of Rheumatology Guidelines: Analysis from the CORRONA Gout Registry

OBJECTIVE

To analyze prophylaxis using the CORRONA (COnsortium of Rheumatology Researchers Of North America) Gout Registry according to the American College of Rheumatology (ACR) guidelines, and to evaluate whether differences in disease characteristics influenced prophylaxis.

METHODS

All patients with gout in the CORRONA Gout Registry between November 1, 2012, and November 26, 2013, were included. They were divided into 2 groups: "receiving prophylaxis" versus "not receiving prophylaxis" at the time of enrollment. Patients having a flare at time of visit were excluded. Descriptive statistics and multivariable logistic regression models were performed to evaluate the factors associated with prophylaxis.

RESULTS

There were 1049 patients with gout available for analysis. There were 441 patients (42%) receiving prophylaxis and 608 (58%) not receiving prophylaxis. The most common drugs used for prophylaxis were colchicine (78%) and nonsteroidal antiinflammatory drugs (32%). Prophylaxis drug combination was used by 45 patients (10.2%). Patients in the "receiving prophylaxis" group were more likely to have a gout duration of ≤ 1 year (n = 68, p < 0.001), ≥ 1 flare in the year previous to enrollment (p < 0.001), ≥ 1 healthcare uses in the last year [Emergency Department (p = 0.029); outpatient visit to primary care, rheumatologist, or urgent care clinic (p < 0.001)], have tophi (p < 0.001), report pain > 3 (p = 0.001), and have disease activity > 10 (p < 0.001) compared with patients in the "not receiving prophylaxis" group.

CONCLUSION

Forty-two percent of patients with gout in the CORRONA Gout Registry were receiving prophylaxis. Prophylaxis was significantly more common in patients with a higher disease burden and activity, which is in agreement with the ACR guidelines. Our study highlights disease characteristics influencing prophylaxis and furthers our knowledge on current use of flare prophylaxis.

Path Analysis Identifies Receptor Activator of Nuclear Factor-κB Ligand, Osteoprotegerin, and Sclerostin as Potential Mediators of the Tophus-bone Erosion Relationship in Gout

OBJECTIVE

To determine the relationship between tophus, erosion and bone remodeling factors in gout.

METHODS

Computed tomography bone erosion and circulating bone factors were measured in adults with tophaceous gout. Multiple regression modeling and path analysis were used to determine predictors of erosion.

RESULTS

Tophus number, Māori or Pacific ethnicity, creatinine, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), and sclerostin were independently associated with erosion. Path analysis showed a direct effect of tophus number on erosion, partially mediated through OPG, RANKL, and sclerostin.

CONCLUSION

Tophus number is strongly associated with bone erosion in gout. Circulating RANKL, OPG, and sclerostin are potential mediators of tophus-related erosion.

Diagnostic Arthrocentesis for Suspicion of Gout Is Safe and Well Tolerated

OBJECTIVE

To determine the frequency of adverse events of diagnostic arthrocentesis in patients with possible gout.

METHODS

Consecutive patients underwent arthrocentesis and were evaluated at 6 weeks to determine adverse events. The 95% CI were obtained by bootstrapping.

RESULTS

Arthrocentesis was performed in 910 patients, and 887 (97.5%) were evaluated for adverse events. Any adverse event was observed in 12 participants (1.4%, 95% CI 0.6-2.1). There was 1 case (0.1%, 95% CI 0-0.34) of septic arthritis.

CONCLUSIONS

Diagnostic arthrocentesis is associated with a low frequency of adverse events. Septic arthritis rarely occurs.

Barriers to Care in Gout: From Prescriber to Patient

OBJECTIVE

To explore the understanding of gout and its management by patients and general practitioners (GP), and to identify barriers to optimal gout care.

METHODS

Semistructured interviews were conducted with 15 GP and 22 patients in Sydney, Australia. Discussions were focused on medication adherence, experiences with gout, and education and perceptions around interventions for gout. Interviews were audio recorded, transcribed verbatim, and analyzed for themes using an analytical framework.

RESULTS

Adherence to urate-lowering medications was identified as problematic by GP, but less so by patients with gout. However, patients had little appreciation of the risk of acute attacks related to variable adherence. Patients felt stigmatized that their gout diagnosis was predominantly related to perceptions that alcohol and dietary excess were causal. Patients felt they did not have enough education about gout and how to manage it. A manifestation of this was that uric acid concentrations were infrequently measured. GP were concerned that they did not know enough about managing gout and most were not familiar with current guidelines for management. For example and importantly, the strategies for reducing the risk of acute attacks when commencing urate-lowering therapy (ULT) were not well appreciated by GP or patients.

CONCLUSION

Patients and GP wished to know more about gout and its management. Greater success in establishing and maintaining ULT will require further and better education to substantially benefit patients. Also, given the prevalence, and personal and societal significance of gout, innovative approaches to transforming the management of this eminently treatable disease are needed.

Assessing Elementary Lesions in Gout by Ultrasound: Results of an OMERACT Patient-based Agreement and Reliability Exercise

OBJECTIVE

To test the reliability of the consensus-based ultrasound (US) definitions of elementary gout lesions in patients.

METHODS

Eight patients with microscopically proven gout were evaluated by 16 sonographers for signs of double contour (DC), aggregates, erosions, and tophi in the first metatarsophalangeal joint and the knee bilaterally. The patients were examined twice using B-mode US to test agreement and inter- and intraobserver reliability of the elementary components.

RESULTS

The prevalence of the lesions were DC 52.8%, tophus 61.1%, aggregates 29.8%, and erosions 32.4%. The intraobserver reliability was good for all lesions except DC, where it was moderate. The best reliability per lesion was seen for tophus (κ 0.73, 95% CI 0.61-0.85) and lowest for DC (κ 0.53, 95% CI 0.38-0.67). The interobserver reliability was good for tophus and erosions, but fair to moderate for aggregates and DC, respectively. The best reliability was seen for erosions (κ 0.74, 95% CI 0.65-0.81) and lowest for aggregates (κ 0.21, 95% CI 0.04-0.37).

CONCLUSION

This is the first step to test consensus-based US definitions on elementary lesions in patients with gout. High intraobserver reliability was found when applying the definition in patients on all elementary lesions while interobserver reliability was moderate to low. Further studies are needed to improve the interobserver reliability, particularly for DC and aggregates.

A Validation Process by the OMERACT Ultrasound Working Group

OBJECTIVE

To summarize the work performed by the Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group on the validation of US as a potential outcome measure in gout.

METHODS

Based on the lack of definitions, highlighted in a recent literature review on US as an outcome tool in gout, a series of iterative exercises were carried out to obtain consensus-based definitions on US elementary components in gout using a Delphi exercise and subsequently testing these definitions in static images and in patients with proven gout. Cohen's κ was used to test agreement, and values of 0-0.20 were considered poor, 0.20-0.40 fair, 0.40-0.60 moderate, 0.60-0.80 good, and 0.80-1 excellent.

RESULTS

With an agreement of > 80%, consensus-based definitions were obtained for the 4 elementary lesions highlighted in the literature review: tophi, aggregates, erosions, and double contour (DC). In static images interobserver reliability ranged from moderate to almost perfect, and similar results were found for the intrareader reliability. In patients the intraobserver agreement was good for all lesions except DC (moderate). The interobserver agreement was poor for aggregates and DC but moderate for the other components.

CONCLUSION

These first steps in evaluating the validity of US as an outcome measure for gout show that the reliability of the definitions ranged from moderate to excellent in static images and somewhat lower in patients, indicating that a standardized scanning technique may be needed, before testing the responsiveness of those definitions in a composite US score.

Interventions for tophi in gout: a Cochrane systematic literature review

OBJECTIVE

To systematically review the available literature on the management of tophi in gout. This article is based on the Cochrane Review Interventions for Tophi in Gout published in the Cochrane Database of Systematic Reviews.

METHODS

Medline, Embase, and The Cochrane Library were searched using a strategy developed with an experienced librarian. We also searched American College of Rheumatology and European League Against Rheumatism conference abstracts from 2010-2011. Included articles were reviewed in detail and a risk of bias (using the Cochrane tool) and quality assessment were performed.

RESULTS

In total, 3206 references were recovered. Of these, 72 articles were selected based on our inclusion criteria. This included 1 report of 2 randomized controlled trials, 2 nonrandomized studies, and 69 case series and reports. The study with 2 randomized controlled trials looked at pegloticase. This showed improvement in tophi with treatment. One observational prospective trial looked at allopurinol and benzbromarone individually and in combination. It noted that achieving lower serum urate levels was associated with a faster reduction of tophi. An open-label extension trial noted that longterm maintenance of serum uric acid < 6.0 mg/dl with febuxostat led to a reduction in tophi. The case series and reports looked at surgical, pharmacological, and other interventions, as well as combination therapies. All surgical interventions reported improvement in pain and/or function. No report had objective measures of outcome.

CONCLUSION

Treatment with urate-lowering therapy such as allopurinol, benzbromarone, allopurinol + benzbromarone in combination, febuxostat, or pegloticase can lead to reduction in tophi. There is some evidence that achieving a lower serum urate level leads to a faster rate of tophi reduction.

Cardiovascular risk factors and comorbidities in patients with hyperuricemia and/or gout: a systematic review of the literature

OBJECTIVE

To review the available literature on the likelihood of having cardiovascular (CV) risk factors and on developing CV comorbidities in patients with gout and/or asymptomatic hyperuricemia as an evidence base for generating multinational clinical practice recommendations in the 3e (Evidence, Expertise, Exchange) Initiative in Rheumatology.

METHODS

A systematic literature search was carried out using MEDLINE, EMBASE, and The Cochrane Library, and abstracts presented at the 2010/2011 meetings of the American College of Rheumatology (ACR) and the European League Against Rheumatism, searching for CV risk factors and new CV comorbidities in patients with asymptomatic hyperuricemia and/or a diagnosis of gout. Trials that fulfilled predefined inclusion criteria were systematically reviewed.

RESULTS

A total of 66 out of 8918 identified publications were included in this review. After assessment of the risk of bias, 32 articles with a high risk of bias were excluded. Data could not be pooled because of clinical and statistical heterogeneity. In general, both for asymptomatic hyperuricemia and for gout the hazard ratios for CV comorbidities were only modestly increased (1.5 to 2.0) as were the hazard ratios for CV risk factors, ranging from 1.4 to 2.0 for hypertension and from 1.0 to 2.4 for diabetes.

CONCLUSION

Unlike the common opinion that patients with gout or hyperuricemia are at higher risk of developing CV disease, the actual risk to develop CV disease is either rather weak (for hyperuricemia) or poorly investigated (for gout).

Imaging as an Outcome Measure in Gout Studies: Report from the OMERACT Gout Working Group

OBJECTIVE

The gout working group at the Outcome Measures in Rheumatology (OMERACT) 12 meeting in 2014 aimed to determine which imaging modalities show the most promise for use as measurement instruments for outcomes in studies of people with chronic gout and to identify the key foci for future research about the performance of these imaging techniques with respect to the OMERACT filter 2.0.

METHODS

During the gout session, a systematic literature review of the data addressing imaging modalities including plain radiography (XR), conventional computed tomography (CT), dual-energy computed tomography (DECT), magnetic resonance imaging (MRI), and ultrasound (US) and the fulfillment of the OMERACT filter 2.0 was presented.

RESULTS

The working group identified 3 relevant domains for imaging in gout studies: urate deposition (tophus burden), joint inflammation, and structural joint damage.

CONCLUSION

The working group prioritized gaps in the data and identified a research agenda.

Modifiable factors associated with allopurinol adherence and outcomes among patients with gout in an integrated healthcare system

OBJECTIVE

To identify modifiable patient and provider factors associated with allopurinol adherence and the achievement of a serum urate acid (SUA) goal in gout.

METHODS

We identified a retrospective cohort of patients with gout, newly treated with allopurinol. All patient data came from administrative datasets at a large integrated health delivery system. Patients were ≥ 18 years old at time of initial allopurinol dispensing, and had 12 months or more of membership and drug eligibility prior to the index date. Allopurinol adherence was defined as a proportion of days covered ≥ 0.80, evaluated during the first 12 months of observation after the initial dispensing. Multivariable logistic regression was used to examine factors associated with allopurinol nonadherence and attaining an SUA concentration < 6.0 mg/dl.

RESULTS

We identified 13,341 patients with gout with incident allopurinol use (mean age 60 yrs, 78% men). Of these, 9581 patients (72%) had SUA measured both at baseline and during followup. Only 3078 patients (32%) attained an SUA target of < 6.0 mg/dl during followup. Potentially modifiable factors associated with treatment adherence and obtaining the SUA goal in the multivariable analysis included concomitant diuretic use, prescriber specialty, and allopurinol dosing practices. Adherent patients were 2.5-fold more likely than nonadherent patients to achieve an SUA < 6.0 mg/dl during observation.

CONCLUSION

Among patients with gout initiating allopurinol in our study, 68% did not reach the SUA goal and 57% of patients were nonadherent. Modifiable factors, including allopurinol dose escalation, treatment adherence, rheumatology referral, and concomitant medication use, could be important factors to consider in efforts aimed at optimizing gout treatment outcomes.

Distinguishing gouty arthritis from calcium pyrophosphate disease and other arthritides

OBJECTIVE

Differentiating gout, calcium pyrophosphate deposition disease (CPPD), and non-crystal-related inflammatory arthropathies (non-CRA) is essential but often clinically impossible. The sonographic double contour (DC) sign may have good specificity for gout in highly specialized centers, but it can be challenging to use it to distinguish gout from cartilage hyperenhancements in CPPD. We evaluated the diagnostic value of the DC sign alone and in combination with Doppler signals and uric acid (UA) levels in patients with acute arthritis.

METHODS

We retrospectively investigated 225 acutely inflamed joints and documented the presence of DC, Doppler hypervascularization, and serum UA (SUA) levels. All patients underwent synovial fluid (SF) analysis. Sensitivity, specificity, and positive predictive values were calculated, and correlation analyses and a binary regression model were used to investigate their diagnostic values.

RESULTS

The sensitivity of DC sign for crystalline arthritides was 85% and specificity 80%. Its specificity for gout was 64%, for CPPD 52%. In contrast to non-CRA hypervascularization, degree 2 and 3 Doppler signals were highly associated with gout and less with CPPD (p < 0.01). The combination of DC sign with hypervascularization and elevated UA levels increased specificity for gout to more than 90% and resulted in a 7-fold increase of the likelihood of diagnosis of gout (p < 0.01), but with a loss of sensitivity (42%).

CONCLUSION

The DC sign alone is suitable for predicting crystal-related arthropathies, but it cannot reliably distinguish gout from CPPD in everyday clinical routine. Combining hypervascularization and SUA levels increases the diagnostic value, leading us to propose a diagnostic algorithm.

Cost of illness and determinants of costs among patients with gout

OBJECTIVE

To estimate costs of illness in a cross-sectional cohort of patients with gout attending an outpatient rheumatology clinic, and to evaluate which factors contribute to higher costs.

METHODS

Altogether, 126 patients with gout were clinically assessed. They completed a series of questionnaires. Health resource use was collected using a self-report questionnaire that was cross-checked with the electronic patient file. Productivity loss was assessed by the Work Productivity and Activity Impairment Questionnaire, addressing absenteeism and presenteeism. Resource use and productivity loss were valued by real costs, and annual costs per patient were calculated. Factors contributing to incurring costs above the median were explored using logistic univariable and multivariable regression analysis.

RESULTS

Mean (median) annual direct costs of gout were €5647 (€1148) per patient. Total costs increased to €6914 (€1279) or €10,894 (€1840) per patient per year when adding cost for absenteeism or both absenteeism and presenteeism, respectively. Factors independently associated with high direct and high indirect costs were a positive history of cardiovascular disease, functional limitations, and female sex. In addition, pain, gout concerns, and unmet gout treatment needs were associated with high direct costs.

CONCLUSION

The direct and indirect costs-of-illness of gout are primarily associated with cardiovascular disease, functional limitations, and female sex.

Treatment target and followup measures for patients with gout: a systematic literature review

OBJECTIVE

To systematically review the validity of serum uric acid (SUA) as a treatment target for patients with gout, and the clinimetric properties of the potential tools for monitoring these patients.

METHODS

A search was performed in Medline, Embase and the Cochrane Library from inception to October 2011, and the 2010-2011 American College of Rheumatology and European League Against Rheumatism meeting abstracts. Studies evaluating different SUA levels or SUA reduction with the achievement of outcomes, and studies assessing clinimetric properties of instruments used to follow patients with gout were selected. Intervention studies were also included in order to estimate responsiveness. Titles and abstracts of the identified references were screened, and included articles were reviewed in detail and data collected using ad hoc standard forms.

RESULTS

In total, 4575 articles were retrieved, 120 articles reviewed in detail, and 54 articles were included in the systematic literature review. SUA reduction was significantly associated with a reduction in acute attacks (6 studies), tophi regression (2 studies), and crystal clearance (3 studies). SUA 6.0 mg/dl was used as cutoff point in most of studies, but this level was found to be arbitrary. For followup of patients with gout, tophus measurement by caliper and ultrasound, the physical component of the Medical Outcomes Study Short Form-36 Survey, and Health Assessment Questionnaire have shown excellent clinimetric properties for this purpose.

CONCLUSION

Reducing SUA is a valid treatment target for patients with gout, but the target level of reduction (cutoff point) is not clear. Some tools were found suitable for following patients with gout.

Treatment of gout patients with impairment of renal function: a systematic literature review

OBJECTIVE

To assess the efficacy and safety of gout-specific medications in gout patients with a comorbidity and/or comedication.

METHODS

A systematic literature search for gout, its medication, and the most common comorbidities and comedications, using serum uric acid (SUA) levels as the primary, and adverse events as the secondary outcomes.

RESULTS

Eight trials met inclusion criteria. Trials covered treatment with allopurinol, benzbromarone, rasburicase, or febuxostat in a gout population with mild or moderate renal insufficiency. High risk of bias (5/8 trials) and heterogeneity precluded formal metaanalysis. The trials showed the following hierarchy in efficacy (lowering the SUA below 6.0 mg/dl): febuxostat 80 mg (44%-71%) > febuxostat 40 mg (43%-52%) > allopurinol 100 mg or 200 mg (0-46%) after 6 months of therapy; rasburicase (46%) > allopurinol 300 mg (16%) after 7 days of therapy; benzbromarone 100-200 mg (93%) > allopurinol 100-200 mg (63%) after 9-24 months of therapy. The combination of allopurinol and benzbromarone seemed to be effective, with a significant reduction in the SUA from 7.8 to 5.7 mg/dl (p < 0.05) after 1 month. One study showed that 89% achieved the target SUA using higher doses of allopurinol than usually recommended for patients with renal impairment without an apparent increase in adverse events. In addition, allopurinol and benzbromarone significantly improved renal function.

CONCLUSION

In gout patients with renal insufficiency febuxostat, rasburicase, benzbromarone, and allopurinol + benzbromarone seemed to be effective and safe; allopurinol may be cautiously titrated until the target uric acid level has been reached, and may improve renal function.

Preventing attacks of acute gout when introducing urate-lowering therapy: a systematic literature review

OBJECTIVE

To systematically review the evidence on treatment available to prevent an acute attack of gout when initiating a urate-lowering therapy (ULT) and for how long this treatment should be continued. To also evaluate the evidence on the optimal time to start a ULT after an acute attack of gout.

METHODS

A systematic review as part of the 3e (Evidence, Expertise, Exchange) Initiative on Diagnosis and Management of Gout was performed using Medline, Embase, Cochrane Central Register of Controlled Trials (from 1950 to October 2011), and the European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) 2010/2011 meeting abstracts. Two reviewers independently screened titles and abstracts for selection criteria. Included articles were reviewed in detail, and a risk of bias assessment (using the Cochrane tool) was performed.

RESULTS

The search identified 8168 articles and 197 abstracts, from which 4 randomized controlled trials were included in the review. Two of these studies compared placebo with colchicine, 1 compared differing durations of colchicine, and 1 compared colchicine with canakinumab.

CONCLUSION

Two randomized controlled trials have shown that colchicine prophylaxis for at least 6 months, when starting a ULT, reduces the risk of acute attacks. Canakinumab, although not currently licensed for gout, has been shown to provide prophylaxis superior to colchicine, when starting a ULT. There is no evidence on the optimum time to start a ULT after an acute gout attack.

Diagnostic value of clinical, laboratory, and imaging findings in patients with a clinical suspicion of gout: a systematic literature review

OBJECTIVE

To analyze the diagnostic utility of clinical, laboratory, and imaging items for gout.

METHODS

A systematic literature search was performed in MEDLINE, EMBASE, and The Cochrane Library; and a manual search of abstracts from the 2010/2011 meetings of the American College of Rheumatology (ACR) and the European League Against Rheumatism, as well as the reference lists of retrieved papers. Studies were included if they evaluated the diagnostic utility of clinical, laboratory, or imaging features or criteria for the diagnosis or classification of gout in adult patients. Two independent reviewers selected papers, extracted the data, and assessed the risk of bias.

RESULTS

Nineteen studies were included in the review; 4 used the identification of monosodium urate (MSU) crystals as the reference standard (RS) and the rest used expert opinion or the ACR preliminary criteria. Most features were evaluated in a single study. Evidence for diagnostic utility, using MSU crystals as RS, of over 50 individual clinical, laboratory, and radiographic features was retrieved. Most items showed a positive likelihood ratio (LR+) < 3, except for the following: response of arthritis to colchicine (LR+ 4.3); presence of tophi on physical examination (LR+ 15.6-30.9); identification of the double-contour sign in ultrasound (US) (LR+ 13.6); and detection of urate deposits by dual-energy computed tomography (DECT) (LR+ 9.5).

CONCLUSION

Individual clinical features show low diagnostic utility, with the exception of tophi and response to colchicine. Some US and DECT findings show better performance than most clinical features.

Lifestyle interventions for the treatment of gout: a summary of 2 Cochrane systematic reviews

OBJECTIVE

To determine the efficacy and safety of lifestyle interventions for treating gout.

METHODS

Two Cochrane systematic reviews assessed the efficacy and safety of lifestyle interventions for the treatment of acute and chronic gout. We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials up to September 2011, and the 2010-2011 American College of Rheumatology and European League Against Rheumatism conference abstracts. Primary outcomes of interest were joint pain for acute gout, frequency of gout attacks for chronic gout, and withdrawals due to adverse events for both reviews.

RESULTS

One trial met inclusion criteria for each review. An unblinded trial (19 participants), at high risk of bias, found that topical ice added to prednisolone and colchicine for acute gout resulted in significantly greater pain reduction at 1 week [mean difference (MD) -3.33 cm, 95% confidence interval (95% CI) -5.84 to -0.82 on 10 cm visual analog scale]. Adverse events were not described. The second trial (120 participants), at moderate risk of bias, compared enriched skim milk powder (glycomacropeptide and G600 milk fat extract) to non-enriched skim milk and lactose powders for treating chronic gout. There were no between-group differences in gout attack frequency over 3 months [MD -0.21 (95% CI -0.76 to 0.34)] or withdrawals due to adverse events [relative risk 1.27 (95% CI 0.53 to 3.03)].

CONCLUSION

While there is observational evidence for an association between lifestyle risk factors and gout development, there are no high quality trials to support or refute the use of lifestyle interventions for treating acute or chronic gout.

Urate-lowering therapy for the management of gout: a summary of 2 Cochrane reviews

OBJECTIVE

To systematically review the evidence on the efficacy, safety, and cost-effectiveness of urate-lowering therapy for gout: xanthine oxidase inhibitors (allopurinol and febuxostat), uricosuric medications (benzbromarone, probenecid and sulfinpyrazone), and uricases (pegloticase and rasburicase).

METHODS

A systematic review was performed as part of the 3e (Evidence, Expertise, Exchange) Initiative on Gout. The primary efficacy outcomes were frequency of acute gout attacks, study participant withdrawal due to adverse events, and cost-effectiveness. Serum urate-lowering was a secondary outcome and was the most commonly reported outcome in the included trials.

RESULTS

The search identified 17 articles for efficacy, 31 for safety, and 3 for cost-effectiveness. The main outcome described in these studies was serum urate-lowering. Allopurinol, febuxostat, and pegloticase are all effective at lowering serum urate compared to placebo and febuxostat (≥ 80 mg) was more effective at lowering serum urate than allopurinol. Compared to probenecid, benzbromarone was more effective at lowering serum urate. Regarding acute gout attacks, pegloticase and febuxostat (≥ 120 mg) resulted in more acute attacks than placebo. Regarding the primary safety outcome, more withdrawals due to adverse events were seen only when pegloticase was compared to placebo. The two trials of cost-effectiveness were inconclusive.

CONCLUSION

There is currently moderate quality data supporting the efficacy and safety of allopurinol, febuxostat, benzbromarone, and probenecid in gout. Pegloticase, while efficacious, is associated with more withdrawals due to adverse events and infusion reactions. There is insufficient evidence currently with respect to the cost-effectiveness or the most optimal sequencing of urate-lowering therapy.

Clinical characteristics of and relationship between metabolic components and renal function among patients with early-onset juvenile tophaceous gout

OBJECTIVE

Age of onset of gout has recently decreased; however, patients with early-onset gout remain uncommon, and relevant information is scant. We hypothesized that these patients might exhibit differences in serum urates and other comorbidities compared with adult-onset patients.

METHODS

Early-onset gout patients (i.e., juveniles) with (n = 40) and without tophi (n = 47) were enrolled for study. Their clinical characteristics were compared with those of 353 patients with middle-age-onset tophaceous gout and 64 age-matched healthy participants.

RESULTS

Early-onset gout patients with tophi exhibited significantly higher body mass indices and serum urate levels and lower estimated glomerular filtration rates (eGFR) than did those without tophi. Early-onset gout patients with or without tophi demonstrated significantly abnormal lipid profiles and impaired liver or renal function compared with healthy patients. Serum urate levels and gout duration were identified as the principal determinants of tophi development. The presence of tophi might be crucial in decreasing eGFR, which is inversely related to tophi duration or gout duration. Unexpectedly, the most common site of initial gout attacks in early-onset tophaceous gout patients was the ankle, not the toe, which was the most common site in middle-age-onset tophaceous gout patients. The most common site of first tophi occurrence in early-onset patients was a finger, not a toe, which was the most common site in middle-age-onset patients.

CONCLUSION

Early-onset tophaceous gout patients are more likely to exhibit comorbidities and renal dysfunction than middle-age-onset patients and exhibit distinct first sites of gout attack and tophi occurrence patterns.

Outcome measures in acute gout: a systematic literature review

OBJECTIVE

Five core domains have been endorsed by Outcome Measures in Rheumatology (OMERACT) for acute gout: pain, joint swelling, joint tenderness, patient global assessment, and activity limitation. We evaluated instruments for these domains according to the OMERACT filter: truth, feasibility, and discrimination.

METHODS

A systematic search strategy for instruments used to measure the acute gout core domains was formulated. For each method, articles were assessed by 2 reviewers to summarize information according to the specific components of the OMERACT filter.

RESULTS

Seventy-seven articles and abstracts met the inclusion criteria. Pain was most frequently reported (76 studies, 20 instruments). The pain instruments used most often were 100 mm visual analog scale (VAS) and 5-point Likert scale. Both methods have high feasibility, face and content validity, and within- and between-group discrimination. Four-point Likert scales assessing index joint swelling and tenderness have been used in numerous acute gout studies; these instruments are feasible, with high face and content validity, and show within- and between-group discrimination. Five-point Patient Global Assessment of Response to Treatment (PGART) scales are feasible and valid, and show within- and between-group discrimination. Measures of activity limitations were infrequently reported, and insufficient data were available to make definite assessments of the instruments for this domain.

CONCLUSION

Many different instruments have been used to assess the acute gout core domains. Pain VAS and 5-point Likert scales, 4-point Likert scales of index joint swelling and tenderness and 5-point PGART instruments meet the criteria for the OMERACT filter.

Application of the OMERACT filter to measures of core outcome domains in recent clinical studies of acute gout

OBJECTIVE

To determine the extent to which instruments that measure core outcome domains in acute gout fulfill the Outcome Measures in Rheumatology (OMERACT) filter requirements of truth, discrimination, and feasibility.

METHODS

Patient-level data from 4 randomized controlled trials of agents designed to treat acute gout and 1 observational study of acute gout were analyzed. For each available measure, construct validity, test-retest reliability, within-group change using effect size, between-group change using the Kruskall-Wallis statistic, and repeated measures generalized estimating equations were assessed. Floor and ceiling effects were also assessed and minimal clinically important difference was estimated. These analyses were presented to participants at OMERACT 11 to help inform voting for possible endorsement.

RESULTS

There was evidence for construct validity and discriminative ability for 3 measures of pain [0 to 4 Likert, 0 to 10 numeric rating scale (NRS), 0 to 100 mm visual analog scale (VAS)]. Likewise, there appears to be sufficient evidence for a 4-point Likert scale to possess construct validity and discriminative ability for physician assessment of joint swelling and joint tenderness. There was some evidence for construct validity and within-group discriminative ability for the Health Assessment Questionnaire as a measure of activity limitations, but not for discrimination between groups allocated to different treatment.

CONCLUSION

There is sufficient evidence to support measures of pain (using Likert, NRS, or VAS), joint tenderness, and swelling (using Likert scale) as fulfilling the requirements of the OMERACT filter. Further research on a measure of activity limitations in acute gout clinical trials is required.

OMERACT endorsement of measures of outcome for studies of acute gout

OBJECTIVE

To determine the extent to which participants at the Outcome Measures in Rheumatology (OMERACT) 11 meeting agree that instruments used in clinical trials to measure OMERACT core outcome domains in acute gout fulfill OMERACT filter requirements of truth, discrimination, and feasibility; and where future research efforts need to be directed.

METHODS

Results of a systematic literature review and analysis of individual-level data from recent clinical studies of acute gout were presented to OMERACT participants. The information was discussed in breakout groups, and opinion was defined by subsequent voting in a plenary session. Endorsement was defined as at least 70% of participants voting in agreement with the proposition (where the denominator excluded those participants who did not vote or who voted "don't know").

RESULTS

The following measures were endorsed for use in clinical trials of acute gout: (1) 5-point Likert scale and/or visual analog scale (0 to 100 mm) to measure pain; (2) 4-point Likert scale for joint swelling; (3) 4-point Likert scale for joint tenderness; and (4) 5-point Likert scale for patient global assessment of response to treatment. Measures for the activity limitations domain were not endorsed.

CONCLUSION

Measures of pain, joint swelling, joint tenderness, and patient global assessment in acute gout were endorsed at OMERACT 11. These measures should now be used in clinical trials of acute gout.

Serum urate and incidence of kidney disease among veterans with gout

OBJECTIVE

To study the association between serum urate level (sUA) and the risk of incident kidney disease among US veterans with gouty arthritis.

METHODS

From 2002 through 2011 adult male patients with gout who were free of kidney disease were identified in the data from the Veterans Administration VISN 16 database and were followed until incidence of kidney disease, death, or the last available observation. Accumulated hazard curves for time to kidney disease were estimated for patients with average sUA levels > 7 mg/dl (high) versus ≤ 7 mg/dl (low) based on Kaplan-Meier analyses; and statistical comparison was conducted using a log-rank test. A Cox proportional hazard model with time-varying covariates was used to estimate the unadjusted and adjusted hazard ratios for kidney disease.

RESULTS

Eligible patients (n = 2116) were mostly white (53%), with average age 62.6 years, mean body mass index 31.2 kg/m(2), and high baseline prevalence of hypertension (93%), hyperlipidemia (67%), and diabetes (20%). Mean followup time was 6.5 years. The estimated rates of all incident kidney disease in the overall low versus high sUA groups were 2% versus 4% at Year 1, 3% versus 6% at Year 2, and 5% versus 9% at Year 3, respectively (p < 0.0001). After adjustment, high sUA continued to predict a significantly higher risk of kidney disease development (HR 1.43, 95% CI 1.20-1.70).

CONCLUSION

Male veterans with gout and sUA levels > 7 mg/dl had an increased incidence of kidney disease.

Efficacy and tolerability of probenecid as urate-lowering therapy in gout; clinical experience in high-prevalence population

OBJECTIVE

Probenecid is recommended as urate-lowering therapy (ULT) in patients with gout where xanthine oxidase inhibitors are ineffective, not tolerated, or contraindicated. The aim of our study was to determine the efficacy of probenecid to achieve serum urate (SU) targets (< 0.36 mmol/l) in clinical practice.

METHODS

We identified 57 patients prescribed with probenecid from a database of 521 rheumatology clinic attenders with gout. Demographic characteristics, indications for probenecid, probenecid doses, side effects, and laboratory data including estimated glomerular filtration rate (eGFR) and SU were recorded.

RESULTS

There were 30/57 (53%) patients treated with probenecid as monotherapy and 27/57 (47%) patients treated with probenecid in combination with allopurinol. Target SU concentrations (< 0.36 mmol/l) were achieved in 10/30 (33%) of the probenecid monotherapy group and 10/27 (37%) of the combination treatment group. Baseline SU concentrations, but not eGFR or probenecid dose, independently predicted achievement of target SU. Target SU was achieved in 5/15 (33%) patients with eGFR < 50 ml/min/1.73 m(2). There was no difference in the percentage of patients achieving SU target in those with eGFR < 50 ml/min/1.73 m(2) compared with those with eGFR ≥ 50 ml/min/1.73 m(2). Adverse events attributed to probenecid were observed in 8/42 (19%) patients with eGFR ≥ 50 ml/min/1.73 m(2) and in 2/15 (13%) patients with eGFR < 50 ml/min/1.73 m(2).

CONCLUSION

Probenecid has moderate efficacy as ULT in clinical management of patients with complex gout who have a lack of efficacy or intolerance to allopurinol. Patients with chronic kidney disease may respond to probenecid with similar rates of adverse events.