Gout in the elderly--a population health study

Adherence and Treat-to-Target Benchmarks in Older Adults With Gout Initiating Urate-Lowering Therapy in Ontario, Canada: A Population-Based Study

OBJECTIVE

We sought to evaluate urate-lowering therapy (ULT) adherence and treatment-to-target (T2T) serum uric acid (SUA) levels among older adults with gout starting ULT.

METHODS

We performed a population-based retrospective cohort study in Ontario, Canada in patients with gout aged ≥66 years newly dispensed ULT between 2010 and 2019. We defined successful T2T as patients having SUA levels <360 μmol/L (6 mg/dL) within 12 months after ULT dispensation. We also assessed adherence to ULT. Multilevel logistic regression clustered by ULT prescriber evaluated patient, physician, and prescription factors associated with reaching target SUA levels.

RESULTS

Among 44,438 patients (mean ± SD age 76.0 ± 7.3 years; 64.4% male), 30,057 (67.6%) patients had ≥1 SUA test completed. Overall, 52.3% patients reached SUA target within 12 months, improving from 45.2% in 2010 to 61.2% in 2019 (P < 0.0001). ULT adherence was 55.3% overall and improved annually. Key factors associated with achieving T2T included febuxostat treatment (odds ratio [OR] 11.40, 95% confidence interval [95% CI] 5.10-25.43) (was only dispensed in 88 patients), ULT adherence (OR 5.17, 95% CI 4.89-5.47), allopurinol starting doses >50 mg (OR 2.53, 95% CI 2.14-2.99), colchicine/oral glucocorticoids co-prescription (OR 1.24, 95% CI 1.14-1.34), and ULT prescription from a rheumatologist.

CONCLUSION

Only 52.3% of patients achieved an optimal SUA level within 1 year of ULT initiation. ULT adherence was suboptimal, although improving over time. ULT adherence and higher allopurinol starting doses had the strongest associations of achieving a target SUA level. This study highlights room for improvement in gout management and potential strategies to address care gaps.

Clinical characteristics and risk factors associated with bone erosion in patients with tophi

INTRODUCTION

If a large amount of urate crystals is deposited in a joint cavity for an extended period of time, bone erosion will occur and gradually cause skeletal muscle necrosis and joint deformity. The aim of this study was to describe the clinical characteristics and factors associated with bone erosion in gout patients with tophi.

METHODS

A total of 210 gout patients with tophi were enrolled and divided into a bone erosion group (n = 135) and a non-bone erosion group (n = 75). Digital radiography (DR) was performed to detect bone erosion in the elbow, wrist, knee, ankle joints, interphalangeal and metatarsophalangeal joints. The clinical characteristics were recorded and compared between the two groups. Multivariate logistic regression analysis was conducted to explore the factors associated with bone erosion.

RESULTS

Compared with the non-bone erosion group, the bone erosion group had an older age, longer disease duration of gout and tophi, higher level of serum creatinine (sCr), higher proportion of drinking history and ulceration, and a lower glomerular filtration rate (GFR). Univariate logistic regression analysis results showed that sex, age, body mass index (BMI), gout duration, tophi duration, GFR, white blood cell (WBC) count, sCr level, smoking history, drinking history, and presence of ulceration were associated with bone destruction. Multivariable logistic regression analysis results indicated that tophi duration, drinking history, ulceration and sCr were positively and independently related to bone erosion.

CONCLUSIONS

Tophi patients with bone erosion presented different clinical characteristics. Tophi duration, drinking history, ulceration and sCr were associated with bone erosion in gout patients with tophi.

Serum Urate Monitoring Among Older Adults With Gout: Initiating Urate-Lowering Therapy in Ontario, Canada

OBJECTIVE

To assess the proportion of, and factors associated with, older adults with gout receiving a serum urate (SUA) test after starting urate-lowering therapy (ULT).

METHODS

We performed a population-based retrospective cohort study in Ontario, Canada in patients ages ≥66 years with gout, newly dispensed ULT between 2010 and 2019. We characterized patients with SUA testing within 6 and 12 months after ULT dispensation. Multilevel logistic regression clustered by ULT prescriber evaluated the factors associated with SUA monitoring within 6 months.

RESULTS

We included 44,438 patients with a mean ± SD age of 76.0 ± 7.3 years and 64.4% male. Family physicians prescribed 79.1% of all ULTs. SUA testing was lowest in 2010 (56.4% at 6 months) and rose over time to 71.3% in 2019 (P < 0.0001). Compared with rheumatologists, family physicians (odds ratio [OR] 0.26 [95% confidence interval (95% CI) 0.23-0.29]), internists (OR 0.34 [95% CI 0.29-0.39]), nephrologists (OR 0.37 [95% CI 0.30-0.45]), and other specialties (OR 0.25 [95% CI 0.21-0.29]) were less likely to test SUA, as were male physicians (OR 0.87 [95% CI 0.83-0.91]). Patient factors associated with lower odds of SUA monitoring included rural residence (OR 0.81 [95% CI 0.77-0.86]), lower socioeconomic status (OR 0.91 [95% CI 0.85-0.97]), and patient comorbidities. Chronic kidney disease, hypertension, diabetes mellitus, and coprescription of colchicine/oral corticosteroids (OR 1.31 [95% CI 1.23-1.40]) were correlated with increased SUA testing.

CONCLUSION

SUA testing is suboptimal among older adults with gout initiating ULT but is improving over time. ULT prescriber, patient, and prescription characteristics were correlated with SUA testing.

Comparative Study of Real-Life Management Strategies in Gout: Data From Two Protocolized Gout Clinics

OBJECTIVE

To compare outcomes of 2 gout clinics that implemented different treatment strategies.

METHODS

Patients newly diagnosed with gout and a follow-up of 9-15 months were included. Co-primary outcomes were the proportion of patients reaching a serum uric acid (UA) ≤0.36 mmoles/liter and free of flares. Secondary outcomes were the proportion of patients requiring treatment intensification and experiencing adverse events. One clinic adopted a strict serum UA (≤0.30 mmoles/liter target) strategy, with early addition of a uricosuric to allopurinol, and the other clinic adopted a patient-centered (PC) strategy emphasizing a shared decision based on serum UA and patient satisfaction with gout control. Independent t-tests or chi-square tests were used to test differences in outcomes, and logistic regressions were used to adjust the effect of the treatment center on outcomes for confounders.

RESULTS

In total, 126 and 86 patients had a follow-up mean ± SD of 11.3 ± 1.8 versus 11.1 ± 1.9 months. In the UA strategy, 105 of 126 patients (83%) compared to 63 of 86 (74%) in the PC strategy (P = 0.10) reached the threshold of ≤0.36 mmoles/liter; and 58 of 126 (46%) versus 31 of 86 (36%) were free of flares (P = 0.15). In the UA strategy, 76 of 126 patients (60%) were on allopurinol monotherapy compared to 63 of 86 (73%) in the PC strategy (P = 0.05), yet the number of adverse events was not different (n = 25 [20%] versus n = 20 [23%]; P = 0.55). Adjusting for confounders did not substantially change these associations.

CONCLUSION

A strict UA strategy resulted in a nonsignificantly higher proportion of patients reaching a serum UA ≤0.36 mmoles/liter and being free of flares. This result was accomplished with significantly more therapy intensification. The small sample size plays a role in the significance of results.

Goals of gout treatment: a patient perspective

To assess the goals of gout treatment from a patient perspective, a convenience sample of consecutive patients with doctor-diagnosed gout seen at a community-based outpatient clinic were invited. Sex-stratified nominal groups were conducted until saturation was achieved. Responses were collected verbatim, discussed, and rank-ordered by each participant. Thirty-six patients with doctor-diagnosed gout participated in 12 nominal groups: 6 male only, 5 female only, and 1 group with both. Mean age was 61.9 years (SD, 12.3); mean gout duration was 13.3 years (SD, 12.5); 53% were men, 64% African-American, 42% retired, 47% currently married, 87% were using either allopurinol and/or febuxostat, and 40% had had no gout flares in the last 6 months. The top 5 treatment goals accounted for 91% of all votes and included the following: (1) prevent and better manage flare-ups and improve function (25%), (2) eliminate flare-ups/disease remission (30%), (3) diet and activity modification/lifestyle change (13%), (4) patient education and public awareness (12%), and (5) medication management and minimization of side effects (11%). When examining the top-rated concern for each nominal group, the first two goals were nominated by four groups each, diet/activity modification and medication management by 1 group each, and patient education by 3 groups. There were no differences evident by sex in top-ranked treatment goal. People with gout identified and rank-ordered treatment goals relevant to them. Providers of gout care need to be cognizant of these goals. Disease management concordant with these treatment goals might lead to a more satisfied, informed patient.

Health care utilization in patients with gout: a prospective multicenter cohort study

BACKGROUND

All published studies of health care utilization in gout have been cross-sectional to date, and most used a patient-reported diagnosis of gout. Our objective was to assess health care utilization and its predictors in patients with physician-confirmed gout in a prospective cohort study.

METHODS

In a multi-center prospective cohort study of U.S. veterans with rheumatologist-confirmed gout (N = 186; two centers), we assessed patient self-reported overall and gout-specific health care utilization with the Gout Assessment Questionnaire (GAQ) every 3-months for a 9-month period. Comparisons were made using the student's t test or the chi-square, Wilcoxon rank sum test or Fisher exact test, as appropriate. Mixed effects Poisson regression was used to assess potential correlates of gout-related health care utilization.

RESULTS

Mean age was 64.6 years, 98% were men, 13% Hispanic or Latino, 32% were African-American, 6% did not graduate high school, mean serum urate was 8.3 and mean Deyo-Charlson score was 3.1. During the past year, mean gout-related visits were as follows: rheumatologist, 1.5; primary care physician, 2 visits; ≥1 inpatient visits, 7%; ≥1 ER visits, 26%; and urgent care/walk-in visit, 33%. In longitudinal analyses, African-American race and gout flares in the last 3 months were associated with significantly higher rate ratio of gout-related outpatient visits. African-American race and lack of college education were associated with significantly higher rate ratio for gout-related urgent visits and overnight stays.

CONCLUSIONS

African-American race and recent gout flares were associated with higher outpatient utilization and African-American race and no college education with higher urgent or inpatient utilization. Future studies should examine whether modifiable predictors of utilization can be targeted to reduce healthcare utilization in patients with gout.

The Direct Economic Burden of Gout in an Elderly Canadian Population

Objective.

To estimate the direct healthcare cost and resource use from the public payer perspective between patients with incident gout and matched gout-free patients in Ontario.

Methods.

Patients with incident gout aged ≥ 66 with uninterrupted Ontario Health Insurance Plan (OHIP) coverage in the 1-year baseline period were included in the study. Patients with gout were indexed at first gout diagnosis or prescription over the study period April 1, 2008, to March 31, 2014. Gout-free patients with no gout diagnosis within history were matched (up to 5:1) to each patient with gout. Linked medical records were analyzed until end of study, death, or OHIP ineligibility. Bang and Tsiatis adjusted healthcare costs and resource use were compared using bootstrap p-values and 95% CI.

Results.

A total of 29,894 patients with gout and 148,231 gout-free patients were included in the study. Patients were 56% male, had a median Adjusted Clinical Group healthcare resource use band of moderate morbidity, and had a median age of 75–79 years. Baseline comorbidities were similar between groups except for renal disease. Analyzing 5-year total healthcare costs, patients with gout ($44,297) incurred a significantly higher average healthcare cost compared to gout-free patients ($33,965), for an incremental cost of $10,332 (95% CI $9617–$11,039; p < 0.01). Similar trends were observed in all individual healthcare component cost and use metrics.

Conclusion.

Following onset of gout, patients in Ontario incur significantly greater healthcare costs and resource use compared to matched gout-free patients. Alternative gout management strategies should be investigated to reduce the incremental burden of gout borne by the Ontario healthcare system.

The Human and Economic Burden of Difficult-to-Treat Gouty Arthritis

Gouty arthritis, one of the most painful and common forms of adult arthritis, is caused by monosodium urate crystal deposits in joints, most often in the lower extremities. Crystals trigger an inflammatory response leading to acute flares characterized by a rapid onset of pain, warmth, swelling, and redness in involved joints. Over time, continued monosodium urate crystal deposits and inflammation can lead to chronic tophaceous gout that result in bone erosion, progressing to joint destruction and significant disability. The goal of therapy in an acute gout flare is prompt and safe termination of pain and inflammation. Acute gouty arthritis is usually treated with nonsteroidal anti-inflammatory drugs, colchicine, or corticosteroids. However, for a growing number of patients, current standard treatments are ineffective or are contraindicated, largely due to the presence of comorbidities. Gouty arthritis can have a major negative impact of health-related quality of life, especially in patients with difficult-to-treat disease, as revealed by recent studies comparing health-related quality of life with that of the general population. Additionally, gouty arthritis also constitutes an important economic burden through absence from work and medical costs. This burden is even greater in patients with difficult-to-treat disease.

A Systematic Review of the Economic and Humanistic Burden of Gout

BACKGROUND

Gout is a chronic and inflammatory form of arthritis that is often overlooked despite the associated pain caused by acute flares and associated joint damage caused by the development of debilitating tophi. The increasing burden of gout, due to an aging population and the increased prevalence of known risk factors for hyperuricaemia, means that there is a continued need for new and effective urate-lowering treatments. The evaluation of these treatments will require a comprehensive and comparative evidence base describing the economic and humanistic burden of gout, taken from the perspective of patients, the healthcare system, and wider society.

OBJECTIVE

The objective of this study is to review and summarise the current evidence of the disease burden related to chronic gout, assessed in terms of both cost and health-related quality of life (HRQL), and to identify key factors correlated with an increased burden. The overall aim is to support the economic evaluation of new treatments for gout, and to highlight key data gaps that may need further study and exploration.

METHODS

Relevant literature dating from January 2000 to July 2014 was sourced through searches of the MEDLINE database via PubMed and The Cochrane Library. Articles published in English and reporting either the economic burden (cost) or the humanistic burden (HRQL/utility) of gout were identified, and key data were extracted and summarised, with key themes and data gaps identified and discussed.

RESULTS

Of the 323 studies identified, 39 met the inclusion criteria, of which 17 and 26 were relevant to the economic and humanistic burden, respectively. The economic burden of gout varied according to numerous factors, most notably serum urate acid levels and number of flares and tophi, resulting in higher healthcare resource use most often attributed to hospitalisation and inpatient stay. The incremental direct cost of gout has been suggested in the range of US$3165 to US$5515 (2004 and 2005 values, respectively) climbing to US$10,222 to US$21,467 (2008 values) per annum where patients are experiencing regular acute flares and have tophi present. The humanistic burden of gout was largely due to physical disability and pain resulting from chronic clinical manifestations. Short Form 6 dimensions (SF-6D) assessed utility weights are estimated at 0.53 for a patient with severe gout (≥3 flares/year and tophi) compared with 0.73 for an asymptomatic gout patient with serum acid levels <6 mg/dl.

CONCLUSIONS

The evidence confirms that gout has a growing overall prevalence and represents a significant burden in terms of both direct healthcare cost and HRQL outcomes. In light of this, effective urate-lowering treatments are likely to be valued if they can be clearly demonstrated to be both clinically effective and cost effective. Published data to support healthcare decision making in non-US countries with regards to treatments for gout are currently limited, which is a key limitation of the current evidence base. More research is also required to extend our understanding of the impact of gout on indirect costs, and a need also exists to develop a more comprehensive set of comparative HRQL utility assessments.

Hospital burden of gout, pseudogout and other crystal arthropathies in France

OBJECTIVE

To describe the hospital burden of microcrystal arthropathies in France.

METHODS

Data were extracted from the 2009-2011 French hospital national databases. We selected all hospital stays for microcrystal arthropathies (gout, chondrocalcinosis, other) encoded as primary or secondary diagnoses in patients older than 18. A descriptive analysis focused on number of patients and hospital stays, age, gender, comorbidities related to metabolic syndrome, and hospital costs based on 2012 public-sector costs.

RESULTS

132,275 hospitalizations involving 109,734 patients were related to microcrystal arthropathies encoded as primary or secondary diagnosis (61% related to gout, 34% to chondrocalcinosis, and 5% to other microcrystal arthropathies). 23,362 hospitalizations involving 25,105 patients were due to microcrystal diseases, encoded as primary diagnosis, (48% related to gout, 43% to chondrocalcinosis, and 9% to other microcrystal arthropathies). In this population, patients with chondrocalcinosis were older (mean 75.6±13.5 versus 71±16 years for other microcrystal arthropathies and 69.7±14.7 for gout). Men represented 70% of the patients with gout, 39% of those with chondrocalcinosis and 52% of the patients with other microcrystal arthropathies. Hypertension, diabetes, dyslipidemia, cardiac ischemia, and renal failure were more frequent in patients with gout than other patients. The hospital costs for microcrystal arthropathies encoded as primary diagnosis were 82.3 million Euros, 45% related to gout, 45% to chondrocalcinosis and 11% to other microcrystals.

CONCLUSION

In terms of hospital costs, gout and chondrocalcinosis represented the main part of the economic burden of crystal arthropathies and a high level of diseases belonging to the metabolic syndrome. Specific education programs favouring accurate microcrystal diagnosis and adherence to treatment could diminish this hospital economic burden.

The economic burden of gout: A systematic review

OBJECTIVE

Gout is a painful and disabling joint disease that constitutes the most common inflammatory arthritis in the US. To clarify the economic impact of gout, we systematically reviewed the literature on the direct and indirect costs associated with this disease.

METHODS

We conducted a literature search of MEDLINE, EMBASE, International Pharmaceutical Abstracts, NHS Economic Evaluation, and CINAHL databases to identify studies of gout and economics. We systematically reviewed published studies that met our inclusion criteria and extracted and summarized all relevant economic parameters. Reported costs were inflation-adjusted to 2013 US dollars (USD).

RESULTS

A total of 15 studies met all eligibility criteria. Three controlled studies reported all-cause total direct costs based on specific populations (i.e., $4733, $16,925, and $18,362 per capita among employed, elderly, and treatment-refractory gout populations, respectively, and $2562, $10,590, and $7188 among corresponding non-gout patients). Two additional studies, although uncontrolled, allowed for estimation of total all-cause direct costs in unselected gout populations ($11,080 and $13,170). Gout-related costs ranged from $172 to $6179, depending on population characteristics. Six studies reported positive associations of direct costs with SUA level, gout attack frequency, or presence of tophi. Four studies reported on indirect costs, which were estimated to be as high as $4341 USD.

CONCLUSION

The available data suggest that gout patients incur substantially greater direct and indirect costs as compared with gout-free individuals among elderly and treatment-refractory gouty patients, whereas the costs are considerably less among younger, employed gouty patients. Further, direct costs increased with worsening disease characteristics.

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.

Cost-effectiveness of febuxostat in chronic gout

Our objective was to evaluate data on the cost-effectiveness of febuxostat compared with standard clinical practice with allopurinol in patients with gout that was presented to the Scottish Medicines Consortium (SMC) in 2010. A Markov health-state model estimated the direct health-related costs and clinical benefits expressed as quality-adjusted life-years (QALYs). Adults with chronic gout and established hyperuricaemia received treatment sequences of daily doses of allopurinol 300 mg alone or allopurinol 300 mg followed by febuxostat 80 mg/120 mg. The proportion of patients achieving the target serum uric acid (sUA) level of less than 6 mg/dl (0.36 mmol/l) was linked to the utility per sUA level to generate an incremental cost-effectiveness ratio (ICER). Second-line therapy with febuxostat 80 mg/120 mg versus with allopurinol alone resulted in an ICER of £3,578 per QALY over a 5-year time horizon. Additional univariate analyses showed that ICER values were robust and ranged from £2,550 to £7,165 per QALY when different parameters (e.g., low- and high-dose allopurinol titrations and variations in treatment-induced flare rates) were varied. Febuxostat reduces sUA below the European League Against Rheumatism target of 0.36 mmol/l (6 mg/dl) in significantly more patients with gout than allopurinol in its most frequently prescribed dose of 300 mg per day. The SMC accepted febuxostat as cost-effective as a suitable second-line option for urate-lowering therapy for the treatment of patients with chronic hyperuricaemia in conditions where urate deposition has already occurred (including a history or presence of tophus and/or gouty arthritis) when treatment with allopurinol was inadequate, not tolerated, or contraindicated.

Epidemiology of gout

Gout is the most prevalent inflammatory arthritis in men. The findings of several epidemiologic studies from a diverse range of countries suggest that the prevalence of gout has risen over the past few decades. Although incidence data are scarce, data from the United States suggests that the incidence of gout is also rising. Evidence from prospective epidemiologic studies has confirmed dietary factors (animal purines, alcohol, and fructose), obesity, the metabolic syndrome, hypertension, diuretic use, and chronic kidney disease as clinically relevant risk factors for hyperuricemia and gout. Low-fat dairy products, coffee, and vitamin C seem to have a protective effect.

Use of diuretics and risk of incident gout: a population-based case-control study

OBJECTIVE

Use of diuretics has been associated with an increased risk of gout. Data on different types of diuretics are scarce. We undertook this study to investigate the association between use of loop diuretics, thiazide or thiazide-like diuretics, and potassium-sparing agents and the risk of developing incident gout.

METHODS

We conducted a retrospective population-based case-control analysis using the General Practice Research Database established in the UK. We identified case patients who were diagnosed as having incident gout between 1990 and 2010. One control patient was matched to each case patient for age, sex, general practice, calendar time, and years of active history in the database. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs), and we adjusted for potential confounders.

RESULTS

We identified 91,530 incident cases of gout and the same number of matched controls. Compared to past use of diuretics from each respective drug class, adjusted ORs for current use of loop diuretics, thiazide diuretics, thiazide-like diuretics, and potassium-sparing diuretics were 2.64 (95% CI 2.47-2.83), 1.70 (95% CI 1.62-1.79), 2.30 (95% CI 1.95-2.70), and 1.06 (95% CI 0.91-1.23), respectively. Combined use of loop diuretics and thiazide diuretics was associated with the highest relative risk estimates of gout (adjusted OR 4.65 [95% CI 3.51-6.16]). Current use of calcium channel blockers or losartan slightly attenuated the risk of gout in patients who took diuretics.

CONCLUSION

Use of loop diuretics, thiazide diuretics, and thiazide-like diuretics was associated with an increased risk of incident gout, although use of potassium-sparing agents was not.

Tophi and frequent gout flares are associated with impairments to quality of life, productivity, and increased healthcare resource use: Results from a cross-sectional survey

Background

The prevalence of gout is increasing, and most research on the associated burden has focused on serum urate (sUA) levels. The present study quantifies the impact of the presence of tophi and frequency of acute gout attacks on health-related quality of life (HRQOL), productivity, and healthcare resource utilization.

Methods

Patients with self-reported gout (n = 620; 338 in US and 282 across France, Germany, and UK) were contacted based on inclusion in the 2010 US and EU National Health and Wellness Surveys (Kantar Health) and the Lightspeed Research ailment panel. Respondents were categorized into mutually-exclusive groups based on number of gout flares experienced in the past 12 months (0/don’t recall, 1–2, 3, 4–5, 6+), current presence of tophi (none, 1+, or not sure), and sUA level awareness (yes, no). HRQOL (SF-12v2), healthcare provider visits in the last 6 months, and work productivity and activity impairment (WPAI) were compared across groups.

Results

Most patients were males, mean age of 61 years, who reported experiencing at least one acute gout flare in the past 12 months, and 12.3% (n = 76) reported presence of tophi. Among the 27.7% (n = 172) of patients who were aware of their sUA levels, higher sUA was associated with more flares and tophi. Decreased HRQOL was associated with more frequent flares and presence of tophi. In multivariable models predicting outcomes based on presence of tophi and number of flares, both flares (≥4) and tophi (≥1) were associated with HRQOL decrements on physical and mental component summary scores and health utilities (all p < 0.05), after adjustment for age, gender, and time since diagnosis. Flares were also associated with greater activity impairment.

Conclusions

Impairments associated with gout flares and presence of tophi, across patients in the US and EU, underscore the importance of effective management of this potentially curable condition.

Systematic review of the prevalence of gout and hyperuricaemia in Australia

AIMS

Gout is a growing health problem worldwide especially in affluent countries, such as Australia. Gout and hyperuricaemia are associated with the metabolic syndrome, diabetes mellitus, obesity and hypertension. More importantly, Australia has a growing prevalence of these important health problems. The aim of this study was to systematically review published information regarding the prevalence of gout and hyperuricaemia in Australia.

METHODS

A systematic search was undertaken of the MEDLINE, EMBASE and Web of Science databases, as well as relevant websites for journal articles and reports relating to the prevalence of hyperuricaemia and gout in Australia.

RESULTS

Twenty-five journal articles and five reports were included in the review. Data collected in a standardised way show gout increased in prevalence from 0.5% population prevalence to 1.7% population prevalence from 1968 to 1995/1996. There has been a significant rise in the prevalence of gout in the Australian Aboriginal population from 0% in 1965 to 9.7% in men and 2.9% in women in 2002. Consistent with the rise in gout prevalence, serum uric acid in blood donors has increased from 1959 to 1980 (17% in 30- to 40-year-old men).

CONCLUSIONS

The rate of gout and hyperuricaemia in Australia is high in relation to comparable countries and is increasing. The prevalence of gout in elderly male Australians is second only to New Zealand, which has the highest reported rate in the world. Further research on Aboriginal and Torres Strait Islander gout and hyperuricaemia is required as a result of the lack of contemporary data.

Treating hyperuricemia of gout: safety and efficacy of febuxostat and allopurinol in older versus younger subjects

Despite an increasing incidence of gout in older age patients with multiple metabolic and cardiovascular comorbidities, there are limited data addressing whether currently available urate-lowering therapy is comparably effective and safe in older (≥65 years of age) versus younger (<65 years of age) patients. In this secondary analysis of data from the CONFIRMS trial, we found that among 374 older subjects, urate-lowering therapy with approved doses of febuxostat or commonly prescribed doses of allopurinol was at least comparable to that in 1894 younger subjects and was well tolerated despite high rates of renal impairment and cardiovascular comorbidities in the older subjects.

The efficacy and safety of febuxostat for urate lowering in gout patients ≥65 years of age

Background

The incidence of gout rises with increasing age. Management of elderly (≥65 years) gout patients can be challenging due to high rates of comorbidities, such as renal impairment and cardiovascular disease, and concomitant medication use. However, there is little data specifically addressing the efficacy and safety of available urate-lowering therapies (ULT) in the elderly. The objective of this post hoc analysis was to examine the efficacy and safety of ULT with febuxostat or allopurinol in a subset of elderly subjects enrolled in the CONFIRMS trial.

Methods

Hyperuricemic (serum urate [sUA] levels ≥ 8.0 mg/dL) gout subjects were enrolled in the 6-month, double-blind, randomized, comparative CONFIRMS trial and randomized, 1:1:1, to receive febuxostat, 40 mg or 80 mg, or allopurinol (200 mg or 300 mg based on renal function) once daily. Flare prophylaxis was provided throughout the study duration.

Study endpoints were the percent of elderly subjects with sUA <6.0 mg/dL at the final visit, overall and by renal function status, percent change in sUA from baseline to final visit, flare rates, and rates of adverse events (AEs).

Results

Of 2,269 subjects enrolled, 374 were elderly. Febuxostat 80 mg was significantly more efficacious (82.0%) than febuxostat 40 mg (61.7%; p < 0.001) or allopurinol (47.3%; p < 0.001) for achieving the primary efficacy endpoint. Febuxostat 40 mg was also superior to allopurinol in this population (p = 0.029). In subjects with mild-to-moderate renal impairment, significantly greater ULT efficacy was observed with febuxostat 40 mg (61.6%; p = 0.028) and febuxostat 80 mg (82.5%; p < 0.001) compared to allopurinol 200/300 mg (46.9%). Compared to allopurinol 200/300 mg, the mean percent change in sUA from baseline was significantly greater for both febuxostat 80 mg (p < 0.001) and febuxostat 40 mg (p = 0.011) groups. Flare rates declined steadily in all treatment groups. Rates of AEs were low and comparable across treatments.

Conclusions

These data suggest that either dose of febuxostat is superior to commonly prescribed fixed doses of allopurinol (200/300 mg) in subjects ≥65 years of age with high rates of renal dysfunction. In addition, in this high-risk population, ULT with either drug was well tolerated.

Trial registration

clinicaltrials.gov NCT#00430248

Use of diuretics and the risk of gouty arthritis: a systematic review

OBJECTIVE

To systematically review the literature investigating the relationship between use of diuretics and the risk of gouty arthritis.

METHODS

PubMed (1950-October 2009), Embase (1974-October 2009), and the Cochrane Library (up to October 2009) were searched using keywords and MeSH terms diuretics, adverse effects, and gout. For this review, the technique of "best evidence synthesis" was used. Studies reporting frequency, absolute or relative risks, odds ratio, or rate ratio of gouty arthritis in diuretic users compared with nonusers were selected and evaluated. Studies had to be published in English. Checklists from the Dutch Cochrane Centre were used to assess the quality of randomized controlled trials (RCTs), cohort, and case-control studies.

RESULTS

Two RCTs, 6 cohort studies, and 5 case-control studies met the inclusion criteria. The overall quality of the studies was moderate. In a RCT the rate ratio of gout for use of bendrofluazide vs placebo was 11.8 (95% CI 5.2-27.0). The other RCT found a rate ratio of 6.3 (95% CI 0.8-51) for use of hydrochlorothiazide plus triamterene vs placebo. Three cohort studies and 4 case-control studies found higher risks of gouty arthritis in users compared with nonusers of diuretics.

CONCLUSIONS

There is a trend toward a higher risk for acute gouty arthritis attacks in patients on loop and thiazide diuretics, but the magnitude and independence is not consistent. Therefore, stopping these useful drugs in patients who develop gouty arthritis is not supported by the results of this review.

Risk factors for gout and prevention: a systematic review of the literature

PURPOSE OF REVIEW

Our objective was to perform a systematic review of risk factors and prevention of gout. We searched Medline for fully published reports in English using keywords including but not limited to 'gout', 'epidemiology', 'primary prevention', 'secondary prevention', 'risk factors'. Data from relevant articles meeting inclusion criteria were extracted using standardized forms.

RECENT FINDINGS

Of the 751 titles and abstracts, 53 studies met the criteria and were included in the review. Several risk factors were studied. Alcohol consumption increased the risk of incident gout, especially beer and hard liquor. Several dietary factors increased the risk of incident gout, including meat intake, seafood intake, sugar sweetened soft drinks, and consumption of foods high in fructose. Diary intake, folate intake, and coffee consumption were each associated with a lower risk of incident gout and in some cases a lower rate of gout flares. Thiazide and loop diuretics were associated with higher risk of incident gout and higher rate of gout flares. Hypertension, renal insufficiency, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, diabetes, obesity, and early menopause were each associated with a higher risk of incident gout and/or gout flares.

SUMMARY

Several dietary risk factors for incident gout and gout flares are modifiable. Prevention and optimal management of comorbidities are likely to decreased risk of gout. Research in preventive strategies for the treatment of gout is needed.

Health care utilization in patients with gout

OBJECTIVE

To study health care utilization patterns in patients with gout.

METHODS

In a gout population from primary care and rheumatology clinics in 3 U.S. metropolitan cities, we collected data on gout-related utilization (primary care, rheumatology, urgent care, emergency room, and other) in the past year. We evaluated the association of comorbidities, age, gender, gout characteristics (time since last gout attack and tophi), and gout severity ratings (mean of serum uric acid, patient-rated, and physician-rated gout severity) and with emergency/urgent care and primary care utilization using regression and correlation analyses.

RESULTS

Of the 296 patients who reported visiting at least 1 type of health practitioner for gout in the past year, the percentage of patients utilizing the service at least once and annual utilization rates among utilizers were as follows: primary care physician, 60%, 3.0 ± 3.4; nurse practitioner/physician assistant, 26%, 2.7 ± 2.5; rheumatologist, 51%, 3.7 ± 5.7; urgent care, 23%, 2.1 ± 2.2; emergency room, 20%, 2.0 ± 1.7; and hospitalization, 7%, 2.1 ± 1.4. Higher overall gout severity was associated with greater use of each resource type and with overall gout-related utilization. Nonemergency/nonurgent care utilization (primary care physician, nurse practitioner, physician's assistant, and rheumatologist for gout) was the strongest predictor of gout-related emergency/urgent care utilization. Patients with more comorbidities had greater gout-related primary care utilization.

CONCLUSIONS

Overall gout severity was associated with all types of gout-related utilization. This may help to screen high utilizers for targeted behavioral and therapeutic interventions. Having a higher number of comorbid conditions was a risk factor for higher gout-related primary care utilization.

Adherence to treatment guidelines in two primary care populations with gout

Published guidelines for the treatment of gout aim to improve the evidenced-based management of this disorder. Unfortunately, several studies suggest that these guidelines are not routinely followed in clinical practice. Limited data exist comparing different groups of primary care providers regarding compliance with published gout guidelines. We conducted a retrospective study comparing two different general internal medicine (IM) practices and evaluated compliance with these guidelines. All patients with a billing code for gout seen in two large IM clinics (Clinic A, an inner-city urban clinic, and Clinic B, a suburban clinic) between January 2004 and December 2007 were selected for chart review. Patients referred to a rheumatologist for management of gout were excluded. The care received by these patients for gout was compared to recommendations from published guidelines, with the primary outcome assessing the percentage of patients who received at least yearly monitoring of serum uric acid (SUA) levels. In both clinics, yearly monitoring of SUA levels occurred in approximately one quarter of the patients with gout (Clinic A 27.5% vs. Clinic B 28.9%, P = 0.87). Compared to SUA, renal function was monitored more frequently in each of the groups. Listed indications for antihyperuricemic therapy were similar between groups, although gouty flares were reported more frequently in clinic B (P = 0.005). In this retrospective review of gout management in two IM clinics, general care for patients with this condition did not differ significantly. However, overall compliance with recommendations from published guidelines was low.