Factors associated with initiation and persistence of urate-lowering therapy

Improving Gout Care in a Canadian Academic Medical Center Through a Multidisciplinary, Nurse-Led Protocol

OBJECTIVE

Following Health Canada's knowledge translation framework, we report the results of a clinical audit from 2012 to 2015 followed by a multidisciplinary, nurse-led gout care protocol with a treat-to-target (T2T) strategy implemented in April 2018.

METHODS

A clinical audit with chart reviewing was completed for adults with gout and urate-lowering therapy (ULT) indication at the Centre Hospitalier Universitaire de Sherbrooke. A nurse-led treatment algorithm using allopurinol was then developed. Titration of ULT by a nurse every 4 weeks was done until serum uric acid (SUA) target. In the postprotocol implementation, adults with gout and ULT indication were retrospectively recruited through a billing agency until December 2020. The main outcome was SUA target achievement at 6 months.

RESULTS

Of 50 patients identified in the audit, 31% reached SUA target at 6 months and 16% were lost to follow-up. A 74-patient postprotocol implementation cohort was recruited, with 43 in the protocol group and 31 under usual care. Most prevalent ULT indication was ≥ 2 gout attacks per year (n = 52) at 70%. Target SUA was reached in 65% (n = 28) in the protocol group at 6 months compared to 19% (n = 6) in the usual care group (P < 0.001). Failing to titrate medication in the usual care group was the leading cause for nonachievement of SUA target at 6 months. Five percent of patients were lost to follow-up, all in the usual care group.

CONCLUSION

A multidisciplinary, nurse-led protocol with a T2T strategy implemented after a clinical audit significantly improved gout care. Such protocol could be replicated elsewhere in Canada.

Allopurinol use and risk of acute coronary syndrome in gout patients: a population-based cohort study in Sweden

OBJECTIVES

To investigate the impact of allopurinol use on the risk of first-ever acute coronary syndrome (ACS) event in patients with gout.

METHODS

Using national and regional register data, we included all patients with a gout diagnosis at primary or specialised care in Western Sweden in the period 2007-2017 (n=18 862; 67% male patients). Patients with a prior history of coronary heart disease (CHD) were excluded. Follow-up started at the first gout diagnosis and ended at the first-ever ACS event, death or study end. The main outcome was the risk of first-ever ACS in: (1) allopurinol users versus non-users, by defining three categories of allopurinol exposure: exposed to 100 mg, >100 mg and no exposure (reference) and (2) allopurinol initiators (within 125 days) versus long-term users (reference). Multivariable logistic regression analysis was used to calculate ORs and 95% CIs.

RESULTS

In analysis 1 (n=18 862), 15.3% (n=2892) were exposed to 100 mg, 9.1% (n=1717) to >100 mg and 75.6% (n=14 253) were not exposed. Allopurinol users were older and had more comorbidities compared with non-users. Allopurinol exposure (100 mg and >100 mg) was associated with significantly lower odds of first-ever ACS (OR 0.77; 95% CI 0.63 to 0.94, and OR 0.61; 95% CI 0.47 to 0.81, respectively). In Analysis 2, allopurinol initiators (n=489) had significantly higher odds of first-ever ACS compared with long-term users (n=2916) (OR 1.68; 95% CI 1.03 to 2.75).

CONCLUSIONS

In patients with gout and without CHD, long-term allopurinol use protects against first-ever ACS compared with non-users. In contrast, allopurinol initiators, possibly having more systemic inflammation, had a higher risk of first-ever ACS compared with long-term users.

Gout: An Overlooked Disease in Patients With Diabetes? A Danish Prospective Cohort Study With 2 Years of Follow-Up

Diabetes affects approximately 6% of the population, with 20% developing foot ulcers. Gout affects about 3% of the population, but <40% receive sufficient urate-lowering therapy to prevent or dissolve urate crystal (tophi) deposition in the feet, which can ulcerate and become infected. Among patients with diabetes, 20% also have gout. This study aimed to assess adherence to recommended gout treatment in patients with diabetes and to compare usual care with initial care provided by a nurse-led gout care program. In patients with diabetes, gout is frequently undertreated, particularly when not initially managed in a nurse-led gout care program.

Optimising gout treatment: insights from a nurse-led cohort study

OBJECTIVES

Currently, gout management, particularly urate-lowering therapy (ULT), is often suboptimal. Nurses successfully manage various diseases including gout. As gout prevalence is rising, and rheumatologists and general practitioners face shortages, a new approach is imperative. This real-life prospective cohort study evaluated the effectiveness of nurse-led care employing a treat-to-target strategy for gout management over a 2-year period.

METHODS

All consecutively confirmed gout patients were included. The nurse-led clinic provided a structured treatment plan with consultations, patient leaflets, telephone contacts and laboratory monitoring. After a year of nurse-led care, patients transitioned to continued care in general practice. Follow-up data were complete through registries. The primary outcome was achieving target p-urate levels (<0.36 mmol/L) at 2 years after diagnosis. Secondary outcomes included treatment continuation and achievement of target p-urate levels in specific subgroups. The results were compared with patients diagnosed in the same clinic but followed up in 'usual care'.

RESULTS

In the nurse-led group (n=114), 83% achieved target p-urate levels and ULT was continued by 98%. This trend persisted across various patient subgroups. Only 44% of patients in usual care achieved target p-urate and with insufficient doses of allopurinol . Nurse-led care involved an average of two visits and three telephone contacts over 336 days. The 2-year mortality rate was 15%.

CONCLUSIONS

Nurse-led gout care, employing a targeted approach, was associated with a very high uptake of and adherence to ULT. The encouraging results were not achieved in usual care although a direct comparison might be influenced by selection bias.

Sex and country differences in gout: cross-country comparison between Sweden and the UK

OBJECTIVE

Compare characteristics, sex differences, and management of gout in Sweden and the UK.

METHOD

The results from two separate primary care gout surveys from Sweden and the UK were compared. Participants aged ≥18 years with gout were sent a questionnaire asking about lifestyle, gout characteristics, uratelowering therapy (ULT), comorbidities, disability, and disease impact. For sex comparison, participants were pooled across countries.

RESULTS

In total, 784 (80% male) participants from Sweden and 500 (87% male) from the UK were included. Swedish patients were significantly older at gout onset, mean (SD) age 72 (12) versus 63 (13) years, (p<0.0001), with more comorbidities, and more frequent use of ULT (48% vs 35%, p=0.0005, age-adjusted). Use of alcohol and diuretics was significantly more common among UK patients, who also reported a higher number of gout flares, mean (SD) 2.2 (1.7) versus 1.6 (3.6), (p=0.003) age-adjusted. Females with gout were older at gout onset, mean (SD) age 67 (13) versus 56 (15), (p<0.0001), more often obese, and reported higher use of diuretics. Furthermore, females reported greater impact of gout, more pain and physical limitations, whereas no sex differences were seen in ULT or flares.

CONCLUSIONS

In the UK, gout was more frequently associated with modifiable risk factors. People with gout in Sweden were more commonly taking ULT and had lower frequency of gout flares and impact of gout. Females with gout more commonly took diuretics, had higher body mass index, and reported greater physical disability, which should be considered when managing gout in women.

Gout in Dalarna, Sweden - a population-based study of gout occurrence and compliance to treatment guidelines

OBJECTIVE

This study aimed to describe the incidence and prevalence of gout, describe the use of allopurinol among prevalent gout cases, and determine persistence with allopurinol and degree of compliance with treat-to-target recommendations before and after the publication of Swedish national guidelines in 2016.

METHOD

Prospectively registered data on gout diagnoses and allopurinol prescriptions were used to calculate incidence and prevalence, and the proportion of prevalent patients on allopurinol. Gout patients starting allopurinol during 2013-2015 versus 2016-2018 were compared regarding persistence and compliance with treat-to-target principles.

RESULTS

The incidence of gout was 221-247 per 100 000 person-years during 2014-2019, prevalence in 2018 was 2.45%. Among prevalent cases, the proportion on allopurinol ranged from 21% to 25%. Allopurinol persistence was better for individuals starting therapy during 2016-2018 compared with 2013-2015 (45% vs 39%, p = 0.031), as were several outcomes related to treat-to-target principles, e.g. measuring baseline serum urate (SU) (84% vs 77%, p < 0.001), follow-up SU (50% vs 36%, p < 0.001), and the proportion of patients reaching an SU level < 360 µmol/L (45% vs 30%, p < 0.001).

CONCLUSION

Incidence and prevalence were slightly higher than in previous Swedish reports. Allopurinol use among prevalent gout patients did not increase during 2014-2019. Only a minor improvement in persistence was seen, and a moderate increase in compliance with guidelines, suggesting a need for improved management and extended patient involvement to increase and optimize the use of urate lowering therapy.

Gender differences in illness perceptions and disease management in patients with gout, results from a questionnaire study in Western Sweden

BACKGROUND

Aims were to examine gender differences in patients with gout with regard to a) self-reported gout severity, b) illness perceptions (IP), c) impact on daily activities and Quality of Life (QoL), d) advice from healthcare professionals, e) having changed dietary- or alcohol habits.

METHODS

Adult patients with gout identified in primary and secondary care in Sweden between 2015 and 2017 (n = 1589) were sent a questionnaire about demographics, gout disease severity, IP (using the Brief Illness Perception Questionnaire, (B-IPQ)) and disease management. T-tests, Chi square tests, ANalysis Of VAriance (ANOVA) and linear regression models were used for gender comparisons.

RESULTS

Eight hundred sixty-eight patients responded to the questionnaire. Women, n = 177 (20%), experienced more severe gout symptoms (p = 0.011), albeit similar frequencies of flares compared to men. Women experienced modest but significantly worse IP with regard to consequences, identity, concerns and emotional response (p < 0.05) as well as daily activities such as sleeping (p < 0.001) and walking (p = 0.042) and QoL (p = 0.004). Despite this and a higher frequency of obesity in women (38 vs 21%, P < 0.001) and alcohol consumption in men (p < 0.001), obese women had received significantly less advice regarding weight reduction (47 vs 65%, p = 0.041) compared to obese men. On the other hand, women reported having acted on dietary advice to a larger degree.

CONCLUSIONS

Despite only modestly worse gout severity and perception, women appear to have been given less information regarding self-management than men. These gender differences should be given attention and addressed in clinical care.

Management of gout following 2016/2017 European (EULAR) and British (BSR) guidelines: An interrupted time-series analysis in the United Kingdom

Background

Following studies reporting sub-optimal gout management, European (EULAR) and British (BSR) guidelines were updated to encourage the prescription of urate-lowering therapy (ULT) with a treat-to-target approach. We investigated whether ULT initiation and urate target attainment has improved following publication of these guidelines, and assessed predictors of these outcomes.

Methods

We used the Clinical Practice Research Datalink to assess attainment of the following outcomes in people (n = 129,972) with index gout diagnoses in the UK from 2004-2020: i) initiation of ULT; ii) serum urate ≤360 µmol/L and ≤300 µmol/L; iii) treat-to-target urate monitoring. Interrupted time-series analyses were used to compare trends in outcomes before and after updated EULAR and BSR management guidelines, published in 2016 and 2017, respectively. Predictors of ULT initiation and urate target attainment were modelled using logistic regression and Cox proportional hazards.

Findings

37,529 (28.9%) of 129,972 people with newly-diagnosed gout had ULT initiated within 12 months. ULT initiation improved modestly over the study period, from 26.8% for those diagnosed in 2004 to 36.6% in 2019 and 34.7% in 2020. Of people diagnosed in 2020 with a serum urate performed within 12 months, 17.1% attained a urate ≤300 µmol/L, while 36.0% attained a urate ≤360 µmol/L. 18.9% received treat-to-target urate monitoring. No significant improvements in ULT initiation or urate target attainment were observed after updated BSR or EULAR management guidance, relative to before. Comorbidities, including chronic kidney disease (CKD), heart failure and obesity, and diuretic use associated with increased odds of ULT initiation but decreased odds of attaining urate targets within 12 months: CKD (adjusted OR 1.61 for ULT initiation, 95% CI 1.55 to 1.67; adjusted OR 0.51 for urate ≤300 µmol/L, 95% CI 0.48 to 0.55; both p < 0.001); heart failure (adjusted OR 1.56 for ULT initiation, 95% CI 1.48 to 1.64; adjusted OR 0.85 for urate ≤300 µmol/L, 95% CI 0.76 to 0.95; both p < 0.001); obesity (adjusted OR 1.32 for ULT initiation, 95% CI 1.29 to 1.36; adjusted OR 0.61 for urate ≤300 µmol/L, 95% CI 0.58 to 0.65; both p < 0.001); and diuretic use (adjusted OR 1.49 for ULT initiation, 95% CI 1.44 to 1.55; adjusted OR 0.61 for urate ≤300 µmol/L, 95% CI 0.57 to 0.66; both p < 0.001).

Interpretation

Initiation of ULT and attainment of urate targets remain poor for people diagnosed with gout in the UK, despite updated management guidelines. If the evidence-practice gap in gout management is to be bridged, strategies to implement best practice care are needed.

Funding

National Institute for Health Research.

Professionals' perspectives on existing practice and conditions for nurse-led gout care based on treatment recommendations: a qualitative study in primary healthcare

BACKGROUND

Gout affects nearly 2 % of the population and is associated with repeated painful flares of arthritis. Preventive urate-lowering therapy is widely available, but only one third of patients receive adequate treatment. Lack of knowledge among healthcare professionals and patients within primary healthcare are implicated as partial explanations for this undertreatment. Nurse-led care has proved to be an effective model when treating patients with gout, but there is a need for more knowledge about factors that can be expected to influence the future implementation of such care. The aim of this study was to describe factors influencing existing gout care in primary healthcare and the conditions for a future implementation of nurse-led gout care based on national treatment recommendations.

METHODS

In this qualitative study, focus group discussions with 56 nurses and physicians and individual interviews with eight managers were conducted at nine primary healthcare units in central Sweden. A deductive qualitative content analysis based on the main constructs of the framework Integrated Promoting Action on Research Implementation in Health Services was followed by an inductive analysis within the frames of the main constructs: innovation, recipients and context.

RESULTS

Gout-related contacts with primary healthcare was described as being patient initiated, diagnostics was in some respects complex and nurse-led care was experienced as a favourable primary healthcare model in general (innovation). Gout was seen as a low-priority condition with acute flares and there was inadequate knowledge of gout, including preventive treatment (recipients). Primary healthcare was perceived as having a holistic but fragmented responsibility for gout care, recommendations against keeping waiting lists complicated follow-up appointments and a need for motivation and support when introducing new practices was emphasised (context).

CONCLUSION

In this study, investigating the perspective of professionals, several factors were found to influence existing gout care. It will be crucial to target these factors in the development of a future implementation strategy.

Incident Gout: Risk of Death and Cause-Specific Mortality in Western Sweden: A Prospective, Controlled Inception Cohort Study

Background

Excess mortality in gout has been attributed to cardiovascular diseases (CVD). Considering the decline in CVD mortality in the general population, we wanted to evaluate overall mortality in gout and cause-specific contributions to mortality beyond CVD and temporal trends.

Methods

All incident cases of gout between 2006 and 2015 in western Sweden and 5 population controls per case matched for age, sex, and county were identified. Comorbidities were identified for 5 years preceding the index date. Follow-up ended at death, migration, or end of study on December 2017. Effect of gout on death risk was calculated using COX regression on the whole population and stratified by sex, adjusted for demographics, and comorbidities. Death incidence rates were compared between the two time periods, 2006-2010 and 2011-2015.

Results

We identified 22,055 cases of incident gout and 98,946 controls, median age (Q1, Q3) 69-68 (57, 79/56, 78) years and 67.6-66.5% males. Except for dementia, all comorbidities were significantly more common at baseline among gout cases. Overall, the risk for death in incident gout was neither increased overall nor in men, but women had a 10% elevated risk. In adjusted models for cause-specific mortality, death from CVD, renal disease, and digestive system diseases were significantly increased in the total gout population while death from dementia, cancer, and lung diseases were significantly decreased. There were no significant differences in overall incident death rate ratios between cases and controls in the two time periods examined.

Conclusions

An increased risk for CVD, renal disease, and diseases of the digestive system in patients with gout highlights the importance of addressing CVD risk factors in gout management. Gout was associated with reduced mortality from dementia, which may have implications on urate lowering therapy and possible effects on dementia risk.

Lifestyle factors and comorbidities in gout patients compared to the general population in Western Sweden: results from a questionnaire study

OBJECTIVE

This study aimed to identify lifestyle factors associated with gout in patients with prevalent gout compared to the general population.

METHOD

Adult patients with gout identified in primary and secondary care in Western Sweden between 2015 and 2017 were sent a questionnaire asking about demographics, lifestyle, and comorbidities. Five age- and gender-matched controls were identified in a random sample of 52 348 individuals aged 16-84 years who participated in the National Public Health survey in Sweden, year 2015. Logistic regression models were used to compare cases and controls with regard to lifestyle factors and comorbidities.

RESULTS

Of the 1589 invited gout patients, 868 (55%) responded. After matching for age and gender, 728 were included in the analysis (82.4% male; mean ± sd age 69.3 ± 10.5 years for men and 71.8 ± 9.9 years for women with gout). Male and female gout patients were significantly more likely to be overweight or obese (men 79% vs 66%; women 78.5% vs 65.3%), to have binge-drinking behaviour (men 29.9% vs 11%; women 13.7% vs 2.9%), and to be ex-smokers, compared to controls. Moreover, male gout patients reported lower levels of physical activity, while diabetes and hypertension were more common in both genders with gout than in controls.

CONCLUSION

In this questionnaire study, gout patients reported significantly more obesity and binge-drinking behaviour and less physical activity than controls. This suggests that there are great unmet needs for the management of lifestyle factors, particularly regarding overweight/obesity and binge drinking, in patients with gout.

Treat-to-Target urate-lowering therapy in primary gout patients: A real-world retrospective study at a dedicated gout clinic in China

BACKGROUND

Gout is the most common inflammatory arthritis affecting 1.1% of the population in mainland China with a higher prevalence in coastal areas.

OBJECTIVE

The purpose of the study was to investigate the clinical outcomes following urate-lowering therapy (ULT) in a real-world group study of primary gout patients in China.

METHODS

Electronic medical records of all the gout patients (n= 1588) that visited the Clinical Medical Center of Gout of the Affiliated Hospital of Qingdao University from September 2016 to February 2018 were analyzed in this study. The patients were treated with a standard treat-to-target (T2T) ULT strategy according to the 2016 EULAR Guidelines. Clinical data were collected in the first visit and one-month (defined as the baseline of ULT), 7-month, and 13-month follow-ups were completed.

RESULTS

Amongst the patients in the study, 92.70% accepted ULT and 82.93% completed ULT for 3 months, 63.54% for 6 months, and 40.49% (n= 643) for 12 months. Further analysis of the 643 patients included the following data: the sUA level reduced at month 7 and reduced further at month 13. The gout flares, patient global pain visual analogue score, and health assessment questionnaire score improved at month 7 but did not improve further at month 13, and the index tophus size did not.

Changing paradigms in the management of gout

The incidence and prevalence of gout have increased, as have comorbid obesity, diabetes mellitus, hypertension, chronic kidney and cardiovascular disease. Gout is now the commonest type of inflammatory arthritis despite availability of safe, effective and potentially 'curative' urate-lowering drugs. Modern imaging studies show that gout is a chronic inflammatory crystal deposition disorder even at the first acute attack and they illuminate the need to eliminate urate crystals by continuing reduction of the serum urate below its solubility threshold. Clinical outcomes, adherence to therapy and quality of gout care in primary care and hospital practice can be greatly improved by better use of allopurinol and flare prophylaxis, greater patient engagement, education and follow-up, and by nurse-led models of care that employ a 'treat-to-target' principle (SUA< 360 or 300µmol/l). Advances in understanding the physiology and genetic control of urate transport in the kidney and gut have led to novel, more selective uricosuric drugs, and basic research on mediators of urate crystal-induced inflammation has pointed to alternative therapeutic targets for treating and preventing gout flares. Current guidelines for the management of gout and indications for the use of some more recently introduced drugs; febuxostat, lesinurad, pegloticase and interleukin-1 antagonists are also briefly reviewed.

Gout of feet and ankles in different disease durations: diagnostic value of single-source DECT and evaluation of urate deposition with a novel semi-quantitative DECT scoring system

OBJECTIVES

To investigate the diagnostic performance of single-source dual-energy computed tomography (DECT) based on gemstone spectral imaging technology (including Discovery CT750HD and Revolution CT) in patients with suspected feet/ankles gouty arthritis, and evaluate the urate deposition with a novel semi-quantitative DECT scoring system.

METHODS

A total of 196 patients were consecutively included. Feet and ankles were evaluated in all patients by single-source DECT scan. The 2015 EULAR/ACR criteria were used as the reference for the diagnosis of gout. The sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of DECT for the diagnosis of gout in the early (≤1 year), middle (1-3 years), and late (> 3 years) disease durations were calculated. Besides, a novel semi-quantitative DECT scoring system was assessed for the measurement of urate deposition, and the correlation between the scores and the clinical and serological data were also evaluated. Moreover, the influences of artifacts on the diagnostic performance of DECT were also determined.

RESULTS

The sensitivity, specificity, and AUC of DECT in 196 patients were 38.10, 96.43%, and 0.673 in the early-stage group; 62.96, 100.00%, and 0.815 in the middle-stage group; and 77.55, 87.50%, and 0.825 in the late-stage group, respectively. The overall diagnostic accuracies in the AUC of DECT (Discovery CT750HD and Revolution CT) in the middle and late stages of gout were higher than that in the early stage of gout. Besides, the monosodium urate crystals were deposited on the first metatarsophalangeal joints and ankles/midfeet. Age, the presence of tophus, bone erosion, and disease duration considerably affected the total urate score. No statistical difference in the positive detection of nail artifact, skin artifact, vascular calcification, and noise artifact was found between the case and control groups.

CONCLUSION

DECT (Discovery CT750HD and Revolution CT) showed promising diagnostic accuracy for the detection of urate crystal deposition in gout but had limited diagnostic sensitivity for short-stage gout. Longer disease duration, the presence of tophus, and bone erosion were associated with the urate crystal score system. The artifacts do not remarkably affect the diagnostic performance of DECT in gout.

Global epidemiology of gout: prevalence, incidence, treatment patterns and risk factors

Gout is the most common inflammatory arthritis and occurs when hyperuricaemia, sustained elevation of serum urate levels resulting in supersaturation of body tissues with urate, leads to the formation and deposition of monosodium urate crystals in and around the joints. Recent reports of the prevalence and incidence of gout vary widely according to the population studied and methods employed but range from a prevalence of <1% to 6.8% and an incidence of 0.58-2.89 per 1,000 person-years. Gout is more prevalent in men than in women, with increasing age, and in some ethnic groups. Despite rising prevalence and incidence, suboptimal management of gout continues in many countries. Typically, only a third to half of patients with gout receive urate-lowering therapy, which is a definitive, curative treatment, and fewer than a half of patients adhere to treatment. Many gout risk factors exist, including obesity, dietary factors and comorbid conditions. As well as a firmly established increased risk of cardiovascular disease and chronic kidney disease in those with gout, novel associations of gout with other comorbidities have been reported, including erectile dysfunction, atrial fibrillation, obstructive sleep apnoea, osteoporosis and venous thromboembolism. Discrete patterns of comorbidity clustering in individuals with gout have been described. Increasing prevalence and incidence of obesity and comorbidities are likely to contribute substantially to the rising burden of gout.

Is HLA-B*58:01 genotyping cost effective in guiding allopurinol use in gout patients with chronic kidney disease?

Aim: Concerns for fatal severe cutaneous adverse reactions (SCARs) hamper allopurinol use. Methods and material: We adopted a health system perspective to evaluate the cost-effectiveness of HLA-B*58:01 genotyping before allopurinol initiation. A decision tree compared three treatment strategies in gout patients with chronic kidney disease who have higher risk for SCAR. They were standard allopurinol treatment followed by febuxostat in nonresponders, test-positive patients receive febuxostat while test-negative receive allopurinol and universal use of febuxostat. Results: The first strategy was the most cost effective. Genotyping dominated universal febuxostat use. Time horizon and SCAR incidence were the most influential factors on the incremental cost-effectiveness ratio. Conclusion: HLA-B*58:01 genotyping compared with standard allopurinol-febuxostat sequential treatment does not provide good value for money in gout with chronic kidney disease.

Dual energy CT findings in gout with rapid kilovoltage-switching source with gemstone scintillator detector

Background

A definite diagnosis of gout requires demonstration of monosodium urate crystals in synovial fluid or in tophi, which in clinical practice today seldom is done. Dual energy CT (DECT) has repeatedly been shown to be able to detect monosodium urate crystals in tissues, hence being an alternative method to synovial fluid microscopy. The vast majority of these studies were performed with CT scanners with two X-ray tubes. In the present study we aim to investigate if and at what locations DECT with rapid kilovoltage-switching source with gemstone scintillator detector (GSI) can identify MSU crystals in patients with clinically diagnosed gout. We also performed a reliability study between two independent readings.

Methods

Patients with new or established gout who had been examined with DECT GSI scanning of the feet at Sahlgrenska University Hospital, Mölndal between 2015 and 2018 were identified. Their medical records were sought for gout disease characteristics using a structured protocol. Urate deposits in MTP1, MTP 2–5, ankle/midfoot joints and tendons were scored semiquantatively in both feet and presence of artifacts in nail and skin as well as beam hardening and noise were recorded. Two radiologists performed two combined readings and scoring of the images, thus consensus was reached over the scoring at each occasion (Espeland et al., BMC Med Imaging. 2013;13:4). The two readings were compared with kappa statistics.

Results

DECT GSI could identify urate deposits in the feet of all 55 participants with gout. Deposits were identified in the MTP-joints of all subjects but were also present in ankle/midfoot joints and tendons in 96 and 75% respectively. Deposition of urate was predicted by longer disease duration (Spearman’s Rho 0.64, p < .0001) and presence of tophi (p = 0.0005). Artifacts were common and mostly found in the nails (73%), a minority displayed skin artifacts (31%) while beam hardening and noise was rare. The agreement between the two readings was good (Κ = 0.66, 95% CI = 0.61–0.71).

Conclusion

The validity of DECT GSI in gout is supported by the identification of urate in all patients with clinical gout and the good correlations with clinical characteristics. The occurrence of artifacts was relatively low with expected locations.

Variation in methods, results and reporting in electronic health record-based studies evaluating routine care in gout: A systematic review

OBJECTIVE

To perform a systematic review examining the variation in methods, results, reporting and risk of bias in electronic health record (EHR)-based studies evaluating management of a common musculoskeletal disease, gout.

METHODS

Two reviewers systematically searched MEDLINE, Scopus, Web of Science, CINAHL, PubMed, EMBASE and Google Scholar for all EHR-based studies published by February 2019 investigating gout pharmacological treatment. Information was extracted on study design, eligibility criteria, definitions, medication usage, effectiveness and safety data, comprehensiveness of reporting (RECORD), and Cochrane risk of bias (registered PROSPERO CRD42017065195).

RESULTS

We screened 5,603 titles/abstracts, 613 full-texts and selected 75 studies including 1.9M gout patients. Gout diagnosis was defined in 26 ways across the studies, most commonly using a single diagnostic code (n = 31, 41.3%). 48.4% did not specify a disease-free period before 'incident' diagnosis. Medication use was suboptimal and varied with disease definition while results regarding effectiveness and safety were broadly similar across studies despite variability in inclusion criteria. Comprehensiveness of reporting was variable, ranging from 73% (55/75) appropriately discussing the limitations of EHR data use, to 5% (4/75) reporting on key data cleaning steps. Risk of bias was generally low.

CONCLUSION

The wide variation in case definitions and medication-related analysis among EHR-based studies has implications for reported medication use. This is amplified by variable reporting comprehensiveness and the limited consideration of EHR-relevant biases (e.g. data adequacy) in study assessment tools. We recommend accounting for these biases and performing a sensitivity analysis on case definitions, and suggest changes to assessment tools to foster this.

Efficacy and cost-effectiveness of nurse-led care involving education and engagement of patients and a treat-to-target urate-lowering strategy versus usual care for gout: a randomised controlled trial

BACKGROUND

In the UK, gout management is suboptimum, with only 40% of patients receiving urate-lowering therapy, usually without titration to achieve a target serum urate concentration. Nurses successfully manage many diseases in primary care. We compared nurse-led gout care to usual care led by general practitioners (GPs) for people in the community.

METHODS

Research nurses were trained in best practice management of gout, including providing individualised information and engaging patients in shared decision making. Adults who had experienced a gout flare in the previous 12 months were randomly assigned 1:1 to receive nurse-led care or continue with GP-led usual care. We assessed patients at baseline and after 1 and 2 years. The primary outcome was the percentage of participants who achieved serum urate concentrations less than 360 μmol/L (6 mg/dL) at 2 years. Secondary outcomes were flare frequency in year 2, presence of tophi, quality of life, and cost per quality-adjusted life-year (QALY) gained. Risk ratios (RRs) and 95% CIs were calculated based on intention to treat with multiple imputation. This study is registered with www.ClinicalTrials.gov, number NCT01477346.

FINDINGS

517 patients were enrolled, of whom 255 were assigned nurse-led care and 262 usual care. Nurse-led care was associated with high uptake of and adherence to urate-lowering therapy. More patients receiving nurse-led care had serum urate concentrations less than 360 μmol/L at 2 years than those receiving usual care (95% vs 30%, RR 3·18, 95% CI 2·42-4·18, p<0·0001). At 2 years all secondary outcomes favoured the nurse-led group. The cost per QALY gained for the nurse-led intervention was £5066 at 2 years.

INTERPRETATION

Nurse-led gout care is efficacious and cost-effective compared with usual care. Our findings illustrate the benefits of educating and engaging patients in gout management and reaffirm the importance of a treat-to-target urate-lowering treatment strategy to improve patient-centred outcomes.

FUNDING

Arthritis Research UK.

The risk of clinically diagnosed gout by serum urate levels: results from 30 years follow-up of the Malmö Preventive Project cohort in southern Sweden

Background

Hyperuricemia (HU) is in the causal pathway for developing clinical gout. There are few population-based assessments of the absolute and relative risk of clinically diagnosed incident gout in subjects with HU. We aimed to explore the long-term risk of developing incident gout among asymptomatic adults with different levels of serum urate (SU).

Methods

Malmö Preventive Project was a population-based screening program for cardiovascular risk factors, alcohol abuse, and breast cancer in Malmö, Sweden. The study population was screened between 1974 and 1992. At baseline, subjects were assessed with a questionnaire, physical examination, and laboratory tests. Follow-up ended at first gout diagnosis, death, moving from area, or December 31, 2014. Incident gout (using ICD10 codes) was diagnosed based on national registers for specialized inpatient and outpatient care, and from 1998 onward in the Skåne Healthcare Register including primary healthcare. Incidence rates, absolute risk, hazard ratios (HRs) and potentially associated factors were analyzed by baseline SU levels, i.e. normal levels (≤ 360 μmol/L); 361–405 (levels below tissue solubility of SU), and > 405 (HU), overall, and by sex.

Results

Overall, 1275 individuals [3.8%; 1014 men (4.5%) and 261 women (2.4%)] of the 33,346 study participants (mean age: 45.7 (SD: 7.4), 67% men), developed incident gout during follow-up (mean 28.2 years). Of those with HU, 14.7% of men and 19.5% of women developed gout. Compared to subjects in the lowest SU category, the age-adjusted HR in men increased from 2.7 to 6.4, and in women from 4.4 to 13.1 with increasing baseline SU category, and with a statistically significant interaction of sex (p < 0.001). Body mass index, estimated glomerular filtration rate (negative), triglycerides, alcohol risk behavior (only in men), and comorbidities such as hypertension, cardiovascular disease, and diabetes were strongly associated with SU at baseline in both sexes.

Conclusions

The absolute risk for developing clinically diagnosed gout over 30 years in middle-aged subjects was 3.8%, and increased progressively in both men and women in relation to baseline SU. This risk increase was significantly higher in women than in men, whereas the associations between baseline risk markers and SU levels were similar in both sexes.

Comorbidity clusters in people with gout: an observational cohort study with linked medical record review

Objective

To investigate how comorbid conditions cluster in patients with gout in a UK primary care population.

Methods

A cross-sectional study was performed using baseline data from a primary-care-based prospective observational cohort of people aged ⩾18 years with gout. Participants with gout were identified through primary care medical records. Factor analysis was performed to obtain distinct clusters of comorbidity variables including obesity, hypertension, diabetes mellitus, hyperlipidaemia, coronary heart disease, heart failure, chronic kidney disease (CKD) and cancer. Hierarchical cluster analysis of patient observations was also performed to identify homogenous subgroups of patients based on combinations of their comorbidities.

Results

Four distinct comorbidity clusters (C1-C4) were identified in 1079 participants [mean (s.d.) age 65.5 years (12.5); 909 (84%) male]. Cluster C1 (n = 197, 18%) was the oldest group and had the most frequent attacks of gout; 97% had CKD. Participants in C2 (n = 393, 36%) had isolated gout with few comorbidities but drank alcohol more frequently. In cluster C3 (n = 296, 27%), hypertension, diabetes mellitus, hyperlipidaemia, coronary heart disease and/or CKD were prevalent, and urate-lowering therapy was prescribed more frequently than in other clusters. All patients in C4 (193, 18%) had hypertension and were more likely to be obese than other clusters.

Conclusion

Four distinct comorbidity clusters were identified. People with multiple comorbidities were more likely to receive allopurinol. Tailoring of treatments depending on cluster and comorbidities should be considered.

Cost-effectiveness analysis of HLA-B*58: 01 genetic testing before initiation of allopurinol therapy to prevent allopurinol-induced Stevens-Johnson syndrome/toxic epidermal necrolysis in a Malaysian population

OBJECTIVE

Studies found a strong association between allopurinol-induced Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and the HLA-B*58:01 allele. HLA-B*58:01 screening-guided therapy may mitigate the risk of allopurinol-induced SJS/TEN. This study aimed to evaluate the cost-effectiveness of HLA-B*58:01 screening before allopurinol therapy initiation compared with the current practice of no screening for Malaysian patients with chronic gout in whom a hypouricemic agent is indicated.

METHODS

This cost-effectiveness analysis adopted a societal perspective with a lifetime horizon. A decision tree model coupled with Markov models were developed to estimate the costs and outcomes, represented by quality-adjusted life years (QALYs) gained, of three treatment strategies: (a) current practice (allopurinol initiation without HLA-B*58:01 screening); (b) HLA-B*58:01 screening before allopurinol initiation; and (c) alternative treatment (probenecid) without HLA-B*58:01 screening. The model was populated with data from literature review, meta-analysis, and published government documents. Cost values were adjusted for the year 2016, with costs and health outcomes discounted at 3% per annum. A series of sensitivity analysis including probabilistic sensitivity analysis were carried out to determine the robustness of the findings.

RESULTS

Both HLA-B*58:01 screening and probenecid prescribing were dominated by current practice. Compared with current practice, HLA-B*58:01 screening resulted in 0.252 QALYs loss per patient at an additional cost of USD 322, whereas probenecid prescribing resulted in 1.928 QALYs loss per patient at an additional cost of USD 2203. One SJS/TEN case would be avoided for every 556 patients screened. At the cost-effectiveness threshold of USD 8695 per QALY, the probability of current practice being the best choice is 99.9%, in contrast with 0.1 and 0% in HLA-B*58:01 screening and probenecid prescribing, respectively. This is because of the low incidence of allopurinol-induced SJS/TEN in Malaysia and the lower efficacy of probenecid compared with allopurinol in gout control.

CONCLUSION

This analysis showed that HLA-B*58:01 genetic testing before allopurinol initiation is unlikely to be a cost-effective intervention in Malaysia.

Gout prevalence and predictors of urate-lowering therapy use: results from a population-based study

Background

Gout has an increasing global prevalence. Underutilization of urate-lowering therapy (ULT) is thought to be common, via both suboptimal dosing and poor medication adherence. The aims of this study were to determine the prevalence of self-reported gout and the key predictors of ULT use in those with gout in a representative population survey in South Australia.

Methods

Data were obtained from the Spring 2015 South Australian Health Omnibus Survey, a multilevel, systematic, survey in a representative population sample involving face-to-face interviews (n = 3005). This study analyzed responses from respondents aged ≥ 25 years (n = 2531) about self-reported gout, ULT use, sociodemographic factors, lifestyle factors, and comorbidities, using survey weighting. Univariate and subsequent adjusted logistic regression analyses on self-reported gout were performed. ULT use was divided into three categories (never use, prior use, and current use) and these data were analyzed using a multinomial logistic regression model.

Results

Self-reported gout prevalence was 6.8% (95% CI 5.8, 7.9). The mean age of respondents with gout was 64 years (standard deviation 16) and 82% were male. As expected, older age, male gender, lower socioeconomic status (SES), and higher body mass index (BMI) were associated with gout, as were high alcohol consumption, current smoking, other forms of arthritis, and hypertension or hypercholesterolemia medication, after adjustment for sociodemographic variables. Two thirds of respondents with gout reported ULT use (36% current; 29% previous) with only 55% continuing treatment. Predictors of ULT use included male gender, low SES, and concomitant cholesterol-lowering therapy. Respondents with gout with a higher BMI were more likely to remain on ULT.

Conclusions

Despite gout being a common, potentially disabling joint disease, only 55% of respondents with gout in this study adhered to ULT. Identification of key predictors of ULT use will provide guidance on prescribing strategy in clinical practice and on the quality of gout care in the community.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1633-9) contains supplementary material, which is available to authorized users.

Improving adherence to gout therapy: an expert review

Gout is the most common form of inflammatory arthritis and is a considerable burden to patients and health care systems worldwide. Despite its clinical, economic, and social impact, patient persistence and adherence to prescribed urate-lowering therapies (ULT), ranging from 20% to 70%, is considered to be among the poorest of all chronic conditions. The majority of gout patients consequently receive suboptimal benefits of their prescribed pharmacotherapies. As gout is associated with several comorbidities along with an increased risk of premature mortality, achieving improved outcomes through adherence to ULT is crucial. Adherence to medication is complex and multidimensional and includes a combination of treatment-, patient-, and physician-related factors. This review explores the factors related to ULT adherence with the overall aim of helping health care providers better understand the barriers to adherence. Several interventions targeting pharmacists, nurses, and patients are being investigated to improve adherence. Furthermore, enhanced awareness and understanding of the need to treat-to-target in order to improve patient outcomes is needed among health care professionals. Greater understanding of the multidimensional nature of non-adherence can help physicians to treat gout more effectively and empower patients to improve self-management of this long-term disease.

Work disability in gout: a population-based case-control study

OBJECTIVES

To examine the extent and cost of work disability among patients with gout compared with matched population controls and to analyse predictors of work disability.

METHODS

A regional cohort study using data from Swedish national and regional registries from January 2000 through December 2012, including 4571 patients with gout of working age, with a first recorded diagnosis of gout in the years 2003-2009 and 22 482 population controls, matched by age, sex and place of residence. Differences in baseline characteristics (educational level, income, previous employment and comorbidities) and the number of work-loss days (absenteeism) due to sick leave and disability pension for 3 years after identification were calculated. Predictors for new-onset work absenteeism (>90 days/year) in a subset were determined by conditional logistic regression.

RESULTS

Patients with gout (median age 53 years) had significantly more comorbidities, lower income and lower level of education than matched controls. The average work absentee rate during the 3-year follow-up period was higher among patients with gout than controls, 22% and 14%, respectively (P<0.0001). New-onset absenteeism was in multivariate analyses significantly predicted by gout (OR 1.47; 95% CI 1.23 to 1.75). Other variables independently related to new-onset absenteeism were education ≤12 years, previous unemployment and history of sick leave, in addition to several comorbidities (renal disease, cardiovascular disease, alcohol abuse and obesity).

CONCLUSIONS

Gout is associated with substantially higher work absenteeism and costs for society due to productivity loss, after adjusting for associated comorbidities and socioeconomic differences. Whether more intensive treatment of gout is cost-effective needs to be addressed in future studies.

Burden of gout in the Nordic region, 1990-2015: findings from the Global Burden of Disease Study 2015

OBJECTIVE

To explore the burden of gout in the Nordic region, with a population around 27 million in 2015 distributed across six countries.

METHOD

We used the findings of the 2015 Global Burden of Diseases study to report prevalence and disability associated with gout in the Nordic region.

RESULTS

From 1990 to 2015, the number of prevalent gout cases rose by 30% to 252 967 [95% uncertainty interval (UI) 223 478‒287 288] in the Nordic region. In 2015, gout contributed to 7982 (95% UI 5431‒10 800) years lived with disability (YLDs) in the region, an increase of 29% (95% UI 24‒35%) from 1990. While the crude YLD rate of gout increased by 12.9% (95% UI 7.8‒18.1%) between 1990 and 2015, the age-standardized YLD rate remained stable. Gout was ranked as the 63rd leading cause of total YLDs in the region in 2015, with the highest rank in men aged 55-59 years (38th leading cause of YLDs). The corresponding rank at the global level was 94. Of 195 countries studied, four Nordic countries [Greenland (2nd), Iceland (12th), Finland (14th), and Sweden (15th)] were among the top 15 countries with the highest age-standardized YLD rate of gout.

CONCLUSION

The burden of gout is rising in the Nordic region. Gout's contribution to the total burden of diseases in the region is more significant than the global average. Expected increases in gout burden owing to population growth and ageing call for stronger preventive and therapeutic strategies for gout management in Nordic countries.

Temporal trends and regional disparity in rheumatoid arthritis and gout hospitalizations in Sweden, 1998-2015

Hospitalization is an important component of rheumatoid arthritis (RA) and gout economic burden. This study aimed to assess temporal trends and regional disparities in RA and gout hospitalizations among people aged ≥ 20 years in Sweden during 1998–2015. Data on hospital admissions with a principal diagnosis of RA or gout were collected from the National Patient Register. Age-standardized hospitalization rates (ASHRs) were calculated by means of direct standardization. The absolute and relative regional disparities were assessed. The temporal trends in ASHR and proportion of RA and gout hospitalizations from all and musculoskeletal disorders hospitalizations were analyzed using joinpoint regression. Between 1998–2000 and 2013–2015, the ASHR for RA declined by 78.9% from 109.9 to 23.2 per 100,000 Swedish adults, while it almost doubled for gout (from 10.5 to 20.8 per 100,000 Swedish adults). While in 1998–2000, RA hospitalizations were 10.3 times more frequent than gout (0.54 vs 0.05% of all hospitalizations), this ratio declined to 1.1 in 2013–2015 (0.13 vs 0.11% of all hospitalizations). The joinpoint regression revealed that, on average, the ASHR for RA declined by 10.2% (95% CI: 9.3–11.1) per year whereas for gout, it rose by 4.3% (3.2–5.4) per year during 1998–2015. While the relative regional disparities were stable, the absolute regional disparity declined for RA and increased for gout over the study period. While substantial decline in RA hospitalization is encouraging, the substantial rise in gout hospitalization is of concern, reflecting potential increase in prevalence of gout and suboptimal management of the disease.

Incidence of and risk factors for nephrolithiasis in patients with gout and the general population, a cohort study

BACKGROUND

Nephrolithiasis (NL) is known to be associated with gout, although there are few comparative studies on risk and risk factors for NL in gout compared to population cohorts. In this cohort study we investigated: (1) overall incidence of NL in gout (cases) and general population controls; (2) risk and risk factors (common comorbidities and medications) for first-time NL in cases and controls separately.

METHODS

Cases (n = 29,968) and age-matched and sex-matched controls (n = 138,678) were identified from the regional healthcare database in western Sweden (VEGA). The analyzed risk factors (comorbidities and current medication use) for first-time NL, and socioeconomic factors were retrieved from VEGA and other national Swedish registers. For cases, follow up began on 1 January 2006 or on the first diagnosis of gout if this occurred later, and for controls on their index patient's first diagnosis of gout. Follow up ended on death, emigration or 31 December 2012. Incidence rates (IR) per 1000 person-years and hazard ratios (HR) were calculated. The incidence calculations were performed for cases (regardless of prior NL) and their controls. HRs with first occurrence of NL as outcome were calculated only in those without previous NL.

RESULTS

In cases there were 678 NL events (IR: 6.16 events per 1000 person-years (95% CI: 5.70-6.64) and in controls 2125 NL events (IR 3.85 events per 1000 person-years (95% CI: 3.69-4.02), resulting in an age-sex-adjusted incidence rate ratio of 1.60 (95% CI:1.47-1.74). Point estimates for predictive factors were similar in cases and controls, except for a significant interaction for losartan which increased the risk of NL only in controls (HR = 1.49 (95% CI: 1.03-2.14). Loop diuretics significantly decreased the risk of NL by 30-34% in both cases and controls. Further significant predictors of NL in gout cases were male sex, diabetes and obesity and in controls male sex and kidney disease.

CONCLUSIONS

The risk (age and sex adjusted) of NL was increased by 60% in cases compared to controls. None of the commonly used medications increased the risk of NL in gout patients.