Factors Influencing Allopurinol Initiation in Primary Care

Cohort study investigating gout flares and management in UK general practice

BACKGROUND

Gout is the most common inflammatory arthritis and is almost exclusively managed in primary care, however the course and severity of the condition is variable and poorly characterised. This research aims improve understanding about the frequency of, and factors associated with, gout flares in the UK and characterise the factors associated with the initiation of ULT.

METHODS

Using the Clinical Practice Research Database, patients with a coded incident gout diagnosis without a prior prescription for urate-lowering therapy (ULT) were identified. Gout flares post diagnosis and ULT initiation were identified through prescribing and coded data. Patient characteristics, co-morbidities and co-prescribing were co-variants. Factors associated with gout flares and ULT initiation were analysed using cox-proportional hazard model and logistic regression.

RESULTS

Fifty-one thousand seven hundred eighty-four patients were identified: 18,605 (35.9%, 95%CI 35.5-36.3%) had experienced ≥ 1 recurrent flare, 17.4% (95%CI 17.1-17.8%) within 12 months of diagnosis. Male sex, black ethnicity, higher BMI, heart failure, CKD, CVD and diuretic use were associated with flares, with the highest HR seen with high serum urate levels (≥ 540 µmol/L HR 4.63, 95%CI 4.03-5.31). ULT initiation was associated with similar variables, although higher alcohol intake and older age were associated with lower odds of ULT initiation but were not associated with flares. ULT was initiated in 27.7% (95%CI 27.3-28.0%): 5.7% (95%CI 5.5-5.9%) within 12 months of diagnosis. ULT initiation rates were higher in patients with recurrent flares.

CONCLUSION

Approximately one in six people with incident gout had a second flare within 12 months. Factors associated with flare recurrence and ULT initiation were similar, but ULT initiation occurred later after diagnosis than previously thought.

Effectiveness of Allopurinol in Reducing Mortality: Time-Related Biases in Observational Studies

OBJECTIVE

The treatment of gout with allopurinol is effective at reducing urate levels and the frequency of flares. Several observational studies have shown important reductions in mortality with allopurinol use, with wide variations in results. We undertook this review to assess the extent of bias in these studies, particularly time-related biases such as immortal time bias.

METHODS

We searched the literature to identify all observational studies describing the effect of allopurinol use versus nonuse on all-cause mortality.

RESULTS

We identified 12 observational studies, of which 3 were affected by immortal time bias and 3 by immeasurable time bias, while the remaining 6 studies avoided these time-related biases. Reductions in all-cause mortality with allopurinol use were observed among the studies with immortal time bias, with a pooled hazard ratio (HR) of death associated with allopurinol of 0.71 (95% confidence interval [95% CI] 0.50-1.01), as well as in those with immeasurable time bias (pooled HR 0.62 [95% CI 0.56-0.67]). The 6 studies that avoided these biases demonstrated a null effect of allopurinol on mortality (pooled HR 0.99 [95% CI 0.87-1.11]), though the lack of an analysis based on treatment adherence may have attenuated the effect.

CONCLUSION

Observational studies are important to provide real-world data on medication effects. The observational studies showing significantly decreased mortality with allopurinol treatment cannot be used as evidence, however, mainly due to time-related biases that tend to greatly exaggerate the potential benefit of treatments. The ALL-HEART randomized trial, which is currently underway and evaluates the effect of adding allopurinol to usual care (compared to no added treatment), will provide reliable evidence on mortality.

Compliance of Primary Care Providers With Gout Treatment Recommendations—Lessons to Learn: Results of a Nationwide Survey

Objectives: Gout is generally managed in the primary health care sector. Compliance of primary care physicians with gout management recommendations has been shown to be insufficient in the past. The primary aims of this study were to assess primary care providers' knowledge regarding gout and to determine if their treatment decisions are influenced by recommendations. Facing considerable variations in postgraduate training options in Austria, we secondly looked for possible knowledge differences between urban and rural areas and eastern and western parts of Austria.

Methods: We conducted a survey among 343 primary care physicians in Austria, using a questionnaire consisting of 10 questions on acute, intercritical and general gout management. Gout treatment recommendations served as the therapeutic gold standard.

Results: Of the 343 physicians surveyed, 336 completed the questionnaire, leading to a very high return rate of 98%. 289 (86%) physicians were aware of the agreed-upon SUA target (<6 mg/dl). 323 (96.1%) reported change of therapy in case of missing this target. 112 (33.3%) physicians voted for long term ULT. No geographical differences in knowledge regarding gout or its management were revealed, except that colchicine was rated as being a safe medication significantly more often in rural areas (p = 0.035) and in western Austria (p = 0.014).

Conclusion: As opposed to former studies, gout knowledge among primary care physicians has improved - however, treatment patterns are still not fully concordant with gout recommendations. Our findings may help to better tailor future postgraduate training to improve primary care physicians' education in gout.

What factors contribute to uncontrolled gout and hospital admission? A qualitative study of inpatients and their primary care practitioners

OBJECTIVE

To provide deeper insight into why patients are admitted to hospital with gout and discover potential targets for better disease control.

DESIGN

Data from semi-structured interviews were analysed using a thematic analysis approach.

PARTICIPANTS AND SETTING

Eleven inpatients from a tertiary institution in the Australian Capital Territory of Australia and their respective general practitioners (GPs) were invited to participate in the semi-structured interviews.

RESULTS

Despite significant pain and disability that accompanied acute flares, patients continue to experience shame in seeking treatment and regarded gout as being not particularly important. Other barriers included patients' poor continuity of care with and lack of confidence in GPs, suboptimal management in outpatient and inpatient settings, poor understanding of disease and treatment, and misconceptions held by both patients and physicians leading to uncontrolled disease activity.

CONCLUSIONS

Barriers to optimal gout management including patient and health practitioner factors have produced a complex effect which has led to a cycle of treatment avoidance behaviours and recurrent hospitalisations for severe acute gout flares. These barriers could be addressed using a multipronged approach guided by the chronic care model which has been applied in a variety of other chronic diseases with improved patient and professional-level outcomes. Managing gout according to best practice for chronic disease is more likely to prevent recurrent hospitalisations and improve health outcomes in patients with gout.

Gout Severity, Socioeconomic Status, and Work Absence: A Cross-Sectional Study in Primary Care

OBJECTIVE

To examine the association between gout severity and socioeconomic status (SES) and gout severity and work absence.

METHODS

Postal questionnaires were sent to adult patients who were registered with 20 general practices and who had consultations regarding gout or had been prescribed allopurinol or colchicine in the preceding 2 years. Gout severity was defined using the following proxy measures: number of attacks, history of oligoarticular/polyarticular attacks, disease duration, and allopurinol use. SES was defined using the English index of multiple deprivation (area level) and using self-reported educational attainment (individual level). Work absence was defined as taking time off from work in the past 6 months because of gout. Adjusted odds ratios (OR_adj ; 95% confidence intervals [95% CIs]) were calculated using logistic regression models (adjusted for age, sex, body mass index, gout severity, and comorbidities).

RESULTS

A total of 1,184 completed questionnaires were returned. The mean age of patients was 65.6 years, and 84% were male. Not having attended further education ("further education" is defined as attendance after the statutory minimum school-leaving age of 16 years) was associated with having had ≥2 gout attacks in the last year (OR_adj 0.54 [95% CI 0.36-0.81]) and oligoarticular/polyarticular attacks (OR_adj 0.72 [95% CI 0.50-1.05]). Lower area-level deprivation was associated with fewer attacks (≥2) (OR_adj 0.71 [95% CI 0.51-0.98]). Work absence was associated with having had ≥2 gout attacks in the last year (OR_adj 2.91 [95% CI 1.22- 6.92]), oligoarticular/polyarticular attacks (OR_adj 3.10 [95% CI 1.46-6.61]), and shorter disease duration (>18 years) (OR_adj 0.13 [95% CI 0.03-0.50]).

CONCLUSION

Gout severity was associated with individual-level deprivation, countering the historic and negative perception of gout as a "rich man's disease." The association of gout severity with work absence reinforces the argument for earlier urate-lowering therapy to prevent attacks from becoming frequent and debilitating.

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.