Allopurinol Adherence Research Articles

Patient-Led Urate Self-Monitoring to Improve Clinical Outcomes in People With Gout: A Feasibility Study.

Self-monitored point-of-care urate-measuring devices are an underexplored strategy to improve adherence to urate-lowering therapy and clinical outcomes in gout. This study observed patient-led urate self-monitoring practice and assessed its influence on allopurinol adherence, urate control, and health-related quality of life. People with gout (n = 31) and prescribed allopurinol self-monitored their urate concentrations (HumaSens2.0plus) at baseline and thereafter monthly for 12 months (3 months per quarter). Adherence to allopurinol was measured using medication event monitoring technology (Medication Event Monitoring System cap). Time spent below the target urate concentration (<0.36 mmol/L) was determined. Health-related quality of life was measured using a survey (EuroQoL EQ-5D-5L). Gout flares were recorded. Two-tailed Spearman correlation and the Wilcoxon matched-pairs signed-rank test (P < 0.05) were used for statistical comparisons. Most participants were male (94%) and had urate concentrations below the target (74%) at baseline. Overall, seven participants demonstrated repeated periods of "missed doses" (two or fewer allopurinol doses missed consecutively) and "drug holidays" (three or more missed doses). Most participants (94%) persisted with allopurinol. Time spent within the target urate concentration increased 1.3-fold (from 79% to 100%; P = 0.346), and the incidence of gout flares decreased 1.6-fold (from 8 to 5; P = 0.25) in the final quarter compared to that in the first quarter of the study. Health-related quality of life was reduced for participants reporting at least one gout flare (median utility values 0.9309 vs 0.9563, P = 0.04). Patient-led urate self-monitoring may support the maintenance of allopurinol adherence and improve urate control, thus reducing the incidence of gout flares. Further research on patient-led urate self-monitoring in a randomized controlled study is warranted.

Optimizing adherence to allopurinol for gout: patients' perspectives.

Poor adherence to allopurinol among people with gout contributes to suboptimal gout management. This study sought to understand the facilitators and barriers to allopurinol adherence across the three stages of medication adherence, and patient perspectives on strategies to improve adherence, including self-monitoring urate concentration. Semi-structured interviews were conducted with 26 people with gout, previously or currently taking allopurinol. De-identified verbatim transcripts were thematically analysed using an inductive and deductive approach. Facilitators of adherence during allopurinol initiation were motivation to prevent gout flares and trust in the advice of their healthcare professionals (HCPs). Reluctance to commence long-term medication was a barrier to allopurinol initiation. Believing in the effectiveness and necessity of allopurinol and reminder systems were facilitators of implementation. Barriers to implementation included forgetfulness, gout flares and limited feedback on allopurinol's effectiveness. Patients discontinued therapy when allopurinol was perceived as ineffective or unnecessary. Discontinuation coincided with patients experiencing gout flares while adhering to allopurinol and receiving suboptimal advice about gout management. Patients identified receiving accurate advice from HCPs and regular urate monitoring for feedback on allopurinol's effectiveness as potential strategies to improve adherence. Perceived benefits of self-monitoring urate as a strategy to promote adherence included the ability to self-manage gout and make informed decisions about allopurinol therapy with their HCP. Patient perceptions of the effectiveness and necessity of allopurinol influenced intentional adherence during medication initiation, implementation and discontinuation. Strategies that inform patients of their urate control and provide accurate medical advice have the potential to improve adherence to allopurinol.

An allopurinol adherence tool using plasma oxypurinol concentrations.

This study aimed to develop and evaluate an allopurinol adherence tool based on steady-state oxypurinol plasma concentrations, allopurinol's active metabolite. Plasma oxypurinol concentrations were simulated stochastically from an oxypurinol pharmacokinetic model for allopurinol doses of 100-800 mg daily, accounting for differences in renal function, diuretic use and ethnicity. For each scenario, the 20th percentile for peak and trough concentrations defined the adherence threshold, below which imperfect adherence was assumed. Predictive performance was evaluated using both simulated low adherence and against data from 146 individuals with paired oxypurinol plasma concentrations and adherence measures. Sensitivity and specificity (S&S), negative and positive predictive values (NPV, PPV) and receiver operating characteristic (ROC) area under the curve (AUC) were determined. The predictive performance of the tool was evaluated using adherence data from an external study (CKD-FIX). The allopurinol adherence tool produced S&S values for trough thresholds of 89-98% and 76-84%, respectively, and 90%-98% and 76-83% for peak thresholds. PPV and NPV were 79-84% and 88-94%, respectively, for trough and 80-85% and 89-98%, respectively, for peak concentrations. The ROC AUC values ranged from 0.84 to 0.88 and from 0.86 to 0.89 for trough and peak concentrations, respectively. S&S values for the external evaluation were found to be 75.8% and 86.5%, respectively, producing an ROC AUC of 0.8113. A tool to identify people with gout who require additional support to maintain adherence using plasma oxypurinol concentrations was developed and evaluated. The predictive performance of the tool is suitable for adherence screening in clinical trials and may have utility in some clinical practice settings.

Allopurinol adherence, persistence and patterns of use in individuals with diabetes and gout: A retrospective, population-based cohort analysis

ObjectiveThere has been growing interest in the potential role for allopurinol to reduce cardiovascular events in people with diabetes. While adherence to allopurinol is poor in those with gout, our aim was to characterize persistence, patterns of use, and predictors of allopurinol use in a population-based cohort of individuals with diabetes and gout. MethodsIndividuals with diabetes older than 66 (thus eligible for prescription medication coverage) and newly prescribed allopurinol were followed for up to three years in a retrospective cohort study. Allopurinol use patterns were categorized as adherer (used continuously throughout follow-up), interrupter (non-persistent but subsequently resumed), or discontinuer (non-persistent with no subsequent resumption). Main outcomes were allopurinol non-persistence (no subsequent prescription accounting for a grace period), and indicators of gout severity throughout follow-up (prescriptions for prednisone or colchicine, outpatient gout visits, hospitalization/emergency department visits for gout). Outcome frequencies were determined, a multivariable Cox proportional hazards model evaluated associations between predictors and non-persistence, and zero-inflated negative binomial (ZINB) models evaluated associations between allopurinol use pattern and indicators of gout severity. Results22,056 individuals were followed for a maximum of 3.0 years (17,410 with 3 years of follow-up). 9092 (41.2%) were non-persistent with allopurinol. Higher risks of non-persistence were associated with female sex (HR, 95% CI: 1.28, 1.23–1.33), dementia (1.23, 1.11–1.35), and an outpatient visit for gout in the prior year (1.19, 1.09–1.29). There were 12,964 (58.8%) allopurinol adherers, 4618 interrupters (20.9%), and 4474 (20.3%) discontinuers. Allopurinol interrupters and discontinuers had indicators of more severe gout over time compared to adherers, including greater odds of being prescribed prednisone. ConclusionAllopurinol non-persistence and interruptions were frequent in individuals with diabetes and gout and were associated with prescriptions for prednisone. Suboptimal allopurinol adherence may not only increase the risk of gout complications in this population but also potentially diabetes complications through greater prednisone use and its negative effects on glycemic control.

Allopurinol adherence and its predictors in gout: a national cohort study in US veterans.

Allopurinol is a frequently used, effective, and affordable medication for gout. However, poor adherence to allopurinol is a key reason for patients not reaching treatment goals. The aim of this study was to comprehensively assess factors associated with high allopurinol adherence in gout. In this national cohort study, we used the health-care databases of the US Department of Veterans Affairs (VA) from 2002 to 2016 and a new-user design to assess potential predicting factors of allopurinol adherence. Veterans were included in this study if they had International Classification of Diseases (ninth revision) code 274.x for gout in two or more outpatient encounters or one or more inpatient encounters during 2002-16; incident allopurinol use; and at least 12 months of observation. Potential predictors of allopurinol adherence (defined as medication possession ratio [days used divided by days prescribed] of >80%) were examined using Andersen's health-care utilisation model and multivariable-adjusted logistic regression analyses. Between Oct 1, 2002, and Sept 30, 2016, 565 812 potentially eligible patients were included in the VA database, of whom 264 614 (46·8%) met the eligibility criteria and were included in the study cohort. The mean age was 67·8 years (SD 11·7) and mean body-mass index was 33·0 kg/m2 (6·4). Factors significantly associated with higher odds of allopurinol adherence in multivariable-adjusted analyses were older age (odds ratio 1·01, 95% CI 1·01-1·01); Deyo-Charlson comorbidity index score of 1 (1·05, 1·02-1·07) or 2 or more (1·05, 1·03-1·07) versus a score of 0; higher body-mass index (all categories from 25 to <30 [1·12, 1·08-1·17] to ≥45 [1·47, 1·39-1·55] vs 18·5 to <25); a military service connection of 50% or higher (1·37, 1·29-1·46) versus 0%; care in a community-based outpatient clinic (1·11, 1·08-1·14) versus in a VA Medical Center; and rural residence (1·02, 1·00-1·05). Factors significantly associated with lower odds of allopurinol adherence were black (0·74, 0·72-0·76), Hispanic (0·68, 0·65-0·72), or other race or ethnicity (0·86, 0·82-0·89) versus white race; non-rheumatologist care provider (0·83, 0·79-0·88); allopurinol start dose of 101-200 mg per day (0·93, 0·91-0·95) or more than 300 mg per day (0·75, 0·72-0·79) versus 100 mg per day or less; or allopurinol use in the previous year (0·80, 0·79-0·82). Compared with residence in the Midwest, patients in other US regions had lower odds of adherence (mid-Atlantic 0·89, 0·87-0·92; northeast 0·84, 0·81-0·87; south 0·85, 0·83-0·88; west 0·86, 0·83-0·89). Compared with a baseline serum urate of 360 to less than 480 μmol/L, serum urate of less than 360 μmol/L was associated with higher odds of adherence (1·28, 1·25-1·32), whereas baseline serum urate of 480 to less than 600 μmol/L (0·86, 0·84-0·88) or 600 to less than 720 μmol/L (0·92, 0·89-0·94) was associated with lower odds of adherence. We identified several important factors associated with high allopurinol adherence. Clinicians and policy makers can now target modifiable factors at the patient, provider, or systems level, with the aim of improving allopurinol adherence, and thereby overall gout care.

A National Cohort Study of Allopurinol Adherence and Its Predictors in Gout

A National Cohort Study of Allopurinol Adherence and Its Predictors in Gout

PHS11 - Predictors of Allopurinol adherence in patients with Gout

To assess the factors associated with high allopurinol adherence. Allopurinol prescription was defined as at least 30 days of a filled allopurinol prescription. Patients were censored when they switched from allopurinol to one of the other ULT. Index allopurinol prescription was defined as not exposed to allopurinol for 121 days (which contains 30 days grace period for refilling and 91 days for washout In multivariable-adjusted that adjusted for all factors except medication and disease severity factors (model 5), we found that the following factors were significantly associated with higher odds of allopurinol MPR ≥80%: older age, Caucasian race, being currently married; gout care from primary care provider specialty, smaller facility bed size, community-based outpatient clinic and Midwest location; means test, service connection ≥50% and longer distance to the nearest VA. Higher BMI had a non-significant trend towards higher odds of allopurinol MPR ≥80%. In this study, we identified several novel factors associated with allopurinol adherence. This new knowledge can be used to improve the likelihood of success of lowering serum urate with allopurinol pharmacotherapy by targeting modifiable risk factors identified in our study.

Allopurinol adherence among patients with gout: an Italian general practice database study.

Allopurinol is used as long-term therapy to reduce the occurrence of gout flares. This study estimated the impact of patient adherence to allopurinol on hyperuricaemia (serum uric acid levels, sUA > 6 mg/dl) and the identification of non-adherence predictors. The Italian Health Search-CSD Longitudinal Patient Database was accessed to identify outpatients aged ≥ 18 years with gout and prescribed with allopurinol during the years 2002-2011. Patients with a proportion of days covered ≥ 80% were considered adherent to allopurinol. Data on sUA levels over the first year of therapy were categorised in three time-windows (30-89; 90-149; 150-365 days). Logistic regressions were used to estimate the association between adherence and hyperuricaemia, as well as non-adherence predictors. A total of 3727 patients were included. In the interval 0-29 days, the proportion of patients adherent to allopurinol was 45.9%, while up to 89, 149 and 365 days the percentages were 16.7%, 10.0% and 3.2%, respectively. The proportions of hyperuricaemic patients for each time-window were 43.1%, 42.4%, 32.6% and 59.0%, 64.0%, 66.4% among adherent and non-adherent patients, respectively. In the multivariable analysis, adherence was associated with a significant lower risk of hyperuricaemia. The adjusted ORs were 0.49 (95% CI: 0.33-0.73), 0.40 (95% CI: 0.24-0.67) and 0.23 (95% CI: 0.15-0.34) for the first, second and third time-window, respectively. Patients with hypertension (adjusted OR = 0.64, 95% CI: 0.42-0.99) and history of gout flares (adjusted OR = 0.55, 95% CI: 0.32-0.95) were significantly adherent to allopurinol. Adherence monitoring in patients with gout is pivotal to ensure the effectiveness of therapy. To gain a better patient adherence, the communication between physicians and patients should be improved.

Time course of changes in the clinical manifestations of gout in men: data of a 7-year retrospective follow-up

To estimate the time course of changes in the clinical manifestations of gout and their risk factors during a long-term follow-up. A total of 160 male patients with gout were examined and followed up for a mean of 6.9 ± 2.0 years. Their clinical assessment included determination of the type of arthritis over time, the frequency of arthritis attacks during one year prior to the examination, the presence and number of subcutaneous tophi, inflamed joints, comorbid or co-occurring diseases (CD), allopurinol adherence, dietary compliance, frequency of taking non-steroidal anti-inflammatory drugs (NSAIDs), diuretics, and alcohol. The serum levels of uric acid (UA), glucose, total cholesterol, and glomerular filtration rate were estimated. The number of patients taking allopurinol increased from 19% to 64% (p < 0.0001), its average daily dose was 167.6 ± 94.6 mg. The serum level of UA decreased; 16% of the patients achieved its target level. The number of patients with chronic arthritis was not significantly changed. Their serum level of UA was unchanged; the detection rate of subcutaneous tophi and CD rose. During one year, arthritis attacks were absent in 13% of the patients; 90% of them took allopurinol. In these patients, serum UA levels and body mass index significantly declined and the rate of CD was unchanged. None of 18 patients who had their diet and no allopurinol achieved the target level of UA. Among the gouty patients, 36% refrain from the use of allopurinol, only 23% out of them require that its dose be adjusted to achieve the target level of UA. Dietary compliance is insufficient to reach the target level of UA. Chronic arthritis is associated with the increased incidence of CD.

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

To identify modifiable patient and provider factors associated with allopurinol adherence and the achievement of a serum urate acid (SUA) goal in gout. We identified a retrospective cohort of patients with gout, newly treated with allopurinol. All patient data came from administrative datasets at a large integrated health delivery system. Patients were ≥ 18 years old at time of initial allopurinol dispensing, and had 12 months or more of membership and drug eligibility prior to the index date. Allopurinol adherence was defined as a proportion of days covered ≥ 0.80, evaluated during the first 12 months of observation after the initial dispensing. Multivariable logistic regression was used to examine factors associated with allopurinol nonadherence and attaining an SUA concentration < 6.0 mg/dl. We identified 13,341 patients with gout with incident allopurinol use (mean age 60 yrs, 78% men). Of these, 9581 patients (72%) had SUA measured both at baseline and during followup. Only 3078 patients (32%) attained an SUA target of < 6.0 mg/dl during followup. Potentially modifiable factors associated with treatment adherence and obtaining the SUA goal in the multivariable analysis included concomitant diuretic use, prescriber specialty, and allopurinol dosing practices. Adherent patients were 2.5-fold more likely than nonadherent patients to achieve an SUA < 6.0 mg/dl during observation. Among patients with gout initiating allopurinol in our study, 68% did not reach the SUA goal and 57% of patients were nonadherent. Modifiable factors, including allopurinol dose escalation, treatment adherence, rheumatology referral, and concomitant medication use, could be important factors to consider in efforts aimed at optimizing gout treatment outcomes.

Allopurinol use in a New Zealand population: prevalence and adherence

Allopurinol is effective for the control of gout and its long-term complications when taken consistently. There is evidence that adherence to allopurinol therapy varies across population groups. This may exacerbate differences in the burden of gout on population groups and needs to be accurately assessed. The aim of this study was to describe the prevalence of allopurinol use in a region of New Zealand using community pharmacy dispensing data and to examine the levels of suboptimal adherence in various population groups. Data from all community pharmacy dispensing databases in a New Zealand region were collected for a year covering 2005/2006 giving a near complete picture of dispensings to area residents. Prevalence of allopurinol use in the region by age, sex, ethnicity and socioeconomic position was calculated. Adherence was assessed using the medication possession ratio (MPR), with a MPR of 0.80 indicative of suboptimal adherence. Multiple logistic regression was used to explore variations in suboptimal adherence across population groups. A total of 953 people received allopurinol in the study year (prevalence 3%). Prevalence was higher in males (6%) than in females (1%) and Māori (5%) than non-Māori (3%). The overall MPR during the study was 0.88, with 161 (22%) of patients using allopurinol having suboptimal adherence. Non-Māori were 54% less likely to have suboptimal allopurinol adherence compared to Māori (95% CI 0.30-0.72, p = 0.001). These findings are consistent with those from other studies nationally and internationally and point to the important role for health professionals in improving patient adherence to an effective gout treatment.

The Descriptive Epidemiology of Allopurinol Use and Adherence for Gout in a New Zealand Population

The Descriptive Epidemiology of Allopurinol Use and Adherence for Gout in a New Zealand Population