D Owens, B Whelan, G McCarthy Department of Rheumatology, Mater Misericordiae Hospital, Eccles St, Dublin 7
Abstract There is no information available regarding current practice and standards in management of gout in Irish general practice. This study aims to assess current practice in the context of the 2006 EULAR evidence based recommendations for diagnosis and management of gout. A 20 point questionnaire was circulated to all 170 general practitioners in the North Dublin GP Partnership assessing frequency of diagnostic and therapeutic interventions undertaken. 91% of practitioners manage gout exclusively in primary care. 89% make a diagnosis on clinical grounds and 77% routinely measure serum urate. Diagnostic joint aspiration is rarely performed (3%). 86% routinely assess and manage risk factors for gout. 66% initiate urate-lowering therapy. Only 32% routinely monitor urate levels in patients receiving urate-lowering therapy. Thus, although management of gout in primary care in Ireland is generally in line with the EULAR recommendations some aspects of care remain suboptimal
IntroductionAs a result of increasing medical complexity in an aging population gout is becoming ever more of an issue. In addition it is one of the few curable rheumatic conditions. In 2006 EULAR published evidence-based recommendations for the diagnosis and management of gout aiming to optimise diagnosis and treatment1,2. Prior to this the only internationally recognised guidelines were the American college of Rheumatology criteria published in 19773. Existing Irish guidelines include those posted on the Irish College of General Practitioners website4. A search of the literature revealed no information about management of gout in Ireland, and this survey aims to assess current practice in management of gout in primary care in the context of the recommendations of the EULAR task force, and to identify areas of uncertainty or deficiency in current practice.
The prevalence of gout in Ireland has not been established. However data from the UK general Practice Research Database suggest a prevalence of 1.4%, rising to nearly 7% in men over the age of 755,6. Hyperuricaemia was found in 5-8% of white adult American males and in these patients the annual incidence of gouty arthritis ranges from 0.5% to 4.9%, increasing with serum urate level7, thus prophylaxis can be of significant benefit.
Diagnosis and management of gout are usually uncomplicated; however an important differential diagnosis for an acute monoarthritis is that of septic arthritis, emphasising the need for accurate and reliable diagnosis9. In addition gout commonly coexists with underlying cardiovascular disease and diabetes10,11 and appears to be an independent risk factor for cardiac events12.
MethodsA postal questionnaire was circulated to 170 individual general practitioners in the North Dublin GP Partnership. Baseline data was collected on individual practice size, proportion of private versus public patients in the practice and the average number of cases of gout seen per month by the general practitioner.
Questions regarding diagnosis and management of gout were formulated in such a way as to assess respondent’s habitual practice in relation to those aspects of the EULAR guidelines felt to be most applicable to primary care. The questionnaire allowed a choice of responses in regard to those diagnostic and therapeutic interventions assessed, ranging from ‘usually’ (performed in more than 2/3 of cases), ‘sometimes’ (performed in between 1/3 and 2/3 of cases) to ‘rarely’ (performed in less than 1/3 of cases). Factors influencing joint aspiration and decisions to initiate uratelowering therapy allowed multiple responses. Respondents were also asked about their approach to referral of suspected cases of gout for further specialist assessment. Data were analysed with a view to establishing the prevalent approach to the various interventions suggested and comparing this to the approach recommended by the EULAR task force on gout.
Results170 individual general practitioners were surveyed covering a total practice population of approximately 250,000 patients. The response rate was 47%, which is in line with similar surveys carried out in Irish general practice13. The majority of general practitioners (GPs) reported themselves satisfied to manage gout exclusively in a primary care setting (91% versus 9%). Patients with suspected gout are rarely referred to rheumatology outpatients or to hospital emergency departments. The main reasons for eventual referral were chronic tophaceous gout or poly-articular gout (76%), and diagnostic uncertainty (71%). Recurrent attacks of gout are usually managed in primary care (56%).
Of the GPs surveyed 53% diagnose less than one case of gout per month (relevant total practice population of 105,000 patients), 35% diagnose 1 to 2 cases per month (across a total of 86,500 patients), and the remaining 11% diagnose more than 2 cases per month (total of 19,000 patients). There was no significant difference in the number of cases seen in public medicine versus private.
89% of respondents usually make a diagnosis of gout based on recognised clinical criteria (severe pain, swelling, tenderness and erythema which reach a maximum within 6-12 hours of onset, with or without evidence of tophi) and initiate treatment on this basis (Table 1). 77% of practitioners usually measure serum urate in cases of suspected gout. 86% usually assess risk factors for gout. 24% of GPs reported usually taking steps to out-rule septic arthritis. However only 3% of respondents aspirate joints in suspected gout. Reasons given for not aspirating include lack of experience (70%), lack of time (47%), uncertainty regarding analysis or processing of samples (51%), and uncertainty regarding management of results (32%). 19% of GPs usually and 38% sometimes request radiographs of affected joints in suspected gout.
Other recommendations, including aspiration of assymptomatic joints for diagnosis of inter-current gout and routine microscopy of all joint aspirates were not assessed as they were felt to be less relevant in primary care.
With respect to recommendations for management of gout 89% of respondents usually address risk factors for gout and associated co-morbidities as part of routine management (Table 2 and Figure 1). 93% use non-steroidal drugs or colchicine as first line treatment for acute gout. 66% of GPs usually initiate uratelowering therapy in the context of an acute attack of gouty arthritis and elevated serum urate. 73% will not usually prescribe urate-lowering therapy during an acute attack of gout. The reasons for prescribing urate-lowering therapy were given as recurrent attack of gouty arthritis (88%), elevated serum urate with a history of gout (56%) and specialist advice (31%). Only 26% of respondents usually recheck serum urate after resolution of an acute attack, and only 32% routinely monitor serum urate levels in patients receiving long term urate-lowering treatment.
DiscussionThe aim of the study was to assess current practice in the management of gout in Irish primary care and to compare this with the recommendations of the EULAR task force on gout. The first finding was that gout in Ireland is predominantly managed in the setting of primary care with referral to general hospital emergency departments or specialist rheumatology services very much the exception. The survey assessed habitual practice rather than case specific management as it was felt that recall of habitual practice would be more reliable and yield more robust data. For this reason precise data on prevalence is difficult to extrapolate. There was no significant difference in the typical number of episodes of gout seen when analysed according to the proportion of patients availing of public versus private medicine.
In their analysis the EULAR task force used likelihood ratios to establish the diagnostic value for various criteria and combinations of criteria. The presence of a clinical picture of rapid onset of severe pain, swelling and erythema, combined with podagra and hyperuricaemia, gives an 80% likelihood of a correct diagnosis of gout1,2. Addition of the presence of tophi, characteristic radiographic changes or the presence of monosodium urate crystals in joint aspirates raises the probability to 100%1,2. Given that tophi and X-ray changes are typically late features, early definitive diagnosis of gout requires demonstration of monosodium urate crystals in joint aspirates using polarised light microscopy. The majority of GPs surveyed based their diagnosis on a combination of recognised clinical criteria and hyperuricaemia, the diagnostic value of which is considered reasonably accurate. Very few GPs undertake joint aspiration for a variety of reasons, most commonly lack of experience. The most important differential diagnosis for a single inflamed joint is that of septic arthritis, which can not be excluded on clinical grounds alone, requiring microscopy and gram-staining of aspirated synovial fluid9. In addition, urate lowering therapy, though generally well tolerated, is not without side effects and clearly definitive diagnosis is desirable prior to its institution. It is noted that serum urate levels can be normal during acute attacks14, and it is recommended that serum urate be re-checked following resolution of the attack. However this is not commonly done (26%).
Assessment and management of risk factors for gout, including lifestyle factors and features of the metabolic syndrome, is routinely undertaken by the majority of GPs surveyed. The importance of this lies both in the opportunity to intervene in factors which influence the development of gout, such as diet, alcohol and weight, and in the detection of co-morbidities which require treatment in their own right, such as hypertension and diabetes10,11,12. Non-steroidal anti-inflammatory drugs or colchicine represent the first line of treatment for 93% of GPs in line with current recommendations1,2. Intra-articular injection of steroid is recommended as a useful and effective therapy; however it is rarely used in Irish primary care. 66% of GPs usually initiate long term urate lowering therapy in patients with gout and hyperuricaemia and 88% do so in the context of recurrent attacks of gout. Allopurinol is the urate-lowering agent most commonly used. The goal of urate-lowering therapy is to promote dissolution of crystals and to prevent further crystal formation. This requires lowering the serum urate level well below its saturation point and may require adjustment of the allopurinol dose according to the patient. However only 32% of those surveyed routinely monitor serum urate levels in patients on allopurinol. Thus the effectiveness of therapy as instituted is unclear. Similar findings were reported in a review of primary care management of gout in the UK16,17. It is known that changes in serum urate levels can precipitate or worsen acute attacks17. 73% of GPs will not prescribe allopurinol during an acute attack, suggesting that a significant proportion will, despite the risk of exacerbating an attack. The EULAR recommendations advise that low dose colchicine used during initiation of urate-lowering therapy is an effective prophylactic agent1,2, though the necessary duration of such prophylaxis is not established. No recommendations are made regarding introduction of allopurinol during an attack and available evidence suggests that treatment should be deferred until after the attack has resolved.
The results of this survey show that management of gout in primary care in Ireland is broadly appropriate, and in line with the recommendations of the EULAR task force on gout. However there are deficiencies. In particular monitoring of serum urate is suboptimal, as is the low rate of joint aspiration. The usefulness of joint aspiration and its ease of use in the setting of primary care suggest that increased availability of training in this area may be helpful to many practitioners as lack of experience is cited as the primary deterrent in this survey.
References