Comparison of three screening tools to detect psoriatic arthritis in patients with psoriasis (CONTEST study).

BACKGROUND: Multiple questionnaires to screen for psoriatic arthritis (PsA) have been developed but the optimal screening questionnaire is unknown. OBJECTIVES: To compare three PsA screening questionnaires in a head-to-head study using CASPAR (the Classification Criteria for Psoriatic Arthritis) as the gold standard. METHODS: This study recruited from 10 U.K. secondary care dermatology clinics. Patients with a diagnosis of psoriasis, not previously diagnosed with PsA, were given all three questionnaires. All patients who were positive on any questionnaire were invited for a rheumatological assessment. Receiver operating characteristic (ROC) curves were used to compare the sensitivity, specificity and area under the curve of the three questionnaires according to CASPAR criteria. RESULTS: In total, 938 patients with psoriasis were invited to participate and 657 (70%) patients returned the questionnaires. One or more questionnaires were positive in 314 patients (48%) and 195 (62%) of these patients attended for assessment. Of these, 47 patients (24%) were diagnosed with PsA according to the CASPAR criteria. The proportion of patients with PsA increased with the number of positive questionnaires (one questionnaire, 19·1%; two, 34·0%; three, 46·8%). Sensitivities and specificities for the three questionnaires, and areas under the ROC curve were, respectively: Psoriatic Arthritis Screening Evaluation (PASE), 74·5%, 38·5%, 0·594; Psoriasis Epidemiology Screening Tool (PEST), 76·6%, 37·2%, 0·610; Toronto Psoriatic Arthritis Screen (ToPAS), 76·6%, 29·7%, 0·554. The majority of patients with a false positive response had degenerative or osteoarthritis. CONCLUSION: Although the PEST and ToPAS questionnaires performed slightly better than the PASE questionnaire at identifying PsA, there is little difference between these instruments. These screening tools identify many cases of musculoskeletal disease other than PsA.

The impact of psoriasis guidelines on appropriateness of referral from primary to secondary care: a randomized controlled trial.

BACKGROUND: Most patients with psoriasis have limited disease which can be managed effectively in primary care. There is a marked variation in the frequency of referrals between practices reflecting, in part, inadequate training of general practitioners (GPs) in the management of psoriasis. OBJECTIVES: To assess the effectiveness of guidelines and training sessions on the management of psoriasis in reducing inappropriate referrals from primary care. METHODS: Patients aged 18 years or over with psoriasis were eligible for the cluster-randomized, randomized controlled trial if they were referred by their GP between 9 September 2002 and 31 December 2003 to one of four hospital dermatology departments in Greater Manchester, North-West England. All GPs from 165 health centres were invited to a lecture by a local dermatologist on the diagnosis and management of psoriasis. Health centres in the intervention arm received guidelines on the management of psoriasis in primary care, developed by local dermatologists, supplemented by the offer of a practice-based nurse-led training session; those in the control arm received neither guidelines nor training sessions. RESULTS: Eighty-two health centres were randomized to the intervention arm and 83 to the control arm. Outcome data were available for 188 of the 196 eligible patients referred during the study period. Patients in the intervention arm were significantly more likely to be appropriately referred in comparison with patients in the control arm [difference = 19.1%; odds ratio (OR) 2.47; 95% confidence interval (CI) 1.31-4.68; intracluster correlation coefficient (ICC) = 0]. Only 25 (30%) health centres in the intervention arm took up the offer of training sessions. There was no significant difference in outcome between health centres in the intervention arm that received a training session and those that did not (OR 1.28, 95% CI 0.50-3.29, ICC = 0). CONCLUSIONS: Dissemination of guidelines on the management of psoriasis in primary care can significantly enhance the appropriateness of referral of patients to secondary care.