Development and Testing of New Candidate Psoriatic Arthritis Screening Questionnaires Combining Optimal Questions From Existing Tools

Abstract

Objective. Several questionnaires have been developed to screen for psoriatic arthritis (PsA), but head-to-head studies have found limitations. This study aimed to develop new questionnaires encompassing the most discriminative questions from existing instruments. Methods. Data from the CONTEST study, a head-to-head comparison of 3 existing questionnaires, were used to identify items with a Youden index score of >0.1. These were combined using 4 approaches: CONTEST (simple additions of questions), CONTESTw (weighting using logistic regression), CONTESTjt (addition of a joint manikin), and CONTESTtree (additional questions identified by classification and regression tree [CART] analysis). These candidate questionnaires were tested in independent data sets. Results. Twelve individual questions with a Youden index score of >0.1 were identified, but 4 of these were excluded due to duplication and redundancy. Weighting for 2 of these questions was included in CONTESTw. Receiver operating characteristic (ROC) curve analysis showed that involvement in 6 joint areas on the manikin was predictive of PsA for inclusion in CONTESTjt. CART analysis identified a further 5 questions for inclusion in CONTESTtree. CONTESTtree was not significant on ROC curve analysis and discarded. The other 3 questionnaires were significant in all data sets, although CONTESTw was slightly inferior to the others in the validation data sets. Potential cut points for referral were also discussed. Conclusion. Of 4 candidate questionnaires combining existing discriminatory items to identify PsA in people with psoriasis, 3 were found to be significant on ROC curve analysis. Testing in independent data sets identified 2 questionnaires (CONTEST and CONTESTjt) that should be pursued for further prospective testing.

Comparison of screening questionnaires to identify psoriatic arthritis in a primary-care population: a cross-sectional study

“…At the study visit, following informed consent, patients were asked to complete a questionnaire booklet including the PEST and CONTEST questionnaires, PsA Quality of Life (PsAQoL), Dermatology Life Quality Index and Health Assessment Questionnaire (HAQ) . They were then reviewed independently by a dermatologist (L.S.)…”

“…Three potential questionnaires were developed using different analyses. 4 They were then tested retrospectively in similar PsA screening datasets from Dublin and Utah. The weighted CON-TEST questionnaire did not work well in the independent datasets, but the simple CONTEST score, which included the most discriminant items from the other questionnaires, and the CONTESTjt score, which was identical to CONTEST with the addition of a joint manikin, did suggest some advantage over PEST.…”

“…The weighted CON-TEST questionnaire did not work well in the independent datasets, but the simple CONTEST score, which included the most discriminant items from the other questionnaires, and the CONTESTjt score, which was identical to CONTEST with the addition of a joint manikin, did suggest some advantage over PEST. 4 The aim of this study was to test prospectively the two candidate CONTEST questionnaires alongside the existing PEST questionnaire, this time in a primary-care cohort, where a full spectrum of psoriasis disease activity can be identified. In addition, we sought to identify retrospectively any potential clinical risk factors that might aid the identification of PsA in primary-care patients with psoriasis.…”

“…The PEST questionnaire did seem to perform slightly better than the others, but given the relatively low specificity, we sought to create a new questionnaire incorporating the most discriminative items from each of the existing questionnaires. Three potential questionnaires were developed using different analyses . They were then tested retrospectively in similar PsA screening datasets from Dublin and Utah.…”

Early Psoriatic Arthritis

“…More recently, another questionnaire (CONTEST) was derived combining optimal questions from existing tools and requires further evaluation. 22 The efficacy of screening questionnaires in various health care settings, including the frequency of use and characteristics of the target population to which they are applied still, remains to be determined.…”