| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations |
At the consensus meeting, experts agreed that both tools should be feasible to implement in daily clinical practice. As such, some domains were clustered (e.g. disease activity, swollen and tender joints, inflammatory parameters, joint pain and patient global disease For validation, from 80 clinical cases (40 with peripheral PsA and 40 with axial PsA phenotypes) assessed, 30 cases for the peripheral PsA and 25 cases for the axial PsA tools’ validation were used. |
| 1. RELIABILITY | |
| A. Internal Consistency | Not Tested |
| Cronbach's (Describe) | |
| B. Reliability intraobserver or test-retest | Not Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
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| C. Reliability interobserver or Measurement error | Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
An analysis was conducted for the cases where rheumatologists disagreed between themselves regarding the quality of the switch (without the agreement of at least 2 out of 3 rheumatologists) to understand the main reasons for rheumatologists to evaluate the biologic switch differently from the tools. In 40 peripheral PsA cases the cases where the rheumatologists gave a different classification (red crosses). Notably, cases considered “Moderate” by the tool (considering the outcomes of all domains) are classified as“Good” by the rheumatologists mainly because they accepted some residual “Disease Activity” if the patient has a considerable improvement from the baseline (e.g. patient with a DAPSA=5.6 but with an improvement from the baseline of 64%). |
| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
The development of the PASQAL comprised a modified-Delphi method in a four-step procedure: 1) literature search and experts’ opinion collection about quality indicators for PsA management; 2) Delphi design to address the development of the measurement tool; 3) three Delphi questionnaire rounds; 4) final consensus meeting. This phase resulted in the definition of two measurement tools, one to evaluate the quality of biologic switch in peripheral (pPASQAL) and another one in axial PsA (axPASQAL). For the validation of PASQAL, 12 experienced rheumatologists were asked to evaluate and classify the biologic switch of 80 clinical cases (40 with predominant peripheral and 40 with predominant axial PsA). |
| B. Construct Validity: Structural validity |
Not Tested |
| Hypotheses-testing | Not Tested |
| Cross-cultural validity | Not Tested |
| Brief Description | |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Clinical judgement was defined to be the “gold standard” against which the performance of PASQAL was assessed. The results were used to assess tools’ performance (sensitivity/specificity analysis). Regarding the performance of the tools, the peripheral PsA tool was found to be more sensitive (92%) for the “Good” quality level and more specific (97%) for the “Insufficient” quality level. The axial PsA tool was found to be more sensitive (100%) for the “Good” quality level and more specific (100%) for the “Insufficient” quality level. Both tools showed to be less sensitive for the “Moderate” quality level. Agreement between the tool and the gold standard: The agreement between the output of each tool and the gold standard was quantified using the Cohen’s kappa. Generally, Cohen’s kappa ranges from 0 to 1, whereas larger numbers (i.e. above 0.6) represent a good level of agreement. For the calculation of Cohen’s kappa, a 95% confidence interval (CI) was also reported. Agreement between PASQAL and rheumatologists showed good levels in both tools: pPASQAL: k=0.71, 95% CI = 0.59-0.83 aPASQAL: k=0.87, 95% CI = 0.78-0.96) |