Table 3

Diagnostic group (pooled datasets) results of Rasch analysis

Item fit residualPerson fit residualχ2 Interaction
Diagnostic groupAnalysisMeanSDMeanSDValue (df)p ValuePSINProportion of significant t tests (95% CI)
Pooled ASAnalysis 10.5632.959−0.5572.584683.931 (351)<0.0010.972661
Analysis 20.3140.905−0.4931.34772.674 (63)0.1890.9386600.074 (0.058 to 0.092)
Pooled PsAAnalysis 10.9573.096−0.4992.517787.691 (351)<0.0010.975780
Analysis 20.5751.218−0.4451.27970.460 (63)0.2420.9447770.071 (0.056 to 0.086)
Pooled SScAnalysis 10.6992.232−0.5322.634527.415 (351)<0.0010.976333
Analysis 20.6641.270−0.3841.26243.006 (35)0.1660.9493330.051 (0.026 to 0.074)
Pooled SLEAnalysis 10.5602.559−0.4972.551476.407 (234)<0.0010.969360
Analysis 20.5141.166−0.4211.29839.817 (42)0.5670.9323580.051 (0.028 to 0.074)
Pooled FMSAnalysis 10.6072.482−0.2511.972450.441 (273)<0.0010.972329
Analysis 20.3780.986−0.2571.01647.060 (42)0.2730.9503290.025 (0.001 to 0.048)
Pooled OAAnalysis 10.7752.689−0.7013.022709.905 (351)<0.0010.976430
Analysis 20.4061.845−0.4341.27399.906 (63)0.0020.950429Misfit
Expected values for a perfect model fit0101>0.05>0.70Lower-bound CI <0.05
  • Analysis 1=Rasch analysis of the ENAT as a 39-item scale; Analysis 2=Rasch analysis of the ENAT as a 7-testlet scale.

  • AS, ankylosing spondylitis; DF, degrees of freedom; ENAT, educational needs assessment tool; FMS, fibromyalgia syndrome; OA, osteoarthritis; p, χ2 probability (non-significant p, fit to the model); PsA, psoriatic arthritis; PSI, Person Separation Index; SLE, systemic lupus erythematosus; SSc, systemic sclerosis.