Table 1.
Demographic characteristics of the Dutch AMS-PAIN sample (n = 1085) and the US ACPA sample (n = 967).
Table 2.
IRT item characteristics for the Dutch-Flemish PROMIS Pain Interference item bank.
Fig 1.
Standard errors across the range of the Dutch-Flemish PROMIS Pain Interference T-scores.
Upper plot shows the standard errors of the Dutch-Flemish PROMIS Pain Interference 4-item short form (v1.0.4a), the 8-item short form (v1.0.8a), the 8-item simulated CAT, and the total item bank. Lower plot shows the distribution of the Dutch AMS-PAIN (Dutch clinical) sample, the US ACPA (US clinical) sample and the US Wave1 sample (US general population) along the T-score scale.
Fig 2.
The overall impact of DIF for language on the test characteristic curves (TCC).
The TCC shows the relation between the total item scores (y-axis) and theta (x-axis). Left graph shows the TCC for all 40 Dutch-Flemish (DF) and United States (US) PROMIS Pain Interference items (ignoring DIF); the right graph shows the TCC for just the 2 items having DIF.