Table 2.
Psychometric results for the experimental items presented in three different item formats
| Item | Formatb | Content | Slope | Thresholdc | Item fit: p (S-X 2)d | Imax (at T-score)e | Area under the curvef | Percentage floor/percentage ceilingg | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | Mean | ||||||||
| A1 | A | Do 2 hours of physical labor | 3.49 | 38.6 | 42.9 | 47.8 | 54.9 | 46.1 | 0.6523 | 3.71 (T = 42) | 92.9 | 10.4/41.6 | |
| B1a | B | 4.53 | 38.0 | 43.0 | 48.4 | 53.1 | 45.6 | 0.1133 | 5.93 (T = 49) | 132.9 | 10.0/42.7 | ||
| C1 | C | 4.01 | 37.7 | 42.0 | 46.3 | 52.7 | 59.8 | 47.7 | 0.0358 | 4.88 (T = 42) | 140.3 | 10.2/19.6 | |
| A2a | A | Do yard work | 4.09 | 36.3 | 40.1 | 44.3 | 50.7 | 42.9 | 0.1473 | 5.10 (T = 40) | 111.1 | 6.6/57.3 | |
| B2 | B | 4.79 | 35.7 | 40.8 | 46.1 | 50.6 | 43.3 | 0.0751 | 6.58 (T = 47) | 144.0 | 6.7/52.7 | ||
| C2 | C | 4.53 | 34.3 | 39.1 | 43.1 | 49.3 | 56.0 | 44.4 | 0.0300 | 6.10 (T = 40) | 167.5 | 5.3/32.1 | |
| A3 | A | Climb several flights of stairs | 3.78 | 35.2 | 40.3 | 45.2 | 52.0 | 43.2 | 0.1722 | 4.28 (T = 41) | 107.0 | 5.8/51.5 | |
| B3a | B | 4.20 | 34.2 | 40.8 | 46.7 | 51.3 | 43.3 | 0.8460 | 5.16 (T = 48) | 126.0 | 5.1/51.3 | ||
| C3 | C | 3.78 | 33.3 | 39.8 | 44.0 | 51.0 | 57.1 | 45.0 | 0.1174 | 4.31 (T = 42) | 135.0 | 6.3/25.4 | |
| A4a | A | Go for a walk of at least 15 minutes | 3.78 | 33.2 | 36.4 | 40.2 | 45.5 | 38.8 | 0.2497 | 4.45 (T = 37) | 91.3 | 3.7/73.5 | |
| B4 | B | 4.03 | 32.1 | 37.2 | 42.0 | 45.8 | 39.3 | 0.3555 | 4.93 (T = 43) | 107.0 | 3.4/71.6 | ||
| C4 | C | 3.99 | 30.3 | 35.6 | 39.5 | 44.9 | 50.8 | 40.2 | 0.0033 | 4.85 (T = 37) | 134.7 | 3.6/47.5 | |
| A5a | A | Open previously opened jars | 1.91 | 18.8 | 28.4 | 37.9 | 28.4 | 0.2434 | 1.10 (T = 28) | 36.5 | 0.9/85.8 | ||
| B5 | B | 1.90 | 12.9 | 22.8 | 32.3 | 39.6 | 26.9 | 0.5429 | 1.10 (T = 33) | 39.9 | 0.3/81.9 | ||
| C5 | C | 1.57 | 5.0 | 15.5 | 23.4 | 34.0 | 45.4 | 24.7 | 0.1877 | 0.77 (T = 20) | 33.6 | 0.3/62.4 | |
aItem is part of the final Patient Reported Outcomes Measurement Information System Physical Function (PROMIS PF) item bank version 1.0. bFormat A: “Are you able to …” (five-category response scale from “Without any difficulty” to “Unable to do”); format B: “Does your health now limit you in …” (five-category response scale from “Not at all” to “Cannot do”); format C: “How difficult is it for you to …” (six-category response scale from “Very easy” to “Impossible”). cThresholds are transformed to a T-score of 50 ± 10, where 50 = mean and 10 = standard deviation of the analytic sample; slopes are reported unchanged. d X 2 statistics (S-X 2) were evaluated after adjusting for multiple testing (p < 0.0033). eImax (at T-score) depicts the maximum of item information (upper number) of a given item at the corresponding point on the T-score continuum. fTotal area under the item information curve (IIC) on the empirically observed T-score range in the calibration sample (T-score = 11.1–73.6). gPercentage of participants who answered the item with the lowest (floor) or highest (ceiling) possible response category