RAND IAQL Score Conversion Table
| Summed Score | Original AQLQ-Marks score | RAND-IAQL scale T-score | RAND-IAQL scale T-score SE |
|---|---|---|---|
| 0 | 0 | 29.4 | 4.8 |
| 1 | 0.125 | 33.4 | 3.6 |
| 2 | 0.25 | 35.6 | 3.1 |
| 3 | 0.375 | 37.3 | 2.8 |
| 4 | 0.5 | 38.6 | 2.6 |
| 5 | 0.625 | 39.7 | 2.4 |
| 6 | 0.75 | 40.7 | 2.2 |
| 7 | 0.875 | 41.6 | 2.1 |
| 8 | 1 | 42.4 | 2.0 |
| 9 | 1.125 | 43.1 | 2.0 |
| 10 | 1.25 | 43.8 | 1.9 |
| 11 | 1.375 | 44.4 | 1.8 |
| 12 | 1.5 | 45.0 | 1.8 |
| 13 | 1.625 | 45.6 | 1.8 |
| 14 | 1.75 | 46.1 | 1.7 |
| 15 | 1.875 | 46.7 | 1.7 |
| 16 | 2 | 47.2 | 1.7 |
| 17 | 2.125 | 47.7 | 1.6 |
| 18 | 2.25 | 48.1 | 1.6 |
| 19 | 2.375 | 48.6 | 1.6 |
| 20 | 2.5 | 49.1 | 1.6 |
| 21 | 2.625 | 49.5 | 1.6 |
| 22 | 2.75 | 49.9 | 1.6 |
| 23 | 2.875 | 50.3 | 1.6 |
| 24 | 3 | 50.8 | 1.6 |
| 25 | 3.125 | 51.2 | 1.6 |
| 26 | 3.25 | 51.6 | 1.6 |
| 27 | 3.375 | 52.0 | 1.6 |
| 28 | 3.5 | 52.4 | 1.5 |
| 29 | 3.625 | 52.8 | 1.5 |
| 30 | 3.75 | 53.2 | 1.6 |
| 31 | 3.875 | 53.6 | 1.6 |
| 32 | 4 | 54.0 | 1.6 |
| 33 | 4.125 | 54.4 | 1.5 |
| 34 | 4.25 | 54.7 | 1.5 |
| 35 | 4.375 | 55.1 | 1.5 |
| 36 | 4.5 | 55.5 | 1.5 |
| 37 | 4.625 | 55.8 | 1.5 |
| 38 | 4.75 | 56.2 | 1.5 |
| 39 | 4.875 | 56.6 | 1.5 |
| 40 | 5 | 57.0 | 1.5 |
| 41 | 5.125 | 57.3 | 1.5 |
| 42 | 5.25 | 57.7 | 1.5 |
| 43 | 5.375 | 58.0 | 1.5 |
| 44 | 5.5 | 58.4 | 1.5 |
| 45 | 5.625 | 58.8 | 1.5 |
| 46 | 5.75 | 59.2 | 1.5 |
| 47 | 5.875 | 59.5 | 1.5 |
| 48 | 6 | 59.9 | 1.5 |
| 49 | 6.125 | 60.2 | 1.5 |
| 50 | 6.25 | 60.6 | 1.5 |
| 51 | 6.375 | 60.9 | 1.5 |
| 52 | 6.5 | 61.3 | 1.5 |
| 53 | 6.625 | 61.7 | 1.5 |
| 54 | 6.75 | 62.1 | 1.5 |
| 55 | 6.875 | 62.4 | 1.5 |
| 56 | 7 | 62.8 | 1.5 |
| 57 | 7.125 | 63.1 | 1.5 |
| 58 | 7.25 | 63.5 | 1.5 |
| 59 | 7.375 | 63.9 | 1.5 |
| 60 | 7.5 | 64.3 | 1.5 |
| 61 | 7.625 | 64.7 | 1.5 |
| 62 | 7.75 | 65.1 | 1.5 |
| 63 | 7.875 | 65.5 | 1.6 |
| 64 | 8 | 65.9 | 1.6 |
| 65 | 8.125 | 66.4 | 1.6 |
| 66 | 8.25 | 66.8 | 1.6 |
| 67 | 8.375 | 67.3 | 1.7 |
| 68 | 8.5 | 67.7 | 1.7 |
| 69 | 8.625 | 68.2 | 1.7 |
| 70 | 8.75 | 68.8 | 1.8 |
| 71 | 8.875 | 69.3 | 1.8 |
| 72 | 9 | 69.9 | 1.9 |
| 73 | 9.125 | 70.6 | 2.0 |
| 74 | 9.25 | 71.3 | 2.1 |
| 75 | 9.375 | 72.1 | 2.2 |
| 76 | 9.5 | 73.0 | 2.4 |
| 77 | 9.625 | 74.1 | 2.6 |
| 78 | 9.75 | 75.4 | 2.9 |
| 79 | 9.875 | 77.0 | 3.2 |
| 80 | 10 | 79.9 | 4.0 |
Note: T-score metric is a linear transformation from the IRT theta scale: T-score = 10 * theta + 50. SE in the table is the standard error on T-score metric.
This table was published in Clinical Therapeutics, Vol. 36, No.5, Edelen MO, Stucky B, Eberhart N, Lara M, Sherbourne CD. Correspondence between the RAND-Negative Impact of Asthma on Quality of Life Item Bank and the Marks Asthma Quality of Life Questionnaire. p. 686, Copyright Elsevier, 2014.