Relation of IPF preliminary core set instruments to aspects of OMERACT filter in IPF
| IPF | Dyspnoea | Cough | HRQoL | Lung physiology | Lung imaging | Survival | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Instruments | D-12 | MRC | UCSD-SBQ | LCM | SGRQ | SF-36 | FVC | DLCO | HRCT—overall extent of disease | All-cause mortality |
| Truth | ||||||||||
| Face validity | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| Content validity | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| Construct validity | Y | Y | Y | NT | Y | Y | Y | Y | Y | Y |
| Criterion validity | NT | NT | NT | NT | NT | NT | No | No | Y | Y |
| Discrimination | ||||||||||
| Discriminatory | NT | NT | Y | NT | NT | NT | ± | ± | Y | No |
| Reliable | NT | NT | NT | NT | Y | Y | Y | N | Y | Y |
| Reproducible | NT | NT | NT | NT | Y | NT | Y | ± | Y | N/A |
| Sensitive to change | NT | NT | Y | NT | Y | Y | Y | Y | Yes but relatively slow | N/A |
| Feasibility | ||||||||||
| Cost effective | Y | Y | Y | Y | Y | Y | Y | Y | Y | No* |
| Interpretability | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| Readily available | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| Safe for patients | Y | Y | Y | Y | Y | Y | Y | Y | ± | Y |
| Patient-derived content† | Y | No | No | No | No | No | N/A | N/A | N/A | N/A |
*Not cost effective as a primary efficacy endpoint but highly cost effective as a secondary endpoint to detect treatment toxicity—see text for discussion on ‘survival’.
†US Food and Drug Administration advocates patient-reported instruments be developed by qualitative data supplied by patients.18 ,19
±, ambiguous; D-12, Dyspnea-12; DLCO, diffusion capacity of lung for carbon monoxide; FVC, forced vital capacity; HRCT, high-resolution CT; IPF, idiopathic pulmonary fibrosis; LCM, Leicester Cough Monitor; MRC, Medical Research Council Dyspnea Scale; N/A, not applicable; NT, not yet tested; OMERACT, Outcome Measures in Rheumatology; SGRQ, St George's Respiratory Questionnaire; SF-36, Short Form 36; UCSD, University of San Diego Shortness of Breath Questionnaire; Y, yes.