A first look at the reliability, validity and responsiveness of L-PF-35 dyspnea domain scores in fibrotic hypersensitivity pneumonitis

BACKGROUND

Dyspnea impairs quality of life (QOL) in patients with fibrotic hypersensitivity pneumonitis (FHP). The Living with Pulmonary Fibrosis questionnaire (L-PF) assesses symptoms, their impacts and PF-related QOL in patients with any form of PF. Its scores have not undergone validation analyses in an FHP cohort.

METHODS

We used data from the Pirfenidone in FHP trial to examine reliability, validity and responsiveness of the L-PF-35 Dyspnea domain score (Dyspnea) and to estimate its meaningful within-patient change (MWPC) threshold for worsening. Lack of suitable anchors precluded conducting analyses for other L-PF-35 scores.

RESULTS

At baseline, Dyspnea's internal consistency (Cronbach's coefficient alpha) was 0.85; there were significant correlations with all four anchors (University of California San Diego Shortness of Breath Questionnaire scores r = 0.81, St. George's Activity domain score r = 0.82, percent predicted forced vital capacity r = 0.37, and percent predicted diffusing capacity of the lung for carbon monoxide r = 0.37). Dyspnea was significantly different between anchor subgroups (e.g., lowest percent predicted forced vital capacity (FVC%) vs. highest, 33.5 ± 18.5 vs. 11.1 ± 9.8, p = 0.01). There were significant correlations between changes in Dyspnea and changes in anchor scores at all trial time points. Longitudinal models further confirmed responsiveness. The MWPC threshold estimate for worsening was 6.6 points (range 5-8).

CONCLUSION

The L-PF-35 Dyspnea domain appears to possess acceptable psychometric properties for assessing dyspnea in patients with FHP. Because instrument validation is never accomplished with one study, additional research is needed to build on the foundation these analyses provide.

TRIAL REGISTRATION

The data for the analyses presented in this manuscript were generated in a trial registered on ClinicalTrials.gov; the identifier was NCT02958917.

Is it time to include oxygen needs as an endpoint in clinical trials in patients with fibrosing interstitial lung disease? If so, how?

Many patients with fibrosing interstitial lung disease (fILD) will need to use supplemental oxygen (O2) to maintain normoxia at some point in their illness. If it is not needed at the time of diagnosis, then if fILD progresses-or if a comorbid condition like pulmonary hypertension develops-O2 will become necessary, often, initially, during exertion and all-too-often, eventually, at rest as well. But presumably, if all else remains stable, if fILD progression is halted or slowed, O2 needs follow in parallel. Despite perceived or unnoticed benefits of O2, and prescribers' good intentions to improve patients' sense of well-being, patients with fILD generally view O2 with frustration and fear, as it threatens their already-impaired quality of life. Because of how meaningful and impactful O2 is to the lives of patients with fILD, 'O2 need' is a critically important-and perhaps the most-patient-centred metric that should be considered for incorporation as an endpoint in therapeutic trials. It is unclear how this should be done, but in this paper, we offer some possible approaches that merit consideration.

The Attitudes and Practices of Physicians Caring for Patients with Rheumatoid Arthritis-Interstitial Lung Disease: An International Survey

OBJECTIVES

This study sought to determine the level of understanding and opinion amongst rheumatologist and pulmonologists regarding risk factors, diagnostic approach and treatment of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

We conducted an international electronic survey of rheumatologists and pulmonologists utilizing two separate Redcap-based surveys with questions on the epidemiology, workup and management of RA-ILD as well as ILD screening questions using case-based scenarios directed at rheumatologists. The survey also collected demographic data on participants including their practice setting, years in practice and country of practice.

RESULTS

We received a total of 616 responses (354 rheumatologists and 262 pulmonologists) from 6 continents. There were significant differences in responses between pulmonologists and rheumatologists in estimated prevalence and mortality, risk factors for the development of ILD in RA and medications that are effective or should be avoided. Rheumatologists were much less likely to consider assessment for ILD in high risk, asymptomatic patients compared with high-risk patients with either symptoms or exam findings suggestive of ILD.

CONCLUSION

Our study brought to light the variability in disease assessment and clinical practice amongst providers caring for patients with RA-ILD and indicate that greater education is needed to optimize clinical decision making in the risk assessment, screening and treatment of RA-ILD. Research questions that address appropriate screening and treatment strategies for RA-ILD will be valuable for rheumatologists given their central role in the overall health and lung health of patients with RA.