Making Sense of Dyspnea in Interstitial Lung Disease

Authors: Yet H. Khor

“Dyspnea” derives from the Greek words “dus” (difficult) and “pnoē” (breathing) (1). It is a generic term used to describe a range of subjective respiratory discomforts of varying qualities and severities due to different underlying diseases. As dyspnea is one of the most commonly reported symptoms in patients with interstitial lung disease (ILD), conversations about the presence of dyspnea and its severity occur regularly during clinical assessments. Patient-reported outcome measures (PROMs) are available to capture patients’ direct reporting of their dyspnea experience, such as the University of California, San Diego, Shortness of Breath Questionnaire (UCSD SOBQ), the Dyspnea-12 Questionnaire, the Medical Research Council dyspnea scale, and visual analog scales for dyspnea. There is no doubt that as clinicians and researchers, we acknowledge the debilitating nature of dyspnea in patients with ILD, which is associated with impaired quality of life and increased survival (2, 3). However, do we understand what patients mean and how much they are affected when they describe their dyspnea experience or complete PROMs?

In this issue of AnnalsATS, Swigris and colleagues (pp. 1147–1154) report the first study of PROM bookmarking in ILD for the evaluation of dyspnea severity (4). The PROM bookmarking procedure is a qualitative method to enhance interpretability by assigning meaningful labels to scores or items with the establishment of thresholds for different degrees of severity on the basis of inputs from different relevant stakeholders (5). First, using data on the activity items for the UCSD SOBQ from 1,760 patients in the PPF-PR (Pulmonary Fibrosis Foundation Patient Registry) at enrollment, 21 hypothetical vignettes for the spectrum of dyspnea severity were created. Twenty-five patients with ILD and 19 ILD physicians then individually rank ordered vignettes by severity, with 20 and 19 subsequently participating in consensus discussion for each group to place bookmarks between vignettes to define the thresholds for six degrees of severity ranging from no dyspnea to very severe dyspnea. There were no differences in bookmarking for classifying vignettes between patients using and not using supplemental oxygen, as well as between female and male physicians. Of note, although patients and physicians agreed on the thresholds for very mild/mild and mild/moderate dyspnea, there were differences for the severe end, with physicians setting higher thresholds that “tolerated” more dyspnea compared with patients. This discrepancy led to reclassification in 10% of patients from moderate to severe dyspnea and from severe to very severe dyspnea when applying patients’ bookmarks for degrees of dyspnea severity in the PPF-PR cohort compared with physicians’ bookmarks. The authors took a further step to develop meaningful dyspnea severity categories for different types of activities, which allows clinicians to appreciate the likely perceived degrees of dyspnea for a given activity, such as doing laundry and walking upstairs, for individual patients on the basis of their reported overall dyspnea severity.

Patient-reported outcomes, including dyspnea, are increasingly incorporated in research settings and recognized by regulatory bodies to measure how patients feel using PROMs to inform the impact of disease and the efficacy of its treatments (6, 7). They also offer values for integration into clinical care for symptom screening and monitoring for timely management, evaluation of treatment responses, and prognostication (8, 9). In addition, discussing patient-reported outcomes can facilitate patient–clinician interactions to improve patient engagement in goal setting and shared decision making (10). Most PROMs are developed for research purposes, focusing on their clarity and suitability for the target population with demonstrated psychometric properties to provide valid and reliable measurements that are sensitive to detect changes over time (6). For application in clinical practice, the value of patient-reported outcomes hinges on the extent to which clinicians can easily interpret to understand the meaning for delivering care that is important to patients (Figure 1).

Previous studies have consistently shown poor agreement between patients’ and physicians’ perceptions of a range of patient-reported outcomes, which include physical and emotional symptoms, health-related quality of life, and other outcomes (11, 12). This study similarly demonstrated ILD physicians’ inaccuracy in estimating patients’ perceived dyspnea severity, highlighting the need for a simple guide to support better clinician interpretation and prompt conversations. Swigris and colleagues’ work (4) bridges this gap by assigning descriptors of “how bad my dyspnea would be” for common daily activities that are included in the UCSD SOBQ stratified by the reported overall dyspnea severity in patients with ILD. This allows clinicians to be more cognizant of patients’ day-to-day experiences of dyspnea and anticipated challenges. This enhanced awareness can be beneficial in facilitating more effective and streamlined communication to identify opportunities for improving patient-centered care in ILD. Furthermore, interprofessional communication for patient tracking and management of dyspnea among the ILD multidisciplinary team may be optimized with shared understanding.

The in-depth engagement of relevant stakeholders, both patients and physicians, is a major strength of this study. Recalibrating with repeating the PROM bookmarking procedure in different groups of stakeholders can help improve confidence in the relevance of study findings for wide application. The vast majority of patients who participated in this study were White. Cultural factors can mediate symptom perception, as seen in reported pain intensity (13). Thus, there is a need to determine the bookmark placement of different degrees of dyspnea severity in patients of diverse backgrounds for validation, which is similar to the requirement of cultural adaptation for the development of PROMs. In addition, further evaluation in larger numbers of female and younger patients, who were less represented in this study, can be informative, given the known gender and age differences in symptom perception and illness behavior (14, 15). The involvement of caregivers and nonphysician clinicians, particularly ILD nurses, respiratory therapists, and physiotherapists, in the bookmarking procedure for dyspnea severity, is another important next step, given their crucial roles in caring for patients with ILD.

The work by Swigris and colleagues (4) moves the field of patient-reported outcomes in ILD forward beyond the psychometric development. With the availability of meaningful dyspnea severity categories for different types of activities, we can now make better sense of patients’ dyspnea experiences during clinical consultations for tailored patient care of ILD. The approach of using overall dyspnea severity without the need to complete a PROM for its application is a welcome step to negate the challenge associated with the administration and completion of questionnaires, which is a significant barrier with time and resource constraints together with patient burden (16). The key question we face now is how to best embed and gain the most from patient-reported outcome–informed clinical practice to improve dyspnea management in ILD, a critical area of unmet patient need.