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Abstract

Objective: to examine the validity of a novel dyspnea scale, Edmonton Dyspnea Inventory in idiopathic pulmonary fibrosis (IPF). Methods: Edmonton Dyspnea Inventory (EDI), is a clinical instrument to measure dyspnea severity with activities of daily living, exercise and rest using a numeric rating scale (0 -10). Consecutive IPF patients (2012-2018) with baseline MRC and EDI were included. To validate EDI, psychometric analysis was conducted. Correlations between EDI, MRC and lung function were examined. Group-based trajectory modeling was used to group patients based on dyspnea severity. Net Reclassification Improvement (NRI) was calculated to assess the improvement in 1-year mortality prediction by adding trajectory groups to MRC grade. Results: 100 consecutive IPF patients were identified; mean age 73 years (SD = 9) and 65% males; 73% were in MRC grades ≥3. Item analysis showed all 8 EDI components have excellent discrimination power with ability to differentiate patients with varying dyspnea severity. EDI has good internal consistency (Cronbach α = .92). Exploratory factor analysis showed a one-factor solution with loadings from .66 to .89 suggesting 8 EDI components measured essentially one dimension of dyspnea. All EDI components were correlated with MRC and some with lung function. Modeling data identified three EDI dyspnea severity groups with differing mortality (P = .009). The addition of EDI dyspnea severity groups to the MRC score improved 1-year mortality prediction (NRI = .66; 95% CI, .18-1.14). Conclusions: EDI is a valid dyspnea instrument, correlated with MRC and lung function. It can categorize IPF patients into 3 dyspnea severity groups associated with increased mortality. Key Message: We describe the development of a novel scale, Edmonton Dyspnea Inventory, that facilitates measurement of dyspnea severity in the context of daily activities in patients with IPF. The results indicate that the new instrument is valid and correlated to MRC. It identifies 3 categories of severity not recognized by MRC with impact on mortality. Knowledge of dyspnea severity can help triage patients and assign appropriate therapies.

Keywords

Edmonton dyspnea inventory idiopathic pulmonary fibrosis crisis dyspnea episodic dyspnea baseline dyspnea medical research council

Introduction

Dyspnea (breathlessness) is a common and highly distressing symptom of chronic cardiorespiratory conditions. Over 90% of patients with Idiopathic Pulmonary Fibrosis (IPF), the most common form of fibrosing lung diseases, present with dyspnea.¹ Dyspnea is associated with mortality and poor health-related quality of life in IPF.^2,3 Despite the availability of several validated dyspnea scales, in clinical practice, systematic assessment of dyspnea is not routinely performed, and there is no universally accepted approach to managing dyspnea in patients with IPF.^3-6

The Medical Research Council (MRC), or modified MRC (mMRC), is the most commonly used dyspnea scale worldwide because of ease of use and brevity.⁴ The scale measures disability due to dyspnea but does not assess dyspnea severity directly. The American Thoracic Society (ATS) defines dyspnea as “a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity.”.⁷ Hence, assessment of severity is essential for comprehensive dyspnea evaluation. In one study, 90% of US-based hospitalists stated that awareness of dyspnea severity rating influences their management decisions, and 65% reported it influences their decision to prescribe opioids.⁸ The American College of Chest Physicians (ACCP) statement on dyspnea management in patients with advanced lung or heart disease recommends that patients should be asked to rate their dyspnea, and this rating should be used to guide management.⁹ Yet, only 2.3% of practitioners report using a scale in clinic to rate dyspnea severity.⁸

Several multidimensional dyspnea tools exist including one that measures dyspnea severity, but they are typically used only in research settings,and it is unclear whether or how their results effect dyspnea management.¹⁰ Patients with interstitial lung disease (ILD) and various stakeholders also recommend the use of a numeric ratings scale to measure dyspnea and its impact on physical function and daily living.¹¹ We developed the Edmonton Dyspnea Inventory (EDI), a simple, easily-administered patient-reported outcome measure to assess dyspnea severity in the clinic. In this study, we examine the validity of EDI scores for assessing dyspnea in patients with IPF. We hypothesized that EDI is a unidimensional tool with acceptable internal consistency and that its scores possess validity for assessing dyspnea severity across activities of varying intensity in patients with IPF; specifically, item scores would be associated with MRC scores, measures of IPF severity and mortality.

Methods

This is a retrospective study of IPF patients seen in the Multidisciplinary Collaborative ILD clinic, Edmonton, Canada. The study population includes all consecutive IPF patients with baseline MRC and EDI (Nov 2012 – Jun 2018) who were eligible for inclusion. IPF diagnosis was made in accordance with the ATS 2011 guidelines.¹² IPF patients without baseline MRC and EDI were excluded. All data were extracted from the medical record and included demographics, disease history, pulmonary physiology (percent predicted forced vital capacity or FVC%, diffusion capacity or DLCO%), submaximal exercise (6-minute walk test or 6MWT) and questionnaire response data. Pulmonary physiology and 6MWT were performed within 7 days of the baseline visit and according to ATS standards. Gender-Age-Physiology (GAP) stages were calculated using baseline data.¹³

Edmonton Dyspnea Inventory (EDI)

Development

We developed the EDI to assess dyspnea in patients with IPF. We aimed to create a dyspnea severity profile across three phases (with activities of daily living (ADL), exercise and rest) to inform the systematic application of dyspnea therapies.^14,15 The original EDI had 8 items, ordered by metabolic equivalents, from low to high intensity, and response options on a numeric rating scale, ranging 0-10 (0: no breathlessness to 10: worst possible breathlessness).¹⁶

The items were chosen for their relevance to daily life and include rest, eating, talking (low metabolic demand), showering, dressing, bowel movement (moderate metabolic demand), stairs and exercise (high metabolic demand).¹⁷ Based on item review and informal patient feedback, walking was recently added as a new item to make the current 9-component EDI. Scores for walking were not included in this analysis due to limited data collected during this period (n = 17).

In addition, we ask about dyspnea crises as these episodes result in frequent hospitalizations and lead to panic and anxiety amongst patients and their informal caregivers. This is a free text response detailing triggers for acute onset distress, event details and resolution or outcomes.

Administration

The clinic nurse or physician administers the instrument in person or by phone. Wording for items is as follows: “Please score your breathing when (state context)”. The question about crisis dyspnea is phrased as follows: “Have you had episodes where your breathing worsened to point of needing urgent help (felt like calling or called 911 or going to hospital)?" If yes, number of episodes and context are documented.

Scoring

Each item (except crisis dyspnea response) yields a score; there is a total score. We use the individual scores for each item to determine therapies, track progression and assess responses to intervention. Per convention, item scores ≥4/10 are considered moderate to severe.^18,19

Statistical Analysis

We report means (SD) or median (IQR) for continuous variables and counts and percentages for categorical variables.

Dimensionality, Structure and Internal Consistency

We conducted several psychometric analyses to examine the structure of the EDI instrument and its individual items; these included exploratory factor analysis, item correlational analysis (item-item and item-total [without the given item] using Pearson correlation), and an examination of internal consistency using Cronbach’s coefficient alpha.

We used group-based trajectory modeling (GBTM) on EDI scores to group patients with similar patterns of dyspnea behavior and to further explore the response structure. We ordered the components of EDI by the metabolic equivalents from low intensity to high intensity in order (rest, talking, eating, bowel movement, dressing, showering, exercise and stairs) and applied the GBTM to identify groups of patients following similar patterns of dyspnea scores with the increasing intensity of activities. The order of exercise and stairs is arbitrary (some patients treated walking around house as exercise), so the model was also tested by switching these two activities.²⁰ We also compared the baseline clinical features and survival amongst the 3 groups identified by GBTM.

Validation

We examined the relationship between EDI scores, MRC grade and IPF severity (FVC%, DLCO%, distance walked during 6MWT) using one-way ANOVA and Spearman correlation coefficients to establish convergent validity.

Survival Analysis

In order to explore the relationship responses to the EDI we created a series of logistic regression models. In order to quantify the impact of adding the EDI to the other predictors of mortality we calculated net reclassification improvement (NRI) and pseudo-c indices.²¹ NRI was calculated comparing the 1-year mortality model with MRC as the only predictor to a model with both MRC and EDI as predictors. Subsequently we compared the model using age, gender and FVC as predictors to one with the additional EDI variable. Missing Data were considered missing at random.

All statistical analyses and visualisations were conducted using SAS 9.4 (Cary, NC.), R 4.0.0 (Vienna), and Tableau (Seattle, WA.). This study received ethics approval from the University of Alberta Health Ethics Research Board (Pro00082981).

Results

One hundred and nine consecutive IPF patient records were examined; 9 that were missing baseline EDI scores were excluded; final cohort comprises 100 with both MRC and EDI at baseline. The mean age was 73 ± 9 years (51-91 years) and 65% were male. Median dyspnea duration was 7 years (IQR 4-9 years); 73% were in MRC grade 3 or higher (Table 1). EDI component scores are summarized in Table 2. Median item scores increased with increasing activity intensity, with stairs having the highest severity rating: 6 (range 4-8). The distribution of each EDI component scores within each MRC grade was plotted in Figure 1. The means (std), distribution of EDI item and total scores across MRC grades are given Figure 1 and Table 3. There was a significant increase in EDI scores between each MRC grade. Resting dyspnea and dyspnea with lower intensity activities such as eating and talking is perceived even in the lower MRC grades (e.g., 1-3). Median EDI scores for moderate to high intensity activities increased with increasing MRC grade.

Table 1.

Demographic Characteristics and Patient Profile.

Characteristic^a	N = 100
Age, mean years (range)	73 ± 9 (51-91)
BMI, mean(range)	30 (17-54)
Ever smokers	69% (69/100)
MRC ^b
1	5.0% (5/100)
2	20% (20/100)
3	26% (26/100)
4	35% (35/100)
5	12% (12/100)
O ₂ use	47% (47/100)
Dyspnea duration, years	7 (2-18)
% pred FVC, mean±SD	73% (37-118)
% pred DLCO, mean±SD	47% (16-94)
6MWD, mean m (range)	316 (50-595)
Nadir exertional SpO ₂ , mean % (range)	84 ± 6% (59-95)
Gap index, mean (range)	4.4 + 1.7(1-8)

^aUnless otherwise indicated, results were expressed as percentage (count “yes”/count reported).

^bNot recorded = 2.

Table 2.

Edmonton Dyspnea Inventory Component Scores.

Component	Number of Responses (n = 100)	Median MDDS Score (IQR)	Range
Rest	100	1 (0-2)	0-7
Talk	99	2 (1-4)	0-7
Eat	100	1.5 (0-3)	0-8
Bowel movement	97	2 (0-4)	0-10
Dress	89	3 (1-5)	0-10
Shower	96	3 (1-5)	0-10
Exercise	85	5 (4-8)	0-10
Stairs	88	6 (4-8)	0-10
Baseline dyspnea ³	79	2 (1-8)	1-10
Incident dyspnea ⁴	94	4 (1-10)	1-10
Crisis dyspnea ⁵	11	N/A	N/A

^aBaseline: rest, talk, eat

^bIncident or episodic dyspnea: bowel movement, dress, shower, exercise, stairs.

^cCrisis dyspnea was reported by 11 patients across MRC grades (MRC 1 = 1, 2 = 1, 3 = 2, 4 = 3, 5 = 4 patients).

Figure 1.

Distribution of MDDS scores within each MRC grade.

Table 3.

Differences Between Mean (std) of Edmonton Dyspnea Inventory Items and Total Score Amongst MRC Grades.

	MRC 1	MRC 2	MRC 3	MRC 4	MRC 5	P-Value
Rest	.2 (.45)	.45 (1.0)	1.12 (1.48)	1.40 (1.50)	2.25 (2.63)	.02
Talk	.2 (.45)	1.05 (1.39)	2.12 (1.66)	2.89 (1.83)	4.08 (2.31)	<.0001
Eat	.2 (.45)	.85 (1.42)	1.81 (1.55)	2.54 (1.95)	3.92 (2.54)	<.0001
Shower	.2 (.45)	1.42 (1.71)	3.32 (1.99)	4.37 (2.46)	6.20 (2.82)	<.0001
Dressing	.2 (.45)	1.39 (1.85)	3.14 (1.88)	4.09 (2.40)	5.67 (2.24)	<.0001
Bowel movement	.2 (.45)	1.15 (1.56)	2.28 (2.09)	2.53 (2.46)	5.09 (2.98)	<.0001
Stairs	.8 (.84)	4.25 (1.89)	5.61 (1.90)	6.97 (2.38)	8.50 (1.52)	<.0001
Exercise	2 (1.83)	4.55 (2.06)	5.25 (2.29)	6.2 (2.27)	8.17 (1.83)	.0001
Total	3.6 (4.62)	14.85 (9.68)	22.77 (10.19)	29.4 (14.29)	32.67 (12.87)	<.0001
Pairwise comparison on total MDDS score (P value)	MRC 1 to 2: 11.2 (.02)MRC 1 to 3: 19.1 (.0003)MRC 1 to 4: 25.8 (.0002)	MRC 2 to 3: 7.8 (.01)MRC 2 to 4: 14.5 (.0002)MRC 2 to 5: 29.1 (.0001)	MRC 3 to 4: 6.7 (.05)MRC 3 to 5: 9.9 (.01)	MRC 4 to 5: 3.3 (.49)

Dimensionality, Structure and Internal Consistency

Results of the exploratory factor analysis confirmed unidimensionality with high factor loadings on a single factor (Table 4). The one dominant factor explained 61% of the total item variance. The item-item correlations are shown in Table 5, indicating strong to very strong correlations among items. Item analysis showed that all 8 EDI components has excellent discrimination power, with item-total correlation coefficients showing strong to very strong correlation between an item and the aggregate of all other items (Table 4). This result indicated that EDI components were able to differentiate patients with varying levels of dyspnea. In addition, the internal consistency was very high, with the Cronbach alpha of .92.

Table 4.

Item Analysis and Exploratory Factor Analysis Results for Edmonton Dyspnea Inventory.

Item Name	Item Mean	Correlation with the Rest of Items	Alpha if Item Deleted	Factor Loadings
Rest	1.12	.77	.91	.70
Talk	2.17	.86	.90	.89
Eat	1.92	.89	.90	.87
Shower	3.30	.69	.91	.73
Dressing	3.15	.88	.89	.89
Bowel movement	2.11	.79	.90	.76
Stairs	5.88	.73	.91	.69
Exercise	5.60	.65	.91	.66

Note: The Cronbach alpha is .915.

Table 5.

Correlations Among Dyspnea Instruments and Lung Function Measures.

Value	Instrument	MRC	EDI Components
Value	Instrument	MRC	Rest	Talk	Eat	BM	Dress	Shower	Exercise	Stairs
Rest	ρ		-	.72¹	.69¹	.55¹	.61¹	.47¹	.36¹	.40¹
Talk	ρ		-	-	.87¹	.64¹	.79¹	.70¹	.49¹	.56¹
Eat	ρ		-	-	-	.64¹	.72¹	.66¹	.51¹	.49¹
BM	ρ		-	-	-	-	.67¹	.62¹	.50¹	.59¹
Dress	ρ		-	-	-	-	-	.72¹	.54¹	.71¹
Shower	ρ		-	-	-	-	-	-	.44¹	.58¹
Exercise	ρ		-	-	-	-	-	-	-	.70¹
Stairs	ρ		-	-	-	-	-	-	-	-
MRC	ρ		.33¹	.52¹	.50¹	.45¹	.59¹	.58¹	.44¹	.61¹
FVC%pred	ρ	−.31¹	−.20	−.31¹	−.23¹	−.24¹	−.33¹	−.34¹	−.16	−.27¹
DLCO%pred	ρ	−.52¹	−.32¹	−.43¹	−.37¹	−.29¹	−.55¹	−.56¹	−.09	−.38¹
6MWD	ρ	−.68¹	−.10	−.26¹	−.25¹	−.28¹	−.33¹	−.42¹	−.27¹	−.40¹

1: statistically significant (P < .05).

Examination of Response Structure

The GBTM was optimized with three groups of dyspnea behaviour based on the EDI item scores (Figure 2). Group 1 patients reported no or very low dyspnea during their daily activities and dyspnea was only rated higher during the higher intensity activities. Group 2 patients were grouped around increased dyspnea with moderate intensity activities and Group 3 patients had mild to moderate dyspnea when at rest, and with increasing activity intensity. All three EDI trajectory groups are distributed within MRC grade 2-4, and in general, the proportion of patients in Group 3 increased with increasing MRC grade (Figure 3). Figure 1A-B (Supplement) shows the individual MDDS responses for each patient in MRC 2 and MRC 5 as examples, the individual scores are coloured by their trajectory group.

Figure 2.

Trajectories of dyspnea behavior.

Figure 3.

Distribution of Dyspnea trajectory grouping within MRC grades.

We evaluated patients’ clinical characteristics across the dyspnea severity grouping. We noted that group 2 and 3 patients as identified by GBTM had higher mean GAP index were more likely to be on oxygen and group 1and 2 had more GP visits. There was a trend towards a higher risk of hospitalizations and costs in the year following baseline visit in group 3 (Table 6). This suggests that higher dyspnea severity is seen with increasing disease severity, with higher oxygen use and is related to higher acute care use in IPF.

Table 6.

Clinical Features of various dyspnea trajectory groups as identified by Edmonton Dyspnea Inventory.

EDI Trajectory Groups
	Group 1 (n = 16)	Group 2 (n = 46)	Group 3 (n = 38)
Mean age (Std)	73.6 (8.51)	73.05 (8.18)	72.44 (11.15)
Male % (n)	62.5% (10)	63.04% (29)	57.89% (22)
Current smoker % (n = 44)	25% (1)	5.26% (1)	0 (0)
Ever smoked % (n = 44)	100% (3)	77.78% (14)	69.57% (16)
Mean BMI (Std)	30.29 (7.01)	30.73 (5.18)	29.85 (7.09)
Mean GAP index (Std)	3.27 (1.03)	4.37 (1.57)	4.97 (1.80)
On Oxygen %	11.11% (1)	53.57% (15)	62.96% (17)
% with hospitalization in 1 year following baseline visit (n)	31.25% (5)	34.78% (16)	57.89% (22)
% with ED visit in 1 year (n)	43.75% (7)	56.52% (26)	55.26% (21)
% with GP visit in 1 year (n)	100% (16)	93.48% (43)	76.32% (29)
Average health resource use ($) in 1 year per patient	712 (354-8057)	1274(538-11026)	7927 (878-25819)
Mortality in 1 year	0% (0)	17.39% (8)	52.63% (20)
Median EDI total score	6.5 (1-10)	16.5 (14-24)	35.5 (30-46)
EDI total score range in all pts	0-14	10-31	24-62
Total score range in patients with all scores answered	0-14	11-31	27-55

Validation

We examined the EDI score between the levels of MRC grade, each item demonstrated a significant increase in EDI Score across the levels of MRC (Table 3). In post-hoc analysis we found that the total differed for each level except between MRC 4 and 5. Correlation between all EDI items and the MRC was moderately strong (Table 5). Correlations between EDI items and FVC% or DLCO% were generally weaker, but all were in the hypothesized direction, and many were statistically significant. For FVC%, DLCO% and 6MWD, the strongest correlation was with showering component of EDI (ρ = −.34, −.56 and −.42 respectively, Table 5) establishing convergent validity.

Survival Analysis

One-year mortality was increased for patients in group 2 and 3, P = .0091 (Figure 4) suggesting worse survival with increasing dyspnea severity. To examine the additional benefit of dyspnea severity rating on mortality prediction we compared 2 sets of logistic models on predicting 1-year mortality in IPF. First, we assessed improvement by adding EDI grouping to MRC grade. Logistic model with MRC grade only had a c-statistic of .86 for 1-year mortality prediction. The addition of the EDI grouping to MRC score improved the c-statistic to .90 and had an NRI of .66 (95% CI -.11-1.11). Mortality distribution amongst MRC grades and EDI groups is shown in Supplement Table 1A-B. Second, we assessed improvement by adding EDI grouping to the logistic model predicting 1-year mortality using age, gender and FVC at baseline. Model without EDI grouping had a c-statistic of .78. Addition of EDI grouping improved the c-statistic to .86 and had an NRI of .88 (95% CI 0.45-1.11) indicating EDI aided dyspnea severity rating may improve survival estimates in IPF.

Figure 4.

Kaplan-Meir Survival Curves based on dyspnea severity.

Discussion

We have developed the Edmonton Dyspnea Inventory, a brief, easily-administered, clinically relevant, patient-centered unidimensional tool whose scores possess the validity to assess dyspnea severity in the clinical (or research setting) in patients with IPF. Dyspnea is a prevalent, highly disabling symptom and a strong driver of quality of life impairment in patients with IPF. Despite the availability of myriad scales to assess it, dyspnea remains under-assessed and under-treated in practice. Many professional societies including a recent publication specific to ILD has highlighted the need to use a numeric rating scale to assess dyspnea severity and its impact on daily living and physical function.¹¹ The EDI answers this call.

Our analyses confirm that the EDI is a unidimensional questionnaire whose items, importantly, tap activities that most (if not all) patients with IPF perform on a daily basis – and thus, can respond to directly without having to guess what their level of dyspnea might be while doing it (as suggested in the directions for other dyspnea instruments). The exploratory factor analysis supported the use of a single total score, and the internal consistency analysis showed that the EDI exceeds the psychometric benchmark (0.7).²²

Validity of EDI scores for assessing dyspnea severity in IPF is supported by the general pattern of correlations with another dyspnea measure (MRC) and with metrics hypothesized and previously shown to be associated with dyspnea in this patient population (FVC%, DLCO% and 6MWD): a number of correlations (28 of 32) were statistically significant, and all were in the hypothesized direction. Interestingly and somewhat surprisingly, MDDS scores for exercise was not correlated with FVC or DLCO. This may be due to the non-standardized nature of exercise as reported by patients. Some patients followed a standard regime of home exercises (treadmill, exercise bike etc.), others did gentle stretches and for some walking to their mailbox constituted exercise. Our results reinforce the observation by Gronseth and colleagues that lung function explains only a minimal amount of variability in dyspnea ratings, thus we do not expect EDI scores to correlate strongly with pulmonary physiology.²³ Dyspnea is a complex perception influenced by cognitive factors, illness beliefs, and expectations or priors; chronic breathlessness results in various forms of psychological and physical adaptions, therefore it is expected that dyspnea will be influenced by many other factors rather than physiology alone.²⁴ Finally, validity of EDI is also supported by the GBTM analysis, which identified three groups of patients solely from trends in EDI scores at baseline, who also showed differences in disease severity and treatments including supplemental oxygen needs and prognosis. Higher dyspnea severity as measured by EDI was not only associated with worse survival in IPF but appeared to improve the predictive ability of a model that included baseline age, gender and FVC. This needs further examination in a prospective controlled study but does support its clinical utility and relevance. On top of these, the total score of EDI items varied among the MRC grades and covered different ranges; this may provide the opportunity to use EDI total score as single point dyspnea assessment for research purposes.

MDDS May Improve Care and Research

An aspect of dyspnea in patients with IPF that the EDI captures but one that does not contribute to or influence the current set of validation analyses is dyspnea crisis [30, 31]. From a clinical perspective, identifying the frequency, severity, context and triggers of dyspnea crisis is essential for personalized management.¹⁵ Sixty-four % of crisis dyspnea episodes detected by EDI were in MRC grades 4 and 5; however, patients in the lower MRC grades 1-3 also reported at least one crisis episode signaling the need to explicitly ask about these events regardless of disability level as indicated by MRC.¹⁵ This has not been previously reported in IPF and highlights a missed opportunity that, if addressed, could potentially reduce hospitalizations and related costs.^25,26 Additionally, knowledge of crises can inform development of personalized action plans to improve care.²⁷ Thus EDI answers the call from an ATS workshop report to assess dyspnea intensity using an instrument to facilitate patient centered care.¹⁵ Unlike, other dyspnea scales our tool can also aid dyspnea management. We have previously shown that EDI use in our clinic led to early and systematic implementation of non-pharmacological intervention, initiation and/or adjustment of oxygen therapy, and the prescription of opiates.^28-30 Systematic dyspnea assessment and management has been identified as an urgent need. We believe that EDI can be easily adapted to digital application-based symptom assessment for point-of-care use or home monitoring by patient for tracking symptoms and thus enable self-management.

Research trials of dyspnea interventions in IPF have used MRC or mMRC grade as inclusion criteria or outcomes.^31-33 Our work demonstrates the heterogeneity of dyspnea among patients in any one MRC grade; therefore, we propose that the concurrent use of EDI may facilitate subject stratification and cohort enrichment for more severe dyspnea and its response structure could promote better signal detection in trials of therapeutic efficacy.

Limitations of this study include its single center, retrospective design. However, we used a battery of analyses whose results support the EDI as a tool that generates scores with requisite validity for assessing dyspnea severity in patients with IPF. The EDI was amended to include “walking across the room”, and additional studies are needed to support the validity of the 9-item version, to assess test-retest and generate minimal important change thresholds. Also, more research is needed to examine the applicability of EDI in clinics other than ours and to assess how its scores influence clinical decision-making. A multicenter prospective validation study is underway.

Despite these limitations, we have shown that EDI scores are valid estimates of dyspnea severity in patients with IPF. Its scores are correlated with other direct and indirect measures of dyspnea; they distinguish subgroups of patients with differing levels of dyspnea severity; and they are associated with longitudinal disease behavior. In the clinical arena, EDI scores can facilitate personalized dyspnea management.

Supplemental Material

Supplemental material - Validation of a Novel Clinical Dyspnea Scale – A Retrospective Pilot Study

Supplemental material for Validation of a Novel Clinical Dyspnea Scale – A Retrospective Pilot Study by Meena Kalluri, Ying Cui, Ting Wang, and Jeffrey A. Bakal in American Journal of Hospice and Palliative MedicineÂ®

Footnotes

Acknowledgments

The authors wish to acknowledge Dr. Janice Richman-Eisenstat for her clinical contributions and Ms. Sarah Younus for data collection.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Meena Kalluri

Supplemental Material

Supplemental material for this article is available online.

References

Ryerson

Donesky

Pantilat

Collard

. Dyspnea in idiopathic pulmonary fibrosis: a systematic review. J Pain Symptom Manage. 2012;43(4):771-782. doi:10.1016/J.JPAINSYMMAN.2011.04.026.

Prior

Hoyer

Shaker

, et al. Validation of the IPF-specific version of St. George’s respiratory questionnaire. Respir Res. 2019;20(1):199-210. doi:10.1186/s12931-019-1169-9.

Nishiyama

Taniguchi

Kondoh

, et al. A simple assessment of dyspnoea as a prognostic indicator in idiopathic pulmonary fibrosis. Eur Respir J. 2010;36(5):1067-1072. doi:10.1183/09031936.00152609.

Elliott-Button

Johnson

Nwulu

Clark

. Identification and assessment of breathlessness in clinical practice: a systematic review and narrative Synthesis. J Pain Symptom Manage. 2020;59(3):724-733.e19. doi:10.1016/j.jpainsymman.2019.10.014.

Swigris

Kuschner

Jacobs

Wilson

Gould

. Health-related quality of life in patients with idiopathic pulmonary fibrosis: a systematic review. Thorax. 2005;60(7):588-594. doi:10.1136/thx.2004.035220.

Ahmadi

Wysham

Lundstrom

Janson

Currow

Ekstrom

. End-of-life care in oxygen-dependent ILD compared with lung cancer: a national population-based study. Thorax. 2016;71(6):510-516. doi:10.1136/thoraxjnl-2015-207439.

Consensus statement of the American thoracic S. Dyspnea. Mechanisms, assessment, and management: a consensus statement. American thoracic society. Am J Respir Crit Care Med. 1999;159(1):321-340.

Stefan

Mularski

, et al. Hospitalist attitudes toward the assessment and management of dyspnea in patients with acute cardiopulmonary diseases. J Hosp Med. 2015;10(11):724-730. doi:10.1002/jhm.2422.Hospitalist.

Mahler

Selecky

Harrod

, et al. American college of chest physicians consensus statement on the management of dyspnea in patients with advanced lung or heart disease. Chest. 2010;137(3):674-691. doi:10.1378/chest.09-1543.

10.

Banzett

O'Donnell

Guilfoyle

, et al. Multidimensional Dyspnea Profile: An Instrument for Clinical and Laboratory Research. European Respiratory Society; 2015:1681-1691.

11.

Wijsenbeek

Molina-Molina

Chassany

, et al. Developing a conceptual model of symptoms and impacts in progressive fibrosing interstitial lung disease to evaluate patient-reported outcome measures. ERJ Open Res. 2022;8(2):00681-2021. doi:10.1183/23120541.00681-2021.

12.

Raghu

Collard

Egan

, et al. An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management. Am J Respir Crit Care Med. 2011;183:788-824. doi:10.1164/rccm.2009-040GL.

13.

Ley

Ryerson

Vittinghoff

, et al. A multidimensional index and staging system for idiopathic pulmonary fibrosis. Ann Intern Med. 2012;156:684-691.

14.

Simon

Weingärtner

Higginson

Voltz

Bausewein

. Definition, categorization, and terminology of episodic breathlessness: consensus by an international Delphi survey. J Pain Symptom Manage. 2014;47(5):828-838. doi:10.1016/j.jpainsymman.2013.06.013.

15.

Mularski

Reinke

Carrieri-Kohlman

, et al. An official American thoracic society workshop report: assessment and palliative management of dyspnea crisis. Ann Am Thorac Soc. 2013;10(5):S98-S106. doi:10.1513/AnnalsATS.201306-169ST.

16.

Swigris

Streiner

Brown

, et al. Assessing exertional dyspnea in patients with idiopathic pulmonary fibrosis. Respir Med. 2014;108(1):181-188. doi:10.1016/j.rmed.2013.12.009.

17.

Victorson

Anton

Hamilton

Yount

Cella

. A conceptual model of the experience of dyspnea and functional limitations in chronic obstructive pulmonary disease. Value Health. 2009;12(6):1018-1025. doi:10.1111/j.1524-4733.2009.00547.x.

18.

Stevens

Sheridan

Bernstein

, et al. A multidimensional profile of dyspnea in hospitalized patients. Chest. 2019;156(3):507-517. doi:10.1016/j.chest.2019.04.128.

19.

Wysham

Miriovsky

Currow

, et al. Practical dyspnea assessment: relationship between the 0-10 numerical rating scale and the four-level categorical verbal descriptor scale of dyspnea intensity. J Pain Symptom Manage. 2015;50(4):480-487. doi:10.1016/J.JPAINSYMMAN.2015.04.015.

20.

Nagin

. Group-based trajectory modeling: an overview. Ann Nutr Metab. 2014;65(2-3):205-210. doi:10.1159/000360229.

21.

Pepe

Kerr

Longton

Wang

. Testing for Improvement in Prediction Model Performance; 2013. doi:10.1002/sim.5727.

22.

Lance

Butts

Michels

. What did they really say? Organizational Research Methods 2006;9(2):202-220.

23.

Gronseth

Vollmer

Hardie

, et al. Predictors of dyspnoea prevalence: results from the BOLD study. Eur Respir J. 2014;43(6):1610-1620. doi:10.1183/09031936.00036813.

24.

Williams

Lewthwaite

Brooks

Jensen

Abdallah

Johnston

. Chronic breathlessness explanations and research priorities: findings from an international delphi survey. J Pain Symptom Manage. 2020;59(2):310-319.e12. doi:10.1016/J.JPAINSYMMAN.2019.10.012.

25.

Archibald

Bakal

Richman-Eisenstat

Kalluri

. Early integrated palliative care bundle impacts location of death in interstitial lung disease: a pilot retrospective study. Am J Hosp Palliat Care. 2021;38:104-113. doi:10.1177/1049909120924995.

26.

Vaidya

Hibbert

Kinter

Boes

. Identification of key cost generating events for idiopathic pulmonary fibrosis: a systematic review. Lung. 2017;195(1):1-8. doi:10.1007/s00408-016-9960-6.

27.

Kalluri

Younus

Archibald

Richman-Eisenstat

Pooler

. Action plans in idiopathic pulmonary fibrosis: a qualitative study—‘I do what I can do. BMJ Support Palliat Care. 2021. bmjspcare-2020-002831. doi:10.1136/bmjspcare-2020-002831.

28.

Kalluri

Richman-Eisenstat

. Breathing is not an option; dyspnea is. J Palliat Care. 2014;30(3):188-191. doi:10.1177/082585971403000309.

29.

Kalluri

Richman-Eisenstat

. Early and integrated palliative care to achieve a home death in idiopathic pulmonary fibrosis. J Pain Symptom Manage. 2017;53(6):1111-1115. doi:10.1016/j.jpainsymman.2016.12.344.

30.

van den Bosch

Kalluri

. Dyspnea Management in Interstitial Lung Disease: An Early Integrated Palliative Care Approach in a Multidisciplinary Setting. American Thoracic Society:A4757-A4757.

31.

Khor

Saravanan

Holland

, et al. A mixed-methods pilot study of handheld fan for breathlessness in interstitial lung disease. Sci Rep. 2021;11(1):1-8. doi:10.1038/s41598-021-86326-8.

32.

Kronborg-White

Andersen

Kohberg

Hilberg

Bendstrup

. Palliation of chronic breathlessness with morphine in patients with fibrotic interstitial lung disease - a randomised placebo-controlled trial. Respir Res. 2020;21(1):195. doi:10.1186/S12931-020-01452-7.

33.

Wright

Hart

Allgar

, et al. A feasibility, randomised controlled trial of a complex breathlessness intervention in idiopathic pulmonary fibrosis (BREEZE-IPF): study protocol. ERJ Open Res. 2019;5(4):00186-2019. doi:10.1183/23120541.00186-2019.

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