Dyspnea Index: An upper airway obstruction instrument; translation and validation in Swedish

Mapping quality of life after balloon dilatation in subglottic stenosis using Dyspnea index and Short Form Health Survey-36

PURPOSE

An accurate diagnosis and proper treatment plan are required to restore an adequate patent airway in fibrotic subglottic stenosis (SGS). Currently, the definitive treatment entails single-stage balloon dilatation with steroid injections. The primary aim was to evaluate successful airway restoration and general quality of life in cases with SGS in northern Sweden using robust patient reported outcomes.

METHODS

All participants with need of surgical treatment due to SGS that had been referred to the department of otorhinolaryngology, University Hospital of Umeå from September 2020 to August 2023 was included. Exclusion criteria included malignant, extrathoracic or cartilaginous cause, age < 18 years, or incompetent to sign consent documents. We assessed the patient-reported outcome measures pre- as well as 3 months postoperatively.

RESULTS

Of the 40 cases fulfilling the eligibility criteria's, 33 cases completed the Dyspnea index (DI) and the short form health survey (SF-36) pre- as well as 3 months post-operatively. Receiver operating characteristics showed significant improvement in DI as well as in SF 36 scores post-operatively.

CONCLUSIONS

Evaluation of balloon dilatation in SGS in this cohort follow-up analysis shows clear improvement in patient quality of life using robust PROM 3 months postoperatively, ensuring the use of a safe and well-tolerated procedure.

How can we identify subglottic stenosis in patients with suspected obstructive disease?

PURPOSE

Subglottic stenosis, a rare condition of the upper airway, is frequently misdiagnosed as obstructive lung disease. The aim of this study was to investigate whether subglottic stenosis could be identified and distinguished from asthma and chronic obstructive pulmonary disease (COPD) using spirometry or the dyspnea index (DI).

METHODS

The study population included 43 patients with asthma, 31 patients with COPD and 50 patients with subglottic stenosis planned to undergo endoscopic intervention. All patients completed the DI and underwent dynamic spirometry registering both inspiratory and expiratory volumes and flows, including the expiratory disproportion index (EDI), the ratio of forced expiratory volume in 1 s to peak expiratory flow. One-way analysis of variance assessed the discrepancy of the variables among the study groups, and receiver operating curve (ROC) analysis determined the measurement with the best discriminatory power providing a cutoff value, maximizing both sensitivity and specificity.

RESULTS

The only statistically significant variables differing between all three groups were the EDI and the DI. The EDI showed an excellent area under the ROC curve (0.99, p < 0.001) with a cutoff value of 0.39 (98% sensitivity, 96% specificity), followed by DI (0.87, p < 0.001) with a cutoff score of > 25 (83% sensitivity and 78% specificity).

CONCLUSION

In patients with dyspnea of unknown cause, an increase in EDI should arouse a suspicion of extrathoracic airway obstruction, advocating for further evaluation with laryngotracheoscopy.

The Reliability of the Arabic Version of the Dyspnea Index Questionnaire for Upper Airway-Related Dyspnea

Objectives

This study aimed to translate the Dyspnea Index (DI) questionnaire into the Arabic language and determine whether this version is valid and reliable for Arabic-speaking patients with upper airway-related dyspnea.

Methods

A cross-sectional study was conducted at the King Saud University Medical City otolaryngology clinics in Riyadh, Saudi Arabia. The DI questionnaire was translated into Arabic and then back-translated into the English language. Inclusion criteria were preoperative patients presenting to the otolaryngology clinic with upper airway-related dyspnea between November and December 2020. The results of internal consistency and factor analysis among the items were compared to the original DI development results to assess the reliability of the questionnaire.

Results

Among a total of 57 recruited patients, 50 questionnaires were completed with an 88% response rate. The mean age of the included patients was 38 ±14 years. Women constituted 58% of the patients. The most common diagnosis was subglottic stenosis (72%). Principle component extraction in factor analysis revealed a single underlying factor for all the questions. Factor loading ranged from 0.69 to 0.85. Reliability statistics showed a high value of internal consistency among the items. The mean inter-item correlation was 0.58.

Conclusion

Based on our findings, the Arabic version of the DI questionnaire is a reliable instrument for evaluating upper airway dyspnea.

Monitoring Adult Subglottic Stenosis With Spirometry and Dyspnea Index: A Novel Approach

Objective

The aim was to examine the correlations among the anatomic Cotton-Myer classification, pulmonary function tests (PFTs), and patient-perceived dyspnea or dysphonia in patients with subglottic stenosis and identify measurements accurately reflecting treatment effects.

Study Design

Prospective cohort study.

Setting

Tertiary referral center.

Method

Fifty-two adults receiving endoscopic treatment for isolated subglottic stenosis were consecutively included. Correlations were calculated among the preoperative Cotton-Myer scale, PFTs, the Dyspnea Index (DI), and the Voice Handicap Index. Receiver operating characteristic curves were determined for PFT, DI, and Voice Handicap Index pre- and postoperative measurements.

Results

The Cotton-Myer classification correlated weakly with peak expiratory flow (r = −0.35, P = .012), expiratory disproportion index (r = 0.32, P = .022), peak inspiratory flow (r = −0.32, P = .022), and total peak flow (r = −0.36, P = .01). The DI showed an excellent area under the curve (0.99, P < .001), and among PFTs, the expiratory disproportion index demonstrated the best area under the curve (0.89, P < .001), followed by total peak flow (0.88, P < .001), peak expiratory flow (0.87, P < .001), and peak inspiratory flow (0.84, P < .001). Patients treated endoscopically with balloon dilatation showed a 53% decrease in expiratory disproportion index (95% CI, 41%-66%; P < .001) and a 37% improvement in peak expiratory flow (95% CI, 31%-43%; P < .001).

Conclusion

Expiratory disproportion index or peak expiratory flow combined with DI was a feasible measurement for the monitoring of adult subglottic stenosis. The percentage deterioration of peak expiratory flow and increase in expiratory disproportion index correlated significantly with a proportional percentage increase in DI.

Dyspnea Index: An upper airway obstruction instrument; translation and validation in Swedish

OBJECTIVE

Upper airway dyspnoea is a challenging condition in which assessing the discomfort experienced by the patient is essential. There are three patient-reported outcome (PRO) instruments developed particularly for this patient group, none of which is available in Swedish. The aim of this study was to translate the Dyspnea Index (DI) into Swedish and validate the instrument for use in the Swedish-speaking population by investigating its basic psychometric properties.

DESIGN

A prospective instrument validation study.

SETTING

Tertiary referral centre.

PARTICIPANTS

Fifty-three (n = 53) patients with upper airway dyspnoea and 19 healthy controls.

MAIN OUTCOME MEASURES

The questionnaire was translated into Swedish (swDI) with a forward-backward method. Reliability, repeatability, responsiveness and construct validity were assessed by asking the subjects to complete the swDI, a visual analog scale (VAS) at exertion and at rest and the Voice Handicap Index (VHI).

RESULTS

The swDI showed excellent internal consistency (Cronbach's α: 0.85) and repeatability (interclass correlation coefficient: 0.87 and Pearson's r: .89) in the patient group. No ceiling effect was observed (maximum score achieved was 39; 85% of the patients scored ≤ 36). SwDI scores moderately correlated with VAS at exertion (r: .59) and at rest (r: .42), yet poorly with the VHI (r: .36). The effect size (ES) was 3.8.

CONCLUSIONS

The swDI is a valid, robust and reliable questionnaire for self-assessment in Swedish-speaking patients with upper airway obstruction. A future anchor-based longitudinal study is needed to assess the smallest detectable change (SDC) and minimal important change (MIC) that were not estimated in our study.