Modified Borg Scale (mBorg), the Numerical Rating Scale (NRS), and the Dyspnea- 12 Scale (D- 12): cross-scale comparison assessing the development of dyspnea in early-stage lung cancer patients

Background and objective: Assessing breathlessness in early-stage lung cancer has been complicated by using different rating scales, potentially leading to overestimation or underestimation of the experience. This study aims to examine the interscale concordance among three frequently used scales, the Modified Borg Scale (mBorg), the Numerical Rating Scale (NRS), and the Dyspnea-12 scale (D-12) and identify common factors contributing to breathlessness in post-operative early-stage lung cancer patients reported with refractory breathlessness.

Study design and methods: A secondary analysis was conducted using the baseline data from a randomized controlled trial, focusing on 142 early-stage lung cancer patients. Breathlessness was evaluated using mBorg, NRS, and D-12 scales. Generalized linear regression explored relationships across scale ratings and identified factors associated with dyspnea. 

Results: The mean score on the mBorg scale was 4.28 ± 1.57 (range = 0–8), the NRS yielded a mean score of 4.73 ± 1.99 (range = 1–10), and the D-12 was 7.04 ± 2.88 (range = 2–17). This study revealed strong correlations among the mBorg, physical domain of D-12, and NRS scales (r = 0.67, p < 0.000), indicating that these measures yielded similar results in assessing the physical aspects of breathlessness. D-12 Total, and D-12 physical scores correlated highly with quality of life, while the D-12 emotional subscale showed weak correlations. Asthma and insomnia emerged as significant risk factors across all scales. 

Conclusion: This study highlights interscale concordance and key contributors to breathlessness in operable early-stage lung cancer patients. All three scales validly measure dyspnea, with the D-12 and NRS offering a holistic assessment by including affective-dyspnea scores.