DO ASTHMA SYMPTOM SCORES ASSIGNED BY RESPIRATORY THERAPISTS CORRELATE WITH BORG DYSPNEA SCORES IN MODERATE TO SEVERE ASTHMA?

Background: The Borg dyspnea scale is frequently utilized during asthma exacerbations to quantify a patient?s perceived level of dyspnea. The Borg scale was designed in 1962 to rate perceived exertion during exercise and was modified in 1982 to measure a patient?s perceived intensity of dyspnea using a 12-point scale. Respiratory therapists (RT) are trained to approximate the severity of their patients? symptoms based on objective measures of physical assessment. There is a subpopulation of asthma patients whose perception of dyspnea is blunted, and these patients have been shown to be at greater risk for death from asthma. Identification of this subpopulation may enable them to become more aware of escalating asthma symptoms.

Objective: To determine if patients? perceived dyspnea is reflected by the respiratory therapists? clinical assessment of symptom severity in moderate to severe asthmatics.

Methods: Asthma symptom scores and Borg dyspnea scores were obtained from subjects upon enrollment in an asthma disease management study (n=116). The Borg scale is shown in Figure 1. The asthma symptoms severity score (Figure 2) is assigned by the RT and is based upon a brief physical examination that includes pulse oximetry, chest auscultation, and the best of three forced vital capacity maneuvers. Results were determined by Pearson product-moment correlation with P < 0.05 being significant.

Results: There was a modest correlation (r=0.30, P < 0.05) between subjects’ Borg scores and symptom scores assigned by the RT. Based on these results, 9% of the variance (coefficient of determination, r²) in the Borg scores was predicted by symptom scores, indicating that 91% of the time, patients? Borg scores do not correlate with the severity of their symptoms as assessed by the RT.

Conclusions: Patients who have been classified as having moderate to severe asthma are those who experience daily or continual symptoms, have frequent nocturnal symptoms, and routinely have peak flows measuring below 80% of predicted values with significant variability on a day-to-day basis. Thus it is not surprising that such patients become so accustomed to experiencing asthma symptoms that they do not always realize when they are falling into the yellow zone of their action plans. If these patients were more cognizant of how their symptoms feel when they are beginning to worsen, as evidenced by physical assessment and pulmonary function testing, they may realize sooner the importance of seeking medical care in a timely fashion. While there is a modest correlation between Borg scores and RT assessment scores, these results should be interpreted cautiously due to the variability inherent in clinical assessment.