Validation of a verbal rating scale for breathlessness amongst patients referred for cardiac stress tests.
BACKGROUND
Acute shortness of breath (SOB) is a common symptom and a potentially significant marker of cardiorespiratory disease. The subjective and unmeasurable nature of breathlessness can make its clinical evaluation difficult. This study aimed to investigate the convergent validity of a verbal 0-10 rating scale for SOB.


METHODS
This prospective observational study used a convenience sample of patients presenting for cardiac stress tests. Objective and subjective breathlessness parameters were collected before, during and after stress test exercise. Objective measures included respiratory rate (RR), oxygen saturation (S(a)O2), heart rate (HR), systolic blood pressure (SBP) and the subjective breathlessness parameter was verbal dyspnea scores (VDS) for present dyspnea obtained using the SOB rating scale question, "On a scale from 0-10, how bad is your SOB, with zero being no SOB and ten the worst SOB you could ever imagine?"


RESULTS
Within subjects, VDS correlated significantly with RR (mean r=0.95, CI: 0.93-0.97), HR (mean r=0.90, CI: 0.86-0.93) and SBP (mean r=0.95, CI: 0.93-0.97); p<0.05. Between subjects, correlations were significant at all time points for RR only (r=0.45-0.65, p<0.05), indicating high individual variability in dyspnea perception..


CONCLUSIONS
A verbal numerical rating scale is a valid measure of breathlessness and may provide useful insight into a prognostically significant symptom.
Saracino
Amanda
A
St Vincent's Health Melbourne, Australia. amanda.saracino@svhm.org.au
Weiland
Tracey
T
Dent
Andrew
A
Jolly
Brian
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004417:Dyspnea / Q000145:classification / Q000175:diagnosis*; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010358:Patient Participation; D011446:Prospective Studies; D012119:Respiration; D012720:Severity of Illness Index