In a small single-center study, a breathlessness, cough and sputum score of 5.0 or greater was a good predictor of exacerbation risk.
A score of 5.0 on the breathlessness, cough and sputum scale (BCSS) was a good predictor of risk for a clinically confirmed chronic obstructive pulmonary disorder (COPD) exacerbation, according to the results of a single-center study published in Primary Care Respiratory Medicine.
“The three-item BCSS questionnaire successfully did identify COPD exacerbation among patients in our study population,” Rebecca DeVries, ScD, of the department of work environment at the University of Massachusetts Lowell, told Medicinal Economics. “A tool like the BCSS could be used to identify patients who are at risk of exacerbation with the goal of expediting intervention.”
According to DeVries, COPD exacerbation is well known to accelerate the course of disease among patients diagnosed with COPD.
“As such, it is important to research and identify effective and accurate ways to identify early signs of exacerbation,” she said.
With this study, DeVries and her colleagues explored the utility of symptom-based score based on self-reports of breathlessness, cough and sputum to identify and predict COPD exacerbation. The BCSS questionnaire takes the sum of responses to three questions that rate breathlessness, cough and sputum each on a five-point Likert scale with 0 representing no symptoms and 4 representing severe symptoms.
The study compared BCSS reports for 168 patients with COPD at the start of an exacerbation and during non-exacerbation periods. Patients were taken from a disease management group managed by a large group medical practice in central Massachusetts. During the study period, patients enrolled in the program called a nurse when they developed worsening symptoms. If the nurse confirmed an exacerbation, the patient was asked a series of questions, including the standard BCSS questions. In all, the 168 patients contributed information on 231 exacerbations and 389 non-exacerbation periods.
“We found the BCSS to be good predictor of COPD exacerbation, even though COPD patients vary widely in their reported symptoms of breathlessness, cough and sputum,” DeVries said. “Furthermore, we found that no one individual symptom was more strongly associated with COPD exacerbation than another.”
BCSS was strongly associated with risk for exacerbation with an odds ratio of 2.80 (95% CI, 2.27-3.45). This suggested that each one-point increase in the BCSS score increased risk by 180%. An analysis of each of the three BCSS components showed similar risks estimates for each of the symptoms; breathlessness (OR=3.14), cough (OR=2.62) and sputum (OR=3.2). According to the study, this similarity suggests, “it is not necessary to weight any one symptom more heavily than another when computing a BCSS summary measure and that the simple sum of the three symptoms' self-reports is appropriate.”
A BCSS score of 5.0 was identified as the best threshold to identify signs of COPD exacerbation. Using this cutoff, the BCSS had a sensitivity of 83% and a specificity of 68%. If a cutoff of 4.0 was used, the sensitivity would increase to 94% but the specificity would decrease to only 49%, resulting in more false positives.
There was a mean increase of 2.57 points in the BCSS score between exacerbation weeks and non-exacerbation weeks. The increase in score was slightly larger among patients with mild to moderate COPD compared with severe to very severe COPD, but the difference was not significant.