CHEST Guidelines for Clinical Diagnosis of Pertussis-Associated Cough
In children, pooled estimates of sensitivity and specificity were generated for only 1 clinical feature: posttussive vomiting.
A guideline based on a high-quality systematic review has been developed for the clinical diagnosis of pertussis-associated cough in children and adults to justify the decision regarding whether or not antibiotic therapy is necessary. Findings from the current American College of Chest Physicians (CHEST) guideline and expert panel report were published in CHEST.
Investigators used the CHEST methodologic guidelines and the Grading of Recommendations, Assessment, Development, and Evaluation framework to develop the new guideline. The Expert Cough Panel based their recommendations on results obtained from a recently published systematic review on the subject. Final grading was achieved by consensus based on Delphi methodology. The systematic review was conducted to answer the key question: “In patients presenting with cough, how can we most accurately diagnose from clinical features alone those who have pertussis-associated cough as opposed to other causes of cough?”
In adult patients, after prespecified meta-analysis exclusions, pooled estimates of sensitivity and specificity were generated for the following 4 clinical features: paroxysmal cough, posttussive vomiting, inspiratory whoop, and absence of fever. Paroxysmal cough and absence of fever both demonstrated high sensitivity (93.2%; 95% CI, 83.2%-97.4% and 81.8%; 95% CI, 72.2%-88.7%, respectively) and low specificity (20.6%; 95% CI, 14.7%-28.1% and 18.8%; 95% CI, 8.1%-37.9%, respectively). In contrast, both inspiratory whoop and posttussive vomiting in adults exhibited low sensitivity (32.5%; 95% CI, 24.5%- 41.6% and 29.8%; 95% CI, 8.0%-45.2%, respectively) and high specificity (77.7%; 95% CI, 73.1%-81.7% and 79.5%; 95% CI, 69.4%-86.9%, respectively).
In children age 0 to 18 years, on the other hand, following prespecified meta-analysis exclusions, pooled estimates of sensitivity and specificity were generated for only 1 clinical feature: posttussive vomiting. In the pediatric population, only moderate sensitivity and specificity were reported for posttussive vomiting (60.0%; 95% CI, 40.3%-77.0% and 66.0%; 95% CI, 52.5%-77.3%, respectively).
The investigators concluded that in adults with acute (<3 weeks) or subacute (3 to 8 weeks) cough, the presence of whooping or posttussive vomiting should suggest a possible pertussis diagnosis, whereas the lack of a paroxysmal cough or the presence of fever should rule out this diagnosis. Moreover, in children with acute (<4 weeks) cough, posttussive vomiting hints at a possible pertussis diagnosis but is much less useful as a diagnostic test. With the current guideline identifying gaps in our knowledge and areas for future research, it appears to help advance findings in this field.
Moore A, Harnden A, Grant CC, Patel S, Irwin; on behalf of the CHEST Expert Cough Panel. Clinically diagnosing pertussis-associated cough in adults and children: CHEST guideline and expert panel [published online October 12, 2018]. CHEST. doi:10.1016/j.chest.2018.09.027