Definitions for the level of evidence, strength of recommendation, and net benefit follow the "Major Recommendations."
1. When a patient complains of cough that has been present following symptoms of an acute respiratory infection for at least 3 weeks, but not more than 8 weeks, consider a diagnosis of postinfectious cough. Quality of evidence, expert opinion; net benefit, intermediate; strength of recommendation, E/B
2. In patients with subacute postinfectious cough, because there are multiple pathogenetic factors that may contribute to the cause of cough (including postviral airway inflammation with its attendant complications such as bronchial hyperresponsiveness, mucus hypersecretion and impaired mucociliary clearance, upper airway cough syndrome [UACS], asthma, and gastroesophageal reflux disease), judge which factors are most likely provoking cough before considering therapy. Quality of evidence, expert opinion; net benefit, intermediate; strength of recommendation, E/B
3. In children and adult patients with cough following an acute respiratory tract infection, if cough has persisted for >8 weeks, consider diagnoses other than postinfectious cough. Quality of evidence, low; net benefit, intermediate; strength of recommendation, C
4. For adult patients with postinfectious cough, not due to bacterial sinusitis or early on in a Bordetella pertussis infection, while the optimal treatment is not known:
4a. Therapy with antibiotics has no role, as the cause is not bacterial infection. Level of evidence, expert opinion; net benefit, none; grade of evidence, I
4b. Consider a trial of inhaled ipratropium as it may attenuate the cough. Level of evidence, fair; net benefit, intermediate; grade of evidence, B
4c. In patients with postinfectious cough, when the cough adversely affects the patient's quality of life and when cough persists despite use of inhaled ipratropium, consider the use of inhaled corticosteroids. Level of evidence, expert opinion; net benefit, intermediate; grade of evidence, E/B
4d. For severe paroxysms of postinfectious cough, consider prescribing 30 to 40 mg of prednisone per day for a short, finite period of time when other common causes of cough (e.g., UACS due to rhinosinus diseases, asthma, or gastroesophageal reflux disease) have been ruled out. Level of evidence, low; net benefit, intermediate; grade of evidence, C
4e. Central acting antitussive agents such as codeine and dextromethorphan should be considered when other measures fail. Level of evidence, expert opinion; net benefit, intermediate; grade of evidence, E/B
5. When a patient has a cough lasting for >2 weeks without another apparent cause and it is accompanied by paroxysms of coughing, posttussive vomiting, and/or an inspiratory whooping sound, the diagnosis of a Bordetella pertussis infection should be made unless another diagnosis is proven. Level of evidence, low; net benefit, substantial; grade of evidence, B
6a. For all patients who are suspected of having whooping cough, to make a definitive diagnosis order a nasopharyngeal aspirate or polymer (Dacron; INVISTA; Wichita, Kansas) swab of the nasopharynx for culture to confirm the presence of B pertussis. Isolation of the bacteria is the only certain way to make the diagnosis. Level of evidence, low; net benefit, substantial; grade of evidence, B
6b. Polymerase chain reaction (PCR) confirmation is available but is not recommended as there is no universally accepted, validated technique for routine clinical testing. Level of evidence, low; net benefit, conflicting; grade of evidence, I
7. In patients with suspected pertussis infection, to make a presumptive diagnosis of this infection, order paired acute and convalescent sera in a reference laboratory. A four-fold increase in IgG or IgA antibodies to pertussis toxin (PT) or filamentous hemagglutinin (FHA) is consistent with the presence of a recent B pertussis infection. Level of evidence, low; net benefit, intermediate; grade of evidence, C
8. A confirmed diagnosis of pertussis infection should be made when a patient with cough has B pertussis isolated from a nasopharyngeal culture or has a compatible clinical picture with an epidemiologic linkage to a confirmed case. Level of evidence, low; net benefit, substantial; grade of evidence, B
9. Children and adult patients with confirmed or probable whooping cough should receive a macrolide antibiotic and should be isolated for 5 days from the start of treatment because early treatment within the first few weeks will diminish the coughing paroxysms and prevent spread of the disease; treatment beyond this period may be offered but it is unlikely the patient will respond. Level of evidence, good; net benefit, substantial; grade of evidence, A
10. Long-acting beta-agonists, antihistamines, corticosteroids, and pertussis Ig should not be offered to patients with whooping cough because there is no evidence that they benefit these patients. Level of evidence, good; net benefit, none; grade of evidence, D
11. All children should receive prevention against pertussis infection as part of a complete diphtheria, tetanus, acellular pertussis (DTap) primary vaccination series. This should be followed by a single dose DTap booster vaccination early in adolescence. Level of evidence, good; net benefit, substantial; grade of evidence, A
12. For all adults up to the age of 65, vaccination with the stronger formulation of TDap vaccine should be administered according to Center for Disease Control (CDC) guidelines. Level of evidence, expert opinion; net benefit, substantial; grade of evidence, E/A
Definitions:
Quality of the Evidence
Good = evidence is based on good randomized controlled trials (RCTs) or meta-analyses
Fair = evidence is based on other controlled trials or RCTs with minor flaws
Low = evidence is based on nonrandomized, case-control, or other observational studies
Expert opinion = evidence is based on the consensus of the carefully selected panel of experts in the topic field. There are no studies that meet the criteria for inclusion in the literature review.
Strength of Recommendations
A = strong recommendation
B = moderate recommendation
C = weak recommendation
D = negative recommendation
I = no recommendation possible (inconclusive)
E/A = strong recommendation based on expert opinion only
E/B = moderate recommendation based on expert opinion only
E/C = weak recommendation based on expert opinion only
E/D = negative recommendation based on expert opinion only
Net Benefit
Substantial = There is evidence of benefit that clearly exceeds the minimum clinically significant benefit and evidence of little harm
Intermediate = Clear evidence of benefit but with some evidence of harms, with a net benefit between that defined for "substantial" and "small/weak"
Small/weak = There is evidence of a benefit that may not clearly exceed the minimum clinically significant benefit, or there is evidence of harms that substantially reduce (but do not eliminate) the benefit such that it may not clearly exceed the minimum clinically significant benefit
None = Evidence shows that either there is no benefit or the benefits equal the harms
Conflicting = Evidence is inconsistent with regard to benefits and/or harms such that the net benefit is uncertain
Negative = Expected harms exceed the expected benefits to the population
Table: Relationship of Strength of the Recommendations Scale to Quality of Evidence and Net Benefits
|
Net Benefit |
Quality of Evidence |
Substantial |
Intermediate |
Small/Weak |
None |
Conflicting |
Negative |
Good |
A |
A |
B |
D |
I |
D |
Fair |
A |
B |
C |
D |
I |
D |
Low |
B |
B |
C |
I |
I |
D |
Expert Opinion |
E/A |
E/B |
E/C |
I |
I |
E/D |