Definitions for the level of evidence, strength of recommendation, and net benefit follow the "Major Recommendations."
- In patients with chronic cough, before diagnosing interstitial lung disease (ILD) as the sole cause, common etiologies such as upper airway cough syndrome (UACS), which was previously referred to as postnasal drip syndrome, asthma, and gastroesophageal reflux disease (GERD) should be considered. As these common causes may also share clinical features with specific ILDs, a diagnosis of ILD as the cause of cough should be considered a diagnosis of exclusion. Level of evidence, expert opinion; benefit, substantial; grade of recommendation, E/A
- In patients with cough secondary to an ILD, because of the prognostic implications, primary treatment should be dictated by the specific disorder. Level of evidence, low; benefit, substantial; grade of recommendation, B
- In patients with cough secondary to idiopathic pulmonary fibrosis (IPF), corticosteroids may lead to symptomatic improvement; however, as they have been shown to neither prolong survival nor improve quality of life and may be associated with significant side effects, their use requires an individualized analysis of the overall benefits and risks. Level of evidence, expert opinion; benefit, intermediate; grade of recommendation, E/B
- In patients with cough and characteristic clinical and radiographic features, sarcoidosis should be considered as a cause. Level of evidence, expert opinion; benefit, substantial; grade of recommendation, E/A
- In patients with cough secondary to sarcoidosis, although therapy with oral corticosteroids may lead to symptomatic improvement, as they have not been proven to have a durable benefit and are associated with significant side effects, an individualized analysis of the overall benefit and risk is necessary. Level of evidence, fair; benefit, intermediate; grade of recommendation, B
- In patients with cough secondary to sarcoidosis, therapy with oral corticosteroids followed by inhaled corticosteroids may improve symptoms. Level of evidence, fair; benefit, conflicting; grade of recommendation, I
- In patients with cough, ILD, and a concerning environmental, occupational, or avocational exposure, hypersensitivity pneumonitis (HP) should be considered as a potential cause. Level of evidence, expert opinion; benefit, substantial; grade of recommendation, E/A
- In patients with cough due to HP, treatment should include the removal of the offending exposure and systemic corticosteroid therapy in those with evidence of physiologic impairment. Level of evidence, low; benefit, substantial; grade of recommendation, B
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 |