Definitions for the level of evidence, strength of recommendation, and net benefit follow the "Major Recommendations."
- In patients with cystic fibrosis (CF), chest physiotherapy is recommended as an effective technique to increase mucus clearance, but the effects of each treatment are relatively modest and the long-term benefits unproven. Level of evidence, fair; benefit, small; grade of recommendation, C
- In patients with expiratory muscle weakness, manually assisted cough should be considered to reduce the incidence of respiratory complications. Level of evidence, low; benefit, small; grade of recommendation, C
- In persons with airflow obstruction caused by disorders like chronic obstructive pulmonary disease (COPD), manually assisted cough may be detrimental and should not be used. Level of evidence, low; benefit, negative; grade of recommendation, D
- In patients with COPD and CF, huffing should be taught as an adjunct to other methods of sputum clearance. Level of evidence, low; benefit, small; grade of recommendation, C
- In patients with CF, autogenic drainage should be taught as an adjunct to postural drainage as a method to clear sputum because it has the advantage of being performed without assistance and in one position. Level of evidence, low; benefit, small; grade of recommendation, C
- In patients with neuromuscular weakness and impaired cough, expiratory muscle training is recommended to improve peak expiratory pressure, which may have a beneficial effect on cough. Level of evidence, expert opinion; benefit, small; grade of recommendation, E/C
- In patients with CF, positive expiratory pressure (PEP) is recommended over conventional chest physiotherapy because it is approximately as effective as chest physiotherapy, and is inexpensive, safe, and can be self-administered. Level of evidence, fair; benefit, intermediate; grade of recommendation, B
- In patients with CF, devices designed to oscillate gas in the airway, either directly or by compressing the chest wall, can be considered as an alternative to chest physiotherapy. Level of evidence, low; benefit, conflicting; grade of recommendation, I
- In patients with neuromuscular disease with impaired cough, mechanical cough assist devices are recommended to prevent respiratory complications. Level of evidence, low; benefit, intermediate; grade of recommendation, C
- The effect of nonpharmacologic airway clearance techniques on long-term outcomes such as health-related quality of life and rates of exacerbations, hospitalizations, and mortality is not known at this time. The committee recommends that future investigations measure these outcomes in patients with CF, and in other populations with bronchiectasis, COPD, and neuromuscular diseases. Level of evidence, expert opinion; benefit, substantial; grade of recommendation, 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 |