Table 1

Evidence based guideline for the performance of the sweat test for the investigation of cystic fibrosis

Recommendation gradeLevel of evidenceDescription of evidence
Grade AIaEvidence obtained from meta-analysis of randomised controlled trials
IbEvidence obtained from at least one randomised controlled trial
Grade BIIaEvidence obtained from at least one well designed controlled study without randomisation
IIbEvidence for at least one other type of quasi-experimental descriptive studies
IIIEvidence obtained from well designed, non-experimental descriptive studies such as comparative studies, correlation studies, and case studies
Grade CIVEvidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities