Article Text
Abstract
Background The American and European cystic fibrosis (CF) guidelines recommend different diagnostic criteria. This study assessed diagnostic concordance between these recommendations.
Methods Subjects with single organ manifestations suggestive of CF (chronic sinopulmonary disease (RESP), chronic/recurrent pancreatitis (PANC) or obstructive azoospermia (AZOOSP)) were prospectively evaluated by sweat test, nasal potential difference and genotyping. Concordance in diagnostic outcomes between the two algorithms was measured using observed agreement and κ statistics.
Results A total of 208 subjects were evaluated. Observed agreement was 84.8% and level of agreement was excellent (κ=0.87) between the American and European recommendations. The RESP phenotype was associated with the highest degree of concordance (observed agreement ≥90%, κ=0.92) compared with the PANC (observed agreement 86%, κ=0.65) and AZOOSP (observed agreement 80%, κ=0.87) phenotypes. Incorporation of nasal potential difference into the American algorithm failed to improve the overall degree of concordance (good agreement level; κ=0.75); the level of agreement was unchanged in RESP and PANC subjects, but reduced in AZOOSP subjects (from excellent to good). Extensive genotyping had limited clinical utility in the diagnosis of CF in both algorithms.
Conclusions Despite inconsistencies between the American and European diagnostic recommendations, concordance in diagnostic outcomes among subjects presenting with single organ manifestations of CF was good to excellent. These diagnostic guidelines provide guidance and promote rigorous evaluation for the diagnosis of CF but neither guideline should be regarded as dogma.
- Cystic fibrosis
- cystic fibrosis transmembrane conductance regulator
- diagnostic tests
- bronchiectasis
- pancreatitis
- azoospermia
- clinical epidemiology
- respiratory infection
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Footnotes
Funding PD and ET were supported by research grants from the Canadian Cystic Fibrosis Foundation and Genome Canada through the Ontario Genomics Institute as per research agreement 2004-OGI-3-05, the Ontario Research Foundation and from the Lloyd Carr-Harris Foundation. CYO and TG were funded by the Canadian Cystic Fibrosis Foundation Fellowship Awards and CYO received a Canadian Child Health Clinician Scientist Program Career Enhancement Award. RD was funded by a CIHR-Ontario Women's Health Council joint Fellowship.
Competing interests None.
Ethics approval Ethics approval was provided by the ethics boards of the Hospital for Sick Children, St Michael's Hospital and Mt Sinai Hospital, Toronto.
Provenance and peer review Not commissioned; externally peer reviewed.