Diagnostic assessments of spirometry and medical history data by respiratory specialists supporting primary care: are they reliable?

Aim: To determine the intra- and inter-observer reliability of respiratory specialists' diagnostic assessments of spirometry and written medical history data obtained from primary care.

Method: Five respiratory specialists assessed spirometry data and the history of 156 patients randomly selected from referrals to an asthma/COPD-service. The inter-observer reliability was evaluated. After six months, all specialists repeated the assessments and the intraobserver reliability was evaluated.

Results: The diagnostic assessments for all patients had reasonable intra- and inter-observer reliability, resulting in a Cohen's kappa (kappa) of 0.67 and 0.66 respectively. The intra-observer reliability for assessing the need for additional diagnostic examinations had an average kappa 0.56 for new patients and an average kappa 0.39 for follow-up examinations. The assessments of clinical stability in follow-up patients--on which therapeutic advice was based--were inconsistent.

Conclusion: GPs who are reluctant to perform or interpret spirometry themselves may be supported diagnostically by respiratory specialists in an asthma/COPD-service. The reliability of this advice varies. More appropriate criteria for assessing clinical stability in patients with asthma and COPD are necessary to improve the reliability of the therapeutic advice.