Tympanometry interpretation by primary care physicians. A report from the International Primary Care Network (IPCN) and the Ambulatory Sentinel Practice Network (ASPN).

BACKGROUND

The accuracy of data gathered by primary care clinicians in practice-based research networks (PBRNs) has been questioned. Tympanometry, recently recommended as a means of improving accuracy of diagnosing acute otitis media, was included as an objective diagnostic measure in an international PBRN study. We report the level of agreement of interpretations of tympanograms between primary care physicians in PBRNs and experts.

METHODS

Primary care physicians in PBRNs in the Netherlands, United Kingdom, United States, and Canada enrolled 1773 children aged 6 to 180 months who contributed 6358 tympanograms during 3179 visits. The physicians were trained in the use and interpretation of tympanometry using the Modified Jerger Classification. We determined the level of agreement between physicians and experts for interpretation of tympanograms. One comparison used the 6358 individual ear tracings. A second comparison used the 3179 office visits by children as the unit of analysis.

RESULTS

The distribution of expert interpretation of all tympanograms was: 35.8% A, 30% B, 15.5% C1, 12% C2, and 6.8% uninterpretable; for visits, 37.8% were normal (A or C1), 55.6% abnormal (B or C2), and 6.6% could not be classified. There was a high degree of agreement in the interpretation of tympanograms between experts and primary care physicians across networks (kappa=0.70-0.77), age groups of children (kappa=0.69-0.73), and types of visits (kappa=0.66-0.77). This high degree of agreement was also found when children were used as a unit of analysis.

CONCLUSIONS

Interpretations of tympanograms by primary care physicians using the Modified Jerger Classification can be used with confidence. These results provide further evidence that practicing primary care physicians can provide high-quality data for research purposes.