Observer Variation in Detecting Lymphadenopathy on Chest Radiography

Objective: To assess inter- and intra-observer agreement in the detection of lymphadenopathy on chest radiography in children at risk for tuberculosis.

Patients And Methods: Retrospective examination of the antero-posterior and lateral chest radiographs of children aged 1 month to 11 years discharged from the short-stay ward of the Red Cross Children's Hospital, Cape Town, with a diagnosis of tuberculosis or pneumonia. Four paediatric pulmonologists viewed the radiographs independently. The main outcome measures were inter- and intra-observer agreement on the presence or absence of lymphadenopathy, reported as present, absent or equivocal, and expressed as weighted kappa statistics.

Results: Weighted kappa for the six pairs of observers ranged from 0.14 (95%CI 0.02-0.30) to 0.52 (95%CI 0.35-0.69). After a 3-month interval, intra-observer agreement ranged from 0.44 (95%CI 0.25-0.62) to 0.71 (95%CI 0.56-0.87). The average weighted kappa for inter-observer agreement was 0.33, and the average intra-observer kappa was 0.55.

Conclusions: There was 'fair' inter- and 'moderate' intra-observer agreement among paediatric pulmonologists in detecting lymphadenopathy on chest radiography in children. Caution is necessary when basing clinical decisions on the presence of lymphadenopathy on chest radiography.