Diagnostic accuracy of chest radiography in detecting mediastinal lymphadenopathy in suspected pulmonary tuberculosis.
OBJECTIVE
To estimate the diagnostic accuracy of chest radiography in the detection of chest lymphadenopathy in children with clinically suspected pulmonary tuberculosis.


METHODS



METHODS
Prospective cross sectional study.


METHODS
A short stay ward in a children's hospital in South Africa.


METHODS
Consecutive children under 14 years of age admitted with suspected pulmonary tuberculosis.


METHODS
Antero-posterior and/or lateral chest x rays interpreted independently and blind to the reference standard by three primary care clinicians and three paediatricians, all with a special interest in tuberculosis. Reference standard: Spiral chest computed tomography (CT) with contrast injection.


RESULTS
One hundred children (median age 21.5 months) were enrolled. Lymphadenopathy was present in 46 of 100 reference CT scans and judged to be present in 47.1% of x ray assessments. Overall sensitivity was 67% and specificity 59%. Primary care clinicians were more sensitive (71.5% v 63.3%, p = 0.047) and less specific (49.8% v 68.9%, p<0.001) than paediatricians. Overall accuracy was higher for the paediatricians (diagnostic odds ratio 3.83 v 2.49, p = 0.008). The addition of a lateral to an antero-posterior view did not significantly increase accuracy (diagnostic odds ratio 3.09 v 3.73, p = 0.16). Chance adjusted inter-observer agreement (kappa) varied widely between viewer pairs, but was around 30%.


CONCLUSIONS
Detection of mediastinal lymphadenopathy on chest x ray to diagnose pulmonary tuberculosis in children must be interpreted with caution. Diagnostic accuracy might be improved by refining radiological criteria for lymphadenopathy.
Swingler
G H
GH
Division of Paediatric Medicine, School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa. swingler@ich.uct.ac.za
du Toit
G
G
Andronikou
S
S
van der Merwe
L
L
Zar
H J
HJ
D002675:Child, Preschool; D002983:Clinical Competence; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008482:Mediastinum; D008505:Medical Staff, Hospital / Q000592:standards; D015588:Observer Variation; D010821:Physicians, Family / Q000592:standards; D014057:Tomography, X-Ray Computed; D014388:Tuberculosis, Lymph Node / Q000000981:diagnostic imaging*; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging*