Observer Variability of Pediatric Bone Age Assessment by Using The Greulich and Pyle Method

Objective: Determination of skeletal maturity has an important role for diagnosis and management of pediatric growth disorders. We aimed to determine the effects of knowing chronological age on intra / interobserver variability of pediatric bone age determination by using the Greulich and Pyle method. Material and Method: The study group consisted of 115 boys, ages ranging from 3-198 months and 113 girls, ages ranging from 2-186 months. Plain left hand radiographs were obtained from children who came to pediatric outpatient department during 1 year. Patients’ hand radiographs were evaluated by using Greulich and Pyle atlas by radiologists who were blinded to chronological ages. Radiographs were reevaluated with knowledge of chronological ages one month later. Three radiologists interpreted plain radiographs for determination of interobserver variability. Radiographs of 23 boys and 27 girls were reevaluated two months later with and without knowledge of chronological ages for determination of intraobserver variability. Results: Although it was not statistically significant (p>0.05) , all the observers are more likely to interpret the radiograph as showing normal findings when chronological age is known than if the interpretation is performed with the observer unaware of chronological age. When chronological age was known and when the age was not known, in both basal and second interpretations, determination of bone age was consistent with chronological age for each observer (p<0.001). Conclusion: Knowledge of chronological age prior to the assessment of radiographs does not affect reliability.