Ninnie Helén Bakken Oehme1,2, Mathieu Roelants3, Ingvild Særvold Bruserud4,5, Geir Egil Eide6,7, Robert Bjerknes4,5, Karen Rosendahl8,9, Pétur B Júlíusson4,5. 1. Department of Clinical Science, University of Bergen, N-5020, Bergen, Norway. ninnie.oehme@uib.no. 2. Department of Pediatrics, Haukeland University Hospital, Bergen, Norway. ninnie.oehme@uib.no. 3. Environment and Health, Department of Public Health and Primary Care, KU Leuven - University of Leuven, Leuven, Belgium. 4. Department of Clinical Science, University of Bergen, N-5020, Bergen, Norway. 5. Department of Pediatrics, Haukeland University Hospital, Bergen, Norway. 6. Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway. 7. Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. 8. Department of Radiology, Haukeland University Hospital, Bergen, Norway. 9. Department of Clinical Medicine, University of Bergen, Bergen, Norway.
Abstract
BACKGROUND: Prader orchidometry has been the standard method for evaluating testicular size. As this technique is subjective and tends to overestimate the testicular volume, ultrasound (US) has been proposed as more reliable. OBJECTIVE: To evaluate the intra- and interobserver agreement of US measurements of testicular volume and to compare US with the Prader orchidometer. MATERIALS AND METHODS: Dimensions of the right testicle were measured using US in 57 boys ages 6.5 to 16.4 years (mean: 12.0 years). The measurements were performed twice by one main observer and once by a second observer. A third observer estimated testicular volume using a Prader orchidometer. Agreement was investigated with Bland-Altman plots, summarized as the mean and standard deviation (SD) of differences, 95% limits of agreement and technical error of measurement. RESULTS: Mean intra-observer difference of testicular volume was 2.2%, SD=9.2% (limits of agreement: -20.3 to 15.9%) and technical error of measurement 6.5%. The mean interobserver difference was 4.8%, SD=20.7% (limits of agreement: -35.7 to 45.3%) and technical error of measurement 14.6%. Comparing US and orchidometer volumes required conversion that was nonlinear and volume dependent, estimated as VolOM = 1.96×VolUS0.71. The mean difference after transformation was 0.7% with an SD of 18.0% (limits of agreement: -34.5 to 35.9%). CONCLUSION: Our results showed a small mean intra- and interobserver difference that indicates the potential of US for measurement of testicular volume at group level. The intra-observer error was limited, which justifies its use in longitudinal follow-up of testicular development in an individual child, but the larger interobserver variability indicates the need for good standardization of methods. Agreement between the two methods requires a power transformation.
BACKGROUND: Prader orchidometry has been the standard method for evaluating testicular size. As this technique is subjective and tends to overestimate the testicular volume, ultrasound (US) has been proposed as more reliable. OBJECTIVE: To evaluate the intra- and interobserver agreement of US measurements of testicular volume and to compare US with the Prader orchidometer. MATERIALS AND METHODS: Dimensions of the right testicle were measured using US in 57 boys ages 6.5 to 16.4 years (mean: 12.0 years). The measurements were performed twice by one main observer and once by a second observer. A third observer estimated testicular volume using a Prader orchidometer. Agreement was investigated with Bland-Altman plots, summarized as the mean and standard deviation (SD) of differences, 95% limits of agreement and technical error of measurement. RESULTS: Mean intra-observer difference of testicular volume was 2.2%, SD=9.2% (limits of agreement: -20.3 to 15.9%) and technical error of measurement 6.5%. The mean interobserver difference was 4.8%, SD=20.7% (limits of agreement: -35.7 to 45.3%) and technical error of measurement 14.6%. Comparing US and orchidometer volumes required conversion that was nonlinear and volume dependent, estimated as VolOM = 1.96×VolUS0.71. The mean difference after transformation was 0.7% with an SD of 18.0% (limits of agreement: -34.5 to 35.9%). CONCLUSION: Our results showed a small mean intra- and interobserver difference that indicates the potential of US for measurement of testicular volume at group level. The intra-observer error was limited, which justifies its use in longitudinal follow-up of testicular development in an individual child, but the larger interobserver variability indicates the need for good standardization of methods. Agreement between the two methods requires a power transformation.
Authors: E Carlsen; A G Andersen; L Buchreitz; N Jørgensen; O Magnus; V Matulevicuus; I Nermoen; J H Petersen; M Punab; J Suominen; B Zilaitiene; A Giwercman Journal: Int J Androl Date: 2000-08
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Authors: Sjoerd D Joustra; Evelyn M van der Plas; Joery Goede; Wilma Oostdijk; Henriette A Delemarre-van de Waal; Wilfried W M Hack; Stef van Buuren; Jan M Wit Journal: Acta Paediatr Date: 2015-03-11 Impact factor: 2.299
Authors: Andre Madsen; Bjørg Almås; Ingvild S Bruserud; Ninnie Helen Bakken Oehme; Christopher Sivert Nielsen; Mathieu Roelants; Thomas Hundhausen; Marie Lindhardt Ljubicic; Robert Bjerknes; Gunnar Mellgren; Jørn V Sagen; Pétur B Juliusson; Kristin Viste Journal: J Clin Endocrinol Metab Date: 2022-06-16 Impact factor: 6.134