Background: Measuring testicular volumes by orchidometer is a standard method of pubertal staging in boys. A paucity of evidence exists as to its inter and intra-observer reliability and the impact of clinicians gender, experience and training on the accuracy of measurements. We are developing specifically engineered models with different testicular volumes to investigate inter and intra-observer reliability of testicular volume estimation for simulation training.
Methods: A pilot study was conducted using four child-sized manikins with 20, 10, 5 or 3 ml prosthetic testes attached. Observers were asked demographic data (gender, job title, endocrinology experience and specific training) then, using an orchidometer, anonymously recorded their estimation of the four manikins testicular volumes before and after a training session.
Results: There were 16 participants: ten junior doctors, four consultant paediatric endocrinologists and two specialist endocrine nurses. Twelve participants were female, four male. Thirteen repeated testicular volume measurements following training. Overall 46% of participants overestimated testicular volume, 7% underestimated and 46% were accurate. Males were significantly more accurate than females (P=0.04). Males accurately measured 62% of the time, overestimated 31% and underestimated 6% compared to females (40, 51, 8% respectively). Larger volume testicles were more accurately measured: 20 ml volume had the smallest variability (CV 12%) and 3 ml volume the largest (CV 50%). Variation was higher at all volumes in the left testicle. Experience and training did not significantly impact on accuracy.
Discussion: There was considerable variation in the estimation of testicular volume between subjects and at lower testicular volumes. Males are more accurate with their testicular staging than females. Feedback from this pilot study has been used to further develop our specifically engineered prototypes ready for a larger study to be conducted with delegates at BSPED 2015.