Investigation of a significant increase in referrals during neonatal hearing screening: A comparison of Natus ALGO Portable and ALGO 3i

Abstract

Objective: Neonatal hearing screening programs in Flanders and the Netherlands use Natus ALGO screening devices. Since 2006 in Flanders and 2009 in the Netherlands, both programs have replaced the older ALGO Portable devices with the newer ALGO 3i devices. However, in both countries, ALGO 3i devices have a significantly higher rate of referrals than ALGO Portable devices. In Flanders, the refer rate has more than doubled with the switch to ALGO 3i devices. In the Netherlands, screening centers which used ALGO 3i devices also showed a significant increase in referrals. In both countries, the percentage of children diagnosed with permanent hearing loss remained approximately the same. Design: A technical comparison of both device types was carried out to identify possible causes for the increase in referrals. The stimulus output of two ALGO Portable and three ALGO 3i devices was recorded and analysed for stimulus level, spectral properties, and stimulus irregularities. Results: ALGO 3i devices stimulate at a peak level 4.6 dB lower than ALGO Portable devices, have a different stimulus spectrum and show unexplained stimulus irregularities during 4% of the stimulation time. Conclusions: A number of technical differences were found between both device types which could explain the increase in referrals.

Key Words::

• Neonatal hearing screening
• EEG
• AABR

Acknowledgements

Portions of this research have been presented by Erwin Van Kerschaver at the Conference on Neonatal Hearing Screening, Como Lake, Italy, June 8–10, 2010. We would like to thank Luc Stappaerts and Erwin Van Kerschaver of Kind & Gezin for bringing this issue to our attention and for providing us with ALGO devices. We also thank Anneke Meuwese-Jongejeugd from the RIVM for pointing out the results of the hearing screening program in the Netherlands. We acknowledge Tessa Akkerman, Christoph van der Reyden, and Dirk van Hek from Cordial Medical for providing us with ALGO devices and additional measurement equipment. A technical report detailing these findings and a list of technical and scientific questions was communicated to Natus in March 2010. This initial contact and further repeated requests for urgent investigation have not resulted in any concrete communication yet.

Declaration of interest:The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.