Do Real-Ear Measurements Make a Real Difference to Patient Outcomes? Interview with Claire Henson, Leicester Royal Infirmary, England
From a poster presentation at the British Academy of Audiology, Liverpool, England, November 2008, Douglas L. Beck, AuD, interviews Claire Henson, audiologist with the Leicester Royal Infirmary, England, about her poster session and findings.
Academy: Hi, Claire. Thanks for joining me today.
Henson: Hi, Doug. Thanks for the interest in our poster!
Academy: Claire, just a little context for clarification. At the recent British Academy of Audiology (BAA) meeting in Liverpool (November 2008), I noticed the poster you and Pauline Smith had displayed. I thought it was very relevant and I was hopeful you would review what you did and what you learned with me?
Henson: Surely. It’s my pleasure. The basic question we wanted to answer was whether or not real-ear measures (REMs) made a difference in the long term, from the patient’s perspective.
Academy: And just to clarify, REMs are indeed required when fitting hearing aids in the United Kingdom, per the protocols established by the BAA and BSA….is that right?
Henson: Currently in the United Kingdom, REMs are a recommended procedure (BSA, BAA 2007) and therefore all patients should be fitted using REMs. However, we know that a lot of patients do not get REMs at fitting, for a variety of reasons (equipment or technical difficulties, time constraints, lack of training or misunderstanding on the part of audiologists, as well as contraindications such as wax, patient discomfort, etc).
Our study began in 2006, at that point not all audiologists in our department were using REMs on all patients. Therefore, we compared people who had been fitted with hearing aids using REMs, to those who were fitted without using REMs.
Academy: And what was your feeling going into the study? Did you believe REMs mattered?
Henson: Yes, Pauline and I agreed with the literature and fitting the patient individually, but with respect for ear canal individuality and starting points and targets made sense. We both use REMs all the time and experience showed us how much difference REMs made to the frequency response, particularly at the high frequencies.
Academy: So is it fair to say, because the REM specified a certain amount of high frequency gain, the professionals using REMs were more “obligated” to achieve the higher frequency gain?
Henson: Yes, that’s right. So our goal was to match the hearing aid’s gain to the specific needs of the patient, but with their specific ear canal acoustics in mind, to determine the best fit possible. And I should note we use NAL-NL1 in our prescriptions.
Academy: How many patients did you review?
Henson: We reviewed a total of 40 patients at one year post fitting. Of those, 16 attended an additional follow-up appointment, and of those, six were fitted using REMs, 10 were fitted without REMs. All patients had already been followed-up at three months post-fitting, and would only have been seen again at their request.
Academy: And what did you learn?
Henson: We found a significant difference in the insertion gain between those fitted with REM and those not fitted with REMs. Specifically, people fitted with REM had more gain at 3kHz and 4kHz. Not only that, but the patients fitted without REM were indeed “under-fit” with respect to target gain at the same frequencies.
Academy: And so the basic prescription was improved via the REM protocol. Were there any other differences in the two groups?
Henson: Yes. We found something very interesting: The Glasgow Hearing Aid Benefit Profile (GHABP, see Gatehouse, 1999) showed people not fitted using REMs had a greater decline in their satisfaction ratings one year later. The decline they experienced was significant and was some 18 percent. That was significantly different from the satisfaction ratings of the people fitted with REMs. We thought maybe the high frequency gain (which was below target) which patients liked initially, needed to be increased as they acclimatised, to maintain satisfaction in the longer term?
Academy: Did you include any other outcomes?
Henson: Yes. We used the Speech, Spatial, and Qualities of Hearing Questionnaire (SSQ, Gatehouse and Noble, 2004). Although there was not a statistically significant difference, the SSQ scores were consistently higher for those fitted with REM, with regard to Speech Hearing, Spatial Hearing and Quality of Hearing. With regard to this outcome, we believe if a larger sample of patients were included, a significant difference between the two groups of patients might emerge.
Academy: Very good. And so all in all, were there any negatives associated with using REMs?
Henson: Yes. On assessing the additional service used and required by the patients in each group, it was recognized at the one year follow-up, patients from the REM group required additional instruction on using the hearing aid compared to patients who did not have REM at fitting. A possible reason is that conducting REMs takes additional time, and therefore, if no REM is performed, there’s additional time for instruction and explanation. Therefore, we recommend that adequate time is allocated to fit the hearing aid using REM, and carry out appropriate instruction, counseling etc.
Academy: Excellent. Thanks so much for your time and for reviewing your findings with me.
Henson: Thank you, too, Doug. It’s been great having worked with Pauline Smith on this project and poster, and I’m happy to share our information with the Academy.
Douglas L. Beck, AuD, Board Certified in Audiology, is the Web content editor for the American Academy of Audiology.
For More Information, References and Recommendations:
Gatehouse S and Noble W. (2004). The Speech, Spatial and Qualities of Hearing Scale (SSQ). International Journal of Audiology. Volume 43, Number 2, Pages 85-99.
Gatehouse, S. 1999. Glasgow Hearing Aid Benefit Profile: Derivation and Validation of a Client-centred Outcome Measure for Hearing Aid Services. Journal of the American Academy of Audiology, 10: 80-103.