Introduction
Changes in a patient's quality of life (QoL) must be considered when assessing the overall success of a surgical intervention. Patient-reported outcome measures are widely used in surgery to determine the qualitative impact of a particular intervention or device.
The Glasgow Benefit Inventory is a validated questionnaire used fairly frequently in otolaryngology patients when investigating generic patient-reported outcome measures.Reference Robinson, Gatehouse and Browning1,Reference Hendry, Chin, Swan, Akeroyd and Browning2 It was initially designed to be used post-intervention to assess the impact of a procedure. The Glasgow Health Status Inventory is similar to the Glasgow Benefit Inventory questionnaire, and measures the effect of a health problem on an individual's QoL. It can be used for cross comparison of health conditions with different interventions, and can be employed at any point during the patient's timeline.
In 1977, Tjellström et al.Reference Tjellström, Rosenhall, Lindstrom, Hallen, Albrektsson and Branemark3 were the first clinicians to insert a bone conducting hearing implant. Now, more than 40 years later, more than 150 000 individuals have achieved auditory rehabilitation with a bone conducting hearing implant. The success of implantation with a bone-anchored hearing device depends on appropriate patient selection, minimal localised skin complications and good osseointegration of the titanium implant.Reference Kruyt, Banga, Banerjee, Mylanus and Hol4
The audiological and QoL benefits of bone conducting hearing devices have been well documented in many previous studies.Reference Hendry, Chin, Swan, Akeroyd and Browning2,Reference Dutt, McDermott, Jelbert, Reid and Proops5–Reference Mace, Isa and Cooke12 Over the last 40 years, there has been considerable modification of the device size and implant type.Reference Kruyt, Banga, Banerjee, Mylanus and Hol4,Reference Wilkie, Chakravarthy, Mamais and Temple13–Reference Allis, Owen, Chen, Dwight and Moore15 There has also been a move towards less invasive soft tissue techniques and use of the minimally invasive Ponto surgery technique.Reference Calon, van Hoof, van den Berge, de Bruijn, van Tongeren and Hof16–Reference Mohamad, Khan, Hey and Musheer23 Many of the previous QoL studies were performed with older devices and using more invasive soft tissue surgical techniques.Reference Snyder, Moore and Johnson24
Whilst it is clear that bone conducting hearing implants demonstrate a qualitative benefit, there remains a paucity of literature comparing pre- and post-operative QoL benefits. This study assessed the QoL status before and after the bone conducting hearing device is implanted.
Materials and methods
A prospective, cross-sectional study was conducted of all consecutive adult patients who underwent bone conducting hearing implant insertion in a large teaching hospital in the east of England over a period of five years. Eighty-eight patients were approved and scheduled to receive a bone conducting hearing implant between March 2012 and March 2017.
The Glasgow Health Status Inventory questionnaire contains 18 questions, which relate to 4 domains: general, psychological, social and physical wellbeing. Responses are scaled and averaged using a five-point Likert scale. The poorest outcome score is −100 and the best outcome score is +100. The Glasgow Health Status Inventory questionnaire was completed by the patient and the specialist audiologist pre- and post- implantation. The patients’ clinical and audiological notes were reviewed to assess audiological outcomes and check for any complications regarding the surgery.
Regarding the inclusion criteria of the study, patients were aged 18 years or older, receiving a unilateral bone conducting hearing implant, and able to communicate effectively in order to complete the pre- and post-operative questionnaires. Patients were excluded if they were receiving a second implant, or had not completed any pre- or post-operative questionnaires at the time of the study.
Results
Eighty-eight patients were approved for implantation of a bone conducting hearing device; these were inserted between March 2012 and March 2017. Twenty-six patients were excluded from analysis; 11 patients were having a second bone conducting hearing implant placed, 11 patients did not have pre-operative scores noted or were not contactable, 3 abutments fell out and 1 minimal access procedure failed.
Sixty-two patients had a unilateral bone conducting hearing implant placed and completed both questionnaires. The patients consisted of 27 females and 35 males, with a median age of 65 years (range of 27–87 years).
All 62 patients underwent a single-stage surgical procedure using a soft tissue preservation approach. Fifty-six patients had a linear incision with a punch, and six patients had the new minimally invasive Ponto surgery technique. Of the four failed procedures, one had the minimally invasive Ponto surgery technique. Implants were placed on the right side in 33 patients and on the left side in 29 patients. All patients received a percutaneous implant with an abutment. All operations were performed in the operating theatre under general or local anaesthesia by two ENT consultants.
Reasons for implantation included: recurrent infections, mastoid cavities, behind the ear hearing aids not loud enough, microtia and others (e.g. single-sided deafness, otosclerosis and canal stenosis) (Figure 1).
Fig. 1. Reasons for the unilateral bone conducting hearing implant. BTE = behind the ear hearing aid
Glasgow Health Status Inventory questionnaires were completed pre-operatively and 3–12 months post-implantation. One patient did not attend formal follow up, and two others did not have post-operative questionnaire scores recorded. Three telephone follow-up sessions were conducted, and questionnaires were completed for these patients.
Analysis of the Glasgow Health Status Inventory questionnaire data revealed that the average total score increased from −24 pre-operatively to +53 post-operatively. The general benefit score increased from −35 to +69. The physical score increased from −29 to +26. The social score decreased from +44 to +13. A box plot of the pre- and post-operative scores can be seen in Figure 2.
Fig. 2. Pre- and post-implant scores on the Glasgow Health Status Inventory (GHSI) questionnaire.
Paired t-tests were used to calculate the difference between the pre- and post-implantation Glasgow Health Status Inventory scores. The differences in the means for the total, general and physical scores were statistically significant at the 5 per cent level (p < 0.0001). There was no statistically significant difference between the pre- and post-implant scores in the social support domain (p = 0.70254). Statistical analyses were performed using SAS software, version 9.4 (SAS Institute, Cary, North Carolina, USA).
Discussion
The current study is noteworthy, as it confirms the improvements seen in patients’ QoL after implantation of a bone conducting hearing device.Reference Arunachalam, Kilby, Meikle, Davison and Johnson14,Reference Mylanus, Snik and Cremers25−Reference Macnamara, Phillips and Proops27 It is one of the few prospective studies to show a change in QoL from pre- to post-implantation. Furthermore, it introduces the novel use of the Glasgow Health Status Inventory questionnaire, which is fast and easy to implement before and after an intervention to attain a matched comparison.
• Bone conducting hearing implants are an alternative for patients who may not benefit from air conducting hearing aids
• The Glasgow Health Status Inventory is a validated quality of life (QoL) indicator that is fast and easy to implement, and can be used to get a matched comparison
• A significant improvement was seen in Glasgow Health Status Inventory questionnaire average total, general benefit and physical scores
• There was no post-operative improvement in QoL social score, likely a result of minimal change in patients’ social support networks
• Innovative advances in devices and surgery, and a dedicated multidisciplinary team approach, has streamlined the patient's pathway and increased QoL
The study highlights a vast improvement in patients’ perceived QoL after bone conducting hearing implant surgery. The post-operative Glasgow Health Status Inventory total and general scores showed a statistically significant improvement when compared with the pre-operative scores. The physical score also improved post-operatively. Patients felt that they were healthier, as they were not attending their general practitioner as frequently, and that they had experienced fewer colds or infections since the fitting of the device. A few of the questionnaires included personal comments from patients who reported decreased visits to their otolaryngology clinic for microsuction and treatment of recurrent infections associated with continued use of conventional air conducting hearing aids. These improvements have been noted in other studies.Reference Mylanus, Snik and Cremers25–Reference Macnamara, Phillips and Proops27
The improvements noted in this study are the result of vast progression technologically and the use of a patient-centred approach to implantation. Innovative advances have led to the devices becoming smaller and more powerful. Newer surgical techniques, with a reduction in soft tissue trauma, have improved the efficiency and speed of surgery, and permit the procedure to be performed under local anaesthesia. Patients with complex medical co-morbidities can now benefit from a bone conducting hearing implant; patients have faster recovery and can undergo implantation as a day-stay surgical procedure, thereby also reducing the burden of hospital bed shortages. Additionally, the use of a multidisciplinary team approach and staff dedicated to bone conducting hearing implant patients has streamlined the patient's pathway and continuity of care. These improvements have all led to increased patient satisfaction concerning both the short-term procedure and the long-term hearing outcomes.
The study does have its limitations. It was a relatively small-scale study involving 62 patients. It did not include patients in whom bone conducting hearing implant placement had failed. The post-operative questionnaire requires the device to be loaded onto the implant; therefore, the study was prone to selection bias. The Glasgow Health Status Inventory pre- and post-intervention comparison can result in a misleading interpretation of the raw score. In our cohort, patients reported very good social support prior to the intervention, scoring +44 on the social scale. Post-operatively, patients did not report any changes to their social support, therefore scoring +13 on the social scale. The decline in score may lead to the misinterpretation that the procedure had a negative impact on a patient's social QoL.
Clinical application
It is estimated that approximately ten million people in the UK have a degree of hearing impairment.28 Initial rehabilitation of hearing loss is typically attempted with conventional air conducting hearing aids. When conventional hearing aids are not suitable or do not provide adequate benefit for the patient, then bone conducting hearing devices may be considered. The clinical commissioning policy from NHS England has concluded that there is evidence to suggest that bone conducting hearing implants are beneficial. In order to continue funding unilateral and even bilateral bone conducting hearing devices, it remains crucial to have a wealth of evidence for the audiological and QoL benefits that these hearing aids provide.Reference Ho, Monksfield, Egan, Reid and Proops29
Conclusion
This study adds to the body of evidence suggesting that patients fitted with a unilateral bone conducting hearing implant report immense QoL improvements in nearly all domains of their life.
Acknowledgement
Authors SM and JH were funded by Oticon to attend the 6th International Congress on Bone Conduction Hearing and Related Technologies (‘OSSEO 2017’). (There are no other funding disclosures.)
Competing interests
None declared
