Cost-effectiveness of CI in developing countries

A novel cochlear implant assessment tool: Audiometric and speech recognition analysis

OBJECTIVE

To compare the results of Pure Tone Audiometry (PTA) and speech recognition, of users of Cochlear Implant (CI) between CLABOX with Direct Audio Input (DAI) and the Sound Booth (SB).

METHODS

Fifty individuals with CIs, 33 adults and 17 children, were included. Speech recognition tests in noise fixed and adaptive were applied with the Hearing in Noise Test (HINT), Ling test, and PTA, in the SB (in free field) and in CLABOX.

RESULTS

For speech recognition in noise, averages were better in the CLABOX; for PTA, they were higher in the CLABOX; and for Ling test, there was no significant change in the categories between SB and CLABOX. The fixed noise were higher in the CLABOX (88.3%) than in the SB (78.9%), p-value < 0.001. In the HINT with adaptive noise, the results were significant (p-value = 0.007); the S/N ratio was 2.14 dB in the CLABOX and 3.42 dB in the SB. For the four-tone average, the average thresholds for the CLABOX and the SB were 29.8 dB and 23 dB, respectively (p-values < 0.001).

CONCLUSION

CLABOX was an effective tool to evaluate the PTA and speech recognition tests when compared to the conventional evaluation with a SB in the CI user population.

Preoperative Imaging in Cochlear Implants

OBJECTIVE

To determine the utility of computed tomography (CT) and magnetic resonance imaging (MRI) in cochlear implant candidates.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral hospital.

PATIENTS

A total of 207 cochlear implanted patients with CT and/or MRI.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Age versus abnormal radiologic findings, imaging abnormality versus postoperative outcomes, postoperative outcomes versus electrode design, Cambridge Cochlear Implant Protocol (CCIP) status for imaging abnormalities, sensitivity and specificity of CT and MRI for round-window/cochlear occlusion, and MRI for incomplete partitions.

RESULTS

A total of 207 patients with CT, MRI, or both were reviewed retrospectively. Less than half (15.5%) of CT scans had findings that might affect surgical intervention compared with 5.9% of MRI. No significant difference was found between children and adults for relevant imaging abnormalities (grade 4 or higher) with either CT (p = 0.931) or MRI (p = 0.606). CCIP status correlated with cochlear abnormalities (p = 0.040); however, only 46.2% of radiographic abnormalities on CT would be identified by these criteria. For detecting cochlear occlusion requiring surgical intervention, the sensitivity and specificity for CT were 40% (4 of 10; 95% confidence interval [CI], 12.16-73.76) and 95.73% (95% CI, 91.40-98.27), respectively. For MRI, the sensitivity and specificity were 33.33% (1 of 3; 95% CI, 0.84-90.57) and 96.97% (63 of 65; 95% CI, 89.32-99.63), respectively. There was no difference for postoperative AzBio scores for higher-grade imaging abnormalities (p = 0.6012) or for electrode designs (p = 0.3699).

CONCLUSIONS

Significant radiographic abnormalities were relatively uncommon in cochlear implant patients on either CT or MRI at our single-center institution. If present, abnormal imaging findings rarely translated to management changes. CCIP status does not reliably predict which patients are likely to have abnormalities. Both MRI and CT have low sensitivity for round-window or cochlear occlusion, but detection likely leads to changes in surgical management.

Cochlear implantation in older adults: 15 years' experience of a tertiary centre in a developing country

INTRODUCTION

Cochlear implant (CI) is a viable option of treatment for older patients with severe to profound deafness in resource-rich countries. Implantation is limited in developing countries.

OBJECTIVE

To review factors and outcomes of elderly patients that underwent CI in a pioneer centre in a developing country.

MATERIAL AND METHODS

An observational retrospective review of patients older than 60, implanted between 2005 to 2020.

RESULTS

Eleven patients were included. Patient were aged 60-74 years old with median of 66 years old. Average duration of deafness prior to implantation is 22 years. All implantation was unilateral except for one case that was implanted sequentially after 5 years Three patients were privately funded. Analysis of the hearing aided level with CI and hearing aid showed substantial improvement provided by the CI. The Categories of Auditory performance (CAP-II) scale were in the range of 6-9.

DISCUSSION

Cochlear implant is safe and stable intervention in providing improvement of hearing and self-esteem in the elderly patients. Social isolation and depression also improved with better hearing and communication.

CONCLUSION

Awareness of the CI in elderly patients must be advocated among policy- makers, clinicians, and patients to mitigate the clinical and public health burden of hearing loss among older patients.

Overcoming developing-world challenges in cochlear implantation: A Nigerian perspective

The emergence of cochlear implantation (CI) in the mid-20th century was a transformation to the field of restorative otology. The advance in this field has not been felt in lower-income countries where a huge burden of profound hearing loss lies. The authors sought to review the literature on the practice of cochlea implantation in Nigeria. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews, we conducted a scoping review of the literature on CI in Nigeria. All observational studies with information on cochlear implants and/or implantation in Nigeria were included with no limitations on outcomes. The authors extracted the following data; age, sample size, sex, aetiology, outcome, type of devices, complications, challenges and the location of the surgery. The results were pooled and reported as frequencies and percentages. Three studies were utilised in this review. The study included 25 patients. The age of the identified patients ranged from 1.2 months to 63 years. There were slightly more males than females (52% males). The most common aetiology of deafness in the participants was following a febrile illness (40%), followed by deafness post-meningitis (24%). The challenges identified included high cost, lack of full rehabilitative facilities and staff, scepticism, and lack of funding. CI remains the most effective for those that are profoundly deaf. Although successful CI programmes exist in Nigeria, the number of implant programmes and the affordability are not yet commensurate to the needs of the entire Nigerian population.

Assessing the manufacturable 32-channel cochlear electrode array: evaluation results for clinical trials

Reliability evaluation results of a manufacturable 32-channel cochlear electrode array are reported in this paper. Applying automated laser micro-machining process and a layer-by-layer silicone deposition scheme, authors developed the manufacturing methods of the electrode array for fine patterning and mass production. The developed electrode array has been verified through the requirements specified by the ISO Standard 14708-7. And the insertion trauma of the electrode array has been evaluated based on human temporal bone studies. According to the specified requirements, the electrode array was assessed through elongation & insulation, flexural, and fatigue tests. In addition, Temporal bone study was performed using eight fresh-frozen cadaver temporal bones with the electrode arrays inserted via the round window. Following soaking in saline condition, the impedances between conducting wires of the electrode array were measured over 100 kΩ (the pass/fail criterion). After each required test, it was shown that the electrode array maintained the electrical continuity and insulation condition. The average insertion angle of the electrode array inside the scala tympani was 399.7°. The human temporal bone studies exhibited atraumatic insertion rate of 60.3% (grade 0 or 1). The reliability of the manufacturable electrode array is successfully verified in mechanical, electrical, and histological aspects. Following the completion of a 32-channel cochlear implant system, the performance and stability of the 32-channel electrode array will be evaluated in clinical trials.

Cost Effectiveness of Cochlear Implantation in Single-Sided Deafness

OBJECTIVE

To analyze the cost effectiveness of cochlear implantation (CI) for the treatment of single-sided deafness (SSD).

STUDY DESIGN

Cost-utility analysis in an adapted Markov model.

SETTING

Adults with single-sided deafness in a high-income country.

INTERVENTION

Unilateral CI was compared with no intervention.

MAIN OUTCOME MEASURE

Incremental cost-effectiveness ratios were compared with different cost-effectiveness thresholds ($10,000 to $150,000) for different age, sex, and cost combinations. The calculations were based on the quality-adjusted life year (QALY), national life expectancy tables, and different cost settings. The health utility values for the QALY were either directly collected from published data, or, derived from published data using a regression model of multiple utility indices (regression estimate).

RESULTS

The regression estimate showed an increase of the health utility value from 0.62 to 0.74 for SSD patients who underwent CI. CI for SSD was cost effective for women up to 64 years ($50,000 per-QALY threshold), 80 years ($100,000 per-QALY threshold), and 86 years ($150,000 per-QALY threshold). For men, these values were 58, 77, and 84, respectively. Changing the discount rate by up to 5% further increased the cutoff ages up to 5 years. A detailed cost and age sensitivity analysis is presented and allows testing for cost effectiveness in local settings worldwide.

CONCLUSIONS

CI is a cost-effective option to treat patients with SSD.

Manufacturable 32-Channel Cochlear Electrode Array and Preliminary Assessment of Its Feasibility for Clinical Use

(1) Background: In this study, we introduce a manufacturable 32-channel cochlear electrode array. In contrast to conventional cochlear electrode arrays manufactured by manual processes that consist of electrode-wire welding, the placement of each electrode, and silicone molding over wired structures, the proposed cochlear electrode array is manufactured by semi-automated laser micro-structuring and a mass-produced layer-by-layer silicone deposition scheme similar to the semiconductor fabrication process. (2) Methods: The proposed 32-channel electrode array has 32 electrode contacts with a length of 24 mm and 0.75 mm spacing between contacts. The width of the electrode array is 0.45 mm at its apex and 0.8 mm at its base, and it has a three-layered arrangement consisting of a 32-channel electrode layer and two 16-lead wire layers. To assess its feasibility, we conducted an electrochemical evaluation, stiffness measurements, and insertion force measurements. (3) Results: The electrochemical impedance and charge storage capacity are 3.11 ± 0.89 kOhm at 1 kHz and 5.09 mC/cm2, respectively. The V/H ratio, which indicates how large the vertical stiffness is compared to the horizontal stiffness, is 1.26. The insertion force is 17.4 mN at 8 mm from the round window, and the maximum extraction force is 61.4 mN. (4) Conclusions: The results of the preliminary feasibility assessment of the proposed 32-channel cochlear electrode array are presented. After further assessments are performed, a 32-channel cochlear implant system consisting of the proposed 32-channel electrode array, 32-channel neural stimulation and recording IC, titanium-based hermetic package, and sound processor with wireless power and signal transmission coil will be completed.

Evidence gaps in economic analyses of hearing healthcare: A systematic review

BACKGROUND

Hearing loss is a common and costly medical condition. This systematic review sought to identify evidence gaps in published model-based economic analyses addressing hearing loss to inform model development for an ongoing Lancet Commission.

METHODS

We searched the published literature through 14 June 2020 and our inclusion criteria included decision model-based cost-effectiveness analyses that addressed diagnosis, treatment, or prevention of hearing loss. Two investigators screened articles for inclusion at the title, abstract, and full-text levels. Data were abstracted and the studies were assessed for the qualities of model structure, data assumptions, and reporting using a previously published quality scale.

FINDINGS

Of 1437 articles identified by our search, 117 unique studies met the inclusion criteria. Most of these model-based analyses were set in high-income countries (n = 96, 82%). The evaluated interventions were hearing screening (n = 35, 30%), cochlear implantation (n = 34, 29%), hearing aid use (n = 28, 24%), vaccination (n = 22, 19%), and other interventions (n = 29, 25%); some studies included multiple interventions. Eighty-six studies reported the main outcome in quality-adjusted or disability-adjusted life-years, 24 of which derived their own utility values. The majority of the studies used decision tree (n = 72, 62%) or Markov (n = 41, 35%) models. Forty-one studies (35%) incorporated indirect economic effects. The median quality rating was 92/100 (IQR:72-100).

INTERPRETATION

The review identified a large body of literature exploring the economic efficiency of hearing healthcare interventions. However, gaps in evidence remain in evaluation of hearing healthcare in low- and middle-income countries, as well as in investigating interventions across the lifespan. Additionally, considerable uncertainty remains around productivity benefits of hearing healthcare interventions as well as utility values for hearing-assisted health states. Future economic evaluations could address these limitations.

FUNDING

NCATS 3UL1-TR002553-03S3.

An mHealth App (Speech Banana) for Auditory Training: App Design and Development Study

Background

With the growing adult population using electronic hearing devices such as cochlear implants or hearing aids, there is an increasing worldwide need for auditory training (AT) to promote optimal device use. However, financial resources and scheduling conflicts make clinical AT infeasible.

Objective

To address this gap between need and accessibility, we primarily aimed to develop a mobile health (mHealth) app called Speech Banana for AT. The app would be substantially more affordable and portable than clinical AT; would deliver a validated training model that is reflective of modern techniques; and would track users’ progress in speech comprehension, providing greater continuity between periodic in-person visits. To improve international availability, our secondary aim was to implement the English language training model into Korean as a proof of concept for worldwide usability.

Methods

A problem- and objective-centered Design Science Research Methodology approach was adopted to develop the Speech Banana app. A review of previous literature and computer-based learning programs outlined current AT gaps, whereas interviews with speech pathologists and users clarified the features that were addressed in the app. Past and present users were invited to evaluate the app via community forums and the System Usability Scale.

Results

Speech Banana has been implemented in English and Korean languages for iPad and web use. The app comprises 38 lessons, which include analytic exercises pairing visual and auditory stimuli, and synthetic quizzes presenting auditory stimuli only. During quizzes, users type the sentence heard, and the app provides visual feedback on performance. Users may select a male or female speaker and the volume of background noise, allowing for training with a range of frequencies and signal-to-noise ratios. There were more than 3200 downloads of the English iPad app and almost 100 downloads of the Korean app; more than 100 users registered for the web apps. The English app received a System Usability Scale rating of “good” from 6 users, and the Korean app received a rating of “OK” from 16 users.

Conclusions

Speech Banana offers AT accessibility with a validated curriculum, allowing users to develop speech comprehension skills with the aid of a mobile device. This mHealth app holds potential as a supplement to clinical AT, particularly in this era of global telemedicine.

Estimating the global costs of hearing loss

OBJECTIVE

To estimate the global costs of hearing loss in 2019.

DESIGN

Prevalence-based costing model.

STUDY SAMPLE

Hearing loss data from the 2019 Global Burden of Disease study. Additional non-hearing related health care costs, educational support, exclusion from the labour force in countries with full employment and societal costs posed by lost quality of life were determined. All costs were reported in 2019 purchasing power parity (PPP) adjusted international dollars.

RESULTS

Total global economic costs of hearing loss exceeded $981 billion. 47% of costs were related to quality of life losses, with 32% due to additional costs of poor health in people with hearing loss. 57% of costs were outside of high-income countries. 6.5% of costs were for children aged 0-14. In scenario analysis a 5% reduction in prevalence of hearing loss would reduce global costs by $49 billion.

CONCLUSION

This analysis highlights major economic consequences of not taking action to address hearing loss worldwide. Small reductions in prevalence and/or severity of hearing loss could avert substantial economic costs to society. These cost estimates can also be used to help in modelling the cost effectiveness of interventions to prevent/tackle hearing loss and strengthen the case for investment.

Lassa Fever Induced Hearing Loss: The Neglected Disability of Hemorrhagic Fever

OBJECTIVE

Lassa fever (LF) a hemorrhagic fever endemic to Western has an incidence of approximately 500,000 cases per year. Here, we evaluate hearing loss and other sequelae following LF.

METHODS

This case-control study enrolled laboratory confirmed LF survivors, non-LF Febrile controls and Matched Community controls with no history of LF or recent hospitalization for a febrile illness. Study participants completed a symptom questionnaire. Pure-tone audiometry was completed by a subset of participants.

RESULTS

One hundred forty-seven subjects were enrolled aged from 3-66 years (mean = 23.3). LF survivors were significantly more likely to report balance difficulties (55% vs 20%, p < 0.001), hair loss (32% vs 7%, p < 0.001), difficulty speaking (19% vs 1%, p < 0.001), social isolation (50% vs 0%, p < 0.001), and hearing loss (17% vs 1%, p = 0.002) in comparison to Matched-Community Controls. Similar trends were noted in comparison to Febrile Controls, although these findings were non-significant. Fifty subjects completed audiometry. Audiometry found that LF survivors had significantly more bilateral hearing loss in comparison to Matched-Community Controls (30% vs 4%, p = 0.029).

CONCLUSION

This study characterizes the sequelae of LF and highlights the need for increased access to hearing care in West Africa.

Training for hearing care providers

The lack of an appropriately trained global hearing-care workforce is recognized as a barrier to developing and implementing services to treat ear and hearing disorders. In this article we examine some of the published literature on the current global workforce for ear and hearing care. We outline the status of both the primary-care workforce, including community health workers, and specialist services, including audiologists, ear, nose and throat specialists, speech and language therapists, and teachers of the deaf. We discuss models of training health workers in ear and hearing care, including the role of task-sharing and the challenges of training in low and middle-income countries. We structure the article by the components of ear and hearing care that may be delivered in isolation or in integrated models of care: primary care assessment and intervention; screening; hearing tests; hearing rehabilitation; middle-ear surgery; deaf services; and cochlear implant programmes. We highlight important knowledge gaps and areas for future research and reporting.