Effects of an evidence-based model for cochlear implant aftercare delivery on clinical efficiency and patient outcomes

Abstract

Objectives

To assess an evidence-based model (EBM) approach to cochlear implant (CI) aftercare that includes a modified, reduced treatment schedule for newly-implanted adult CI recipients consisting of four appointments (initial activation, 1-, 3- and 6- months postactivation) in the first year post-surgery.

Method

This prospective multicenter proof-of-concept study was conducted across three clinics in the United States by five experienced CI clinicians. Seventeen newly-implanted adult patients with postlingual hearing loss enrolled in the study. Hearing outcomes were measured using objective speech testing and subjective self-report measures.

Results

Most recipients (14/17; 82%) were able to follow the four-appointment EBM schedule. The reduced number of visits translated into an average time savings of 3 hours per patient. Significant improvements in speech perception were observed at both 3- and 6-months postactivation, as measured by CNC words in quiet and AzBio sentences at +10 dB SNR, consistent with published results achieved by traditional practices. Recipients were significantly satisfied with telephone, music, small group conversation, and television listening at 6 months postactivation. Recipient satisfaction with overall service was rated as ”excellent” by 14/14 (100%) respondents.

Conclusion

The four-appointment EBM approach delivered efficient and effective audiological aftercare to CI recipients in the first year following CI implantation.

Keywords:

• Cochlear implant
• Postoperative
• Care
• Evidence
• Efficiency
• Satisfaction
• Visits

Introduction

Current challenges in the delivery of postoperative CI care

Cochlear implants (CI) have become a widely recognized intervention for moderately-severe to profound sensorineural hearing loss (Boisvert et al., 2020; Deep et al., 2019). As the criteria for candidacy broadens and demand for CI treatment grows, in-clinic resources are likely to come under increasing pressure (Nassiri et al., 2021; Varadarajan et al., 2021; Zwolan et al., 2021). Typically, the traditional care pathway for patient follow-up in the first year postimplantation requires frequent clinic visits (Messersmith et al., 2019), with some clinics routinely scheduling between seven and eight appointments to complete fitting and performance milestones (Dunn, 2018; Müller and Raine, 2013; Waltzman and Kelsall, 2020).

While there is an absence of a universal and standardized approach to the delivery of postoperative CI recipient care, follow-up scheduling and assessment tasks can vary between clinics (Browning et al., 2020; Dunn, 2018; Hemmingson and Messersmith, 2018). Nevertheless, each in-clinic appointment involves clinician consultation plus booth time for implant testing, programming, and troubleshooting. These are against a backdrop of increasing time restrictions, space limitations, reimbursement constraints, as well as training on advancing device technology (Zwolan et al., 2021). For the CI recipient and/or their caregiver, in-clinic follow-up requires commitment and effort. For instance, taking time off work, arranging childcare support, travelling to the appointment, and absorbing the associated financial costs (Dunn, 2018; Messersmith et al., 2019), are burdens made even greater with more complex or frequent follow-up schedules.

Development of an evidence-based model of aftercare delivery

Scheduling of follow-up review

At present, based on limited evidence and expert opinion (Shapiro and Bradham, 2012; Vaerenberg et al., 2014), the American Academy of Audiology guidelines recommend CI recipients to undergo close monitoring and regular audiological review with follow-up at initial activation, and 1-week, 1-month, 3-months, 6-months, and 12-months postactivation. This is followed by additional visits at 18 or 24 months based on patient needs (Messersmith et al., 2019). However, the practical implications of such a schedule was recently assessed in a real-world study, which found that recipient adherence to follow-up visits reduces significantly with increasing time from device activation (Shapiro et al., 2021). On examination of a cohort of adult CI recipients (n = 2,554), extracted from the largest national CI registry in the United States, HIPAASecure, Encrypted, Research, Management and Evaluation Solution (HERMES) database, clinic attendance rates were found to drop from 81% at the 6-month visit to 66%, 41% and 35% at the 12-, 18- and 24-month follow-up appointments, respectively. These significant levels of patient attrition to the recommended follow-up schedule provided clear evidence of the need for a more practical, less time-intensive, personalized approach to CI review (Shapiro et al., 2021).

Implementation of a modified, reduced treatment schedule for newly-implanted CI recipients, involving only four clinic visits (initial activation, 1-month, 3-months and 6-months postactivation) in the first year following surgery, was explored as part of an assessment of an outcomes-driven, computer-assisted approach to CI fitting (Zwolan et al., 2021b). This study demonstrated comparable mean group speech recognition scores postoperatively for CNC words in quiet at 60 dBA and AzBio sentences in noise at 60 dBA +10 dB SNR, to those reviewed using the conventional clinical approach of seven visits. To build on this early evidence supporting a four-appointment schedule, we adopted this approach in the present study while additionally investigating effects on clinic efficiency (i.e. time and visit requirements compared to current clinic approach) and garnering clinician feedback and subjective patient outcomes.

Identifying performance milestones

For our proposed evidence-based model (EBM) approach to CI aftercare, we defined target milestones for individual performance on CNC word recognition tests in quiet at 3-months and 6-months postimplant. These goals were informed by an examination of a study cohort dataset available from Cochlear-sponsored research (Clinicaltrials.gov Identifier: NCT03007472). The data demonstrated the performance trajectory for CNC word scores from pre-implant with a hearing aid to post implant at 3, 6, and 12 months, for adult CI recipients (n = 100 enrolled) implanted unilaterally with the Cochlear™ Nucleus® CI532 cochlear implant (Buchman et al., 2020; Kelsall et al., 2021). Based on the existing literature (Buchman et al., 2020), we anticipate that 80% of adult CI recipients will achieve improvements in their word recognition scores of ≥ 20% at three months and ≥ 30% at six months, in CNC word scores pre vs. post implantation.

Further support for the inclusion of CNC word scores as hearing performance metrics at 3- and 6-months post implant was provided by a separate retrospective analysis of the HERMES database (Grisel et al., 2022). By examining CNC word performance over time (1, 3, 6, 12 and 24 months), it was revealed that the largest degree of improvement for the group occurred between 1 and 6 months following CI implantation. Average word recognition scores increased from below 15% at baseline to approximately 42% at one month, 50% at six months and 53% at 12 months, plateauing thereafter. These data suggest that by six months, for most recipients, hearing performance is likely at or close to its optimal level, allowing for consideration of fewer follow-up visits (Grisel et al., 2022).

Examination of another multicenter clinical database of experienced CI recipients with a minimum of 12 months since activation (n = 5473), provided additional performance milestones for consideration in the proposed EBM approach (Bewley, 2013). These included stabilization of Threshold (T) levels and Comfort (C) levels at three months post implant given observations that T- levels changed on average by 15 units and C levels by 20 units (dynamic range approximately 38–48 units by three months and then stabilizing after this time-period). These findings suggest that T and C levels may not require repeat measures at every follow-up appointment. Furthermore, a longitudinal study that included 33 adults implanted with the Nucleus CI24M, showed that electrode impedance values remained stable one to two months after initial stimulation, thereby offering another performance milestone for the EBM approach (Hughes et al., 2001).

Collectively, these data laid the foundation for the proposed EBM approach for aftercare delivery with the milestone criteria and scheduling of four appointments: initial activation, 1-month, 3-months, and 6-months postactivation (Table 1).

Table 1 Summary of the evidence-based model evaluation schedule

Appointment Post implant	Tasks	Milestones and measures
Initial Activation	Fit device/ Basic use Acclimate to sound Review hearing goals	COSI questionnaire to assess patient hearing goals
Within 1 month	Assess hearing thresholds Introduce accessories Confirm device use	≤ 25 dB HL 250-6000Hz Time on air across environments
Within 3 months	Assess hearing performance Assess hearing satisfaction	Hearing satisfaction survey COSI questionnaire ≥20% improvement on CNC word scores in quiet AzBio sentences in noise at +10 dB SNR
Within 6 months	Assess hearing performance Assess hearing satisfaction Re-evaluate second ear Baseline monitoring (Remote Check)	Hearing satisfaction survey COSI questionnaire ≥30% improvement on CNC word scores in quiet AzBio sentences in noise at +10 dB SNR Remote Check if possible
Monitoring Follow Up Care	Timing based on Remote Check and/or patient outcome/needs Confirm if performance is stable Upgrade counseling through Recipient Solutions Manager	Hearing satisfaction survey COSI questionnaire ≤15% reduction in CNC word scores in quiet* Remote Check if appropriate

*A change of 15% or more was defined as a clinically meaningful change based on the binomial distribution model of Thornton and Raffin, 1978. COSI, Client Oriented Scale of Improvement; CNC, Consonant-Nucleus-Consonant monosyllabic words; SNR, signal-to-noise ratio; EBM, Evidence-Based Model.

This model for aftercare uses evidence and data that are typically collected in general clinical practice to help the audiologist make decisions on when and what should be addressed during the recipients’ clinical visit. Of note, the four scheduled visits proposed, represent the minimum number of appointments recommended during the first year of follow-up post implant. It is expected that some CI recipients may require additional visits over and above the minimum schedule proposed if individual performance metrics fall below the anticipated outcomes for majority of CI recipients in clinical care. The model also includes an opportunity to leverage the Cochlear™ Connected Care platform (a combination of in-clinic, self-management and remote care tools and services) and to explore CI recipient satisfaction with the service provided.

Here, we report on the early experience of implementing the proposed EBM approach to aftercare for newly-implanted CI recipients in three experienced CI clinics. To this end, the primary objective was to assess the effects of the EBM approach, with its tools and services, on clinic efficiency. The secondary objective was to assess the model’s impact on patient outcomes using objective speech testing and self-reported outcomes. An additional secondary objective was to obtain feedback from clinicians trialing the EBM approach and how it compared to routine practices. The collective feedback was then used to help identify and address potential gaps in the model itself and its supportive tools and services, prior to exploring its wider implementation by clinics within the region.

Materials and methods

Study design

This was a 12-month, multicenter, prospective study across three private cochlear implant clinics in the United States. Participating clinics were the Michigan Ear Institute, Farmington Hills, MI; the Cochlear Hearing Center, Bellaire, TX; and, the Texoma Hearing Institute, Wichita Falls, TX. Five CI audiologists with 7–30 years’ experience with CI management, across these sites, evaluated the EBM approach for patient management. This model was also supported by access to self-management tools and services, such as:

• An Engagement Manager (EM). The EM works with patients during the candidate journey prior to implantation to answer questions about the process, expectations, equipment, and accessories. Once the candidate chooses to be implanted, the EM provides materials and resources to prepare them for the activation of the implant.

• A Recipient Services Manager (RSM). The RSM works with recipients who have been implanted to provide personalized product education, counseling, and resources to achieve recipient goals and reduce the burden on clinics. Examples include equipment basics, care, and maintenance, connecting with their smartphones and wireless accessories, getting started with rehabilitation resources and understanding and navigating the upgrade process. The recipient is referred by the clinician for this service and the recipient registers to meet the RSM virtually, or in person. The RSM provides a report to the audiologist summarizing the encounter.

• The Remote Check app. This is an at-home, clinician-enabled testing tool that allows recipients with a Cochlear™ Nucleus® 7 Sound Processor or the Cochlear™ Nucleus® Kanso® 2 Sound Processor to complete a series of hearing tests from their compatible iOS device using the Nucleus Smart App. Remote Check permits monitoring of the patients hearing progress and device status remotely and asynchronously for clinician access and review. Measures include audiological, subjective tests such as self-administered speech recognition in noise, aided thresholds, and questionnaires and objective tests such as automated electrode impedance measures, data logs for time on air as well as photographs of the implant site. Based on the results of the Remote Check test battery, the clinician can determine the patient’s needs for further care in and outside the clinic (Maruthurkkara et al., 2022).

• Information pack. This was provided to the CI recipient either at candidacy evaluation or post-surgery but prior to activation of their sound processor that contained self-driven support and service tools.

Written approval from the Institutional Review Board was obtained following review of the planned study protocol (WIC IRB CAM-SOC-EBM01-2020337).

Participants

Inclusion and exclusion criteria

A total of 17 newly-implanted CI recipients with a Cochlear^™ Nucleus® with Slim Perimodiolar electrode (CI532/CI632) or a Cochlear^™ Nucleus® with Slim Straight electrode (CI522/CI622) who were yet to have their sound processor activated, were enrolled. Patients had to be 18 years or older, have postlingual onset of hearing loss (defined as onset of hearing loss after two years of age) and who meet the local clinic’s candidacy criteria. Willingness to participate and comply with all study requirements, as well as be fluent in spoken English were also prerequisites for study participation. CI recipients who had an acoustic component in the implanted ear or, as determined by the audiologist, presented with significant cognitive, medical, or social impairment that would prevent compliance with study requirements were excluded from entering the study. A total of 17 CI recipients participated across the three centers. The baseline demographics and characteristics of the participants are summarized in Table 2.

Table 2 Baseline characteristics

Characteristic
Age at implantation, mean (SD), range	61.9 years (15.1)
	24–80 years
Mode
Unilateral CI	17.6% (3/17)
Bimodal (CI + HA)	76.5% (13/17)
Bilateral CIs	5.8% (1/17)
Duration of hearing loss, mean (SD), range	19.1 years (13.7)
	5–53 years
Pre CI CNC word score, mean (SD), range	12.9% (±14.6)
	0-44%
Pre CI AzBio +10 dB SNR, mean (SD), range	32.7 (±23.7%)
	0-84%
Owns a smartphone
Yes	88.2% (15/17)
No	11.8% (2/17)
Uses a smartphone as control
Yes	76.5% (13/17)
No	23.5% (4/17)

Data collection

Baseline assessments

Current standard practice for postoperative CI care. To understand the current approach used for postoperative CI care, each clinician completed a customized baseline survey prior to study initiation and interaction `with the CI recipient. The questionnaire was designed to collect information around the timing of adult CI appointments, test assessments and intervals, as well as an estimate of the total clinical hours (billable and non-billable) dedicated to existing CI recipients and new evaluations. The survey data on the routine approach was compared to the study closure survey for the trialed EBM approach to identify and evaluate any differences between them.

Patient inclusion survey. Once a CI recipient was identified and interested in participating in the study, the clinician completed a survey (accessed via an electronic link) to collect basic information and preoperative hearing scores, which were then attached to the patient’s unique identifier. This information was carried through each of the subsequent surveys during the study.

Clinician focused assessments

Clinician Decision Survey. This survey was completed by the audiologist after every individual recipient visit (activation, 1-, 3-, and 6-months). The survey focused on the audiologist’s decision to deviate from the proposed EBM approach to aftercare, the decision to use or not use the recommended tools and / or services and the rationale behind their decision. The response format to the questions were a combination of multiple choice and open text.

Unscheduled Visit Survey. This electronic survey was completed by the audiologist for every newly-implanted recipient requiring an interim clinical visit for programming, counselling, troubleshooting or any other clinical reason outside of the model schedule. The information collected included the date of the visit, reason for the visit, and activities completed.

Clinician Closure Survey. This electronic survey was completed by each audiologist at 12 months. It addressed questions around future use and adoption of the proposed EBM approach to care, possible gaps in clinician training, as well as the rationale and evidence underpinning the value of the model. The response format to the questions were a combination of multiple choice and open text.

Patient outcome measures

• Speech recognition scores. Speech tests were performed in a calibrated sound booth using a single speaker at head height with the patient seated 1 meter away at 0° azimuth.

• For speech testing in quiet (CNC words), recipients were tested in the unilateral aided condition using their preferred program (contralateral ear plugged) preoperatively and postoperatively. One 50-item list of monosyllabic CNC words was administered in quiet at 60 dBA and the percent correct word score recorded.

Speech testing in noise was done using one list of AzBio sentences in co-located noise at +10 dB SNR, S₀N₀, in the daily listening condition (two-ear) and using the recipient’s preferred noise program. Speech tests were performed at 3- and 6-months post activation in the daily listening condition and compared to aided baseline performance before implant.

Audiological measures

To demonstrate audibility across the frequency range, at 1, 3 and 6 months, aided audiometric thresholds in the sound field were obtained using narrow band noise and the standard audiometric technique at 250, 500, 1000, 2000, 3000, 4000, and 6000 Hz. T levels were adjusted if measured thresholds were not ≤25 dB HL.

Hearing goals

To understand patient-specific needs, the Client Oriented Scale of Improvement (COSI) questionnaire was administered preoperatively to define situations where hearing difficulties are experienced and to set personalized goals for hearing improvement following treatment with a CI (Dillon et al., 1997). The scale is completed in consultation with the clinician with the patient listing up to five specific situations in which they experience daily listening difficulties. The ability to hear in each of those situations was subjectively assessed by the recipient preoperatively and at 3-month and 6-month postactivation visits using a 5-point Likert scale (1 “Hardly ever-10%”, 2 “Occasionally-25%”, 3 “Half the Time-50%”, 4 “Most of Time-75%”, 5 “Almost Always-95%”).

Hearing satisfaction

At 6-months postimplantation, recipients completed a custom questionnaire that evaluated their hearing satisfaction in five common listening conditions in daily life: telephone use, listening to and appreciating music, hearing speech in background noise, small group conversations (3–5 people), and understanding speech on the TV. These were rated on a 5-point Likert scale (1 “Very Dissatisfied”, 2 “Dissatisfied”, 3 “Neutral”, 4 “Satisfied”, 5 “Very Satisfied”).

Service satisfaction survey

This survey was completed by newly-implanted CI recipients who completed the study at 12 months. The recipients were asked to rate the quality of service received from both the clinic and hearing health professional as either “Poor”, “Fair”, “Good”, or “Excellent”. They were also asked to rate how likely they were to recommend the clinic to a family or friend as either “Not likely at all”, “Not likely”, “Neutral”, “Likely” or “Very likely”. An electronic link to the patient survey was provided to each clinic participating in the study and the responses were anonymous.

Data analyses

Changes in speech recognition for CNC words and AzBio sentences were analyzed using linear mixed-effects models with timepoint (preoperative, 3, and 6 months) as a fixed factor (planned contrasts comparing preoperative vs. 3 and 3 months vs. 6 months) and participant as a random intercept. The dependent variables were percentage correct scores converted to rationalized arcsine units (Studebaker, 1985). A second linear mixed-effects model was conducted each for CNC words and AzBio sentences to examine the contrast preoperative vs. 6 months. Theoretical Likelihood Ratio Tests were conducted to test for significance of the fixed factor main effect.

CNC word recognition performance was subsequently analyzed based on whether recipients exhibited a clinically significant postoperative improvement relative to their preoperative performance. A clinically significant improvement was defined using a criterion of ≥20% and ≥30% improvement in CNC word recognition at 3 and 6 months, respectively, compared to preoperative performance (Buchman et al., 2020).

Hearing satisfaction ratings for each category (Television, Small Group Conversation, Background Noise, Music, and Telephone) were analyzed using one-sample Wilcoxon signed-ranks tests to determine whether recipients’ ratings were significantly satisfactory (i.e. > neutral).

Wilcoxon signed-rank tests were performed on COSI categories with multiple ratings to examine whether there was significant improvement at six months relative to preoperative baseline.

Results

Participant study flow

Audiologists were requested to follow a specified protocol for the delivery of the EBM approach, which was supported by checklists at each visit. The following protocol deviations were recorded:

• Unscheduled visits: 1 of the 17 participants required an additional appointment between initial activation and one month because the MAP was felt not to be loud enough, and two participants required an additional visit between 3 and 6 months due to a skin flap issue that required surgical intervention and because of a reduction in hearing performance and cognitive scores, respectively

• Lost to follow-up: one patient was lost to follow up after the 1-month visit

• Programming deviations: at the initial activation visit, 3 out of the 17 participants used NRT because of difficulty with the T and C measurements, which also explained deviations at the 1-month visit for 1 out of the 17 participants, and for 2 out of the 16 recipients at the 3-month visit.

Duration of appointments using the EBM and current clinical approaches

Based on clinicians’ responses to the baseline survey, for those CI recipients followed up using the routine clinical approach, clinics spent an average of 7.2 h (5.0–9.0) in the first year post implant. In contrast, clinics spent an average of 4.2 h (4.1–4.2) per CI recipient when using the EBM approach, indicating a mean total time saving of 3.0 h (0.8-4.8). A summary of the findings is provided in Table 3.

Table 3 Number and duration of visits using the existing standard approach and the EBM approach

Routine clinical approach*
Baseline	Clinic 1	Clinic 2	Clinic 3	Average (SD)
No. of visits in first year post implant	7	6	6	6.3 (0.6)
Mean total visit time, per recipient (hours/year) Range per visit (minutes)	7.5 60–90	9 60–120	5.0 30–60	7.2 (2.0)
EBM approach (n = 17)
No. of visits in first year post implant	4	4	4	4 (0.0)
Mean total visit time, per recipient (hours)	4.1	4.2	4.2	4.2 (0.1)
Reduction in mean total visit time with EBM approach (hours) Range per visit (minutes)	3.5 31–90	4.8 46–90	0.8 <30-90	3.0 (2.0)

*Number and duration of appointments based on clinicians’ responses to the baseline survey question, “How much time is scheduled for each visit type (in minutes).” Types of visits listed were initial activation, 1, 2 weeks, 3, 6, 9 and 12 months. For each applicable visit, clinicians selected the time from 30 mins to 120 mins (given in 10-minute intervals).

Speech recognition scores

CNC word recognition results are depicted in Fig. 1. The results of the linear mixed-effects models showed a significant main effect of timepoint (AIC = 421.6 compared to 480.8, p < 0.001) with preoperative performance significantly improved at three months (b [95% CI] = 53.3 [37.1, 69.6], SE = 8.1, t = 6.6, p < 0.001) and six months (b [95% CI] = 64.6 [49.3, 80.0], SE = 7.5, t = 8.6, p < 0.001). Performance at six months was also significantly higher than at three months (b [95% CI] = 9.0 [3.6, 14.4], SE = 2.7, t = 3.3, p < 0.01).

Figure 1 CNC word scores over time. Box spans depict first and third quartile (25th and 75th percentiles), and whiskers depict the minimum and maximum scores. Descriptive statistics for each timepoint are: preoperative (M = 12.9, SD = 14.6, range 0–44, sample size = 17), 3 months (M = 56.5, SD = 21.6, range 12–86, sample size = 15), 6 months (M = 71.1, SD = 16.6, range 40–96, sample size = 16). *indicates significant pairwise comparison (p < 0.01). ** indicates significant pairwise comparison (p < 0.001).

CNC word recognition performance was subsequently analyzed based on whether participants exhibited a clinically meaningful postoperative improvement relative to preoperative performance as defined in the data analysis section.

Postoperative CNC data were not collected for two participants at the 3-month visit and one participant at the 6-month visit. Of the remaining participants, 80% (12/15) met the criterion for clinically meaningful benefit at three months, and 87.5% (14/16) met the criterion for clinically meaningful benefit at six months. Figure 2 depicts the proportion of patients who exhibited a clinically meaningful benefit at 3 (Fig. 2a) and 6 months (Fig. 2b).

Figure 2 Proportion of participants who met vs. not met the ≥20% improvement and ≥30 improvement criteria for a clinically meaningful improvement at 3 months (panel A) and 6 months (panel B), respectively.

AzBio sentence recognition results are depicted in Fig. 3. The results of the linear mixed-effects models showed a significant main effect of timepoint (AIC = 391.5 compared to 416.3, p < 0.001) with preoperative performance significantly improved at three months (b [95% CI] = 28.5 [18.0, 39.0], SE = 5.2, t = 5.5, p < 0.001) and six months (b [95% CI] = 31.2 [13.8, 48.5], SE = 8.5, t = 3.7, p = .001). There was no difference between performance at 3 and 6 months (b [95% CI] = 5.3 [−1.7, 12.3], SE = 3.5, t = 1.5, p = 0.134).

Figure 3 AzBio +10 dB SNR sentence recognition scores over time. Box spans depict first and third quartile (25th and 75th percentiles), and whiskers depict the minimum and maximum scores. Descriptive statistics for each timepoint are: preoperative (M = 32.7, SD = 23.7, range 0–84, sample size = 14), 3 months (M = 56.8, SD = 25.7, range 8-93, sample size = 14), 6 months (M = 58.9, SD = 28.0, range 18-100, sample size = 15). * indicates significant pairwise comparison (p < 0.01); n.s. indicates nonsignificant pairwise comparison (p > 0.05).

Hearing goals

A total of 26 unique responses from 11 participants to the COSI were recorded and categorized by the research team based on the 16 categories of the COSI questionnaire (Dillon et al., 1997), resulting in 10/16 categories represented. Preoperative and 6-month COSI ratings are depicted in Fig. 4. Wilcoxon signed rank tests were performed on 5/10 categories with multiple ratings to examine whether there was significant improvement at six months relative to preoperative baseline. Results were statistically significant for Conversation with 1 or 2 in quiet (p = 0.026) and Familiar speaker on phone (p = 0.024) categories. All other tests failed to reach significance (p > 0.05), primarily due to small sample sizes (Conversation with group in noise n = 4; Hear front doorbell/knock n = 2; Other n = 3).

Figure 4 Bar graphs depicting mean COSI rating preoperative and at 6 months across 10 COSI categories. Error bars represent +/- 2 standard error. *Indicates categories in which ratings were significantly higher at 6 months compared to preoperative (p < 0.05). Sample sizes for each category are: Conversation with 1 or 2 in quiet (n = 6), Conversation with 1 or 2 in noise (n = 1), Conversation with group in quiet (n = 1), Conversation with group in noise (n = 4), Television/Radio (n = 1), Familiar speaker on phone (n = 6), Hear front door bell/knock (n = 2), Feeling left out (n = 1), Feeling upset/angry (n = 1), Other (n = 3).

Hearing and service satisfaction

Ratings of hearing satisfaction at six months are proportionally depicted in Fig. 5. Compared to the proportion of participants who were “dissatisfied” or “very dissatisfied”, there was significantly more who were “satisfied” or “very satisfied” with their hearing ability in the following listening situations: television (p = 0.002), small group conversation (p = 0.012), music (p = 0.023), and telephone (p = 0.007). Hearing satisfaction in background noise failed to reach significance (p = 0.179).

Figure 5 Hearing satisfaction ratings at 6 months for 5 listening categories. *Indicates categories in which ratings were significantly satisfactory (satisfied/very satisfied) vs. not satisfactory (neutral/dissatisfied/very dissatisfied) (p < 0.05).

In a separate survey, participants were also asked to rate their satisfaction with the services received from the clinic and their hearing health professional. Of the 14 respondents completing the survey, all (100%) rated the overall service delivered by the clinic as “excellent”; 13 (93%) rated the quality of care received by the clinician as “excellent” and one (7%) gave a rating of “good”. When participants were asked how likely they were to recommend the clinic to their family or friends, 13 (93%) responded that they were “extremely likely” and one (7%) responded “somewhat likely”.

Recipient use and interest in self-management tools and services

The EBM approach was developed with a complementary suite of supportive tools and services. Table 4 outlines how recipients engaged with these aids. Most of the recipients who owned a Smartphone device expressed an interest in using Remote Check, with 71% responding that they would be “extremely likely” or “likely” to use this tool. There was less engagement with supportive services offered by Engagement and Recipient Services managers.

Table 4 Recipient engagement with self-management tools and services

Supportive tools and services	Proportion of CI recipients
Interested in Remote Check
Yes	70.6% (12/17)
No	29.4% (5/17)
Interacted with an Engagement Manager
Yes	23.5% (4/17)
No	76.5% (13/17)
Interacted with a Recipient Services Manager
Yes	41.2% (7/17)
No	58.8% (10/17)

Discussion

Our experience has shown that the EBM approach for streamlining CI aftercare was appropriate for 70–80% of adult CI recipients enrolled in this assessment, as the majority (14 out of 17 recipients) were able to follow the four-appointment schedule without deviation. Of the three recipients who required additional visits, one was due to cognitive function screening that suggested a need for further management (results not shown) and a reported reduction in self-perceived hearing performance. For the second recipient, the extra visit was for further MAP refinements, and the third recipient experienced skin flap complications. These findings indicate that for the remaining 20-30% of cases with additional or more complex needs, supplementary care via a personalized approach is warranted.

It is therefore important that recipients are counseled to contact their audiology team when issues arise so that they can be managed and treated appropriately. For those CI recipients who live some distance from the clinic, the option of conducting a remote consultation (if available) could provide additional reassurance should there be a specific concern to address. For instance, telehealth options, such as Cochlear™ Remote Check, can be used to help troubleshoot a perceived problem and to develop a treatment plan prior to the CI recipient returning to the clinic when needed.

Indeed, one of the study recipients used Remote Check following a self-perceived decline in their hearing at the conclusion of the study. Using this digital tool allowed an assessment of their aided hearing CI performance. A lack of agreement between the recipient’s subjective assessment and the Remote Check findings flagged the need for further investigation. Consequently, an in-clinic appointment was scheduled, during which a significant decline in the hearing of the non-implanted ear was identified. Counseling on the potential option for a second CI was undertaken and an appointment for CI surgery arranged following the patient’s decision to proceed. This case illustrates how the integration of remote telehealth technologies, such as Remote Check, can be used to enable the clinician to identify and perform the necessary timely reviews and patient triage, especially for patients in need of in person and in clinic attention to address their hearing needs.

Overall, 8 out of 17 recipients (47%) in this study opted to use Remote Check, which was part of a suite of digital tools and support services available with the EBM approach to aftercare. These individuals ranged in age (33–72 years of age) and duration of hearing loss (5–53 years) and reported that it was very easy to use and much simpler than what they had anticipated (not shown). These findings highlight that age and assumption of tech savviness should not be used to preclude counseling and providing access to remote-based options. Rather, it suggests that clinicians consider informing and educating CI recipients on the potential benefits of remote tools as part of their care, and provide the option and guide on its use as and when needed.

Based on the newly-implanted patient group enrolled, all three participating clinics experienced a mean reduction in clinic time for follow-up visits within the first year compared to routine care follow-up schedules. Specifically, they were able to reduce the total patient chair time in the first year by an average of 3.0 h (range of 0.8–4.8 h) per patient. From a clinical workflow perspective, this time saving may allow for more CI recipients to be assessed and offer a more personalized approach to treatment using existing clinical resources. Indeed, when we reflect on the experience of one clinic as an example, when they implemented the four-appointment EBM protocol in early July 2021, the total per patient hours in the first year dropped from an average of 7.5 (range of 1–1.5 h) to 4.1 (range of 0.5–1.5 h). This allowed the clinic to increase their patient capacity with the same clinic staff resources. During a 6-month time frame, almost a doubling of the number of patients (n = 107) were seen for assessment compared to six months earlier (n = 58), with both time intervals occurring outside the restrictions of the COVID-19 pandemic. For patients, the reduced number of scheduled in-clinic visits in the first year may translate into less travel time, time off work and need for childcare support, with a corresponding reduction in the financial burden associated with in-clinic attendance.

As part of the EBM approach, approximately 80% of recipients met hearing milestones for CNC words and AzBio sentences at +10 dB SNR testing at 3 and 6 months. These test results show a similar trend in post-CI outcomes in newly-implanted patients who were managed using the routine in-clinic approach, across all three clinics. Furthermore, these findings support existing literature that show a similar trend in CI outcomes of newly-implanted recipients managed using routine assessment schedules (Grisel et al., 2022). Grisel et al. explored CI performance over time to identify patients who could be safely followed up with a less intense schedule. They created a data model for expected CNC performance at defined time intervals (preoperative, 1, 3, 6, 12, and 24 months after initial activation) for adult CI recipients. In the high performer group (defined as those with ≥ 50% CNC correct) the mean group CNC scores at 3- and 6-months were 69.6% and 68.3%, respectively. While we cannot draw firm conclusions due to limitations of cross study comparisons, similar trends in CNC performance were seen among patients followed up using this de-escalated EBM approach, with mean CNC scores of 56.5% and 71.1% at 3- and 6-months, respectively.

Performance outcomes within the first year are also aligned with observations reported for the CI-adult cohort enrolled in the Nucleus CI532 benchmark study, despite the participants being seen more often for monitoring and programming (Buchman et al., 2020; Kelsall et al., 2021). Collectively, these data support the management of CI recipients via the four-appointment schedule during the first year postimplant.

It was perhaps reassuring that all newly-implanted recipients were satisfied with the overall clinical services provided by the EBM approach with 100% rating it as ‘excellent’. This suggests that the reduced number of visits did not raise issues in the quality of care received through this model.

Limitations of this proof-of-concept study include the small sample size and the small number of participating clinics, as well as a lack of a formal control group of existing CI recipients receiving aftercare via the conventional schedule at each clinic. Additionally, all the clinicians were very experienced with CI recipient care, which may have biased our findings. Conversely, those less familiar with managing CI recipients may have responded differently. Clinician experience and additional assessments of hearing performance and or complementary functions may be used to help the clinician to determine if a patient is an appropriate candidate for the EBM approach or not.

In conclusion, the four-appointment EBM approach delivered efficient and effective audiological aftercare to CI recipients in the first year following CI implantation. Further research involving more patients with a range of profiles and clinicians with varying clinical experience will help inform this aftercare model for broader clinical application. The encouraging first experiences of the EBM approach in this proof-of-concept study are aligned with observations reported by larger CI centers who are also moving to a similar, more streamlined clinical delivery model of four appointments in the first year post-CI implantation (Gifford, 2022). Considered potentially more sustainable in the long term, these delivery models offer an evidence-based, personalized approach that may help maximize clinical efficiency while maintaining quality of care for all CI recipients.

Disclaimer statements

Contributors SP contributed to the study design, patient evaluation, data analyses, manuscript development and review; DMB contributed to the study design, patient evaluation, data analyses and manuscript review; JG contributed to the study design, patient evaluation, data analyses and manuscript review; KR contributed to the study design, patient evaluation, data analyses and manuscript review; BB contributed to the study design, data analyses and manuscript development and review; PR contributed to data analyses and manuscript development and review; RSH contributed to the study design, patient evaluation, data analyses, manuscript development and review

Funding This work was supported by Cochlear Americas, CO, United States.

Conflicts of interest No potential conflict of interest was reported by the author(s).

Ethics approval WIC IRB CAM-SOC-EBM01-2020337.

Acknowledgements

The authors would like to thank the patients and support staff in each clinic for their participation in this study. We would also like to thank Beejal Vyas-Price and Josie Wyss (Cochlear Ltd) for medical writing support.