Audiological and Subjective Benefit Results in Bone-Anchored Hearing Device Users

Transcription

1 Otology & Neurotology 00:00Y00 Ó 2012, Otology & Neurotology, Inc. Audiological and Subjective Benefit Results in Bone-Anchored Hearing Device Users *Maria Soledad Boleas-Aguirre, *Maria Dolores Bulnes Plano, *Iñigo Ruiz de Erenchun Lasa, and Berta Ibáñez Beroiz *Department of Otolaryngology, Complejo Hospitalario de Navarra; and ÞCentro de Investigación Biomédica (Fundación Miguel Servet), Pamplona, Spain Objective: Audiological and subjective benefits in adult boneanchored hearing device users. Study Design: Retrospective evaluation. Setting: Tertiary referral center. Patients: Thirty-eight adult subjects fitted with unilateral boneanchored hearing device. Interventions: Audiometric measurements included soundfield pure-tone and speech audiometries (speech reception threshold, maximum speech discrimination). Subjective benefit was assessed by the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. Ipsilateral and contralateral hearing loss was considered. Comparison was drawn between Compact, Divino, and Intenso processors. Main Outcome: To compare sound-field pure-tone and speech audiometries and APHAB results with and without the device adjusted for the unaided results. Results: With the device, sound-field pure-tone audiometry results revealed an increase gain in all frequencies. Sound-field speech audiometry showed that the mean threshold of speech recognition was 20 db lower, maximum discrimination was attained at 5 db less, and percentage of maximum discrimination increased by 5%. Scores in the APHAB questionnaire decreased except for the aversiveness subscale. Auditoryadjusted gain showed greater benefit in subjects with ipsilateral conductive hearing loss. Subjects with contralateral normal hearing or conductive hearing loss showed greater improvement that those with contralateral mixed or sensorineural hearing loss. There were no differences between Compact, Divino and Intenso processors. Conclusion: When comparisons are adjusted for unaided condition, the bone-anchored hearing device provided auditory and subjective benefit in subjects with ipsilateral conductive hearing loss and contralateral normal hearing or conductive hearing loss. It gave marginal benefit in ipsilateral mixed and contralateral mixed or sensorineural hearing loss. No differences were found between the Compact, Intenso, and Divino processors. Key Words: Abbreviated Profile of Hearing Aid BenefitV Bone-anchored hearing devicevhearing satisfaction. Otol Neurotol 00:00Y00, When reconstructive surgery or conventional air conduction hearing aids cannot offer a satisfactory functional outcome, particularly in chronically draining ears, aural atresia, and external auditory canal (EAC) stenosis, boneconduction devices are suitable. Several research groups have shown the effectiveness of bone-conduction devices in such clinical situations (1). The bone-anchored hearing devices are surgically implantable osseointegrated systems introduced in 1977 and approved for general use by the U.S. Food and Drug Administration in 1996 (2). The implanted systems consist of a titanium screw anchored to the cranial bone, an external abutment, and a sound processor (3). Owing to Address correspondence and reprint requests to M. Soledad Boleas- Aguirre, M.D., Ph.D., Centro de Consultas Externas Príncipe de Viana, Suite 132, Inrularrea, 3, Pamplona, Spain; msboleas18@ gmail.com The authors disclose no conflicts of interest. the direct percutaneous coupling of the vibration transducer to the titanium implant, the bone-anchored hearing devices provide a route for bone-conducted transmission of sound to the cochlea, bypassing the external ear canal and middle ear (4). These devices have shown to be safe and provide improvement in hearing and quality of life for patients with unilateral sensorineural and bilateral conductive hearing losses (3Y6). Owing to the improving audibility, localization, and speech recognition in noise, the boneanchored hearing devices are an attractive option for potential use in adults with unilateral acquired conductive hearing loss (7) and children (3). In fact, individuals diagnosed with severe or profound unilateral sensorineural hearing loss pose a management challenge. Previous reports suggest that semi-implantable bone-conduction sound transmission is useful to overcoming some of the hearing difficulties associated with severe and profound unilateral sensorineural hearing loss (8) and it also 1

2 2 M. S. BOLEAS-AGUIRRE ET AL. improve subjects satisfaction (9,10), although there are some controversy (11). It is expected that the degree of hearing rehabilitation with the bone-anchored hearing device depends on the type of deafness not only in the implanted ear but also in the unaided ear. Patients who experience conductive or mixed hearing loss at both sides are more likely to rely on semi-implantable boneconduction for hearing than those experiencing singlesided deafness (4). Many types of standardized and informal instruments have been used by audiologists to assess patients satisfaction and quality of life with hearing amplification (12) and specifically to assess subjective benefit with semiimplantable bone-conduction (4,8,13,14). In particular, the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire has been used to assess subjective benefit in its users (15Y17). The main purpose of this study was to evaluate auditory benefit and subjective satisfaction in adult fitted with a unilateral bone-anchored hearing device presenting with mixed or conductive hearing loss in the implanted ear and with different auditory profiles in the contralateral ear (normal hearing, mixed, conductive, or sensorineural hearing loss). This study relates hearing loss in the implanted ear to the hearing situation in the unaided ear for both audiological and satisfaction results. Furthermore, it takes into account differences in baseline levels between the groups of patients compared (results without the device). Therefore, all comparisons had been adjusted for the hearing and APHAB results without the device to attribute differences to compared groups. MATERIALS AND METHODS Patients This is a retrospective study conducted in an otologic referral center (Ear Division, Otolaryngology Department, Complejo Hospitalario de Navarra, Pamplona, Spain). It includes 38 adult patients fitted with a unilateral bone-anchored hearing device (Cochlear Limited, Sydney, Australia) between 2002 and Male-to-female ratio was 18:23 and subjects ages ranged from 25 to 81 years (interquartile range, 46Y72 yr). Regarding hearing level in the implanted ear, 50% of patients (n = 19) presented with conductive hearing loss and 50% (n = 19) experienced mixed hearing loss. Neither of the included patients benefited from conventional air conduction hearing aids use in the implanted ear. Pure-tone audiograms in the contralateral ear revealed normal hearing in 18% of cases (n = 7), sensorineural hearing loss in 23% of subjects (n = 9; including 1 case of profound deafness), conductive hearing loss in 29.5% of cases (n = 11), and mixed hearing loss in 29.5% of patients (n = 11; Table 1). Concerning the reason for the hearing troubles in the implanted ear, 74% of subjects (n = 28) suffered from chronic otitis media, 13% of cases (n = 5) presented with congenital unilateral aural atresia, 11% of cases (n = 4) had unilateral ear canal stenosis, and 3% of cases (n = 1) were issued of unsuccessful otosclerosis surgery with residual conductive hearing loss. Methods Audiometric measurements included sound-field pure-tone audiometry and sound-field speech audiometry. They were taken at clinical consultation with and without the semi-implantable bone-conduction sound processor fitted in place. Air-conduction thresholds in sound-field pure-tone audiometry at frequencies 0.5, 1, 2, and 3 khz were recorded using calibrated warble tones. Hearing improvement was calculated by subtracting the aided thresholds at different frequencies from air-conduction thresholds without the device. Speech audiometry was performed using a list of bisyllabic spondees Spanish words to calculate the speech reception threshold and maximum speech discrimination (% and db). Sound stimuli were delivered from 2 loudspeakers placed at horizontal azimuth of 0 degrees. All the measurements were performed/ conducted in sound-treated double-walled booths by 2 experienced audiologist nurses. Subjective hearing benefits were assessed with the APHAB questionnaire. It is a useful tool for quantifying the disability associated with hearing loss and the reduction of the disability with amplification (9). The APHAB is a hearing disabilityy specific questionnaire that assesses auditory functioning with 24 items scored in four 6-item subscales. It produces scores for unaided and aided conditions, and benefit is calculated by comparing the patient s reported difficulty in the unaided condition with their difficulty with amplification. Three of these subscales address speech understanding in various everyday environments: ease of communication (EC, under relatively favorable conditions), listening under reverberant conditions (RV, communication in reverberant rooms), and listening in background noise (BN, in settings with high background noise levels). The aversiveness (AV) of sounds subscale measures the negative reactions to environmental sounds. The APHAB has a scoring scale from 1 to 99; the higher the score, the greater the hearing disability (16,18). According to previous studies, an overall difference in the scores of more than 10 points for a given subscale (EC, RV, BN, and AV) was considered statistically significant (19). In this study, we compared hearing disability with and without the semi-implantable bone-conduction device by means of the APHAB questionnaire. We used the APHAB translation to Spanish (Form A) that is provided by the University of Memphis Web site (20). Most patients (31) were asked to fill out the TABLE 1. Number of patients according to the type of hearing loss in the ear wearing the bone-anchored hearing device and in the contralateral ear Hearing loss in contralateral ear Profound Mixed Sensorineural Normal Conductive Total Hearing loss in aided ear Mixed Conductive Total

3 BONE-ANCHORED HEARING AND SUBJECTIVE RESULTS 3 TABLE 2. Baseline characteristics of the patients Variable Categories n (%) Age, median (interquartile range) 63 (47Y73) Sex Males 17 (45%) Females 21 (55%) Ear Right 21 (55%) Left 17 (45%) Etiology Chronic otitis media 28 (74%) EAC atresia 5 (13%) EAC stenosis 4 (11%) Otosclerosis 1 (3%) Surgical technique Dermatome 31 (82%) Linear incision 7 (18%) Hearing loss in ear with the device Conductive 19 (50%) Mixed 19 (50%) Hearing loss in contralateral ear Normal hearing 7 (18%) Sensorineural 9 (24%) Conductive 11 (29%) Mixed 11 (29%) Follow-up Q1 yr 37 (97%) Q3 yr 25 (65.8%) Processor Compact 10 (26%) Divino 17 (45%) Intenso 11 (29%) questionnaire at clinical consultation. We mailed the questionnaire to the remaining patients. We compared the audiometric and subjective benefit results between 3 sound processors: Compact, Divino, and Intenso. In the group of patients included in this study, 10 subjects (26%) were fitted with the Compact sound processor, 17 (45%) with the Divino, and 11 (29%) with the Intenso processor. All subjects were regularly seen on clinical consultation for follow-up. We assessed short-term use at 1 year after implantation and long-term use at 3 years after implantation. Other authors have reported similar short-term and long-term use follow-up periods (8,21). Surgical techniques to implant the titanium abutment were dermatome made skin flap in 31 cases and linear incision in 7 cases. Surgical complications were evaluated at follow-up regular clinical consultations. They included skin flap problems such keloid formation in 1 case, and skin regrowth around the titanium abutment in 3 patients. All skin problems appeared in cases in which the dermatome skin flap surgical technique was used to implant the titanium abutment. Moreover, there was 1 case of secondary extrusion. All complications required surgical revision. Statistics Research design is a comparison of paired samples. The audiological and APHAB questionnaire data were summarized with medians and interquartile ranges. Comparisons between results with and without the bone-anchored hearing device were performed using the Wilcoxon signed rank test for paired samples because of the lack of normal distribution of data. To determine whether the gain (difference between the aided and the unaided conditions) in audiology and in APHAB questionnaire depends on the type of hearing loss in the implanted ear, on the type of contralateral hearing loss, and on the type of processor, the MannYWhitney and the KruskalYWallis test were used. In addition, to account for possible differences between groups in the basal levels (audiological and APHAB levels without the device), differences in the gains of the audiology and in APHAB scores between groups were also modeled using linear regressions that included the gains as the dependent variable, the group each patient belongs to as the factor variable, and the basal level scores as covariates. Indeed, to the crude comparison of the gain between groups, we have added and adjusted comparison derived from a regression model that accounts for differences in baseline levels that may be present among groups. Significance level was set at 5%. Statistical analysis was performed using the free statistical software R, version RESULTS Table 2 shows the descriptive data of the sample studied. Audiometric Results Concerning sound-field pure-tone audiometry results, the use of the semi-implantable bone-conduction device increased significantly thresholds at frequencies 0.5, 1, 2, and 3 khz (all p G 0.001), with gains in median values of 22, 33, 20, and 15 db, respectively. In other words, there was a significant mean increase gain in all frequencies using the bone-conduction hearing device (Table 3 and Fig. 1). TABLE 3. Comparison of audiometric and APHAB questionnaire results with and without the semi-implantable bone-conduction device Without With p Sound-field speech audiometry Speech reception threshold (db) 75 (55Y85) 55 (45Y65) G0.001 Maximum speech discrimination (db) 90 (78Y90) 85 (73Y90) Percent of maximum speech discrimination 95 (70Y100) 100 (90Y100) Sound-field pure-tone audiometry Air-conduction threshold at 0.5 khz 57 (29Y70) 35 (20Y40) G0.001 Air-conduction threshold at 1 khz 65 (43Y77) 32 (24Y45) G0.001 Air-conduction threshold at 2 khz 45 (35Y65) 25 (19Y40) G0.001 Air-conduction threshold at 3 khz 65 (50Y75) 50 (34Y61) G0.001 APHAB scales Ease of communication 70 (42Y99) 31 (15Y59) G0.001 Background noise 69 (52Y93) 55 (30Y67) Reverberation 81 (57Y93) 52 (32Y63) Aversiveness 29 (19Y48) 42 (28Y67) APHAB global score 64 (50Y76) 45 (37Y59) G0.001 Median values with interquartile ranges and Wilcoxon p values.

4 4 M. S. BOLEAS-AGUIRRE ET AL. FIG. 1. Sound-field pure-tone audiometry results with and without the bone-anchored hearing device. Results of sound-field speech audiometry revealed that speech recognition threshold improved significantly in the aided versus the unaided condition (Table 3 and Fig. 2), lowering down 20 db the median threshold for recognition (p G 0.001), and 5 db the median at which the maximum discrimination is attained (p = 0.004), whereas the percentage of maximum discrimination increased approximately 5% (p = 0.002). APHAB Questionnaire Results The APHAB questionnaire was fully answered by 27 (66%) of the 41 patients. Global APHAB score showed a significant decrease of 19 points (from 64% to 45%, p G 0.001) with the use of the bone-anchored hearing device versus without it. Similarly, the scores for all subscales decreased significantly with the device except for the aversiveness subscale, which increased 13 points (p = 0.045; Table 3). Hearing Loss in the Implanted Ear Table 4 shows hearing level and subjective benefit without the device and hearing and APHAB gains between aided and unaided conditions according to the type of hearing loss in the implanted ear. In the unaided situation, subjects presenting with ipsilateral conductive hearing loss had better auditory and subjective results than those with mixed hearing loss. The last 4 columns of Table 4 reveal that hearing and APHAB improvements with the bone-anchored hearing device are similar in both mixed and conductive groups regardless of their results without the device (crude gain). However, in subjects presenting with mixed hearing loss, there is a trend toward greater gain in the APHAB subscale EC (p = 0.078). FIG. 2. Sound-field speech audiometry results with and without the bone-anchored hearing device.

5 BONE-ANCHORED HEARING AND SUBJECTIVE RESULTS 5 TABLE 4. Hearing and APHAB results without the device and hearing and APHAB gains between aided and unaided conditions by type of hearing loss in the implanted ear Results without the device Gains Mixed a Conductive a Wilcox b Mixed a Conductive a Wilcox b p adj-value c Sound-field speech audiometry Speech reception threshold (db) 80 (75Y86) 60 (42Y85) (13 to 20) 20 (0 to 30) Maximum speech discrimination (db) 90 (90Y90) 90 (65Y90) (0 to 10) 5 (0 to 15) Percent of maximum speech discrimination 95 (55Y100) 95 (85Y100) (0 to 24) 0 (0 to 15) Sound-field pure-tone audiometry Air-conduction threshold at 0.5 khz 60 (50Y75) 40 (17Y65) (10 to 30) 30 (0 to 33) Air-conduction threshold at 1 khz 67 (59Y80) 55 (22Y72) (15 to 30) 30 (5 to 40) G0.001 Air-conduction threshold at 2 khz 57 (45Y69) 40 (15Y50) (10 to 25) 15 (3 to 25) Air-conduction threshold at 3 khz 65 (55Y80) 55 (45Y65) (4 to 16) 15 (10 to 25) APHAB scales Ease of communication 91 (64Y99) 46 (34Y74) (23 to 64) 18 (2 to 30) Background noise 85 (58Y93) 62 (31Y79) (15 to 36) 10 (6 to 29) Reverberation 89 (62Y93) 63 (40Y86) (6 to 31) 22 (10 to 43) Aversiveness 21 (19Y29) 44 (26Y57) j6 (j19 to j1) j9 (j28 to 5) APHAB global score 69 (57Y76) 55 (42Y70) (10 to 28) 11 (2 to 18) a Median values with interquartile ranges. b Wilcoxon test, p values. c Regression model p values for gain adjusted for hearing and APHAB scores without aid. Auditory gain adjusted for the audiometric basal level (without the device) showed greater benefit in subjects with conductive hearing loss for the decibel of maximum speech discrimination (p adj-value = 0.014) and for sound-field pure-tone audiometry at low frequencies (p adj-value = and p adj-value G 0.001). Hearing Loss in the Contralateral Ear Table 5 shows hearing and subjective benefit without the bone-anchored hearing device and hearing and APHAB results between aided and unaided conditions by type of contralateral hearing. The first 5 columns reveal that basal situation in patients presenting with contralateral normal hearing is better than those presenting with contralateral mixed, conductive or sensorineural hearing loss. The last 6 columns of Table 5 show the overall auditory and subjective gains with the device. Gross auditory gain (global benefit regardless of the unaided condition) is higher in those subjects presenting with contralateral conductive hearing loss than those with contralateral normal hearing. In particular, subjects with contralateral conductive hearing loss had higher improvement than patients with normal contralateral hearing in speech reception threshold, in sound-field pure-tone audiometry at frequencies 0.5, 1, and 2 khz, as well as in reverberation and global APHAB scores. Likewise, APHAB results in subjects presenting with contralateral mixed hearing loss revealed more subjective benefit than those with normal contralateral hearing loss in EC and global APHAB scores. In fact, patients with normal contralateral hearing loss do not seem to improve, with interquartile ranges containing the zero for all evaluations considered. Finally, results with the bone-anchored hearing device adjusted for the unaided condition are better at frequencies 0.5 and 1 khz in those subjects presenting with contralateral normal hearing or conductive hearing loss than in those with contralateral mixed or sensorineural hearing loss. Type of Sound Processor Hearing and APHAB results without the boneanchored hearing device and hearing and APHAB gain between aided and unaided conditions by processor are shown in Table 6. Preimplantation results in subjects fitted with the Compact processor are better than those fitted with the Intenso and Divino processors. Comparisons of the gain between aided and unaided conditions with different sound processors showed that the Compact provided significantly lower gain than Intenso and Divino processors in the percentage of maximum discrimination in speech recognition and in the EC score and in the RV score. Adjusted gain for auditory and APHAB results in nonaided conditions revealed no differences between the 3 processors. However, there are marginally better results in Divino and Intenso processors than in Compact. Etiology Table 7 shows hearing and APHAB results without the semi-implantable bone-conduction device and hearing and APHAB gain between aided and unaided conditions comparing subjects experiencing atresia or not. Gross gain (regardless the reason for the hearing troubles) was similar in both groups, although there is a trend toward lower gain in the atresia group. Subjects presenting with atresia have better results than the rests only in the AV score, and this difference is marginally significant. Gains adjusted for unaided results did not differ between groups, although subjects with atresia had slightly better results in the AV score. Use Rate Follow-up period ranges from 1 to 9 years. All patients were using the device within the first year after implantation

6 6 M. S. BOLEAS-AGUIRRE ET AL. TABLE 5. Hearing and APHAB results without the bone-anchored hearing device and hearing and APHAB gains between aided and unaided conditions by type of contralateral hearing loss Results without the device Gains Mixed a,b Sensori a,b Normal Conduct a,c KW d p Mixed a Sensori a,b Normal a Conduct c KW d p p adj-value e Sound-field speech audiometry Speech reception thresh (db) 85 (77Y90) 77 (64Y84) 35 (35Y40) 80 (62Y85) G0.001 f 15 (15 to 22) 20 (16 to 24) 0 (0 to 2.5) 30 (15 to 30) g Maximum speech discrimination (db) 90 (90Y90) 90 (90Y90) 60 (60Y63) 90 (90Y90) G0.001 f 5 (0 to 10) 7.5 (1 to 10) 0 (j2.5 to 5) 10 (5 to 15) Percent maximum speech 80 (50Y100) 100 (62Y100) 100 (100Y100) 88 (70Y95) (0 to 25) 0 (0 to 30) 0 (0 to 0) 12 (0 to 15) discrimination Sound-field pure-tone audiometry 0.5 khz 60 (51Y70) 72 (51Y70) 15 (12Y17) 65 (45Y67) f 20 (15 to 34) 30 (20 to 30) 0 (0 to 3) 30 (17 to 40) g h 1 khz 70 (62Y80) 67 (57Y77) 20 (15Y22) 70 (60Y80) f 25 (20 to 33) 23 (16 to 29) 0 (0 to 7) 40 (32 to 42) g h 2 khz 60 (50Y67) 57 (37Y75) 10 (2Y15) 45 (40Y50) f 15 (10 to 30) 15 (5 to 30) 0 (0 to 7) 20 (15 to 25) g khz 72 (62Y81) 65 (54Y76) 25 (22Y42) 65 (60Y75) f 10 (10 to 16) 15 (0 to 20) 5 (0 to 7) 20 (15 to 25) APHAB scores Ease of communication 99 (84Y99) 91 (81Y99) 31 (19Y39) 68 (54Y83) i 62 (37 to 80) 37 (23 to 50) 1 (0 to 10) 25 (12 to 64) j Background noise 93 (59Y94) 85 (58Y95) 41 (25Y64) 72 (56Y87) (24 to 37) 16 (15 to 20) j4 (j23 to 2) 23 (6 to 49) Reverberation 92 (84Y93) 81 (58Y93) 40 (23Y50) 83 (72Y89) i 29 (5 to 43) 20 (19 to 25) j11 (j14 to 11) 36 (24 to 68) g Aversiveness 19 (19Y22) 29 (19Y31) 50 (44Y70) 31 (25Y48) i j6(j14 to 4) j18 (j20 to j2) j16 (26 to 1) 0 (j12 to 8) APHAB global score 75 (65Y76) 69 (58Y76) 42 (31Y53) 67 (55Y72) i 27 (19 to 33) 11 (10 to 21) j5 (j8 to 1) 18 (17 to 41) g, j a Median values with interquartile ranges. b Sensorineural. c Conductive. d Kruskal-Wallis test, p values. e Regression p values for gain adjusted for hearing and APHAB scores without aid. f Significant differences between patients with contralateral type normal hearing and the rest. g Gain significantly higher in patients with contralateral hearing-type conductive than in patients with contralateral-type normal. h Gain significantly higher in patients with contralateral-type conductive and normal than in patients with contralateral mixed or sensorineural hearing loss. i Significant differences between patients with contralateral-type normal and the rest. j Gain significantly higher in patients with contralateral-type mixed than in patients with contralateral-type normal.

7 BONE-ANCHORED HEARING AND SUBJECTIVE RESULTS 7 TABLE 6. Hearing and APHAB results without the bone-anchored hearing device and hearing and APHAB gains between aided and unaided conditions by processor Results without the device Compact a Divino a Intenso a KW b p Compact a Divino a Intenso a KW a p p adj-value c Sound-field speech audiometry Speech reception 50 (35Y80) 75 (60Y85) 85 (75Y90) (0 to 25) 15 (10 to 30) 20 (5 to 25) thresh (db) Maximum speech discrimination (db) 65 (60Y90) 90 (87Y90) 90 (89Y90) (j1 to 6) 5 (0 to 15) 5 (0 to 6) Percent maximum speech discrimination 100 (100Y100) 95 (84Y100) 50 (49Y89) d 0 (0 to 0) 5 (0 to 16) 32 (11 to 41) e Sound-field pure-tone audiometry 0.5 khz 25 (15Y70) 50 (40Y65) 70 (56Y75) (0 to 30) 15 (5 to 30) 30 (20 to 35) khz 30 (20Y80) 65 (55Y70) 80 (65Y80) (0 to 30) 20 (15 to 40) 30 (20 to 35) khz 30 (5Y50) 45 (40Y55) 60 (47Y72) (0 to 25) 15 (10 to 20) 15 (10 to 35) khz 43 (25Y65) 63 (50Y65) 80 (70Y81) d 10 (4 to 22) 15 (6 to 23) 15 (10 to 17) APHAB scores Ease of communication 37 (21Y67) 59 (48Y88) 99 (93Y99) d 2 (0 to 10) 28 (14 to 73) 39 (26 to 59) e Background noise 66 (25Y77) 55 (46Y76) 93 (65Y95) j2 (j18 to 12) 25 (j1 to 47) 21 (17 to 34) Reverberation 40 (29Y67) 69 (61Y86) 93 (83Y93) d j11 (j13 to 22) 44 (12 to 62) 21 (9 to 37) e e Aversiveness 52 (37Y65) 26 (22Y46) 20 (19Y29) d j8(j22 to 7) j6 (j22 to 3) j4(j21 to 0) APHAB global score 54 (32Y64) 55 (48Y70) 76 (65Y76) j4 (j7 to 9) 17 (5 to 44) 19 (13 to 25) e a Median values with interquartile ranges. b Kruskal-Wallis test, p values. c Regression p values for gain adjusted for hearing and APHAB scores without aid. d Significant differences between patients with Compact processor and with Intenso and Divino processors. e Gain significantly higher in patients with Intenso and Divino processors than in patients with Compact processor. e Gain marginally significant and higher in patients with Divino and Intenso processors than in patients with Compact processor. Gains that is the short-term use period we considered. Twentyeight subjects had a 3-year follow-up period (long-term use). Twenty-six of them were still using the semiimplantable bone-conduction device at that point. Two subjects stopped wearing it because of the lack of subjective acoustic benefit. One of them experienced conductive hearing loss in the implanted ear and was fitted with a Compact processor. The other presented with mixed hearing loss in the ear fitted with an Intenso processor. DISCUSSION Nowadays, the bone-anchored hearing devices are considered a valuable tool for hearing restoration and TABLE 7. Hearing and APHAB results without semi-implantable bone-conduction device and hearing and APHAB gains between aided and unaided conditions comparing subjects experiencing atresia or not Results without the device Gains Atresia a Rest a Wilcox b Atresia a Rest a Wilcox b p adj-value c Sound-field speech audiometry Speech reception threshold (db) 45 (37Y57) 80 (57Y85) (4 to 10) 20 (5 to 27) Maximum speech discrimination (db) 68 (64Y75) 90 (85Y90) (2 to 9) 5 (0 to 10) Percent of maximum speech discrimination 100 (99Y100) 90 (70Y100) (0 to 1) 5 (0 to 22) Sound-field pure-tone audiometry Air-conduction threshold at 0.5 khz 22 (17Y36) 60 (40Y70) (0 to 27) 30 (5 to 32) Air-conduction threshold at 1 khz 22 (17Y40) 65 (52Y77) (1 to 29) 25 (15 to 37) Air-conduction threshold at 2 khz 25 (17Y41) 50 (40Y65) (2 to 35) 15 (10 to 25) Air-conduction threshold at 3 khz 50 (35Y50) 65 (50Y75) (2 to 27) 15 (10 to 20) APHAB scales Ease of communication 39 (32Y60) 78 (52Y99) (17 to 38) 28 (4 to 62) Background noise 58 (41Y72) 69 (52Y93) (4 to 51) 18 (2 to 29) Reverberation 58 (38Y70) 82 (57Y93) (3 to 23) 20 (4 to 43) Aversiveness 44 (37Y44) 27 (19Y51) (24 to 32) 4 (j4 to 18) APHAB global score 50 (39Y60) 66 (53Y76) (2 to 21) 17 (0 to 27) a Median values with interquartile ranges. b Wilcoxon test, p values. c Regression model p values for gain adjusted for hearing and APHAB scores without aid.

8 8 M. S. BOLEAS-AGUIRRE ET AL. quality of life improvement in patients with a wide variety of hearing loss etiologies as chronic otitis media and external or middle ear malformation when they cannot benefit from air-conduction hearing aids (5). The contribution of this work is to show both audiometric and subjective benefit of semi-implantable boneconduction devices in subjects presenting with ipsilateral conductive or mixed hearing loss and all types of auditory profiles in the contralateral ear (normal hearing, sensorineural, conductive and mixed hearing loss). Previous studies had shown either audiometric or subjective benefit (8,9,16,22,23) in some specific types of ipsilateral hearing loss. A few articles considered both audiological and quality of life results in bone-anchored hearing device adult users (11,14) or children (14,21,24). Only one of those articles reports results of pure-tone audiometry and speech audiometry as well as patient subjective benefit (14). In this sense, our data portrayed statistically significant improvements in nearly all audiometric results (sound-field pure-tone audiometry and sound-field speech audiometry) and subjective satisfaction measures. Results revealed an increase gain in all frequencies in pure-tone audiometry using the device. Likewise, sound-field audiometry results were better in mean threshold of speech recognition, level of maximum discrimination, and percentage of maximum discrimination. In all but one APHAB subscales scores, the bone-anchored hearing device use showed greater subjective benefit that the unaided condition. Another valuable aspect of this study is that it relates hearing loss in the implanted ear to the hearing situation in the unaided ear when it comes to consider auditory and subjective benefits. Only a small number of articles showed semi-implantable bone-conduction results relating both ipsilateral and contralateral hearing profiles (4,25). Moreover, these studies included a significant smaller number of subjects than the current study (19 and 21 vs 38). Finally, the greater contribution of this work is that benefits of the semi-implantable bone-conduction device are calculated taking into account auditory and subjective satisfaction preimplantation results. In fact, there may be differences in baseline levels (levels without the device), between groups of patients compared (groups formed by type of hearing loss in the implanted ear, type of contralateral auditory situation, and type of sound processor). These differences may produce a bias when comparing the gain of auditory levels and APHAB scores after implementing the device. To overcome this bias, we include some information that gives some insight to the cause of these differences. On one hand, we have added, for each group, the median levels without the device, and have compared them statistically. On the other hand, all comparisons had been adjusted for the hearing and APHAB results without the device aiming to ascribe differences to compared groups. Therefore, to the crude comparison of the gain between groups, we have added and adjusted comparison derived from a regression model that accounts for differences in baseline levels that may be present among groups. Influence of the Ipsilateral Hearing Condition on the Outcome Our study findings are consistent with those of other authors who state that audiological results in boneanchored hearing device users depend on preimplantation hearing level (15). Indeed, this survey results showed that semi-implantable bone-conduction device users with ipsilateral mixed and conductive hearing loss obtained auditory and subjective benefit regardless of their hearing condition in the contralateral ear. However, benefits are greater in patients experiencing ipsilateral conductive hearing loss when results are adjusted for the unaided condition. Some studies in the literature have focused on the audiological benefit of semi-implantable bone-conduction devices in subjects with congenital unilateral conductive hearing loss due to aural atresia. A review has been published in which the authors aimed to find some evidence to support the use of these devices in such patients. It showed that audiologic measures failed to predict patients success and/or satisfaction with their devices, although most of the studies included in this review reported that subjects perceived some benefits (13). Moreover, other authors found that some patients with congenital unilateral conductive hearing loss had good directional hearing and speech-in-noise scores in the unaided situation so that the bone-anchored hearing device did not provide significant improvement (26). Our series showed that benefit in subjects with congenital unilateral aural atresia and subsequent conductive hearing loss is similar to the other groups, although there is a trend toward lower gain in the atresia group probably because they had better results without the device. However, gains adjusted for unaided results did not differ between patients with atresia and the rest. Patients with unilateral air-bone gaps may experience deterioration in speech recognition performance owing to possible interference caused by amplification of the noise when presented on the same side of the bone-conduction hearing device. Nevertheless, it has been described in the literature that, for adults with EAC atresia, the use of semi-implantable conduction devices did not result in deterioration of performance when noise was on the side with the device and speech was delivered at the normal ear (13). Despite the fact that in our study, subjects with unilateral conductive hearing loss were a mixture of congenital and acquired cases, we found that there is no difference in benefit with the bone-anchored hearing device between subjects with congenital unilateral hearing loss due to atresia and the rest. A correlation between preoperative bone-conduction hearing threshold and postoperative aided threshold and audiological results in speech understanding has also been reported in semi-implantable bone-conduction device users. The authors obtained this correlation in patients with unilateral and bilateral conductive hearing loss and with bilateral mixed hearing loss (15). Likewise, the results of the current study revealed that subjects with conductive ipsilateral hearing loss have satisfactory audiometric results. Moreover, our results revealed that, when basal auditory

9 BONE-ANCHORED HEARING AND SUBJECTIVE RESULTS 9 conditions in the implanted ear are considered, subjects with conductive ipsilateral hearing loss have more benefit than those with ipsilateral mixed hearing loss. However, one would not expect such result because subjects with conductive hearing loss show better results without aid. Therefore, they have a shorter range for improvement. Effect of the Contralateral Hearing Condition on the Outcome This survey results showed that crude auditory gain (global benefit regardless of the unaided results) and APHAB results are better in those subjects presenting with contralateral conductive hearing loss than those with contralateral normal hearing. Likewise, APHAB results in subjects presenting with contralateral mixed hearing loss revealed more subjective benefit than those with normal contralateral hearing loss in EC and global APHAB scores. Moreover, some auditory results adjusted for the unaided condition are better in subjects presenting with contralateral normal hearing and conductive hearing loss than in those with contralateral mixed or sensorineural hearing loss. Regarding these findings, it would be particularly worth considering the auditory condition in the implanted ear of these subjects with contralateral normal hearing and contralateral conductive hearing loss. Patients presenting with contralateral normal hearing had conductive hearing loss in 86% of cases (n = 6) and mixed hearing loss in 15% of cases (n = 1). All subjects presenting with contralateral conductive hearing loss had conductive hearing loss also in the aided ear (Table 1). These findings are consistent with our results that showed greater improvement in subjects with ipsilateral conductive hearing loss than in those with mixed ipsilateral hearing loss. Despite these results, our study is prone to evaluation of the hearing benefit provided by the boneanchored hearing device when presenting noise and speech to the aided or unaided ear. In fact, it has been suggested that speech recognition, particularly in noise, could be compromised in patients with unilateral hearing loss when the noise is placed near the better ear and the speech near the poorer ear (13). Patients Satisfaction To assess semi-implantable bone-conduction users satisfaction, the authors have used several self-reported questionnaires including the APHAB questionnaire (5). The current study showed that the global APHAB decreased by 19 points with the device versus without it. Likewise, the scores for all subscales decreased significantly except for the aversiveness subscale, which increased. These results are similar to those published in the literature finding improvement in the short-term global APHAB score and all subscale scores except for theaversiveness subscale (8,10). In the same way, it has been shown that the bone-anchored hearing device provides better results specifically on the ease of communication subscale (25). However, at long-term follow-up, APHAB results were worse with respect to overall APHAB average as well as to the ease of communication and background noise subscales scores (8). According to our results, APHAB scores for the aided condition did not differ significantly by type of hearing loss in the ear using the device even when adjusting the results for the unaided condition. However, there is a trend toward higher gains in APHAB EC score for the mixed hearing loss group than for the conductive one. This difference was not statistically significant probably because of the high variability of the scores among patients and the sample size. In this study, the APHAB questionnaire was used as a tool to measure a change over time in the subjects satisfaction. Therefore, it is worth considering that its results could be biased by the different average follow-up of the groups compared. The group of contralateral normal hearing subjects has a shorter follow-up because this is a more recent indication for the use of the boneanchored hearing device. Similarly, Compact processor users have a longer follow-up than those using the Divino and Intenso because the latter two became available to the market only more recently. In fact, long-term use would reflect more precisely true satisfaction owing to a more experienced opinion. Influence of Different Sound Processors on the Outcome Comparing the gain between aided and unaided conditions with different sound processors, this study showed that the Compact device provided lower gross gains than the Intenso and Divino. This finding would be explained by the fact than preimplantation results in subjects fitted with the Compact processor are better than in those using the Intenso and Divino processors. Therefore, Compact users in this case would have a shorter range for improvement owing to a ceiling effect. In fact, when comparisons are adjusted for the results of the unaided condition, there were no differences between the Compact, Divino, and Intenso processors. Previous studies comparing hearing benefit with different bone-anchored hearing sound processors highlighted the fact that the Intenso processor provided better results than Divino in a questionnaire assessing subjective hearing device satisfaction (2). However, our survey analysis did not find differences in the audiometric results and in the APHAB scores between the Compact, Intenso, and Divino processors, although there was a trend toward higher gains in the Intenso and Divino than in the Compact group. Increasing the number of subjects included in each group would probably allow finding some statistically significant differences as previously described in the literature. CONCLUSION To conclude, in this study, semi-implantable boneconduction use revealed auditory benefit and subjective satisfaction with high short-term and long-term use rates. When comparisons are adjusted for unaided results, the bone-anchored hearing device provided greater auditory and subjective benefit in subjects with ipsilateral

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