2015 HSC Section 1 Book of Articles

HANG ET AL. / EAR & HEARING, VOL. 36, NO. 1, 8–13

Lost to follow up

11

CI not recommended due to co-morbidities

3

CI not recommended due to residual hearing

0

Received CI

91

0 10 20 30 40 50 60 70 80 90 100

Fig. 2. Clinical outcomes of all included patients.

TABLE 3. Age at ABR diagnosis and timing to behavioral audiometry testing and CI surgery

Age (Months) at Testing/Intervention

Time (Months) Between Testing/Interventions

ABR to Behavioral Testing 0–13 4.71 (2.7) Variable† N/A Variable† N/A

Behavioral Testing to CI Surgery

Behavioral Testing 6–36 10.04 (5.0) 5–131* 34.58 (27.9) 5–131 20.29 (22.0)

ABR to CI Surgery 3–38 10.78 (5.0) 0–22 4.49 (4.9) 0–38 8.15 (5.8)

N (%)

ABR

CI Surgery

Diagnostic ABR (dABR) Confirmatory ABR (cABR)

53 (58.2)

1–36 5.40 (6.2)

8–41 15.98 (6.5) 6–136 40.32 (28.2) 6–136 26.14 (22.3)

1–28 5.87 (3.8) 1–18 5.20 (3.7) 1–28 5.59 (3.8)

38 (41.8)

4–131 35.79 (28.4) 1–131 18.09 (24.1)

Overall

91

For each category, range as well as average and (SD) are shown. *First reliable audiometric data closest to date of NR ABR. †Audiometric data may have been obtained before or after ABR. ABR, auditory brainsem response; CI, cochlear implantation.

is obtained and referral to the CI team is made, the amount of time until CI surgery remains fairly constant regardless of age at initial ABR. The middle graph of Figure 3 shows no sig- nificant correlation between age at ABR testing and time from behavioral testing to CI surgery ( p = 0.713), with average time interval of 5.87 months (SD 3.8). This suggests that delays in progressing to CI in a timely fashion likely arise during the time between dABR testing and reliable behavioral testing when referral to the CI team is made. Only 15 (34.0%) children had more than 1-year duration between the dABR and CI surgery. Reasons for the long elapsed time within this group included delays in behavioral testing because of middle ear pathology ( n = 7), need for other medical interventions ( n = 4), lost to follow-up or scheduling conflicts ( n = 7), and/or parental choice ( n = 1). Appropriate progress with amplification ( n = 0) and too much residual hearing ( n = 0) did not account for delays in this group of children. DISCUSSION Universal NBHS has greatly improved early identification of children with hearing loss. dABR testing allows clinicians to estimate auditory thresholds for the purposes of fitting amplification at a much earlier age than behavioral testing. Despite the advances in early diagnosis, many congenitally deaf children do not receive hearing aids or CIs until 2 years of age or older. The benefits of early intervention in the form of amplification and CI have been described in numerous studies.

testing was 18.09 months (SD 24.1, range 1–131). The overall mean age at the time of CI surgery was 26.14 months (SD 22.3, range 6–136). Since referrals to the CI team are based on behavioral audiometry, not surprisingly the time from behavioral testing to CI surgery for both the dABR and cABR groups is similar, 5.87 versus 5.20 months, respectively. The time from ABR to CI surgery is lowered for the cABR group since many of the ABRs were performed on the day of sur- gery to rule out ANSD and confirm behavioral audiometric test results. To further characterize how the CI evaluation process is affected by the age at ABR testing, only the data from the chil- dren with dABRs were considered for the statistical analysis. Figure 3 shows the relationship between the various time inter- vals between interventions and age of ABR for the dABR group. The correlation coefficient ( r ) was graphically demonstrated for each relationship. Although children progressed through the CI evaluation process at varying rates, those who presented at later ages progressed to CI faster than younger patients. As depicted in the bottom graph of Figure 3, there is a statistically significant negative correlation between age at ABR testing and time to CI surgery ( r = −0.335, p = 0.014). This is, of course, is confounded by the fact that older children are able to perform behavioral testing sooner than younger children as seen in the top graph of Figure 3, which shows a clear negative correlation between time of ABR testing and time to behavioral testing ( r = −0.593, p = <0.001). Once confirmatory behavioral testing

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