Referral criteria for school-based hearing screening in South Africa: Considerations for resource-limited contexts

Ambient noise limits efficacy of smartphone-based screening for hearing loss in children at risk

OBJECTIVE

To determine if hearScreen®, a smartphone-based pure tone audiometric screen, serves as an effective hearing screen for identifying hearing loss in children at risk, such as those with chronic otitis media and/or craniofacial anomalies.

METHODS

A cross-sectional, single-center, prospective study at an urban tertiary care hospital was completed. From June to October 2019, a total of 208 pediatric ears at risk for hearing loss were evaluated by both hearScreen® and conventional pure tone audiometry. The efficacy of hearScreen® for detecting hearing loss in a pediatric population at risk was determined.

RESULTS

A total of 208 pediatric ears at risk for hearing loss were screened. HearScreen® demonstrated a sensitivity of 85%, a specificity of 41%, a positive predictive value of 36%, and a negative predictive value of 87%. Subgroup analysis stratified by hearing loss type showed that hearScreen® screens for conductive hearing loss with increased sensitivity.

CONCLUSIONS

This investigation suggests that hearScreen® may serve as a an accessible, low-cost, and sensitive pure tone audiometric screen for hearing loss in children at risk, particularly those with conductive hearing loss, with the caveat that it may generate a high proportion of false positives due to the influence of ambient noise, especially when screening at 500 Hz. Future investigations should weigh the utility of including 500 Hz in the screening protocol as well as assess methods that may mitigate the influence of ambient noise during a pure-tone audiometric screen.

Contextually appropriate school entry hearing screening protocol for low- and middle-income countries: A scoping review

BACKGROUND

In low- and middle-income countries (LMICs), where universal newborn hearing screening programmes are often not available, school entry hearing screening programmes serve as a safeguard for early detection and intervention for hearing loss in school learners.

OBJECTIVE

To determine a contextually appropriate school entry hearing screening protocol for LMICs.

METHODS

A scoping review was utilised to comprehensively search for relevant publications in the following electronic databases: Africa-Wide Information, CINAHL, Health Source: Nursing/Academic Edition, Cochrane Library, Pubmed, Scopus, and Web of Science. Studies included those that investigated school-based hearing screening protocols or programmes for LMICs among learners aged five to twelve years. The review was conducted and reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews checklist.

RESULTS

The search yielded 1863 studies, and after removing duplicates and ineligible studies, 19 studies were selected for data extraction. Pure tone audiometry screening was the most frequently used age-appropriate hearing screening test in the reviewed studies (n = 17). Conducting pure tone audiometry screening using 1, 2, and 4 kHz frequency combination resulted in referral rates ranging from 3.2% to 21%. In studies that included 0.5 kHz to the screening frequencies, referral rates ranged from 5.8% to 56%. Screening at 25 dB HL intensity level yielded referral rates ranging from 3.2% to 10.3%. Immediate rescreening reduced overall referral rates for learners referred for audiological diagnostic testing by up to 57%. Ambient noise levels were controlled by conducting screening in quiet rooms (n = 14) and utilising screening equipment that allows for monitoring and reducing environmental noise (n = 3).

CONCLUSION

An ideal school entry hearing screening protocol in LMIC contexts could potentially utilise pure tone audiometry screening at 1, 2, and 4 kHz, using 25 dB HL screening intensity level with an immediate rescreen for learners with a refer result. School entry hearing screening should be conducted in a quiet room, preferably using hearing screening equipment capable of monitoring ambient noise levels to reduce false positive referrals.

Referral Criteria for Preschool Hearing Screening in Resource-Constrained Settings: A Comparison of Protocols

Purpose This study aimed to describe and compare the performance of two screening protocols used for preschool hearing screening in resource-constrained settings. Method Secondary data analysis was done to determine the performance of two protocols implemented during a preschool hearing screening program using mobile health technology in South Africa. Pure-tone audiometry screening at 25 dB HL for 1000, 2000, and 4000 Hz in each ear was used by both protocols. The fail criterion for the first protocol (2,147 children screened) constituted a no-response on one or more frequencies in either ear. The second protocol required two or more no-responses (5,782 children). Multivariate logistic regression models were used to investigate associations between outcomes and protocol, age, gender, and duration. Results Fail rates for the one-frequency fail protocol was 8.7% (n = 186) and 4.3% (n = 250) for the two-frequency fail protocol. Children screened with the two-frequency fail protocol were 52.9% less likely to fail (p < .001; OR = 0.471; 95% confidence interval [0.385, 0.575]). Gender (p = .251) and age (p = .570) had no significant effect on screening outcome. A percentage of cases screened (44.7%) exceeded permissible noise levels in at least one ear at 1000 Hz across both protocols. True- and false-positive cases did not differ significantly between protocols. Protocol type (p = .204), gender (p = .314), and age (p = .982) did not affect the odds of being a true-positive result. Average screening time was 72.8 s (78.66 SD) and 64.9 s (55.78 SD) for the one-frequency and two-frequency fail protocols, respectively. Conclusions A two-frequency fail criterion and immediate rescreen of failed frequencies significantly reduced referral rate for follow-up services that are often overburdened in resourced-constrained settings. Future protocol adaptations can also consider increasing the screening levels at 1000 Hz to minimize the influence of environmental noise.

Assessment of hearing screening programmes across 47 countries or regions III: provision of childhood hearing screening after the newborn period

OBJECTIVE

To inventory provision and features of childhood hearing screening after the newborn period (CHS), primarily in Europe.

DESIGN

From each participating country or region, experts provided information through an extensive questionnaire: implementation year, age at screening, test method, pass criteria, screening location, screener profession, and quality indicators: coverage, referral, follow-up and detection rates, supplemented by literature sources.

STUDY SAMPLE

Forty-two European countries or regions, plus Russia, Malawi, Rwanda, India, and China.

RESULTS

CHS was performed universally with pure-tone audiometry screening (PTS) in 17 countries or regions, whereas non-universal CHS was performed in eight with PTS or whisper tests. All participating countries with universal PTS had newborn hearing screening. Coverage rate was provided from three countries, detection rate from one, and referral and follow-up rate from two. In four countries, universal PTS was performed at two ages. Earliest universal PTS was performed in a (pre)school setting by nurses (n = 9, median age: 5 years, range: 3-7), in a healthcare setting by doctors and nurses (n = 7, median age: 4.5 years, range: 4-7), or in both (n = 1).

CONCLUSIONS

Within universal CHS, PTS was mostly performed at 4-6 years by nurses. Insufficient collection of data and monitoring with quality indicators impedes evaluation of screening.

Mhealth hearing screening for children by non-specialist health workers in communities

OBJECTIVES

To compare outcomes of a community-based hearing screening programme using smartphone screening audiometry operated by specialist (School Health Nurses - SHNs) and non-specialist health workers (Community Health Workers - CHWs) in school children.

DESIGN

This study used a two-group comparison of screening outcomes as conducted by SHNs and CHWs using smartphone screening for children in communities.

STUDY SAMPLE

The study included 71 CHWs and 21 SHNs who conducted community-based hearing screening on 6805 children. One thousand one hundred and fifteen hearing screening tests were conducted by the CHWs and 5690 tests by the SHNs.

RESULTS

No significant difference in screening outcome was evident between CHWs and SHNs using a binomial logistic regression analysis considering age, test duration and noise levels as independent variables. Final screening result was significantly affected by age (p < 0.005), duration of test (p < 0.005) and noise levels exceeding at 1 kHz in at least one ear (p < 0.005). Test failure was associated with longer test duration (p < 0.005; B: 119.98; 95% CI: 112.65-127.30). CHWs had significantly (p < 0.005) longer test durations (68.70 s; 70 SD) in comparison to SHNs (55.85 s; 66.1 SD).

CONCLUSION

Low-cost mobile technologies with automated testing facilitated from user-friendly interfaces allow minimally trained persons to provide community-based screening comparable to specialised personnel.

Irish School Entry Screening referral trends and cohort comparison with preschool specialist referrals

OBJECTIVE

To analyse referral cohorts from School Entry Screening, Hearing (SHS) and Vision Screening (SVS) before and after documented changes. To compare referrals to pre-school specialists with subsequent group SHS outcomes.

DESIGN

Randomized cohort, audit analysis of Community Nursing Developmental and SES records (CHRs), plus Audiology file review for SHS referrals.

STUDY SAMPLE

Six hundred and sixty-eight mainstream pupils' CHRs were analysed in four birth cohorts, post-SES, using coded anonymized records.

RESULTS

Significant referral rate differences existed between SHS and SVS. SHS, not SVS, referrals were impacted by nursing staff changes but not by SHS protocol changes. Preschool Audiology referrals outnumbered SHS referrals. All PCHI children with amplification were detected prior to SHS. SHS program yielded conductive hearing loss only. Similar SHS referral rates occurred for pre-school Speech Language Therapy referrals compared to children not referred; just 16% of pre-school Speech Language Therapy primary referrals were referred on to Audiology.

CONCLUSIONS

SHS referral percentage fell slightly; SVS referral percentage remained unchanged. Low referral rates and low SHS hearing loss yield has modest impact upon Audiology services, but audiometrically screened referrals deserve higher priority. UNHS children born after 2011 create bigger Audiology service impact. International comparisons and European SHS research collaboration are encouraged.