Prevalence of childhood hearing impairment in the County of Stockholm – a 40-year perspective from Sweden and other high-income countries

Hearing impairment after asphyxia and neonatal encephalopathy: a Norwegian population-based study

The purpose of this study is to evaluate the association between perinatal asphyxia, neonatal encephalopathy, and childhood hearing impairment. This is a population-based study including all Norwegian infants born ≥ 36 weeks gestation between 1999 and 2014 and alive at 2 years (n = 866,232). Data was linked from five national health registries with follow-up through 2019. Perinatal asphyxia was defined as need for neonatal intensive care unit (NICU) admission and an Apgar 5-min score of 4-6 (moderate) or 0-3 (severe). We coined infants with seizures and an Apgar 5-min score < 7 as neonatal encephalopathy with seizures. Infants who received therapeutic hypothermia were considered to have moderate-severe hypoxic-ischemic encephalopathy (HIE). The reference group for comparisons were non-admitted infants with Apgar 5-min score ≥ 7. We used logistic regression models and present data as adjusted odds ratios (aORs) with 95% confidence intervals (CI). The aOR for hearing impairment was increased in all infants admitted to NICU: moderate asphyxia aOR 2.2 (95% CI 1.7-2.9), severe asphyxia aOR 5.2 (95% CI 3.6-7.5), neonatal encephalopathy with seizures aOR 7.0 (95% CI 2.6-19.0), and moderate-severe HIE aOR 10.7 (95% CI 5.3-22.0). However, non-admitted infants with Apgar 5-min scores < 7 did not have increased OR of hearing impairment. The aOR for hearing impairment for individual Apgar 5-min scores in NICU infants increased with decreasing Apgar scores and was 13.6 (95% CI 5.9-31.3) when the score was 0.          Conclusions: An Apgar 5-min score < 7 in combination with NICU admission is an independent risk factor for hearing impairment. Children with moderate-severe HIE had the highest risk for hearing impairment. What is Known: • Perinatal asphyxia and neonatal encephalopathy are associated with an increased risk of hearing impairment. • The strength of the association, and how other co-morbidities affect the risk of hearing impairment, is poorly defined. What is New: • Among neonates admitted to a neonatal intensive care unit (NICU), decreased Apgar 5-min scores, and increased severity of neonatal encephalopathy, were associated with a gradual rise in risk of hearing impairment. • Neonates with an Apgar 5-min score 7, but without NICU admission, did not have an increased risk of hearing impairment.

Estimated prevalence of permanent hearing loss among newborns and 6-year-olds: An evaluation of the three auditory screenings in Uppsala

OBJECTIVES

This study estimated the permanent hearing loss (PHL) prevalence among newborns and 6-year-olds in the Uppsala region (Sweden), compared how different definitions affected this estimation, and evaluated the outcome of the three hearing screening occasions for children.

METHODS

A retrospective investigation of medical records and audiograms was conducted for children born in 2011-2012. Data extraction was performed when the children had reached 7 years of age. Hearing loss was defined as > 20 dB hearing level in at least one frequency (125-8000 Hz) in one or both ears (clinician's definition).

RESULTS

A total of 1385 children were included, and 95 were diagnosed with PHL. The prevalence of bilateral PHL at 6 years was 5.50 per 1000 children based on the clinician's definition, 3.74 per 1000 children based on the World Health Organization (WHO) 2021 definition, and 2.64 per 1000 children based on the WHO 1991 definition. Adding unilateral PHL resulted in a total prevalence of 10.11 (clinician's definition) and 6.16 (WHO 2021) per 1000 children.

CONCLUSION

This study demonstrates the necessity of repeated hearing testing during childhood to identify PHL and suggests a higher prevalence in 6-year-olds than previously reported. The definition of PHL greatly impacted its estimated prevalence.

Protocol and programme factors associated with referral and loss to follow-up from newborn hearing screening: a systematic review

Background

An effective newborn hearing screening programme has low referral rate and low loss to follow-up (LTFU) rate after referral from initial screening. This systematic review identified studies evaluating the effect of protocol and programme factors on these two outcomes, including the screening method used and the infant group.

Methods

Five databases were searched (latest: April 2021). Included studies reported original data from newborn hearing screening and described the target outcomes against a protocol or programme level factor. Studies were excluded if results were only available for one risk condition, for each ear, or for < 100 infants, or if methodological bias was observed. Included studies were evaluated for quality across three domains: sample, screening and outcome, using modified criteria from the Ottawa-Newcastle and QUADAS-2 scales. Findings from the included studies were synthesised in tables, figures and text.

Results

Fifty-eight studies reported on referral rate, 8 on LTFU rate, and 35 on both. Only 15 studies defined LTFU. Substantial diversity in referral and LTFU rate was observed across studies. Twelve of fourteen studies that evaluated screening method showed lower referral rates with aABR compared to TEOAE for well babies (WB). Rescreening before hospital discharge and screening after 3 days of age reduced referral rates. Studies investigating LTFU reported lower rates for programmes that had audiologist involvement, did not require fees for step 2, were embedded in a larger regional or national programme, and scheduled follow-up in a location accessible to the families. In programmes with low overall LTFU, higher LTFU was observed for infants from the NICU compared to WB.

Conclusion

Although poor reporting and exclusion of non-English articles may limit the generalisability from this review, key influential factors for referral and LTFU rates were identified. Including aABR in WB screening can effectively reduce referral rates, but it is not the only solution. The reported referral and LTFU rates vary largely across studies, implying the contribution of several parameters identified in this review and the context in which the programme is performed. Extra attention should be paid to infants with higher risk for hearing impairment to ensure their return to follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03218-0.

Postnatal hearing loss: a study of children who passed neonatal TEOAE hearing screening bilaterally

BACKGROUND

Universal newborn hearing screening (UNHS) contributes to the early diagnosis of hearing loss. However, not all permanent pediatric hearing impairments can be identified by UNHS.

AIMS/OBJECTIVE

To investigate children who have successfully passed the UNHS, but have later-onset hearing loss at an early stage.

METHODS

UNHS of children, was reviewed retrospectively from databases at Karolinska University Hospital, Sweden. Gender, age, the reason for contact, the first contact and the most recent audiogram, the hearing diagnosis, the degree of hearing loss when they were enrolled in hearing rehabilitation, and the hearing aids they used were analysed.

RESULTS

63 children who had passed the UNHS at birth and were diagnosed with a hearing impairment at a later stage were included in the study. The average age was 3.3 and 3.9 years old when the children were diagnosed and were finally enrolled in the hearing habilitation, respectively. The reasons for diagnostic evaluation of a suspected hearing loss at present study are preschool hearing tests at the Child Health Care Centres, parents suspect, and/or delayed speech and language development.

CONCLUSIONS AND SIGNIFICANCE

Our findings suggest that a passed UNHS does not exclude a future delayed onset of hearing loss, particularly in children with risk factors.

Newborn Hearing Screening and Intervention in Children with Unilateral Hearing Impairment: Clinical Practices in Three Nordic Countries

Studies have limitedly considered children with early-identified unilateral hearing impairment (UHI), and clinical practices regarding screening, diagnostics and habilitation in this group are rarely documented. In this study, routines for newborns with UHI from screening to diagnostics and habilitation were explored in Norway, Sweden and Finland. An online survey was sent to hospitals responsible for the hearing diagnostics of children requesting information about their practices regarding congenital UHI. Responses covered 95% of the children born in the three included countries. The results revealed large variations in ways of organising healthcare and in clinical decisions regarding hearing screening, diagnostics and habilitation of children with congenital UHI. Finally, implications for policy making and research are also discussed.

Hearing impairment among children in Sweden with foreign-born parents and natives: A national Swedish study

AIM

We aimed to estimate the risk of hearing impairment in children and adolescents with foreign-born parents, compared to natives.

METHODS

A nationwide study of 1,923,590 (51.4% boys) individuals aged 0-17 years of age in Sweden. Hearing impairment was defined as at least one registered diagnosis in the National Patient Register between 1 January 1998 and 31 December 2015. We used Cox regression analysis to estimate relative risk (hazard ratios with 99% confidence intervals) of incident hearing impairment in children with foreign-born parents compared to Swedish-born natives. Cox regression models were stratified by sex and adjusted for age, co-morbidities and socioeconomic status.

RESULTS

A total of 20,514 cases (53.7% boys) with extended sensorineural hearing impairment were registered, also including noise-induced hearing impairment and that from other causes, and 6172 cases (50.0% boys) with conductive hearing impairment. The risk of extended sensorineural hearing impairment was higher in boys with parents from Asia, especially from Iraq, fully adjusted HR (99% CI) 1.30 (1.17-1.4), and lower in boys with parents from Nordic countries, South Europe, and North America.

CONCLUSION

The risk of extended sensorineural hearing impairment was higher in boys with parents from Asia, in particular Iraq.