Читать книгу Early Detection and Intervention in Audiology - Группа авторов - Страница 32

Luisa Petrocchi-Bartal, Katijah Khoza-Shangase and Amisha Kanji

This chapter explores the feasibility of implementing early detection of hearing impairment through infant hearing screening in various South African health care contexts, including both the public (primary, secondary and tertiary levels) and private health care sectors. These contexts and levels of service delivery are described, and the practicability and efficiency of implementing early hearing screening in each context discussed. Evidence indicates that: midwife obstetric units (MOUs) appear to be the most viable contexts for infant hearing screening; primary health care (PHC) immunisation clinics are appropriate platforms for screening, provided assets are fine-tuned and barriers formally addressed, especially regarding staffing; screening in the private hospital sector needs to be included as part of the birthing package, with full medical aid reimbursement; and aspects such as the availability of hearing screening space, ambient noise levels and discharge timing all influence the practicability and efficiency of screening in various health care contexts. The chapter illustrates that factors that facilitate or impede the feasibility of early hearing screening vary depending on the level of health care in South Africa. Finally, suggestions are made about how to maximise efficiency within each service delivery level.

When referring to early detection of hearing impairment as a component of child health care best practice, universal newborn hearing screening (UNHS) is regarded as the preferable means to do so (Kanji, Khoza-Shangase, Petrocchi-Bartal, & Harbinson, 2018). This is the first component of what is known as early hearing detection and intervention (EHDI), which has been implemented as best practice in many high-income countries, such as the United States of America, many European countries and China (Russ, White, Dougherty, & Forsman, 2010; World Health Organization [WHO], 2010). However, its implementation has significantly lagged behind in low and middle-income (LAMI) contexts such as Africa (Health Professions Council of South Africa [HPCSA], 2018). In South Africa, reasons for this include resource constraints (Kanji, Khoza-Shangase, Petrocchi-Bartal et al., 2018; Tandwa, 2017; World Bank, 2018), demand versus capacity challenges (Khoza-Shangase, 2019), poverty and inequality (Olusanya, 2005; World Bank, 2018), as well as prioritisation of medical conditions where preservation of life is placed first (Kanji, Khoza-Shangase, Petrocchi-Bartal et al., 2018), such as tuberculosis (TB) and HIV/AIDS, which are highly prevalent (Day, Gray, & Ndlovu, 2018; Streefland, 2005; United Nations Childrens' Fund, 2013; World Bank, 2018). Hearing impairment is considered of secondary importance, as its issues relate more to quality of life than to survival. It is perhaps for these reasons that EHDI and UNHS have not become a legal requirement in South Africa.

The International Monetary Fund (IMF, 2018) describes South Africa as a middle-income economy with an emerging market. Despite significant post-apartheid progress in many spheres of the countrys' development, service delivery, especially regarding health care, has been done in pockets, with little integration between government and private health care sectors (Störbeck & Moodley, 2011). Part of this non-standardised approach relates to the application of EHDI in the South African context: it has not been mandated at a government level (Kanji, Khoza-Shangase, Petrocchi-Bartal et al., 2018), as in many high-income countries, and it appears that mostly non-systematic and non-standardised risk-based hearing screening occurs (Kanji & Khoza-Shangase, 2016). This takes place in a context of significant health care challenges, discussed by Khoza-Shangase in chapter 5. Besides lack of a government mandate for UNHS, these challenges include demand versus capacity issues, resource constraints, a high burden of disease with which EHDI has to compete, as well as poor social determinants of health. Chapter 5 sounds a call for a ‘doing better with less’ approach to ensure that EHDI occurs. This is a realistic approach to adopt in resource-constrained contexts as it is viewed as being cost-effective.

Evidence demonstrates that up to 50 percent of hearing impairment in infants is missed when a targeted newborn hearing screening approach is adopted (Kanne, Schaefer, & Perkins, 1999). Kanji argues in chapter 3 that this approach nevertheless needs to be adopted in South Africa as an interim measure, as no formalised national system is currently in place. This would take into account the HPCSAs' (2018) recommendation for UNHS. Without EHDI and UNHS legislation, EHDI will continue to be relegated to secondary status and children with hearing impairment will be left to experience its negative consequences.

Hearing impairment has been shown to have a negative impact for the hearing-impaired individual on cognition (Olusanya, 2005), language development (Ching, 2015), literacy (DesJardin, Ambrose, Martinez, & Eisenberg, 2009), educational, social and emotional abilities (Northern & Downs, 1991; WHO, 2018), as well as vocational and financial outcomes (Olusanya, Ruben, & Parving, 2006; WHO, 2018). The negative consequences extend to the family of the hearing-impaired child, explored in more depth in chapter 11. These negative consequences emphasise EHDIs' importance to individuals, their families and to society as a whole (Kanji, Khoza-Shangase, Petrocchi-Bartal et al., 2018), as governments will ultimately be required to deal with the long-term negative ramifications of hearing impairment, be it in terms of cost or support. Government plans should thus cater for EHDI with the application of contextually relevant and effective screening measures to identify those with hearing impairment as early as possible. As argued by Kanji and Khoza-Shangase (2018a, 2019), consideration of the South African context extends to the use of contextually relevant risk factors (see chapter 6). Once effective identification has taken place, and factors that influence follow-up return rate (Kanji & Khoza-Shangase, 2018b) and compromise EHDI service delivery (Khoza-Shangase, 2019) have been addressed, early intervention can be successfully implemented to maximise the hearing-impaired individuals' potential at all levels of functioning. In high-income countries, it is recommended that post-diagnosis intervention is initiated by six months of age (Joint Committee on Infant Hearing [JCIH], 2000, 2007, 2019), while in South Africa it is by eight months of age (HPCSA, 2018).

The fastest, most cost-effective and simplest tool for hearing screening in the South African context is the use of otoacoustic emissions (OAEs), despite their known limitations (Kanji, Khoza-Shangase, Petrocchi-Bartal et al., 2018). These limitations include OAEs not being able to comprehensively assess hearing and the fact that they may be negatively affected by the external and middle ear status, such as the presence of vernix in the external auditory canal (Albuquerque & Kemp, 2001; Korres et al., 2003). Automated auditory brainstem responses (AABRs) may also be used as a hearing screening tool to better assess the auditory system and detect auditory neuropathy in this population (Kanji, Khoza-Shangase, Petrocchi-Bartal et al., 2018). Compared to OAEs, AABRs are, however, more expensive to conduct, take longer to administer (Choo & Meinzen-Derr, 2010) and require a greater level of expertise (Kanji & Khoza-Shangase, 2016). Depending on the specific health care context and the level of health care service delivery, such factors may impact hearing screening programme implementation.