Date Published: April 3, 2007
Publisher: Public Library of Science
Author(s): Bolajoko O Olusanya
Abstract: The number of children worldwide with hearing impairment is increasing, and these children face a number of social and educational obstacles.
Partial Text: The number of children worldwide with hearing impairment is increasing, and these children face a number of obstacles and burdens, given that spoken language is the predominant medium of communication and social interaction. Adequate auditory stimulation, in early childhood in particular, is the foundation for optimal speech and language development as well as the acquisition of literacy skills [1,2]. Failure to detect early and effectively manage within the first year of life a permanent hearing impairment that is congenital or that originates in the neonatal period has been associated with significant and irreversible deficits in speech and in linguistic, cognitive, and educational development [3,4].
The WHO global estimate for disabling hearing impairment (of a degree of severity >40 dBHL) has more than doubled from 120 million people in 1995 to at least 278 million in 2005 . Two-thirds of individuals with hearing impairment live in developing countries, and hearing impairment in 68 million people is estimated to have originated from childhood . About two to four babies per 1,000 live births are born annually in developed countries with permanent or sensorineural hearing impairment and this range may extend to six per 1,000 live births within the neonatal period in developing countries . Permanent hearing impairment is an etiologically heterogeneous trait attributable to genetic and environmental causes, half of which are probably preventable .
Every government has a duty to provide health care for its population. In many developed countries health-care services (including universal newborn hearing screening [UNHS]) are freely provided, although some individuals may opt for private health services. The free provision of UNHS in many developed countries perhaps underpins the expectation that such screening should also be publicly funded in developing countries. But most governments are unable to wholly finance such programs, given the competing demands from prevailing communicable and fatal diseases, and thus have to seek external support. Early hearing detection from birth has been noted as an important and achievable goal for all countries . But the failure to recognize childhood hearing impairment as a significant health condition for developing countries at the global level diminishes the prospects for publicly funded UNHS programs and may also divert attention away from the critical role of governments in facilitating private sector–led initiatives for the development of requisite services.
Various levels of government determine public health priorities, taking into account the proportion of total revenue available for health care. Because resources are limited, public spending in low-income countries tends to be entirely concentrated on sustaining health systems rather than providing intervention services. As governments have to rely on additional funds from external sources, national priorities are therefore commonly guided (and sometimes overwhelmed) by diverse interests of multilateral institutions (World Bank, UNICEF, WHO, etc.) and donor partners despite their modest contributions to total health expenditure (Table 1) .
The moral imperatives for providing early hearing intervention services, even in the absence of data on the cost-effectiveness of available interventions relative to other diseases, have been discussed in greater detail elsewhere . A few points are worth restating.
Current global health priorities for developing countries have yet to pay attention to the WHA resolution on hearing impairment, which acknowledges this condition in early childhood as a significant health problem. The prospects of any immediate action are uncertain, since vital data required by the current approaches to global disease prioritization are scarce and of limited value where available. Although external assistance constitutes a small proportion of total health expenditure in low- and middle-income countries, the priorities of multilateral/donor organizations still have a great influence on national health priorities and public sector–led systematic investment in requisite capacity-building for early hearing detection and intervention services. There is an urgent need therefore to stimulate public–private partnerships to preserve the collective/representative legitimacy of WHA resolutions, recognize individual health preferences through out-of-pocket spending, and ensure that those willing to take advantage of time-bound interventions for permanent and early-onset hearing impairment are not unduly disenfranchised by its current omission in the global health agenda for developing countries.