Efficacy of a community-based infant hearing screening program in the Western Cape

Abstract

Apart from isolated programs in private and public health care sectors, South Africa has no existing systematic public infant hearing screening program at community level. As a result, early identification of hearing loss is certainly not being attained for the majority of infants in South Africa with far-reaching effects for individuals, families and society at large. Screening programs at primary health care immunization clinics have been proposed as an alternative to hospital-based programs in South Africa. The objective of this study was to evaluate the first systematic community-based infant hearing screening program in a developing South African community in the Western Cape. A combined descriptive and exploratory research methodology was followed incorporating aspects of a program evaluation design. The study was of a quantitative nature and the required data were collected by means of a questionnaire and OAE testing conducted by clinic nurses on subjects. A community-based universal infant hearing screening program initiated at eight primary health care clinics in the Cape Metropolitan area was evaluated over a 19-month research period. During this time 6227 infants who were candidates for screening attended their 6, 10 or 14-week immunization visit at the relevant clinic. Clinic nurses were trained as screening personnel. A two-stage distortion product otoacoustic emissions screening protocol was utilized. The target disorder for this study was bilateral permanent congenital and early onset hearing loss and infants referring the first screen were scheduled for a 4-week follow-up visit at the clinic. Diagnostic audiological and medical evaluations were scheduled at referral hospitals when indicated. The study evaluated the efficacy of the program based on coverage, referral and follow-up rates and diagnostic outcomes according to guidelines specified by the Health Professions Council of South Africa 2007 Position Statement. Overall coverage rate across the eight clinics was 32.4% with 2018 infants (aged 0- 14 weeks) screened. The mean age of the sample at first stage screen was 3.9 weeks of age and 13.5 weeks of age for first hospital visit. Overall first stage screen referral rate was 9.5% with 62 subjects (3%) referred for diagnostic services at hospital level after a follow-up screen. The average follow-up rate for rescreens at clinic level was 85.1% and for initial diagnostic assessments at hospital level it was 91.8%. Although minimal hearing loss was not the primary focus of the screening program the outcomes did include those subjects with fluctuating conductive hearing loss and permanent unilateral hearing loss. Prevalence rates were 4.5/1000 with significant hearing loss, including sensorineural (1.5/1000) and conductive (3/1000) losses, and 12.9/1000 for subjects with middle ear effusion.<p-> The community-based infant hearing screening program was valuable in attaining high follow-up return rates but reaching sufficient coverage may require dedicated screening personnel as opposed to existing nursing personnel. Furthermore, consideration of an alternative community-based platform such as midwife obstetric units may improve coverage and referral rates and prevalence of permanent congenital and early onset hearing loss.