Page 42 - DISINVESTMENT AND IMPLEMENTATION OF VISION SCREENING TESTS BASED ON THEIR EFFECTIVENESS

CHAPTER 2
DISCUSSION
This study showed that large differences exist in tests used, age, and frequency of testing in paediatric population-based vision and hearing screening programmes throughout the EU. First measurement of VA varies from ages 3-7, but in most countries it is measured before age five. In children aged 3-4, picture charts, including Lea Hyvarinen, are used most; in children over four Tumbling E and Snellen. Vision screening is performed mostly by paediatricians, ophthalmologists, or nurses. As a first hearing screening test, OAE is used most in healthy neonates, and ABR in premature newborns. The majority of hearing testing programmes are staged. Children are referred after one, two, three, or four abnormal tests. Funding is by health insurance, state, regions, municipalities, charity, hospital, parents or private funding. A high coverage is reached in most countries for both vision and hearing screening.
Our study was limited by the difficulty in obtaining referenced or first-hand data sources from respondents. Where possible we tried to maintain the quality of our data by involving clinicians involved in population based screening, and cross-checking their answers with those from general screening professionals. Obtaining accurate information on funding and coverage was the most difficult. Information on tests, personnel, and age was easier to acquire. Coverage may have been overestimated by the country representatives
Screening for vision and hearing deficits has similarities, but also differences. An essential difference is that objective tests are available for hearing screening at a very early age, enabling screening directly after birth. This is probably the reason for the more uniform approach and higher coverage reported for hearing screening compared to vision screening. We assumed that the personnel operating the screening apparatus at the hospital or during home visits would be a technician, so we did not ask the profession explicitly. The only two tests for hearing screening are OAE and aABR, so the major difference in hearing screening is the number of screening stages before referral. Multiple stage screening is more expensive, but yields higher specificity, which reduces the number of false referrals to specialized and expensive audiological care centres.23,26 There are most frequently two or three stages of screening before referral, generally with OAE as the first test and aABR as last test. It has been suggested that three stages may be more cost-effective,26 but this is not based on combined use of OAE and aABR. Pre-school or early school-age hearing tests may potentially discover hearing loss acquired during the years after birth, but this occurs rarely and these tests have been abolished in many European countries.
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