The Rotterdam AMblyopia Screening Effectiveness Study (RAMSES): compliance and predictive value in the first 2 years

BACKGROUND: RAMSES is a 7 year follow up study, aiming at the evaluation of the effectiveness and the efficiency of screening for amblyopia. In this first report, concerning the first 2 years of life, the compliance with the prevention programme and the positive predictive value (PPV) of the screening tests used, are presented. METHODS: All results of the standardised screening test for strabismus, applied by child healthcare physicians, within a birth cohort of 4072 Rotterdam children at the age of 9, 14, and 24 months, were registered. Children with a positive test result were referred to their general practitioner, who was asked to arrange a definitive referral to an ophthalmological centre. The results of the examinations at these centres were registered in standardised forms and served as reference for establishing the PPV. RESULTS: The screening was (at least one time) attended by 3958 children (97%). 160 of these children (4%) were referred, of whom 101 (64%) visited an ophthalmological centre, so that a conclusive diagnostic evaluation was possible. For amblyopia, the predictive value of a positive test result followed by an effective referral was 0.42. CONCLUSION: Referral procedures after a positive test result in the Dutch child healthcare screening programme for amblyopia need to be improved. The Dutch screening test used to detect amblyopia exhibits a relatively favourable PPV.