Validation of the reporting bases of the orthopaedic and paediatric surveillance schemes.

BACKGROUND Nationally representative estimates of treatment rates for congenital dislocation of the hip were required to inform a review of the current United Kingdom screening policy. Cases were ascertained through an active reporting scheme involving orthopaedic surgeons and the existing British Paediatric Association Surveillance Unit (BPASU) scheme. OBJECTIVE To report the methods used to establish, maintain, and validate the orthopaedic and BPASU schemes. METHODS Multiple sources were used to develop the orthopaedic reporting base. Surgeons treating children were identified by postal questionnaire. The orthopaedic and paediatric reporting bases were compared to the 1992 manpower census surveys of surgeons and paediatricians. RESULTS A single source of respondent ascertainment would have missed 12% of the 517 surgeons who treated children. Comparison with the manpower census data suggests the orthopaedic and paediatric reporting bases were 97% and 92% complete. CONCLUSIONS Multiple sources should be used to establish and maintain a reporting base. Targeting respondents avoids unnecessary contact, saves resources, and may improve compliance. Manpower census data can be used for regular validation of the reporting base.