Identification of incident fractures: the Geelong Osteoporosis Study

BACKGROUND: Complete fracture ascertainment is critical for fracture cost estimates and planning for future health care facilities. Virtually complete ascertainment is possible for hip fractures because they nearly always require hospitalisation. AIMS: To validate the use of radiological reports as a resource for ascertaining fracture cases, using hip fracture as a model. METHODS: Hip fracture rates obtained from radiological reports were compared with rates obtained from hospital discharge summaries of medical records using International Classification of Diseases-9 (ICD-9) codes 820.0-820.9 and 733.1 over a three-year period. RESULTS: Hip fracture cases numbered 589 using radiological reports and 585 using medical records. Discharge summaries failed to identify 15 cases ascertained through radiology reports whereas 11 cases ascertained through medical records were not identified from X-ray reports. The age-specific incidence rates for radiological ascertainment were within the 95% confidence limits of the rates derived from medical records. CONCLUSIONS: Among a population of patients generally admitted to hospital for treatment of their fracture, we were able to identify more cases from radiological reports than from medical records. Incidence rates for hip fracture were comparable using the two methods. Radiological reports provide a valuable resource for identifying incident fractures. This method of case ascertainment would be suitable for identifying both major and minor fractures in regions with self-contained health services where access to all radiological reports is possible.