Sensitivity and representativeness of a childhood injury surveillance system.

OBJECTIVE To determine the sensitivity and representativeness of the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP). SETTING The study was conducted in the Ottawa-Carleton region of Ontario, Canada (June through August, 1992). METHODS Surveillance system sensitivity was estimated by dividing the number of injured children attending the Children's Hospital of Eastern Ontario (the only CHIRPP center in Ottawa-Carleton) by the total number of emergency department attended childhood injuries in the region. CHIRPP representativeness was assessed by comparing the injuries missed by the system with those captured on social, demographic, and clinical factors. RESULTS Sensitivity was 65% (1552/2386). Missed and captured injuries were similar on sex, day, time of presentation, injury intent, and delay before presentation. Children older than 14 years, however, were more likely to be missed by the system; adjusted odds ratio 3.52 (95% confidence interval (CI) 2.87 to 4.32). Conversely, children admitted to hospital were less likely to be missed; adjusted odds ratio 0.43 (95% CI 0.23 to 0.80). CONCLUSION Given the systematic errors in capture, CHIRPP data should be used cautiously in studies of etiology.