TY - JOUR
T1 - Intracluster correlation coefficient in multicenter childhood trauma studies
AU - Roudsari, Bahman
AU - Fowler, Raymond
AU - Nathens, Avery
PY - 2007/10
Y1 - 2007/10
N2 - Objective: To calculate the intracluster correlation coefficient (ICC) for emergency department (ED) shock rate, early trauma death (ie, death during the first 24 h after arrival at hospital), and in-hospital trauma death rate for multicenter childhood injuries. Methods: The National Trauma Data Bank (5th revision), the largest multicenter trauma registry in the US, was used. Data from 80 trauma centers were used to calculate the ICC for in-hospital trauma death rate. Thirty three states provided data for calculation of the ICC for ED shock and early trauma death rate. Results: From 2000 to 2004, 13% of the 952 242 patients in the National Trauma Data Bank were <15 years old. Approximately 17 000 of these children had injuries with an injury severity score >15, of whom 84% (14 095 subjects) were hospitalized at 80 level I or II trauma centers in 33 states. The ICCs for ED shock rate, early trauma death rate, and in-hospital death rate were 0.005 (95% CI 0.000 to 0.010), 0.014 (95% Cl 0.004 to 0.024), and 0.023 (95% Cl 0.013 to 0.033), respectively. These ICCs were calculated for boys and girls and also for blunt and penetrating injuries. Conclusion: Clustered childhood trauma studies that aim to compare different aspects of pre-hospital and hospital trauma care should incorporate these ICCs for sample calculation. When cluster randomized clinical trials are mounted, if sample sizes are calculated without adjustment for ICC, then the planned trial is likely to be seriously underpowered.
AB - Objective: To calculate the intracluster correlation coefficient (ICC) for emergency department (ED) shock rate, early trauma death (ie, death during the first 24 h after arrival at hospital), and in-hospital trauma death rate for multicenter childhood injuries. Methods: The National Trauma Data Bank (5th revision), the largest multicenter trauma registry in the US, was used. Data from 80 trauma centers were used to calculate the ICC for in-hospital trauma death rate. Thirty three states provided data for calculation of the ICC for ED shock and early trauma death rate. Results: From 2000 to 2004, 13% of the 952 242 patients in the National Trauma Data Bank were <15 years old. Approximately 17 000 of these children had injuries with an injury severity score >15, of whom 84% (14 095 subjects) were hospitalized at 80 level I or II trauma centers in 33 states. The ICCs for ED shock rate, early trauma death rate, and in-hospital death rate were 0.005 (95% CI 0.000 to 0.010), 0.014 (95% Cl 0.004 to 0.024), and 0.023 (95% Cl 0.013 to 0.033), respectively. These ICCs were calculated for boys and girls and also for blunt and penetrating injuries. Conclusion: Clustered childhood trauma studies that aim to compare different aspects of pre-hospital and hospital trauma care should incorporate these ICCs for sample calculation. When cluster randomized clinical trials are mounted, if sample sizes are calculated without adjustment for ICC, then the planned trial is likely to be seriously underpowered.
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U2 - 10.1136/ip.2007.015313
DO - 10.1136/ip.2007.015313
M3 - Article
C2 - 17916893
AN - SCOPUS:35548970267
SN - 1353-8047
VL - 13
SP - 344
EP - 347
JO - Injury Prevention
JF - Injury Prevention
IS - 5
ER -