Table 1

Ratio and 95% confidence interval (CI) of selected injury characteristics of the “frequent” injury group relative to the “once” group

Age (years)		0–2	6–8	12–14
Admission		0.85 CI 0.62–1.12	0.49 CI 0.38–0.63	0.58 CI 0.51–0.65
Boy		1.17 CI 1.12–1.22	0.95 CI 0.92–0.99	0.85 CI 0.83–0.87
Distance	<10 km	1.23 CI 1.19–1.26	1.22 CI 1.19–1.24	1.21 CI 1.20–1.23
Mechanism	Fall from higher level	0.89 CI 0.80–0.99	0.89 CI 0.82–0.97	0.88 CI 0.84–0.93
	Fall, other	1.00 CI 0.89–1.13	1.08 CI 1.00–1.17	0.96 CI 0.93–0.99
	Contact	1.12 CI 1.01–1.23	1.10 CI 1.04–1.16	1.13 CI 1.11–1.16
	Acute overexertion	1.92 CI 1.57–2.32	1.74 CI 1.49–2.01	1.26 CI 1.20–1.33
Place	Transport area	0.91 CI 0.68–1.19	1.01 CI 0.88–1.14	0.81 CI 0.77–0.86
	Residential area	1.03 CI 1.00–1.06	1.01 CI 0.96–1.06	1.07 CI 1.03–1.10
	Institution, school	0.81 CI 0.67–0.97	1.00 CI 0.94–1.06	1.03 CI 1.00–1.07
	Sports area	Too few	1.21 CI 1.05–1.39	1.10 CI 1.07–1.14
Injury	Superficial	0.98 CI 0.89–1.08	1.46 CI 1.38–1.53	1.33 CI 1.30–1.36
	Open wound	0.86 CI 0.78–0.94	0.56 CI 0.51–0.62	0.45 CI 0.42–0.48
	Fracture	0.80 CI 0.64–0.99	0.79 CI 0.71–0.87	0.70 CI 0.67–0.73
	Dislocation, sprain, and strain	1.82 CI 1.57–2.10	1.59 CI 1.45–1.74	1.25 CI 1.21–1.28
	Burn, corrosion	0.69 CI 0.50–0.92	0.70 CI 0.39–1.15	0.80 CI 0.63–1.00
	Poisoning	1.17 CI 0.76–1.72	0.59 CI 0.27–1.11	0.49 CI 0.28–0.80