Table 5 Incidence rate ratio (IRR) of the correlations between parachute injuries and other factors

 Plane

2.17^****

1.45–3.23

3.70^***

1.47–9.09

1.75

0.68–4.55

 Helicopter

1.00

Reference

1.00

Reference

1.00

Reference

 Side exit

2.22^****

1.59–3.13

1.79^***

1.25–2.56

2.13^****

1.43–3.23

 Rear exit

1.00

Reference

1.00

Reference

1.00

Reference

 Night

0.69

0.44–1.07

2.81^*

1.07–7.41

2.19

0.81–5.90

 Day

1.00

Reference

1.00

Reference

1.00

Reference

 With equipment

1.19

0.85–1.65

1.28

0.88–1.87

 Without

1.00

Reference

1.00

Reference

 Yes

4.47^****

2.52–7.91

3.55^****

2.00–6.31

3.43^****

1.93–6.12

 No

1.00

Reference

1.00

Reference

1.00

Reference

Wind speed (knot) Each 1 knot increase in wind speed

1.58^****

1.35–1.85

1.54^****

1.27–1.87

 ≥ 5

1.58^***

1.15–2.18

 < 5

1.00

Reference

Temperature (°C)

Each 1 °C increase in temperature

1.18^****

1.07–1.31

 ≥ 32

1.06

0.78–1.44

 < 32

1.00

Reference

 NCO

0.75

0.33–1.67

 Cadet

1.04

0.45–2.40

 Officer

1.00

Reference

 ≥ 25.00

1.34

0.78–2.30

 23.00–25.00

1.05

0.72–1.52

 < 23.00

1.00

Reference

 ≥ 29

1.53

0.48–4.86

 24–29

1.29

0.44–3.77

 20–24

1.36

0.49–3.80

 < 20

1.00

Reference