Table 5 Risk estimates of putative exposures (OR and 95%CI)

Age

18 or less years

51

1

1

1

1

19 years

62

1.6 (0.7–3.4)

1.7 (0.8–3.5)

2.2 (0.9–5.0)

2.0 (0.8–5.1)

20 years

46

2.9 (1.2–7.2)

3.6 (1.5–8.7)

4.5 (1.9–10.8)

3.4 (1.3–9.0_

21 years

42

3.0 (1.2–7.6)

3.2 (1.3–7.6)

3.5 (1.5–8.5)

2.4 (1.0–6.5)

22 years

14

2.0 (0.6–7.4)

1.5 (0.4–4.9)

0.5 (0.1–2.5)

0.9 (0.7–4.8)

23+ years

35

2.0 (0.8–5.1)

2.1 (0.9–5.2)

3.1 (1.2–7.7)

2.5 (0.9–6.9)

Gender

0.9 (0.5–1.6)

0.9 (0.5–1.6)

0.9 (0.5–1.5)

1.0 (0.5–1.7)

Occupational exposure

Low

84

1

Medium

83

1.4 (0.5–3.9)

High

83

1.3 (0.8–1.6)

Sports Exposure

Low

84

1

Medium

83

0.9 (0.4–1.8)

High

83

1.2 (0.9–1.5)

Length of study >1

175

2.4 (1.2–5.0)

2.3 (1.4–2.6)

2.0 (1.1–3.6)

1.2 (0.7–2.4)

Height >171 cm

172

1.1 (0.3–4.2)

Weight >63 kgs

176

1.1 (0.5–2.2)

BMI > 21.25

177

1.3 (0.7–2.2)

Fitness

Poor

29

1

1

1

Moderate

132

1.8 (0.8–4.1)

1.7 (0.6–3.7)

2.2 (0.8–6.1)

Good

89

1.6 (0.7–3.7)

1.3 (0.6–3.2)

1.7 (0.6–4.9)

Educational exposures

>20 hrs sitting looking straight ahead

55

0.8 (0.5–1.4)

0.7 (0.4–1.3)

>20 hrs sitting looking down most of the time

58

2.4 (1.4–4.1)

1.7 (0.9–3.1)

>20 hrs practicing techniques on someone else

102

1.5 (0.9–2.7)

1.3 (0.7–2.4)

>20 hrs having techniques practiced on you

98

1.9 (0.9–3.6)

1.7 (0.8–3.4)

>20 hrs treating patients

126

1.9 (1.1–3.6)

2.1 (1.1–4.1)