Table 1 Odds ratio (OR) for cases and controls according to hair dyes use and regular exercise after multiple imputation

 No

(67.91)

(78.04)

1

1

1

 Yes

(32.09)

(21.96)

1.62 (1.12–2.34)*

1.75 (1.16–2.63)**

1.93 (1.17–3.17)*

 Never

(69.93)

(79.05)

1

1

1

  ≥ 60

(9.12)

(7.43)

1.39 (0.77–2.51)

1.18 (0.62–2.25)

1.35 (0.64–2.86)

 50 - < 60

(10.14)

(7.77)

1.47 (0.83–2.62)

2.14 (1.07–4.27)*

2.31 (1.03–5.18)*

  < 50

(10.81)

(5.74)

2.12 (1.14–3.94)

2.24 (1.17–4.26)*

1.98 (0.91–4.32)

 P for trend

< 0.01

< 0.01

< 0.05

 Never

(74.32)

(79.73)

1

1

1

  ≤ 10

(13.18)

(12.84)

1.10 (0.68–1.78)

1.23 (0.72–2.11)

1.29 (0.68–2.43)

  > 10

(12.50)

(7.43)

1.80 (1.03–3.15)*

1.90 (1.04–3.49)*

2.13 (1.03–4.41)*

 P for trend

0.05

< 0.05

< 0.05

 Never

(74.66)

(80.07)

1

1

1

  ≤ 6

(13.51)

(11.15)

1.30 (0.79–2.13)

1.42 (0.83–2.44)

1.41 (0.75–2.65)

  > 6

(11.82)

(8.78)

1.44 (0.84–2.48)

1.79 (0.98–3.31)

2.20 (1.05–4.62)*

 P for trend

0.12

< 0.05

< 0.05

 No

(72.97)

(79.05)

1

1

1

 After 1980

(1.35)

(1.01)

1.10 (0.67–1.78)

1.23 (0.72–2.11)

1.29 (0.67–2.43)

 Before 1980

(25.68)

(19.93)

1.80 (1.03–3.15)*

1.90 (1.04–3.48)*

2.17 (1.03–4.41)*

 P for trend

0.09

< 0.05

< 0.05