Table 3 Crude and Adjusted Prevalence Ratio (PR) of history of involvement in fights with firearm and/or cold weapon among 9^th grade students attending public and private schools in Brazil, 2012

 Age group

<0.001

<0.001

<0.001

<0.001

  ≥14 years

1

1

1

1

  15 or over

1.56 (1.46-1.68)

1.17 (1.09-1.25)

1.58 (1.44-1.74)

1.20 (1.09-1.32)

 Ethnicity/skin color

<0.001

0.056

<0.001

0.012

  White

1

1

1

  Black

1.26 (1.14-1.39)

1.09 (0.99-1.20)

1.33 (1.14-1.56)

1.19(1.02-1.39)

  Yellow

1.12 (0.93-1.34)

0.90 (0.76-1.07)

1.16 (0.93-1.45)

1.11 (0.89-1.38)

  Brown

0.98 (0.91-1.06)

0.97 (0.89-1.04)

1.11 (1.00-1.24)

1.10 (0.99-1.22)

  Indigenous

1.27 (1.07-1.50)

1.10 (0.94-1.29)

1.74 (1.39-2.17)

1.44 (1.15-1.80)

 Type of school

<0.001

<0.001

  Private

1

-

1

-

  Public

1.18 (1.08-1.30)

-

1.42 (1.23-1.64)

-

 Employment

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

1.91 (1.77-2.05)

1.32 (1.22-1.42)

1.96 (1.74-2.20)

1.35 (1.20-1.52)

 Cigarette smoking in the previous 30 days

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

3.74 (3.46-4.04)

1.41 (1.27-1.57)

4.00 (3.56-4.50)

1.58 (1.36-1.84)

 Alcohol intake in the previous 30 days

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

3.00 (2.80-3.20)

2.07 (1.92-2.24)

2.72 (2.48-2.98)

1.77(1.60-1.97)

 Use of illicit drugs

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

4.74 (4.39-5.12)

1.66(1.48-1.86)

5.08 (4.40-5.87)

1.70(1.43-2.03)

 Insomnia

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

1.87 (1.68-2.07)

1.23 (1.11-1.36)

2.10 (1.89-2.34)

1.37 (1.22-1.53)

 Close friends

<0.001

<0.001

<0.001

0.011

  One or more

1

1

1

1

  None

1.81 (1.60-2.05)

1.45 (1.28-1.64)

1.70 (1.35-2.14)

1.36(1.07-1.72)

 Living with mother and/or father

<0.001

  Yes

1

-

1

1

  No

1.38 (1.22-1.57)

-

1.65 (1.42-1.92)

1.29 (1.11-1.50)

 Skipping classes without permission

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

1.92(1.79-2.06)

1.30 (1.20-1.39)

2.32 (2.11-2.55)

1.46 (1.31-1.61)

 Suffering family violence

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

2.72 (2.51-2.94)

1.62 (1.49-1.76)

2.84 (2.57-3.14)

1.72 (1.54-1.93)

 Suffering bullying

<0.001

<0.001

<0.001

  No

1

-

1

1

  Yes

1.37 (1.23-1.53)

-

2.21 (1.92-2.54)

1.55 (1.34-1.79)

 Unsafe on the way to and from and/or at school

<0.001

<0.001

<0.001

<0.001

  No

1

1

1

1

  Yes

2.49 (2.31-2.68)

1.50 (1.38-1.63)

2.35 (2.11-2.62)

1.36 (1.21-1.54)