Table 3 The relationship between the mean DFT/DFRoot of caries and alcohol consumption (results of the negative binomial regression analyses)

 Never/ rarely

ref.

ref.

ref.

ref.

 Sometimes

0.89 (0.72, 1.10)

1.06 (0.83, 1.35)

0.646

0.93 (0.70, 1.24)

1.18 (0.87, 1.61)

0.287

 Often

0.50 (0.35, 0.70)

0.63 (0.44, 0.92)

0.015

0.43 (0.27, 0.68)

0.52 (0.32, 0.84)

0.008

 Male

ref.

ref.

ref.

ref.

 Female

1.36 (1.14, 1.61)

1.07 (0.85, 1.35)

0.550

1.14 (0.91, 1.43)

0.83 (0.62, 1.12)

0.232

 55–64 years

ref.

ref.

ref.

ref.

 65–74 years

1.17 (0.99, 1.39)

1.04 (0.87, 1.25)

0.650

1.29 (1.03, 1.61)

1.02 (0.80, 1.29)

0.874

 Urban

ref.

ref.

ref.

ref.

 Rural

1.03 (0.86, 1.22)

1.11 (0.90, 1.38)

0.341

1.49 (1.19, 1.86)

1.59 (1.20, 2.10)

0.001

  ≤ 6 years

ref.

ref.

ref.

ref.

  > 6, ≤9 years

0.83 (0.68, 1.02)

0.91 (0.72, 1.15)

0.417

0.73 (0.55, 0.95)

0.78 (0.57, 1.05)

0.104

  > 9 years

0.65 (0.51, 0.81)

0.66 (0.51, 0.86)

0.002

0.47 (0.34, 0.64)

0.50 (0.35, 0.71)

< 0.001

 Never/ rarely

ref.

ref.

ref.

ref.

 Often

1.17 (0.95, 1.44)

1.30 (1.04, 1.63)

0.023

1.10 (0.83, 1.45)

1.32 (1.14, 2.06)

0.005

 Never smoked

ref.

ref.

ref.

ref.

  ≤ 10 /day

0.76 (0.54, 1.05)

0.82 (0.57, 1.18)

0.281

0.95 (0.62, 1.46)

0.90 (0.57, 1.42)

0.643

  > 10 /day

0.64 (0.51, 0.80)

0.72 (0.54, 0.96)

0.027

0.74 (0.55, 0.99)

0.71 (0.49, 1.03)

0.070

 Low

ref.

ref.

ref.

ref.

 Medium

0.92 (0.73, 1.16)

0.93 (0.74, 1.18)

0.561

0.81 (0.60, 1.09)

0.86 (0.64, 1.15)

0.307

 High

0.99 (0.75, 1.31)

1.06 (0.78, 1.44)

0.700

0.70 (0.49, 1.01)

0.97 (0.66, 1.44)

0.883