Table 6 Multivariate negative binomial regression coefficients (b), their standard errors, exponentiated coefficients with 95% confidence intervals (CI) for the summary quality of life score, according to categories of potential predictors*, among all participants (Weighted N = 1807)

Age, years

−0.008

0.002

0.001

0.992

(0.988; 0.997)

 Male vs. Female (ref.)

−0.263

0.053

< 0.001

0.769

(0.693; 0.853)

 None/basic

0.019

0.094

0.840

1.019

(0.847; 1.227)

 Middle/technical

−0.017

0.068

0.799

0.983

(0.860; 1.123)

 University (ref.)

–

–

–

 Current

0.287

0.068

< 0.001

1.332

(1.166; 1.522)

 Past

−0.002

0.076

0.974

0.998

(0.860; 1.157)

 Never (ref.)

–

–

–

–

–

 Yes vs. No (ref.)

0.187

0.057

0.001

1.205

(1.078; 1.348)

Number of missing teeth

0.032

0.006

< 0.001

1.033

(1.020; 1.045)

Mean gingival index

0.367

0.070

< 0.001

1.444

(1.259; 1.656)

Mean plaque index

−0.012

0.197

0.951

0.988

(0.672; 1.453)

Mean calculus index

−0.008

0.089

0.925

0.992

(0.833; 1.180)

  ≥ Once per year (ref.)

–

–

–

–

–

 Never

0.131

0.160

0.411

1.140

(0.833; 1.180)

 Only when there is a problem

0.211

0.073

0.004

1.234

(1.071; 1.423)

 Missing

0.201

0.140

0.151

1.223

(0.929; 1.610)

 Yes vs. No (ref.)

−0.061

0.059

0.301

0.941

(0.838; 1.056)

 Kingston

−0.304

0.094

0.001

0.738

(0.613; 0.888)

 Santo Domingo

−0.039

0.080

0.625

0.962

(0.822; 1.125)

 San Juan (ref.)

–

–

–

–

–