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Table 5 Regression model estimates for covariate associations with SF-12 mental health (MH) and physical health (PH) latent variable scores

From: Differential item functioning of the SF-12 in a population-based regional joint replacement registry

Covariate MH Latent Variable PH Latent Variable
No-DIF Model DIF Model d No-DIF Model DIF Model d
Est SE Est SE Est SE Est SE
THA
 AGE1 0.17 0.05 0.21 0.05 0.10 0.08 0.05 0.08 0.05 0.00
 AGE2 0.08 0.05 0.13 0.05 0.50 −0.12 0.05 −0.14 0.05 0.11
 BMI1 0.07 0.05 0.11 0.06 0.43 −0.06 0.05 −0.06 0.05 −0.07
 BMI2 −0.20 0.04 −0.21 0.05 −0.03 − 0.25 0.04 − 0.20 0.04 − 0.20
 SEX 0.32 0.04 0.28 0.04 − 0.21 0.32 0.04 0.32 0.04 −0.04
 COMORB −0.53 0.04 −0.52 0.04 −0.13 − 0.37 0.04 − 0.33 0.04 − 0.10
TKA
 AGE1 0.27 0.04 0.28 0.04 0.10 0.27 0.04 0.24 0.04 −0.11
 AGE2 0.33 0.05 0.28 0.04 −0.09 0.22 0.04 0.19 0.04 −0.19
 BMI1 0.20 0.06 0.15 0.06 −0.15 0.12 0.06 0.13 0.06 0.07
 BMI2 −0.15 0.04 −0.15 0.04 0.12 −0.29 0.04 −0.27 0.04 −0.10
 SEX 0.30 0.04 0.30 0.03 0.09 0.24 0.03 0.22 0.03 −0.12
 COMORB −0.50 0.04 −0.49 0.03 0.06 −0.37 0.03 −0.32 0.03 −0.13
  1. AGE1 = 0 if age ≤ 60 and 1 otherwise; AGE2 = 0 if age ≤ 70 and 1 otherwise; BMI1 = 0 if BMI ≤ 25.0 and 1 otherwise); BMI2 = 0 if BMI ≤ 30.0 and 1 otherwise; COMORB = 0 if < 2 comorbid conditions and 1 otherwise; EST Estimate, SE Standard error, d Relative difference in standardized estimates between DIF model and No-DIF models; Boldface font is used to denote statistically significant estimates at α = 0.05