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Table 3 Parameter estimates for the regression of the slope and intercept of the growth line on subjects’ baseline characteristics

From: Obesity trends and risk factors in the South African adult population

  Slope [kg/m2 per decade]   Intercept [kg/m2]       
Independent variable Coefficient 95 % CI   Coefficient 95 % CI       
Sex            
Male vs female 1.91 (−2.93 ; −0.00)  1.54 (−1.88 ; −1.21)       
Age            
10 year increase 0.90 (−1.20 ; −0.50)   −0.03 (−0.15 ; 0.09)       
Race            
Coloured vs. Black −0.51 (−1.98 ; 0.96)   −0.44 (−0.90 ; 0.03)       
White vs. Black 2.58 (0.46 ; 4.71)   −0.35 (−1.30 ; 0.60)       
Asian vs. Black 0.05 (−1.13 ; 1.0)  0.85 (−1.36 ; -0.33)       
Education            
None vs. primary −0.18 (−1.69 ; 1.34)   −0.27 (−0.75 ; 0.21)       
Secondary vs. primary −0.05 (−1.13 ; 1.04)   0.17 (−0.19 ; 0.53)       
Tertiary vs. primary 0.67 (−0.82 ; 2.16)   0.17 (−0.38 ; 0.72)       
Income Quintile            
I vs. III 0.00 (−1.26 ; 1.26)   −0.18 (−0.60 ; 0.25)       
II vs. III 0.51 (−0.84 ; 1.86)   −0.16 (−0.58 ; 0.25)       
IV vs. III 1.28 (−0.08 ; 2.64)   −0.26 (−0.63 ; 0.10)       
V vs. III 1.59 (0.41 ; 2.78)   −0.21 (−0.58 ; 0.17)       
Residence            
Rural vs. urban 1.16 (0.02 ; 2.31)  0.44 (−0.78 ; −0.09)       
Exercise Frequency            
Moderate vs. low −0.14 (−1.50 ; 1.21)   0.35 (−0.04 ; 0.73)       
High vs. low 1.52 (−2.78 ; −0.25)   0.75 (0.36 ; 1.15)       
Alcohol use −0.14 (−1.10 ; 0.81)   −0.22 (−0.51 ; 0.07)       
Smoking 1.69 (−3.00 ; −0.38)   −0.20 (−0.60 ; 0.21)       
Waist circumference            
10 cm increase 0.70 (0.20 ; 1.2)   1.54 (1.29 ; 1.79)       
BMI class            
Overweight/Obese vs. 7.99 (−9.77 ; −6.21)   7.23 (6.58 ; 7.96)       
Normal/Underweight            
Rural x BMI class 1.98 (−3.80 ; −0.16)   0.01 (−0.60 ; 0.58)       
Moderate Exercise x BMI class 0.92 (−1.35 ; 3.18)  1.10 (−1.88 ; −0.33)       
High Exercise x BMI class 1.96 (−0.43 ; 4.35)  1.43 (−2.22 ; −0.63)       
  1. CI = Confidence Interval. Statistically significant coefficients in italic