Module 33 A: Supplement on Multiple Regression Interpretation
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33A - 1 Module 33 A: Supplement on Multiple Regression Interpretation This module expands the discussion of the interpretation of the regression model parameters for the first example in Module 33 Reviewed 19 July 05 / MODULE 33A
description
Module 33 A: Supplement on Multiple Regression Interpretation. This module expands the discussion of the interpretation of the regression model parameters for the first example in Module 33. Reviewed 19 July 05 / MODULE 33A. y = Quality of Well Being score (QWB) at two years. - PowerPoint PPT Presentation
Transcript of Module 33 A: Supplement on Multiple Regression Interpretation
33A - 1
Module 33 A:
Supplement on Multiple Regression Interpretation
This module expands the discussion of the interpretation of the regression model parameters for the first example in Module 33
Reviewed 19 July 05 / MODULE 33A
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y = Quality of Well Being score (QWB) at two years
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x1: Intervention
x1 = 1 if person was in intervention group
= 0 otherwise
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1
0.0794 Intervention Control
Intervention Controlb x x
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x2: QWB at baseline
x2 = baseline score
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2
Slope
0.6354 means that the QWB score at two years
was 0.6354 units higher for each one unit increase in
the baseline QWB score.
b
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x3: Gender
x3 = 1 if person was a male
= 0 otherwise, i.e. a female
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3 -0.0393 Male Female
Male Femaleb x x
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x4-5: Age
x4 = 1 if age 75-84 x5 = 1 if age 85 +
= 0 otherwise = 0 otherwise
4 75 84 75
4 75 84 75
5 7585
5 7585
-0.0527
-0.1699
Age Age
Age Age
AgeAge
AgeAge
b x x
b x x
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x6-7: GHQ
x6 = 1 if moderate x7 = 1 if severe
= 0 otherwise = 0 otherwise
6
6
7
7
-0.0564
-0.0847
Moderate Low
Moderate Low
Severe Low
Severe Low
b x x
b x x
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x8: Physically active
x8 = 1 if ≥ 3 times per week
= 0 if < three times per week
8 3 3
8 3 3 0.0629 times times
times timesb x x
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x9: Reduced weight
x9 = 1 if tried to lose weight
= 0 otherwise
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9 0.0223 Tried Not
Tried Notb x x
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x10: Medigap (Other insurance)
x10 = 1 if Medigap insurance
= 0 if otherwise, i.e. Medicaid
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10 0.0240
Medigap No
Medigap Nob x x
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x11: Education
x11 = education level in years
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Slope
0.0038 means that the QWB score at two years
was 0.0038 units higher for each one unit increase in
education level in years.
b
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12 Slope for Intervention Group
x12: Education Intervention interaction
x12 = (x11) * (x1)
b12 = -0.0061 means that the QWB score at two years decreases -0.0061units for each year of education for x12 = 1, which is the intervention group. For x12 = 0, the control group, this term is zero.
