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Table 7 Covariate balance check before and after propensity score matching

From: The impact of food fortification on stunting in Zimbabwe: does gender of the household head matter?

 

Mean before matching

Mean after matching

% Bias Reduction

Variables

Treated

Controlled

P-value

Treated

Controlled

P-value

Household head is female

0.241

0.266

0.004

0.241

0.225

0.185

40.6

Household head age [Years]

42.038

42.485

0.153

42.038

42.069

0.938

93.2

Married

0.806

0.794

0.151

0.806

0.81

0.677

62.3

Living with partner

0.024

0.02

0.131

0.024

0.026

0.661

57.1

Divorced/separated

0.042

0.045

0.437

0.042

0.038

0.487

−12.7

Widow/Widower

0.113

0.13

0.018

0.113

0.109

0.572

70

Primary level

0.319

0.405

0

0.319

0.326

0.579

91.8

ZJC level

0.109

0.098

0.069

0.109

0.107

0.86

86.6

O′ level

0.409

0.333

0

0.409

0.404

0.697

93.2

A’ level

0.024

0.017

0.006

0.024

0.026

0.602

69.9

Diploma/Certificate after primary

0.008

0.003

0

0.008

0.009

0.66

79.6

Diploma/Certificate after secondary

0.041

0.012

0

0.041

0.036

0.394

84.5

Graduate/Post-Graduate

0.026

0.006

0

0.026

0.027

0.932

98.2

Household size

4.721

4.714

0.872

4.721

4.716

0.933

30

Proportion of economically active household members

0.456

0.42

0

0.456

0.459

0.615

90.6

Number of chronically ill household members

0.135

0.15

0.128

0.135

0.135

0.975

97.4

Number of mentally ill household members

0.084

0.09

0.407

0.084

0.076

0.358

−36.3

Number of children with sick mothers in the household

0.019

0.028

0.015

0.019

0.016

0.578

76.6

Number of children with sick fathers in the household

0.017

0.017

0.876

0.017

0.014

0.465

− 416.9

Household is located in rural areas

0.921

0.924

0.487

0.921

0.92

0.92

80.3

Bulawayo

0.008

0.019

0

0.008

0.006

0.329

78.7

Manicaland

0.108

0.102

0.322

0.108

0.115

0.461

−2.6

Mash Central

0.093

0.121

0

0.093

0.083

0.228

66.7

Mash East

0.207

0.121

0

0.207

0.21

0.737

95.6

Mash West

0.104

0.111

0.313

0.104

0.1

0.652

42.4

Mat North

0.149

0.118

0

0.149

0.142

0.486

78.3

Mat South

0.087

0.106

0.004

0.087

0.089

0.81

89.8

Midlands

0.079

0.135

0

0.079

0.076

0.61

93.3

Masvingo

0.113

0.132

0.006

0.113

0.124

0.22

43.2

Pseudo R2

  

0.045

  

0.002

 

Mean bias

  

7.5

  

1.5

 

P-value joint equality of means

  

0

  

0.995

 
  1. Notes: Balance check before and after PSM for observations for which 0.1 < e(X) < 0.9. Pseudo R2 indicates how well covariates explain treatment probability; a small value after matching indicates goodness of the matching technique [32]. A standardised absolute mean bias less than 5 after matching indicates effective matching [30]. A non-significant p-value for the joint mean equality test after matching is indicative of no significant differences between treatment and control groups after matching [11]