Table 4.

Treatment-group comparisons on covariates before and after propensity score matching and achieved reduction in bias

Before propensity score matching					After propensity score matching				Bias reduction
Covariate	Mean/prop. (π)	t-value/χ2	P-value	Bias	Mean/Prop. (π)	t-value/χ2	P-value	Bias	(%)
Consultation duration (minutes)
Comparison	20.54	−1.87	0.062	3.85	21.41	−1.3	0.194	3.21	16.62
Intervention	24.39				24.62
Day of the week
Comparison	0.46	11.3	0.001	0.08	0.5	0	1	0	100
Intervention	0.54				0.5
Time of the day
Comparison	0.46	0.78	0.377	0.08	0.5	1.89	0.169	0	100
Intervention	0.54				0.5
Main reason for clinic visit
Comparison	0.46	6.81	0.009	0.08	0.5	0	1	0	100
Intervention	0.54				0.5

Prop. (π) = proportion; x² = Chi-square.