TABLE 4.

Generalized linear regression model on unit price of all procured cardiovascular medicines with difference-in-differences analyses.

Variables	β coefficient	Robust product clustered standard error	z	p>|z|	95% confidence interval
Intervention effect (difference-in-differences)	−0.45	0.16	−2.73	0.006	−0.77 to -0.13
Generic competition (X1)	0.17	0.20	0.87	0.385	−0.22 to 0.57
(X1)2	−0.02	0.02	−0.63	0.526	−0.06 to 0.03
Therapeutic competition (X2)	−0.38	0.13	−3.03	0.002	−0.63 to -0.13
(X2)2	0.01	0.01	1.35	0.176	−0.00 to 0.02
Goodness-of-fit tests
	Akaike Information Criterion (AIC) = 10.67
	Bayesian Information Criterion (BIC) = -79,081.63

Note: Bold values indicate regression coefficients with statistical significance (p < 0.05).