Table 4.

Results of the segmented regression analysis for the probabilities of drug overutilisation and prohibited combination*

		Time		Drug price reduction		Time after drug price reduction		New guideline		Time after new guideline
	Group	Marginal estimates	p Value	Marginal estimates	p Value	Marginal estimates	p Value	Marginal estimates	p Value	Marginal estimates	p Value
Drug overutilisation	All	−0.00033	<0.001	0.00025	0.383	0.00037	<0.001	−0.00008	0.791	−0.00022	0.016
	Health insurance	−0.00032	<0.001	0.00035	0.236	0.00035	<0.001	−0.00017	0.572	−0.00021	0.025
	Medical aid	−0.00125	0.093	−0.00183	0.648	0.00047	0.757	0.00353	0.433	−0.00279	0.151
Prohibited combination	All	−0.00050	<0.001	−0.00019	0.692	0.00088	<0.001	−0.00062	0.212	−0.00073	<0.001
	Health insurance	−0.00052	<0.001	−0.00027	0.596	0.00088	<0.001	−0.00083	0.103	−0.00069	<0.001
	Medical aid	0.00117	0.241	0.00987	0.020	−0.00198	0.246	0.00500	0.254	−0.00128	0.500

*All results were adjusted by age, sex, region, insurance type, Charlson comorbidity index and combinations of hypertension agents.