Evaluating the impact of the single exit price policy on a basket of originator medicines in South Africa from 1999 to 2014 using a time series analysis

Table 2 Interrupted time-series analysis for originator molecules in the regional core list, using pricing data from 1999 to 2014 with 2004 as the interruption in the series. Statistically significant values (P < 0,05)

INN		Trend	(P value)	Change in level	(P value)	Change in slope	(P value)	Constant	(P value)	Int 1	% Change in level 2004
Albendazole 200 mg tabs	15, Zentel^a	0,571	0,002	−2812	0,000	0,740	0,001	12,272	0,000	15,127	−18,59
Amlodipine 5 mg Tabs (99,100,101)^g	16, Norvasc	0,305	0,082	−2447	0,002	−0,201	0,254	4278	0,000	5803	−42,17
Atovastatin 20 mg Tabs (102,103,104)^g	17, Lipitor	0,349	0,001	−2645	0,000	−0,114	0,170	7665	0,000	9,41	−28,11
Beclomethasone100mcg/dose inh	18, Becotide^b	−17,698	0,035	− 6847	0,809	18,412	0,269	164,637	0,000	76,147	−8,99
Cephalexin 250 mg caps	19, Keflex^c	0,78	0,004	−7919	0,000	−0,752	0,093	5665	0,000	9565	−82,79
Enalapril 10 mg tabs	20, Renitec	−0,56	0,000	0,159	0,589	0,573	0,000	3859	0,000	1059	15,01
Fluoxetine 20 mg tabs	21, Prozac	0,579	0,000	−2787	0,000	−0,324	0,001	6021	0,000	8916	−31,26
Gliclazide 80 mg tabs	22, Diamicron^d	0,093	0,004	−0,311	0,010	−0,055	0,084	0,873	0,000	1338	−23,24
Hydrochlorothiazide 25 mg tabs	23, Dichloride^e	0,031	0,178					0,742	0,009	0,897	0,00
Ibuprofen 200 mg tabs	24, Brufen^f	0,034	0,000	−0,103	0,000	−0,019	0,006	0,419	0,000	0,589	−17,49
Metformin 500 mg tabs	25, Glucophage	−0,021	0,027	−0,2	0,000	0,038	0,001	0,606	0,000	0,501	−39,92
Metronidazole 200 mg tabs	26, Flagyl	0,195	0,000	−0,609	0,000	−0,125	0,000	0,721	0,000	1696	−35,91
Nifedipine Retard 10 mg tab	27, Adalat Ret	0,324	0,000	−0,632	0,003	−0,147	0,016	1788	0,000	3408	−18,54
Ranitidine 150 mg tabs	28, Zantac	0,333	0,005	−0,101	0,777	0,024	0,824	4038	0,000	5703	−1,77
Sodium Valproate200mg Tab	29, Epilim	0,151	0,000	−0,307	0,016	−0,035	0,292	1344	0,000	2099	−14,63

ISSN: 1472-6963