Table 1.

Susceptibilities of P. falciparum parasites collected in different years to artesunate and dihydroartemisinin.

Year	N	AS EC50 (nM)*	P	DHA EC50 (nM)*	P	RSA (%)#	P
2007	17	12.4 ± 3.3	<0.0001a	4.5 ± 2.3	0.0002a	2.1 (0.9–7.5)	0.1353a
2008	19	9.7 ± 2.8		4.3 ± 2.0		2.4 (1.2–4.7)
2009	14	11.8 ± 4.1		5.1 ± 1.7		5.3 (1.2–9.8)
2010–2012	9	14.9 ± 5.1		5.0 ± 1.9		4.9 (0.6–10.6)
2013	40	7.8 ± 3.3		3.2 ± 1.1		5.0 (3.0–8.1)
2014–2016	34	14.2 ± 6.4		4.6 ± 1.8		4.8 (3.2–6.3)
Total	133	11.2 ± 5.1	<0.0001b	4.2 ± 1.8	<0.0001b	4.3 (1.9–7.5)	<0.0001b
3D7		5.0 ± 0.1		2.4 ± 0.2		0

*The EC₅₀ values for artesunate (AS) and dihydroartemisinin (DHA) are expressed as geometric mean ± standard deviation (SD), while the ring survival assay (RSA) values (#) are shown as median (interquartile range).

^aComparison among all the years (Kruskal-Wallis test).

^bComparison between all field isolates and 3D7 (Wilcoxon signed rank test).