Table 4. Multivariable-adjusted risk factor analysis using Cox PH model for first recurrence and Cox CGT for all recurrences.

First recurrence		2009 Adjusted			2010 Adjusted
		HR	P-value	95% CI	HR	P-value	95% CI
All PCR-detected recurrences	Effect of ethnicity according to prior P. falciparum infection before P. vivax recurrence:				Effect of ethnicity = nonsignificant
	No P. falciparum infection	2.21	0.002	[1.33; 3.67]	No
	P. falciparum infection	0.07	0.059	[0.003; 1.11]
	Effect of prior P. falciparum infection before P. vivax recurrence according to ethnic groups:				Effect of prior P. falciparum before P. vivax
	M’nong	99.19	0.001	[6.16; 1,597.55]	1
	Cadong	2.98	0.002	[1.48; 5.99]	5.33	0.012	[1.45; 19.62]
Patent	Prior P. falciparum infection before P. vivax recurrence
	No	1			1
	Yes	6.51	<0.001	[3.66; 11.56]	5.92	0.018	[1.36; 25.75]
Symptomatic	Prior P. falciparum infection before P. vivax recurrence
	No	1
	Yes	7.83	<0.001	[4.25; 14.44]
All recurrences		2009			2010
All PCR-detected recurrences	Effect of malaria treatment according to prior P. falciparum infection before P. vivax recurrence:
	No P. falciparum infection	6.35	<0.001	[4.32; 9.33]	8.94	<0.001	[5.07; 15.77]
	P. falciparum infection	0.72	0.118	[0.47; 1.09]	1.53	0.482	[0.47; 5.02]
	Effect of prior P. falciparum infection before P. vivax recurrence according to malaria treatment:
	No malaria treatment	5.89	<0.001	[4.34; 7.98]	5.06	<0.001	[2.57; 9.96]
	Malaria treatment	0.66	0.09	[0.41; 1.07]	0.87	0.800	[0.29; 2.63]
Patent	Effect of malaria treatment according to prior P. falciparum infection before P. vivax recurrence:
	No P. falciparum infection	21.40	<0.001	[10.61; 43.18]
	P. falciparum infection	0.77	0.365	[0.44; 1.35]
	Effect of prior P. falciparum infection before P. vivax recurrence according to malaria treatment:
	No malaria treatment	6.34	<0.001	[4.21; 9.54]
	Malaria treatment	0.23	<0.001	[0.10; 0.50]
	Prior P. falciparum infection before P. vivax recurrence
	No				1
	Yes				1.80	0.07	[0.96; 3.37]
	Prior ACT/CQ treatment before P. vivax recurrence
	No				1
	Yes				13.83	<0.001	[3.85; 49.72]
Symptomatic	Effect of malaria treatment according to prior P. falciparum infection before P. vivax recurrence:
	No P. falciparum infection	6.22	<0.001	[2.80; 13.82]
	P. falciparum infection	1.07	0.88	[0.45; 2.54]
	Effect of prior P. falciparum infection before P. vivax recurrence according to malaria treatment:
	No malaria treatment	5.65	<0.001	[2.81; 11.35]
	Malaria treatment	0.97	0.95	[0.38; 2.46]
	Prior ACT/CQ treatment before P. vivax recurrence
	No				1
	Yes				6.05	0.001	[2.17; 16.86]

Among patients recruited in 2009, a significant interaction term (HR = 0.03; P = 0.016) for the hazard of first PCR-detected recurrence was found between ethnicity and prior P. falciparum infection. Similarly, significant interaction terms were found for the hazard of all PCR-detected recurrences (HR = 0.11, P < 0.001); patent recurrences (HR = 0.035, P < 0.001) and symptomatic recurrences (HR = 0.17, P = 0.03). For patients recruited in 2010, a significant interaction term (HR = 0.17; P = 0.008) for the hazard of all PCR-detected recurrences was found between prior P. falciparum infection and prior antimalaria treatment. Abbreviations: ACT, artemisinin-based combination therapy; CGT, Conditional Gap Time; CQ, chloroquine; HR, Hazard Ratio; PCR, polymerase chain reaction; PH, Proportional Hazard.