Table 1.

Allocation of patients

	RCT (n = 2000)		PRPT (n = 2000)
			Preference arm (n = 1600)		Randomized arm (n = 400)
	Control	Treat	Control	Treat	Control	Treat
Absent	500	500	30	770	100	100
Present	500	500	170	630	100	100
Total	1000	1000	200	1400	200	200