The Importance of Risk and Subgroup Analysis of Nonparticipants in a Geriatric Intervention Study

Table 2

Comparison of participants, refusers, and subgroups of refusers according to readmission and mortality.

Invited to participate,
	Participants, (%)			Refusers, (%)
	Total participants	Total refusers		Too healthy		Too ill		Not interested		No reason
	271 (68)	128 (32)		5 (4)		55 (43)		13 (10)		55 (43)
Readmission to hospital
Within 1 month prior to initial ED admission	40 (15)	17 (13)	0.69	1 (20)	0.56	9 (16)	0.76	2 (15)	1.0	5 (5)	0.25
Within 1 month after initial ED admission	41 (15)	29 (23)	0.07	0	1.00	15 (27)	0.04	4 (31)	0.13	10 (18)	0.58
Within 6 months after initial ED admission	102 (38)	75 (61)	<0.00	3 (60)	0.37	34 (64)	<0.01	9 (69)	0.02	29 (55)	0.02
Mortality
Dead within 1 month	4 (2)	7 (5)	0.02	0	1.00	3 (5)	0.10	0	1.00	4 (7)	0.03
Dead within 6 months	22 (8)	23 (18)	0.01	0	1.00	13 (24)	<0.01	2 (15)	0.30	8 (15)	0.16

Fisher’s exact test.