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

Table 1

Baseline characteristics of participants, refusers, and subgroups of refusers.

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)
Age, mean (SD)	82 (6.6)	81 (7.0)		85 (8.7)	0.39	80 (6.5)	0.10	81 (6.4)	0.67	82 (7.4)	0.98
Female	180 (66)	77 (60)	0.22	1 (20)	0.05	33 (60)	0.37	11 (85)	0.23	11 (58)	0.25
Married	61 (23)	26 (24)	0.70	3 (60)	0.08	15 (32)	0.17	0	0.13	8 (18)	0.47
Medical problems					0.59		0.25		0.98		0.23
Neurological	18 (7)			1 (20)		2 (4)		0		4 (7)
Cardiovascular	36 (13)			0		7 (13)		1 (8)		8 (15)
Respiratory	18 (7)			0		9 (16)		1 (8)		4 (7)
Musculoskeletal	24 (9)			0		2 (4)		1 (8)		2 (4)
Infectious	32 (12)			1 (20)		6 (11)		2 (15)		13 (24)
Other categories	143 (53)			3 (60)		29 (53)		8 (61)		24 (43)
ISAR I score			0.91		0.29		0.18		0.06		0.43
2	100 (37)	40 (37)		1 (20)		12 (22)		7 (54)		20 (36)
3	109 (40)	46 (42)		4 (80)		19 (35)		3 (23)		20 (36)
4–6	62 (23)	23 (21)		0		16 (29)		0		7 (13)
Medication prescribed > 3	237 (92)	96 (93)	0.66	5 (100)	1.00	42 (100)	0.05	6 (75)	0.15	43 (90)	0.58

Fisher’s exact test.