Table 1:

Baseline characteristics of the study cohort (922 074 people)^*

Characteristic	No. of people with unplanned hospital admissions (%)^† n = 149 107 (16.2)	No. of people with planned hospital admissions (%)^† n = 82 702 (8.9)	No. of people with ED visit (%)^† n = 327 164 (35.5)	No. of people with no hospital admission or ED visit (%)^† n = 363 101 (39.4)	Weighted standardized difference
Age, yr, median (IQR)	77 (70–83)	72 (68–77)	72 (68–78)	67 (66–71)	0.56^‡
					0.46^§
					1.18^¶

Age group, yr

66–70	38 529 (25.8)	35 028 (42.4)	138 212 (42.2)	260 591 (71.8)	0.35
					0.35
					1.03

71–75	29 689 (19.9)	22 120 (26.7)	74 573 (22.8)	50 894 (14.0)	0.16
					0.07
					0.16

76–80	29 420 (19.7)	15 232 (18.4)	55 344 (16.9)	28 234 (7.8)	0.03
					0.07
					0.35

81–85	26 364 (17.7)	7656 (9.3)	36 031 (11.0)	14 468 (4.0)	0.25
					0.19
					0.45

86–90	16 849 (11.3)	2270 (2.7)	17 085 (5.2)	6038 (1.7)	0.34
					0.22
					0.40

91–95	6767 (4.5)	365 (0.4)	4991 (1.5)	2197 (0.6)	0.27
					0.18
					0.25

96–100	1489 (1.0)	31 (0.0)	928 (0.3)	679 (0.2)	0.13
					0.09
					0.11

Female sex	77 500 (52.0)	40 702 (49.2)	187 423 (57.3)	197 476 (54.4)	0.06
					0.11
					0.05

Neighbourhood income quintile

1 (lowest)	29 725 (19.9)	12 255 (14.8)	57 071 (17.4)	56 335 (15.5)	0.14
					0.06
					0.12

2	31 767 (21.3)	15 617 (18.9)	65 528 (20.0)	69 448 (19.1)	0.06
					0.03
					0.05

3	28 857 (19.4)	16 278 (19.7)	64 499 (19.7)	70 842 (19.5)	0.01
					0.01
					0.00

4	29 239 (19.6)	17 939 (21.7)	67 829 (20.7)	78 691 (21.7)	0.05
					0.03
					0.05

5 (highest)	28 987 (19.4)	20 413 (24.7)	71 230 (21.8)	86 805 (23.9)	0.13
					0.06
					0.11

Missing	532 (0.4)	200 (0.2)	1007 (0.3)	980 (0.3)	0.02
					0.01

Geographic location

Urban	135 252 (90.7)	74 285 (89.8)	287 538 (87.9)	331 677 (91.3)	0.03
					0.09
					0.02

Missing	24 (0.0)	6 (0.0)	27 (0.0)	16 (0.0)	0.01
					0.01
					0.01

Diabetes	45 182 (30.3)	21 287 (25.7)	79 033 (24.2)	80 394 (22.1)	0.10
					0.14
					0.19

Hypertension	110 245 (73.9)	58 793 (71.1)	211 349 (64.6)	197 562 (54.4)	0.06
					0.20
					0.42

No. of medications

0	12 089 (8.1)	3034 (3.7)	28 616 (8.7)	66 725 (18.4)	0.19
					0.02
					0.31

1	8048 (5.4)	4233 (5.1)	25 209 (7.7)	40 612 (11.2)	0.01
					0.09
					0.21

2	9627 (6.5)	5903 (7.1)	29 668 (9.1)	42 257 (11.6)	0.03
					0.10
					0.18

3	10 748 (7.2)	6891 (8.3)	31 248 (9.6)	37 989 (10.5)	0.04
					0.08
					0.11

4	11 612 (7.8)	7,906 (9.6)	31 605 (9.7)	34 588 (9.5)	0.06
					0.07
					0.06

≥ 5	96 983 (65.0)	54 735 (66.2)	180 818 (55.3)	140 930 (38.8)	0.02
					0.20
					0.54

Has primary care physician	142 210 (95.4)	81 757 (98.9)	318 407 (97.3)	342 147 (94.2)	0.16
					0.09
					0.08

Health care system use in yr. before cohort entry

No. physician visits, median (IQR)	11 (6–18)	18 (13–24)	9 (5–14)	6 (3–10)	0.60
					0.26
					0.96

No. primary care physician visits, median (IQR)	6 (3–10)	6 (4–10)	5 (3–8)	3 (1–6)	0.76
					0.18
					0.96

No. specialist visits, median (IQR)	4 (1–8)	11 (7–15)	3 (1–6)	2 (0–4)	0.53
					0.25
					0.94

Died during hospital admission or in the ED	13 080 (8.8)	533 (0.6)	1931 (0.6)	–	0.39
					0.39
					–

Note: ED = emergency department, IQR = interquartile range.
↵* Baseline characteristics of community-dwelling adults age ≥ 66 years with first hospital admission, ED visit, or neither, residing in Ontario, Canada, between 2007 and 2016.
↵† Unless stated otherwise.
↵‡ Weighted standardized differences for unplanned hospital admission versus planned hospital admission.
↵§ Weighted standardized differences for unplanned hospital admission versus ED visit.
↵¶ Weighted standardized differences for unplanned hospital admission versus no hospital admission or ED visit.