Comparison of readmissions among hospitalized nonvalvular atrial fibrillation patients treated with oral anticoagulants in the United States

Figures & data

Table 1. Demographics, clinical characteristics, and hospital characteristics of unmatched study cohorts.

	Apixaban (n = 104,937)		Warfarin (n = 284,001)		Rivaroxaban (n = 99,998)		Dabigatran (n = 41,047)		p-value*
Demographics
Age (years)
Mean (SD)	73.5 (11.6)		75.6 (10.8)		71.4 (12.0)		72.7 (11.4)		<.001
Median	75		77		73		74
Age group, n %									<.001
18–34 years	393	0.4	591	0.2	614	0.6	163	0.4
35–44 years	1,396	1.3	2,157	0.8	1,840	1.8	469	1.1
45–54 years	5,047	4.8	9,979	3.5	6,732	6.7	2,211	5.4
55–64 years	15,111	14.4	31,942	11.3	17,464	17.5	6,448	15.7
65–74 years	28,972	27.6	69,924	24.6	29,122	29.1	12,093	29.5
≥75 years	54,018	51.5	169,408	59.7	44,226	44.2	19,663	47.9
Gender, n %									<.001
Female	51,102	48.7	129,848	45.7	45,713	45.7	17,931	43.7
Male	53,835	51.3	154,153	54.3	54,285	54.3	23,116	56.3
Race, n %									<.001
White	87,786	83.7	230,525	81.2	81,718	81.7	33,769	82.3
Black	7,513	7.2	20,323	7.2	7,087	7.1	2,594	6.3
Other	9,638	9.2	33,153	11.7	11,193	11.2	4,684	11.4
Payer type, n %									<.001
Commercial	16,486	15.7	26,586	9.4	19,384	19.4	7,131	17.4
Medicare	80,684	76.9	235,609	83.0	72,127	72.1	31,089	75.7
Medicaid	4,166	4.0	11,555	4.1	4,919	4.9	1,463	3.6
Others	3,601	3.4	10,251	3.6	3,568	3.6	1,364	3.3
Clinical characteristics
Charlson Comorbidity Index (CCI)
Mean (SD)	2.5 (2.1)		2.7 (2.1)		2.2 (2.0)		2.2 (2.0)		<.001
Median	2		2		2		2
CHADS2 score
Mean (SD)	2.5 (1.3)		2.8 (1.3)		2.3 (1.3)		2.5 (1.3)		<.001
Median	2		3		2		2
CHA2DS2 -VASc score
Mean (SD)	4.0 (1.7)		4.3 (1.6)		3.7 (1.8)		3.9 (1.7)		<.001
Median	4		4		4		4
HAS-BLED score
Mean (SD)	3.1 (1.2)		3.3 (1.2)		2.9 (1.2)		3.0 (1.2)		<.001
Median	3		3		3		3
Stroke/bleeding history, n %
Prior stroke	2,448	2.3	7953	2.8	2,259	2.3	1,101	2.7	<.001
Stroke in index hospitalization	7,918	7.6	20,562	7.2	5,753	5.8	2,259	5.5	<.001
Prior bleeding	1,962	1.9	7,951	2.8	2,052	2.1	820	2.0	<.001
Bleeding in index hospitalization	9,025	8.6	37,110	13.1	9,022	9.0	3,187	7.8	<.001
Hospital characteristics
Location, n %									<.001
Urban	90,867	86.6	247,379	87.1	87,540	87.5	35,758	87.1
Rural	14,070	13.4	36,622	12.9	12,458	12.5	5,289	12.9
Teaching status, n %									<.001
Yes	41,751	39.8	112,480	39.6	38,391	38.4	16,753	40.8
No	63,186	60.2	171,521	60.4	61,607	61.6	24,294	59.2
Bed size, n %									<.001
0–99 beds	6,092	5.8	17,252	6.1	5,756	5.8	2,429	5.9
100–199 beds	16,177	15.4	42,431	14.9	14,679	14.7	5,807	14.2
200–299 beds	19,867	18.9	52,296	18.4	19,252	19.3	7,971	19.4
300–399 beds	18,699	17.8	50,241	17.7	17,947	18.0	7,306	17.8
400–499 beds	13,832	13.2	38,885	13.7	12,030	12.0	5,281	12.9
≥500 beds	30,270	28.9	82,896	29.2	30,334	30.3	12,253	29.9

*p-values are for comparison across the four study populations treated with the different direct oral anticoagulants.

Abbreviations. CHADS₂, congestive heart failure, hypertension, age = 75 years, diabetes mellitus, stroke; CHA₂DS₂-VASc, congestive heart failure, hypertension, age = 75 years, diabetes mellitus, stroke, vascular disease; HAS-BLED, hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition; SD, standard deviation.

Table 2. Demographics, clinical characteristics, and hospital characteristics of matched study cohorts.

	Warfarin (n = 69,765)		Apixaban (n = 69,765)		p-value	Rivaroxaban (n = 59,747)		Apixaban (n = 59,747)		p-value	Dabigatran (n = 39,604)		Apixaban (n = 39,604)		p-value
Demographics
Age (years)
Mean (SD)	76.0 (9.8)		76.0 (9.8)		.64	72.7 (11.2)		72.8 (11.5)		.09	72.9 (11.3)		72.9 (11.8)		.72
Median	77		77			74		74			74		74
Gender, n %					.42					.81					.52
Female	35,391	50.7	35,239	50.5		28,709	48.1	28,750	48.1		17,626	44.5	17,717	44.7
Male	34,374	49.3	34,526	49.5		31,038	52.0	30,997	51.9		21,978	55.5	21,887	55.3
Race, n %					.36					.12					.96
White	59,045	84.6	58,851	84.4		50,383	84.3	50,625	84.7		32,869	83.0	32,861	83.0
Black	4,570	6.6	4,647	6.7		4,271	7.2	4,117	6.9		2,534	6.4	2,552	6.4
Other	6,150	8.8	6,267	9.0		5,093	8.5	5,005	8.4		4,201	10.6	4,191	10.6
Payer type, n %					.19					.95					.95
Commercial	7,074	10.1	7,034	10.1		10,178	17.0	10,107	16.9		6,759	17.1	6,752	17.1
Medicare	58,582	84.0	58,467	83.8		45,080	75.5	45,167	75.6		30,122	76.1	30,108	76.0
Medicaid	2,073	3.0	2,090	3.0		2,385	4.0	2,372	4.0		1,406	3.6	1,436	3.6
Others	2,036	2.9	2,174	3.1		2,104	3.5	2,101	3.5		1,317	3.3	1,308	3.3
Clinical characteristics
Charlson Comorbidity Index (CCI)
Mean (SD)	2.3 (1.7)		2.3 (1.7)		.45	2.1 (1.9)		2.1 (1.9)		.62	2.2 (2.0)		2.2 (2.0)		.85
Median	2		2			2		2			2		2
CHADS2 score
Mean (SD)	2.6 (1.2)		2.6 (1.2)		.31	2.4 (1.2)		2.3 (1.2)		.12	2.5 (1.3)		2.5 (1.3)		.26
Median	3		3			2		2			2		2
CHA2DS2 -VASc score
Mean (SD)	4.2 (1.6)		4.2 (1.6)		.84	3.8 (1.6)		3.8 (1.6)		.42	3.9 (1.7)		3.9 (1.7)		.51
Median	4		4			4		4			4		4
HAS-BLED score
Mean (SD)	3.1 (1.1)		3.1 (1.1)		1.00	2.9 (1.1)		2.9 (1.1)		1.00	3.0 (1.2)		3.0 (1.2)		.18
Median	3		3			3		3			3		3
Stroke/bleeding history, n %
Prior stroke	1,369	2.0	1,444	2.1	.15	208	.4	208	.4	1.00	998	2.5	998	2.5	1.00
Stroke in index hospitalization	4,855	7.0	4,845	6.9	.92	3,401	5.7	3,300	5.5	.20	2,237	5.7	2,307	5.8	.28
Prior bleeding	1,270	1.8	1,206	1.7	.19	755	1.3	766	1.3	.78	756	1.9	739	1.9	.66
Bleeding in index hospitalization	5,187	7.4	5,201	7.5	.89	3,762	6.3	3,666	6.1	.25	3,087	7.8	3,099	7.8	.87
Hospital characteristics
Location, n %					.31					.36					.55
Urban	59,770	85.7	59,903	85.9		51,724	86.6	51,831	86.8		34,410	86.9	34,353	86.7
Rural	9,995	14.3	9,862	14.1		8,023	13.4	7,916	13.3		5,194	13.1	5,251	13.3
Teaching status, n %					.09					.23					.58
Yes	26,469	37.9	26,778	38.4		22,676	38.0	22,476	37.6		15,984	40.4	15,908	40.2
No	43,296	62.1	42,987	61.6		37,071	62.1	37,271	62.4		23,620	59.6	23,696	59.8
Bed size, n %					.10					.44					.94
0–99 beds	4,524	6.5	4,408	6.3		3,670	6.1	3,648	6.1		2,378	6.0	2,432	6.1
100–199 beds	11,194	16.1	11,308	16.2		9,372	15.7	9,414	15.8		5,699	14.4	5,733	14.5
200–299 beds	13,468	19.3	13,202	18.9		11,611	19.4	11,618	19.5		7,627	19.3	7,551	19.1
300–399 beds	12,630	18.1	12,544	18.0		10,810	18.1	10,984	18.4		7,085	17.9	7,110	18.0
400–499 beds	9,396	13.5	9,354	13.4		7,506	12.6	7,286	12.2		5,112	12.9	5,118	12.9
≥500 beds	18,553	26.6	18,949	27.2		16,778	28.1	16,797	28.1		11,703	29.6	11,660	29.4
Index hospital length of stay
Mean (SD)	4.4 (3.3)		4.4 (3.4)		.34	4.0 (3.0)		4.0 (3.0)		.56	4.5 (4.0)		4.5 (4.1)		.63
Median	4		3			3		3			3		3
Index hospital cost
Mean (SD)	$9,177 ($7,350)		$9,220 ($7,398)		.28	$8,569 ($6,704)		$8,580 ($6,714)		.78	$11,009 ($12,038)		$11,044 ($13,145)		.69
Median	$6,918		$7,032			$6,558		$6,591			$7,148		$7,194

Abbreviations. CHADS₂, congestive heart failure, hypertension, age = 75 years, diabetes mellitus, stroke; CHA₂DS₂-VASc, congestive heart failure, hypertension, age = 75 years, diabetes mellitus, stroke, vascular disease; HAS-BLED, hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition; SD, standard deviation.

Table 3. Unadjusted rates of readmissions, associated LOS, and hospital costs per patient of matched study cohorts.

Readmission category	Warfarin (n = 69,765)		Apixaban (n = 69,765)		p-value	Rivaroxaban (n = 59,747)		Apixaban (n = 59,747)		p-value	Dabigatran (n = 39,604)		Apixaban (n = 39,604)		p-value
All-cause, n %	10,280	14.7	9,844	14.1	<.001	8,155	13.7	7,778	13.0	.001	5,196	13.1	5,353	13.5	.101
All-cause LOS (days)
Mean	1.13		1.02		<.001	.95		.90		.004	.98		.98		.937
SD	3.93		3.62			3.50		3.38			3.64		3.60
All-cause hospital cost
Mean	$2,378		$2,251		.028	$2,053		$2,003		.322	$2,178		$2,268		.194
SD	$10,180		$9,865			$8,287		$8,943			$8,972		$10,347
MB-related, n %	834	1.2	651	.9	<.001	730	1.2	452	.8	<.001	392	1.0	348	.9	.104
MB-related LOS (days)
Mean	.07		.06		<.001	.07		.04		<.001	.06		.05		.111
SD	.86		.79			.75		.70			.84		.80
MB-related hospital cost
Mean	$157		$133		.042	$147		$105		<.001	$160		$135		.235
SD	$1,948		$2,511			$1,816		$2,311			$3,060		$2,820
Stroke-related, n %	294	.4	222	.3	.001	158	.3	153	.3	.776	116	.3	103	.3	.379
Stroke-related LOS (days)
Mean	.03		.02		.003	.02		.01		.466	.02		.02		.158
SD	.56		.43			.42		.38			.77		.43
Stroke-related hospital cost
Mean	$63		$45		.031	$37		$38		.925	$51		$40		.301
SD	$1,851		$1,304			$1,213		$1,285			$1,598		$1,383

These results were across all patients in each of the paired study cohorts, including patients where the LOS and hospital cost of patients without readmissions were equal to 0 days and $0, respectively. Some patients may have had both MB and stroke events (not mutually exclusive).

Abbreviations. LOS, length of stay; MB, major bleeding; SD, standard deviation.

Figure 1. Regression adjusted risks of all-cause, MB-related, and stroke-related readmissions for matched study cohorts. CI, confidence interval; MB, major bleeding.

Table 4. Regression analyses─LOS and associated hospital cost for readmissions per patient of matched study cohorts: other oral anticoagulants (OACs) vs apixaban.

Readmission category	Warfarin vs Apixaban	p-value	Rivaroxaban vs Apixaban	p-value	Dabigatran vs Apixaban	p-value
All-cause LOS (days)
Other OAC	1.13		.95		.978
Apixaban	1.02		.90		.976
Mean difference	.11	<.001	.06	.004	.002	.937
95% CI	.07–.15		.02–.10		−.048–.053
All-cause hospital cost
Other OAC	$2,387		$2,058		$2,194
Apixaban	$2,253		$2,003		$2,270
Mean difference	$134	.010	$55	.280	−$76	.246
95% CI	$32–$243		−$44–$156		−$211–$52
MB-related LOS (days)
Other OAC	.073		.065		.064
Apixaban	.056		.044		.055
Mean difference	.017	<.001	.021	<.001	.009	.111
95% CI	.008–.026		.013–.029		−.002–.021
MB-related hospital cost
Other OAC	$158		$148		$162
Apixaban	$132		$105		$135
Mean difference	$25	.036	$43	<.001	$27	.214
95% CI	$2–$50		$16–$69		−$15–$71
Stroke-related LOS (days)
Other OAC	.027		.016		.022
Apixaban	.019		.014		.016
Mean difference	.008	.003	.002	.466	.006	.158
95% CI	.003–.013		−.003–.006		−.002–.015
Stroke-related hospital cost
Other OAC	$64		$38		$51
Apixaban	$45		$38		$40
Mean difference	$19	.018	$0	.956	$11	.294
95% CI	$3–$38		−$14–$15		−$9–$35

These results were across all patients in each of the paired study cohorts, including patients where the LOS and hospital cost of patients without readmissions were equal to 0 days and $0, respectively.

Abbreviations. LOS, length of stay; MB, major bleeding.