Length of stay and hospital costs among high-risk patients with hospital-origin Clostridium difficile-associated diarrhea

Figures & data

Table 1.  Patient and clinical characteristics (HO-CDAD cases).

	Renal impairment		Age ≥65		Cancer/BMT		IBD		CAbx exposure
	(n = 3236)		rowsep="1"(n = 3064)		(n = 782)		(n = 84)		(n = 1641)
	n	%	n	%	n	%	n	%	n	%
Patient and encounter characteristics
Age, years (mean [SD])	72.9 (13.4)		78.7 (7.4)		69.2 (14.0)		61.2 (18.3)		61.2 (14.8)
Male gender	1427	44.1	1321	43.1	395	50.5	32	38.1	746	45.5
Caucasian race	2596	80.2	2577	84.1	635	81.2	75	89.3	1305	79.5
Patient type surgical (vs medical and unknown)	1068	33.0	937	30.6	267	34.1	32	38.1	629	38.3
Admission source
Hospital/other care facility	214	6.6	205	6.7	40	5.1	5	6.0	106	6.5
SNF/NH/LTC	241	7.4	277	9.0	34	4.4	4	4.8	134	8.2
Emergency room	1895	58.6	1785	58.3	417	53.3	43	51.2	955	58.2
Other/unknown^a	886	27.4	797	26.0	291	37.2	32	38.1	446	27.2
Discharge diagnosis of pseudomembranous colitis (ICD-9-CM 008.45)
Any	2286	70.6	2217	72.4	561	71.7	62	73.8	1179	71.9
As primary Dx	202	6.2	198	6.5	58	7.4	8	9.5	89	5.4
As a secondary Dx	2084	64.4	2019	65.9	503	64.3	54	64.3	1090	66.4
Evidence of impaired immunity	1291	39.9	1062	34.7	585	74.8	84	100	651	39.7
Comorbid conditions^b
Charlson Comorbidity Index score, mean (SD)27	3.0 (2.4)		2.7 (2.4)		5.0 (2.5)		1.8 (2.2)		2.7 (2.4)
Heart failure	1443	44.6	1411	46.0	212	29.0	24	28.6	625	38.1
Coronary artery disease	1262	39.0	1276	41.6	233	31.8	15	17.9	533	32.5
Diabetes	1140	35.2	982	32.0	197	26.9	18	21.4	482	29.4
COPD	917	28.3	941	30.7	223	30.5	19	22.6	461	28.1
Cerebrovascular disease	557	17.2	578	18.9	88	12.0	9	10.7	260	15.8
Cirrhosis/chronic liver disease	156	4.8	93	3.0	35	4.8	4	4.8	81	4.9
Severity of illness measures
Any organ system dysfunction around time of index toxin	2132	65.9	1807	59.0	483	61.8	35	41.7	1076	65.6
Critical care use within 48 h of admission	801	24.8	717	23.4	150	19.2	13	15.5	517	31.5
Severity of CDAD^c
Mild/moderate/indeterminate	1645	50.8	1596	52.1	416	53.2	38	45.2	644	39.2
Severe	1088	33.6	1018	33.2	246	31.5	24	28.6	566	34.5
Severe/complicated	503	15.5	450	14.7	120	15.4	22	26.2	431	26.3

BMT, bone marrow transplant; CAbx, concomitant antibiotic; CDAD, Clostridium difficile-associated diarrhea; COPD, chronic obstructive pulmonary disease; Dx, diagnosis; IBD, inflammatory bowel disease; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; LTC, long-term care; NH, nursing home; SD, standard deviation; SNF, skilled nursing facility.

^aIncludes physician referral, clinic referral, transfer from home health agency, court/law enforcement.

^bComorbid conditions defined by diagnosis codes present during the index encounter or up to 12 months prior to admission.

^cVariable not included in LOS or cost models.

Table 2.  CDAD antimicrobial exposure data (HO-CDAD cases).

	Renal impairment		Age ≥65		Cancer/BMT		IBD		CAbx exposure
	(n = 2315)^a		(n = 2211)^a		(n = 532)^a		(n = 59)^a		(n = 1641)^a
First CDAD antibiotic (n, %)
Vancomycin (oral/nasogastric/rectal)	193	8.3	180	8.1	41	7.7	4	6.8	106	6.5
Metronidazole	1902	82.2	1832	82.9	449	84.4	47	79.7	1372	83.6
Both	220	9.5	199	9.0	42	7.9	8	13.6	163	9.9
Vancomycin exposure
Exposure to oral slurry^b (n, %)	430	56.8	399	56.4	83	47.7	14	45.2	367	59.3
Maximum daily dose, mg (mean [SD])^c	880 (519)		866 (503)		912 (458)		1174 (909)		927 (535)
Total days ordered (mean [SD])	9.7 (10.4)		8.8 (9.3)		9.5 (9.0)		10.6 (9.4)		11.9 (13.5)
Metronidazole use
First daily dose ordered, mg (mean [SD])^c	1419 (273)		1423 (270)		1438 (268)		1417 (287)		1454 (258)
Total days ordered (mean [SD])	9.1 (8.6)		8.9 (7.9)		9.0 (7.6)		10.9 (9.8)		11.8 (10.3)

BMT, bone marrow transplant; CAbx, concomitant antibiotic; CDAD, Clostridium difficile-associated diarrhea; IBD, inflammatory bowel disease; SD, standard deviation.

^aNumber of patients who had any CDAD-associated antibiotic exposure. The percentage of all patients in each group with any exposure ranged from 68% in the cancer group to 100% in the CAbx use group.

^bAmong patients with any vancomycin exposure.

^cAmong patients with dose data available.

Table 3.  Unadjusted clinical and resource utilization outcomes (HO-CDAD cases).

	Renal impairment	Age ≥65	Cancer/BMT	IBD	CAbx exposure
	(n = 3236)	(n = 3064)	(n = 782)	(n = 84)	(n = 1641)
Total hospital LOS, days (mean [SD])	22.7 (28.2)	21.3 (25.3)	21.3 (18.5)	21.0 (19.1)	29.3 (34.7)
Total hospital costs, index admission, 2010$ (mean [SD])^a	46,358 (66,147)	44,842 (62,066)	44,244 (66,536)	36,834 (41,097)	72,349 (91,402)
In-hospital mortality (n, %)^b	480 (14.83%)	452 (14.75%)	121 (15.47%)	10 (11.90%)	259 (15.78%)

BMT, bone marrow transplant; CAbx, concomitant antibiotic; CDAD, Clostridium difficile-associated diarrhea; IBD, inflammatory bowel disease; LOS, length of stay; SD, standard deviation.

^aCost data available for ∼75% of patients.

^bApproximately 0.3–0.5% of patients were missing discharge disposition; mortality was calculated among those with available discharge disposition data.

Figure 1.  Adjusted total hospital LOS. Data shown are differences (95% confidence interval) in days between HO-CDAD and control patients. BMT, bone marrow transplant; CAbx, concomitant antibiotics; IBD, inflammatory bowel disease. *p-value for difference < 0.001.

Figure 2.  Adjusted total hospital costs. Data shown are differences (95% confidence interval) between HO-CDAD and control patients. BMT, bone marrow transplant; CAbx, concomitant antibiotics; IBD, inflammatory bowel disease. *p-value for difference < 0.001; **p-value for difference = 0.012.

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