The effect of major adverse renal cardiovascular event (MARCE) incidence, procedure volume, and unit cost on the hospital savings resulting from contrast media use in inpatient angioplasty

Figures & data

Table 1. Annual US inpatient angioplasties, MARCE adverse events, and costs.

Variable	Value
Weighted annual number of primary inpatient angioplasties^a	513,882
Weighted annual number of MARCE events^a	35,038
Estimated annual reduction in MARCE events if switch from “LOCM only” strategy to an “IOCM only” strategy*^,^b	2,900
Average total cost of a primary inpatient angioplasty ($US 2017)**^,^a
w/MARCE	$34,765
w/o MARCE	$19,061
Average additional contrast media cost per angioplasty “IOCM only” vs “LOCM only” strategies ($US 2017)***^,^a	$8.24
Base case additional contrast media cost per procedure ($US 2017)^a	$32.97

^a Source: Premier Hospital Data (2014 Q4–2015 Q3); weighted estimates project Premier Hospital Data to national level.

^b Source: Author calculation based on Premier Hospital Data (2008 Q1–2013 Q3) and Premier Hospital Data (2014 Q4–2015 Q3).

* This measure applies the 9.3% relative risk reduction for MARCE incidence as determined in previously conducted work (under review) and accounts for the relative share of contrast media currently used in inpatient angioplasty (including those who receive no contrast media due to contraindication). Given our data, we applied a method which assessed this value using difference in absolute risk and one which used relative risk reduction solely. The relative risk reduction methods were slightly more conservative (biased against finding a global savings result), so we present that here.

** The cost figures have been updated to $US 2017 from $US 2015 dollars using the Medical CPI from the US Bureau of Labor Services (BLS). We applied the “medical care commodities” index to the contrast media costs and the “hospital service” index to the total inpatient angioplasty costs.

*** These measures account for volume differences and price differences per procedure. The difference was found to be $7.75 ($US 2015) given that procedures using “IOCM only” typically had lower levels of volume, but a higher price per volume than procedures which solely used LOCM. We multiplied this figure by 4× to be additionally conservative in our base case estimate.

Table 2. Frequency and costs of inpatient angioplasties with and without MARCE adverse events (by hospital type).

Hospital characteristic	Weighted number of inpatient angioplasty procedures^a	Frequency of MARCE events^a	Average total cost of primary inpatient angioplasty with MARCE event^b	Average total cost of a primary inpatient angioplasty without MARCE event^b	Difference in cost between angioplasty with and without MARCE event
Region
West	94,743	7.22%	$42,953	$23,628	$19,325
Midwest	133,034	6.61%	$30,295	$17,296	$12,999
Northeast	86,157	5.42%	$44,800	$21,889	$22,911
South	200,225	7.35%	$30,443	$16,837	$13,606
Teaching status
Teaching	139,147	6.67%	$36,567	$19,358	$17,209
Non-teaching	375,012	6.87%	$34,115	$18,950	$15,165
Location
Urban	501,178	6.83%	$34,871	$19,079	$15,792
Rural	12,980	6.13%	$30,174	$18,385	$11,789
Bed size
0–99	18,308	6.07%	$33,026	$17,396	$15,630
100–199	65,195	6.73%	$31,726	$19,391	$12,335
200–299	69,915	6.74%	$34,871	$20,379	$14,492
300–399	118,939	7.01%	$30,174	$19,951	$10,223
400–499	75,860	7.26%	$32,059	$17,993	$14,066
500+	165,941	6.62%	$34,869	$18,411	$16,458
US total	513,882	6.8%	$34,765	$19,061	$15,704

^a Source is Premier Hospital Data (Q4 2014–Q3 2015), which is scaled up to estimate national totals.

^b The cost figures have been updated to US$2017 from US$2015 dollars using the Medical CPI from the US Bureau of Labor Services.

Table 3. Estimated annual aggregate, per hospital and per procedure global savings associated with adoption of an “IOCM only” strategy vs “LOCM only” strategy for inpatient angioplasties.

Hospital characteristic	Annual global cost savings estimate^a	Estimated hospital count^b	Avg annual cost savings per hospital	Avg cost savings per angioplasty procedure
Region
West	$8,212,211	919	$8,937	$87
Midwest	$5,622,156	1,444	$3,893	$42
Northeast	$6,376,609	627	$10,167	$74
South	$10,803,097	1,872	$5,771	$54
Teaching status
Teaching	$9,196,029	983	$9,353	$66
Non-teaching	$21,511,001	3,879	$5,546	$57
Location
Urban	$30,290,936	3,033	$9,987	$60
Rural	$402,021	1,829	$220	$31
Bed size
0–99	$908,850	2,537	$358	$50
100–199	$2,599,280	984	$2,641	$40
200–299	$4,075,126	554	$7,351	$58
300–399	$8,704,440	338	$25,718	$73
400–499	$4,222,638	184	$22,972	$56
500+	$10,170,939	265	$38,447	$61
US total	$30,707,491	4,862	$6,316	$60

^a Total cost savings for each of the hospital group are estimated using the reduction in relative risk methodology. With respect to aggregate cost savings, sub-group totals do not sum precisely to the national total due to use of national average data rather than sub-group specific data within the model (sub-group data was not available for all estimates, given restricted access to the database at more refined levels).

^b Hospital count statistics were generated by applying shares based on publicly available US community hospital data to the overall non-federal community hospital count data from the AHA (Overall number of community hospitals, AHA 2017; Geographic distribution by region, Kaisar Family Foundation and US Census; Teaching Status and Bed Size, AHRQ’s HCUP (2012)).

Table 4. Relative impact of key determinants on global hospital cost savings associated with adoption of an “IOCM only” strategy vs “LOCM only” strategy across hospital sub-groups.

Hospital characteristic	Key determinant category
	Volume			Incidence	Cost
	Procedure share	Hospital share	Procedures per hospital	MARCE rate	MARCE cost differential
Region
West	0.70	0.71	0.98	1.06	1.23
Midwest	1.43	1.64	0.87	0.97	0.83
Northeast	0.82	0.63	1.30	0.80	1.46
South	1.12	1.11	1.01	1.08	0.87
Teaching status
Teaching	0.90	0.68	1.34	0.98	1.10
Non-teaching	1.04	1.14	0.91	1.01	0.97
Location
Urban	0.99	0.63	1.56	1.00	1.01
Rural	1.93	28.72	0.07	0.90	0.75
Bed size
0–99	1.20	17.61	0.07	0.89	1.00
100–199	1.50	2.39	0.63	0.99	0.79
200–299	1.02	0.86	1.19	0.99	1.00
300–399	0.82	0.25	3.32	1.03	1.12
400–499	1.07	0.27	3.90	1.06	0.90
500+	0.97	0.16	5.93	0.97	1.05
US Total	1.00	1.00	1.00	1.00	1.00

^a Relative impact is a measure which reflects how important a factor is in determining the overall savings for the hospital sub-group relative to the importance in determining savings at the national level. A figure greater (less) than 1 indicates that the effect of the factor was greater (less) than the effect of the same factor at the national level in determining the total global cost savings for that particular sub-group. To estimate the procedure and hospital share factors, we divide the national share of procedures (or hospitals) for each level of the sub-group by the share of global savings which that sub-group generates relative to the national total. To estimate the procedures per hospital, MARCE rate and MARCE cost differential factors, we divide the sub-group value by the national value for each metric.

Figure 1. Cost savings: one way sensitivity analyses.

Figure 2. Annual per hospital MARCE savings, contrast media cost and global savings vs share of inpatient angioplasty procedures with IOCM.