Burden of venous leg ulcers in the United States

Figures & data

Figure 1. Selection of VLU patients and non-VLU patients. Notes: 1. Total patient population includes all beneficiaries with at least one medical claim in years evaluated. 2. VLU patients defined as those with at least one claim with ICD-9-CM: 454.0x, 454.1x, 454.2x, 459.11, 459.13, 459.31, 459.33, and 459.81 in years evaluated. 3. Index date defined as the most recent VLU diagnosis date meeting all sample selection criteria. 4. Index date defined as the date of a random medical claim in years evaluated.

Table 1. Patient characteristics, resource utilization, and healthcare costs during the 12 months prior to the index date—Medicare.

	Pre-match characteristics^a			Post-match characteristics^a
	VLU (n = 60,840)	Non-VLU (n = 349,753)	p^b	VLU (n = 58,672)	Non-VLU (n = 58,672)	p^b
Demographic characteristics
Age,^c mean (SD)	77.9 (7.4)	75.7 (7.1)	<0.0001	77.9 (7.4)	78.0 (7.5)	0.0001
Male, %	35.2	41.3	<0.0001	34.9	34.9	1.0000
Year of index date, %
2007	30.4	33.3	<0.0001	30.7	30.7	1.0000
2008	33.5	32.5	<0.0001	33.4	33.4	1.0000
2009	36.0	34.2	<0.0001	35.9	35.9	1.0000
Select comorbid conditions, %
Hypertension	78.2	67.4	<0.0001	77.6	79.3	<0.0001
Hyperlipidemia	55.3	53.0	<0.0001	54.9	56.5	<0.0001
Mild-to moderate diabetes	16.8	16.1	<0.0001	16.9	17.4	0.0258
Diabetes with complications	16.3	7.8	<0.0001	15.0	14.9	0.7994
Peripheral vascular disease	26.6	12.6	<0.0001	25.0	24.8	0.3816
Congestive heart failure	24.0	11.8	<0.0001	22.3	21.9	0.0388
Cerebrovascular disease	16.2	11.3	<0.0001	15.5	15.9	0.0287
COPD	18.8	12.2	<0.0001	17.8	17.7	0.8661
Cellulitis of lower limb	14.6	4.0	<0.0001	12.7	11.6	<0.0001
Osteomyelitis of lower limb	1.0	0.2	<0.0001	0.7	0.5	<0.0001
Periostitis of lower limb	0.1	0.0	<0.0001	0.1	0.1	0.5708
Other infection in lower limb	0.0	0.0	<0.0001	0.0	0.0	0.3532
Septicemia	2.4	1.0	<0.0001	1.8	1.6	0.0005
Depression	12.4	8.9	<0.0001	11.7	12.2	0.0045
Any malignancy	13.5	11.9	<0.0001	13.4	13.7	0.1211
Obesity	8.2	3.7	<0.0001	7.4	7.3	0.2142
Myocardial infarction	6.3	4.3	<0.0001	5.8	5.8	0.7569
Smoking	6.5	5.6	<0.0001	6.4	6.3	0.6304
Deep vein thrombosis	4.9	1.4	<0.0001	4.1	3.4	<0.00011
Phlebitis	3.6	1.0	<0.0001	3.0	2.5	<0.0001
Renal disease	12.0	6.2	<0.0001	11.0	10.6	0.0471
Metastatic solid tumor	1.5	1.1	<0.0001	1.4	1.3	0.5920
Other ulcers	3.9	1.2	<0.0001	3.1	2.6	<0.0001
Venous insufficiency	0.0	0.0	–	0.0	0.0	–
Medical resource use, mean (SD)
Hospitalization days	1.3 (5.4)	0.7 (3.6)	<0.0001	1.0 (4.0)	0.9 (3.5)	<0.0001
Emergency department visits	0.8 (1.4)	0.4 (1.1)	<0.0001	0.7 (1.3)	0.7 (1.2)	0.0187
Outpatient visits	42.0 (34.2)	27.2 (25.6)	<0.0001	39.3 (29.4)	39.1 (30.1)	<0.0001
Total healthcare costs,^d mean (SD)	$14,801 ($25,165)	$8211 ($17,685)	<0.0001	$12,415 ($18,889)	$12,415 ($18,890)	0.3651

^aVLU patients were matched one-to-one to non-VLU patients based on gender, year of index date, pre-index healthcare costs (±10%), and likelihood of developing a leg ulcer as determined by propensity scores (calipers equal to ¼ standard deviation) using greedy matching. All characteristics reported in this table other than those accounted for during one-to-one matching (i.e., gender, index year, and total healthcare costs) were included as covariates in the propensity score estimation model,

^bCalculated using Wilcoxon-rank sum tests for continuous variables and chi-square tests for categorical variables prior to matching and Wilcoxon signed-rank tests for continuous variables and McNemar’s tests for categorical variables post-match.

^cEstimated in quarter 4 of the year preceding index quarter.

^dOnly medical costs were used as Medicare data does not contain prescription drug information. Dollar values were inflated to 2012 USD using the medical care component of the Consumer Price Index.

Table 2. Patient characteristics, resource utilization, and healthcare costs during the 12 months prior to the index date—Private insurance.

	Pre-match characteristics^a			Post-match characteristics^a
	VLU (n = 26,096)	Non-VLU (n = 130,045)	p^b	VLU (n = 22,476)	Non-VLU (n = 22,476)	p^b
Demographic characteristics
Age,^c mean (SD)	50.6 (9.3)	44.5 (12.2)	<0.0001	50.0 (9.4)	49.9 (9.9)	0.0115
Male, %	33.2	49.9	<0.0001	31.2	31.2	1.0000
Year of index date, %
2007	21.6	27.3	<0.0001	21.8	21.8	1.0000
2008	24.8	24.2	0.0300	25.0	25.0	1.0000
2009	28.8	27.3	<0.0001	28.6	28.6	1.0000
2010	24.8	21.2	<0.0001	24.6	24.6	1.0000
Select comorbid conditions, %
Hypertension	33.9	20.2	<0.0001	29.9	29.2	0.0951
Hyperlipidemia	33.1	23.2	<0.0001	31.0	30.3	0.0704
Mild-to-moderate diabetes	10.7	5.8	<0.0001	9.5	9.2	0.3490
Diabetes with complications	5.5	1.4	<0.0001	3.2	3.0	0.2433
Peripheral vascular disease	5.8	1.1	<0.0001	3.3	2.7	<0.0001
Congestive heart failure	4.7	1.4	<0.0001	2.6	2.3	0.0175
Cerebrovascular disease	3.9	1.5	<0.0001	2.6	2.3	0.0804
COPD	3.7	1.3	<0.0001	2.4	2.2	0.2243
Cellulitis of lower limb	7.6	1.3	<0.0001	3.6	3.8	0.3687
Osteomyelitis of lower limb	0.7	0.1	<0.0001	0.2	0.2	0.0620
Periostitis of lower limb	0.0	0.0	0.0074	0.0	0.0	1.0000
Other infection in lower limb	0.0	0.0	0.0248	0.0	0.0	0.5637
Septicemia	1.1	0.2	<0.0001	0.3	0.2	0.0702
Depression	8.2	6.5	<0.0001	7.3	8.5	<0.0001
Any malignancy	5.7	2.7	<0.0001	4.7	4.8	0.7850
Obesity	6.5	2.4	<0.0001	4.7	4.9	0.5424
Myocardial infarction	0.9	0.5	<0.0001	0.6	0.5	0.1707
Smoking	1.8	1.7	0.2750	1.6	1.7	0.8228
Deep vein thrombosis	3.5	0.3	<0.0001	1.3	0.8	<0.0001
Phlebitis	4.9	0.4	<0.0001	1.4	1.0	<0.0001
Renal disease	2.9	0.7	<0.0001	1.5	1.1	0.0001
Metastatic solid tumor	1.7	0.4	<0.0001	1.0	0.5	<0.0001
Other ulcers	0.7	0.1	<0.0001	0.2	0.1	0.0011
Venous insufficiency	0.1	0.0	<0.0001	0.0	0.0	1.0000
Medical resource use, mean (SD)
Hospitalization days	6.2 (18.1)	2.4 (9.3)	<0.0001	3.8 (11.2)	3.3 (9.6)	<0.0001
Emergency department visits	0.6 (1.6)	0.4 (1.1)	<0.0001	0.5 (1.2)	0.5 (1.3)	0.0455
Outpatient visits	11.9 (12.9)	6.5 (9.0)	<0.0001	9.7 (9.4)	9.8 (10.9)	<0.0001
Any immunosuppressant use, %	0.7	0.3	<0.0001	0.4	0.4	0.6434
Unique medications,^d mean (SD)	7.9 (8.4)	4.7 (5.8)	<0.0001	6.6 (6.7)	6.9 (7.1)	<0.0001
Total healthcare costs,^e mean (SD)	$13,959 ($42,588)	$6197 ($33,633)	<0.0001	$6856 ($11,361)	$6856 ($11,358)	0.8498

^aVLU patients were matched one-to-one to non-VLU patients based on gender, year of index date, pre-index healthcare costs (±10%), availability of work-loss data, and likelihood of developing a leg ulcer as determined by propensity scores (calipers equal to ¼ standard deviation) using greedy matching. All characteristics reported in this table other than those accounted for during one-to-one matching (i.e., gender, index year, and total healthcare costs) were included as covariates in the propensity score estimation model.

^bCalculated using Wilcoxon-rank sum tests for continuous variables and chi-square tests for categorical variables prior to matching and Wilcoxon signed-rank tests for continuous variables and McNemar’s tests for categorical variables post-match.

^cEstimated at index date.

^dCalculated as the number of prescriptions filled with unique NDC codes according to the first 9 digits.

^eCalculated as the sum of medical and prescription drug costs. Dollar values were inflated to 2012 USD using the medical care component of the Consumer Price Index.

Figure 2. Components of per-patient all-cause healthcare cost differential during the 12-month follow-up period (VLU—matched non-VLU patients). Notes: 1. Percentages reflect the share of excess costs attributable to the place of service. 2. Prescription drug claims were not available for Medicare.

Table 3. Healthcare resource utilization and direct costs during the 12 months following the index date among matched VLU and non-VLU patients*.

	Medicare		Privately-insured
	VLU (n = 58,672) Mean [Median] (SD)	Non-VLU (n = 58,672) Mean [Median] (SD)	VLU (n = 22,476) Mean [Median] (SD)	Non-VLU (n = 22,476) Mean [Median] (SD)
Medical resource use
Hospitalization days	1.6 [0.0] (6.0)	0.9 [0.0] (4.3)**	6.8 [1.0] (18.6)	3.6 [1.0] (11.0)**
Emergency department  visits	0.9 [0.0] (1.5)	0.6 [0.0] (1.3)**	0.6 [0.0] (1.7)	0.4 [0.0] (1.3)**
Outpatient/physician  visits	48.3 [38.0] (39.1)	37.9 [30.0] (32.4)**	14.3 [11.0] (13.2)	10.1 [7.0] (11.1)**
Home healthcare days	0.8 [0.0] (1.9)	0.5 [0.0] (1.5)**	1.4 [0.0] (5.7)	0.4 [0.0] (2.5)**
Other	4.4 [1.0] (7.9)	3.5 [0.0] (7.0)**	4.9 [2.0] (8.3)	4.2 [2.0] (7.5)**
Direct healthcare costs
Total all-cause medical	$18,986 [$6637] ($29,642)	$12,595 [$4006] ($22,464)**	$13,653 [$4766] ($39,342)	$6623 [$1911] ($19,658)**
Total all-cause medical  and prescription drug^a	–	–	$15,296 [$6156] ($40,071)	$8210 [$3164] ($20,756)**
Total VLU-related  medical costs^b	$2611 [$0] ($10,169)	–	$3066 [$422] ($16,190)	–

*Statistically significant difference vs VLU patients at p < 0.05 using Wilcoxon signed-rank tests; **Statistically significant difference vs VLU patients at p < 0.0001 using Wilcoxon signed-rank tests.

^aPrescription drug data were not available for Medicare patients.

^bVLU-related costs include costs for claims with an ulcer or infection diagnosis or other related procedure codes.

Table 4. Disability, absenteeism, and related costs among matched VLU and non-VLU patients—privately-insured primary beneficiaries only^a.

	VLU (n = 5309) Mean [Median] (SD)	Non-VLU (n = 5309) Mean [Median] (SD)
12 months prior to the index date
Work-loss days
Total	9.4 [4.5] (24.3)	9.4 [4.0] (24.1)
Disability	3.3 [0.0] (23.7)	3.1 [0.0] (23.2)
Absenteeism^b	6.1 [4.0] (7.0)	6.3 [4.0] (7.7)
12 months following the index date
Work-loss days
Total	14.0 [7.0] (27.5)	10.0 [4.5] (24.7)**
Disability	4.5 [0.0] (25.5)	3.3 [0.0] (23.6)**
Absenteeism^b	9.5 [6.5] (11.4)	6.7 [4.0] (8.3)**
Work-loss costs^c, mean (SD)
Total	$2481 [$1258] ($4667)	$1924 [$875] ($3736)**
Disability	$506 [$0] ($3141)	$345 [$0] ($2599)**
Absenteeism	$1975 [$1147] ($3489)	$1579 [$812] ($2630)**

*Statistically significant difference vs VLU patients at p < 0.05 using Wilcoxon signed-rank tests, **Statistically significant difference vs VLU patients at p < 0.0001 using Wilcoxon signed-rank tests.

^aPrimary beneficiaries include those claimants in the OptumInsight database who were actively employed for the entirety of the period of interest (i.e., 12 months prior to or following the index date) and had disability as well as wage information.

^bAbsenteeism includes missed work due to medical visits. It is assumed that outpatient and other visits result in half-days of missed work; inpatient and ED visits result in full days of missed work.

^cCosts related to absenteeism consist of the product of the number of absenteeism days and employee’s daily wage, whereas costs due to disability were directly available from the database.

Table 5. Estimated annual incidence of VLU in Medicare and private insurance.

	Medicare			Private insurance
Year	New patients^a	Total patients^b	Incidence^c	New patients^a	Total patients^b	Incidence^c
2007	23,644	1,116,983	2.1%	8322	1,917,988	0.4%
2008	23,348	1,094,325	2.1%	7556	1,545,801	0.5%
2009	24,369	1,089,946	2.2%	7592	1,507,734	0.5%
2010	–	–	–	10,009	1,656,530	0.6%
Total	71,361	3,301,254	2.2%	33,479	6,628,053	0.5%

^aNew patients defined as those with at least one VLU diagnosis in the calendar year but no VLU diagnosis in the previous year. Patients were also required to meet other sample selection criteria (in terms of age restrictions and enrollment).

^bTotal patients were defined as those with at least one medical claim and continuous non-HMO insurance coverage in the year of estimation as well as the previous year.

^cIncidence was calculated by dividing the number of new patients by the number of total patients in the calendar year.

Table 6. Estimated economic burden of VLUs in the US—by payer type.

	Population	Incidence	VLU patients	Per-patient healthcare costs	Total burden (in billions)
	[a]	[b]	[c] = [a] × [b]	[d]	[e] = [c] × [d]
Medicare^a	42,204,000	2.2%	928,488	$6391	$5.9
Private insurance^b	161,160,406	0.5%	805,802	$7086	$5.7
Other^c,d	37,173,514	1.3%	483,256	$6739	$3.3
Total burden (all payers combined)					$14.9

^aOnly includes Medicare beneficiaries aged 65+.

^bAssumed to be 67% of the total US population aged 18+ years.

^cCalculated as the total 2012 US population aged 18+ (n = 240,537,920) less the number of Medicare and privately-insured beneficiaries.

^dBurden estimates for the ‘other’ population are calculated using the average incidence and average per-patient healthcare costs across Medicare and private insurance.