Costs, Readmissions, and Negative Pressure Wound Therapies
Abstract and Introduction
Objective A retrospective national claims database analysis evaluated total and wound-related costs (eg, hospital readmission rates) for patients with chronic wounds treated with negative pressure wound therapy (NPWT), comparing NPWT-V (V.A.C. Therapy, KCI, an Acelity company, San Antonio, TX) and NPWT-O (other non-KCI models of NPWT, the brands of which were not known to the researchers).
Methods Patients with ≥ 1 NPWT claim from January 2009-June 2012 in outpatient settings in the United States were included, if they had continuous medical and pharmacy benefits for 12 months before the initial index date of their NPWT claim and at least 3 months post index. Mean total health care costs were assessed at 3 months and 12 months; wound-related hospital readmission rates were assessed at 3 months and 6 months. Cost differences between cohorts were analyzed by t test and readmission rates were analyzed by chi-square test.
Results At 3 months, the cohort of NPWT-V patients was significantly younger (59.2 vs 63.6 years, P < 0.01). The same patients were followed at 3, 6, and 12 months, although some fell out as time progressed. At the 3-month assessment, mean comorbidity scores did not differ between the NPWT-V group and the NPWT-O groups (3.38 vs 3.66). Total costs were lower for NPWT-V vs NPWT-O at 3 months ($35,498 vs $39,722, respectively; P = 0.08) and 12 months ($80,768 vs $111,212; P = 0.03). Significantly lower inpatient (P = 0.01), emergency room (P < 0.01), and home (P = 0.05) costs, despite higher (P = 0.04) NPWT costs, accounted for lower 12-month NPWT-V total costs. Wound-related readmission rates were significantly lower for NPWT-V at 3 months (5% vs 8%; P ≤ 0.01) and 6 months (6% vs 11%; P ≤ 0.01). For all wound types, NPWT-O patients had a 17-fold higher rate of switching to alternate NPWT models compared with NPWT-V patients.
Conclusion In this retrospective analysis, NPWT-V patients had lower total costs, lower wound-related costs, and lower hospital readmission rates than NPWT-O patients at all time points assessed.
Chronic wound care continues to pose a significant challenge to the US health care system, as the prevalence of diabetes and obesity increases and the population ages. Lazarus and colleagues define chronic wounds as "those that have failed to proceed through an orderly and timely reparative process to produce anatomic and functional integrity" of the injured site. Patients who are not healthy have a higher risk of developing nonhealing wounds.
Diabetic foot ulcers (DFUs), venous leg ulcers (VLUs), and pressure ulcers (PrUs) are common chronic wounds often treated in the outpatient setting. Among patients with diabetes, DFU prevalence has been reported as ranging from 4%-10% with an estimated lifetime incidence rate of 10%-25%. Diabetic foot ulcers are associated with 20% of hospital admissions and 40%-70% of nontraumatic amputations in the lower extremities occur in patients with diabetes. The prevalence of chronic venous ulcers in the general population is 1% compared to 4% in the population > 65 years of age. As many as 33% of patients treated for VLUs are estimated to have ≥ 4 recurrences. In US health care institutions, an estimated 2.5 million patients will develop PrUs, with an associated mortality rate of 60,000 deaths. During the period of 1993 to 2003, PrUs in hospitalized patients increased by 79%. According to the Agency for Healthcare Research and Quality, 72% of the patients who had PrUs during hospitalization in 2006 were ≥ 65 years old.
The increase in chronic wound patients has been reflected in rising health care costs. In 2009, Sen and coauthors reported 6.5 million patients in the United States were living with chronic wounds. Moreover, in 2007 the annual cost associated with chronic wounds was estimated at $25 billion. Estimated US costs related to treatment of a DFU ranged from $4,595 per ulcer episode to nearly $28,000 (in 1995 US dollars) for the 2-year period following diagnosis and more than $30,000 during the life of the ulcer. Many DFUs lead to minor or major amputations. In 2001 the average cost of a DFU-related amputation was $38,077 and annual cost for DFU care and related amputations was estimated to be $10.9 billion. In 1998, the annual US cost of treating VLUs was estimated at $2.5–$3.5 billion. In 2008, the average cost to treat a PrU as a secondary diagnosis was estimated at $43,180 per hospital stay, and $11 billion was the projected annual cost to treat PrUs.
Negative pressure wound therapy (NPWT) is an advanced adjunctive therapy used to facilitate healing in chronic wounds. For example, in a randomized controlled trial (RCT), Blume and colleagues14 compared NPWT (n = 169) to advanced moist wound therapy (AMWT) (n = 166) for treatment of DFUs. Significantly more DFUs achieved 100% wound closure with NPWT (73 of 169, 43.2%) than with AMWT (48 of 166, 28.9%) within the 112-day active treatment phase (P = 0.007). Patients treated with NPWT also had significantly (P = 0.035) fewer secondary amputations (7 of 169, 4.1% vs 17 of 166, 10.2%). While the majority of literature reports outcomes using 1 model of NPWT with reticulated open-cell foam dressings (V.A.C. Therapy, KCI, an Acelity company, San Antonio, TX), the number of NPWT alternatives has grown significantly in the past few years. Because material costs of NPWT may be higher than other therapies, the cost effectiveness of NPWT in terms of total costs and wound-related costs is an important consideration. Additionally, the varying costs across the range of NPWT models raise the issue of comparative effectiveness.
To better understand the comparative effectiveness of NPWT as a treatment for chronic wounds, this study analyzed de-identified insurance claim data for patients receiving any model of NPWT for costs and hospital readmission rates for the period following the initial NPWT claim in an outpatient setting.