Is HBOT Cost-Effective For Diabetic Foot Ulcers?
Faglia et al., reported impressive results in a prospective, randomized trial of HBOT in diabetic foot ulcers. In this study, researchers showed an 8.6 percent major amputation rate (below knee or higher) in the HBOT patients in comparison to 33.3 percent for the controls.11 Most interestingly, Faglia and colleagues were also able to show that a course of HBOT improved baseline transcutaneous values to a statistically significant degree, inferring an improvement in the vascular supply to the area.
From 1987 to 1996, six studies involved 435 patients who underwent HBOT with an 80 percent success rate. A retrospective study of the outcome of 1,144 diabetic foot ulcer patients receiving HBOT showed a 76 percent overall success rate, including a 42 percent benefit rate among patients with foot gangrene.12
Remember that patients with foot gangrene have been excluded from all prospective pharmaceutical trials since 1996. Although there are ongoing clinical trials of stem cells for revascularization, HBOT is the only modality that can improve tissue oxygen levels of DFUs, according to the currently published research.
Does The Data Support The Cost-Effectiveness Of HBOT?
In a review of HBOT and DFU, the Cochrane collaboration evaluated three randomized controlled trials, including a total of 118 patients, for whom the relative risk for major amputation was 0.31. The study concluded it is necessary to treat four patients with DFUs with HBOT in order to avert one major amputation.13
Guo et al., subsequently performed a study to evaluate the cost benefit of HBOT.14 The study population was a hypothetical cohort of 1,000 patients who were 60 years of age and had severe DFUs. Researchers constructed a decision tree model to estimate the cost effectiveness of HBOT in the treatment of diabetic foot ulcers at one, five and 12 years.
In this theoretical cohort, the HBOT group had 45 more minor amputations. However, 155 major lower extremity amputations would be averted and these patients gained approximately 50, 265 and 608 quality-adjusted life years (QALY) at one, five and 12 years respectively. This exercise suggests the benefits of HBOT accrue over time in part due to savings from averted major amputations.
Apelquist et al., analyzed the three-year follow-up costs for patients with diabetic foot ulcers from the time of healing (with or without amputation).15 Total average costs for patients who achieved primary healing and did not have critical ischemia were $16,000 (in 1995) in comparison to $63,000 for patients who had required major amputation. This suggests that a course of HBOT in appropriately selected patients is cost-effective.
As a result of the data to support its benefit, hyperbaric oxygen therapy has garnered recommendations from seven independent evidence-based reviews: Blue Cross Blue Shield (1999), the American Diabetic Association Foot Council (1999), the Wound Healing Society (2006), the British Journal of Medicine (2001-2002), the Agency for Healthcare Research and Quality (AHRQ) Report to CMS (2001) and the Medical Services Advisory Committee of Australia (2000).
The Centers For Medicare and Medicaid Services (CMS) issued a Coverage Decision for HBOT in Diabetic Foot Wounds in 2002. The CMS maintains that HBOT is reasonable and necessary in the treatment of limb-threatening diabetic wounds of the lower extremity if the ulcer is a Wagner grade III or worse with no measurable signs of healing for at least 30 days despite standard wound therapy.
Keys To Gauging Proper Patient Selection
The cost effectiveness of HBOT is dependent on ensuring that patients who would heal anyway do not undergo HBOT, and patients who cannot benefit from HBOT are similarly excluded.
Transcutaneous oximetry has been suggested as one way of enhancing patient selection. An evidence-based approach to the use of transcutaneous oximetry is in press.16 The first step is to assess whether wounds are likely to heal spontaneously by using baseline TcPO2.17After vascular status has been optimized, repeat transcutaneous oximetry can assist in determining whether healing is likely.