Economic Study of Collagen-Glycosaminoglycan Biodegradable Matrix for Chronic Wounds

Collagen-glycosaminoglycan biodegradable matrix (Integra™ Bilayer Matrix Wound Dressing, Integra LifeSciences, Plainsboro, NJ) is a bovine collagen/shark cartilage matrix with a silicone backing that allows the patient to generate a “neo-dermis.” Soon after the success of collagen-glycosaminoglycan biodegradable matrix in treating burn wounds was established, centers familiar with its potential for decreasing scar at donor sites began using it to treat chronic wounds of many different types with good success.^1–3 Many reported wonderful outcomes,^1–3 but no analysis of cost has been reported. Some reports have eluded to the functionality, durability, and cosmesis of collagen-glycosaminoglycan biodegradable matrix,^1–3 but what is the additional cost? The authors attempted to determine if collagen-glycosaminoglycan biodegradable matrix was more costly then split-thickness skin grafts (STSGs).

Study Design

A retrospective study was designed to identify patients with similar wounds and similar medical conditions that were treated with the 2 modalities (collagen-glycosaminoglycan biodegradable matrix vs. STSG). Medical diagnosis codes were identified for 5 types of chronic wounds: nonhealing surgical wound, decubitus ulcer, venous stasis ulcer, fasciitis, and leg ulcer. The codes were obtained by conducting a search of the hospital’s computerized billing system. This list was then cross referenced for surgical codes to help identify patients who received STSG and those who received collagen-glycosaminoglycan biodegradable matrix as their treatment. The patients’ wounds and medical conditions were then matched as close as possible. Charts of these patients from the hospital and the wound care center were reviewed and data extracted. Only charges related to wound care were extracted from the chart. These included operative cost (based on hospital charges per each 15 minute interval of operative time or portion thereof, hospital charges for supplies consumed during the operation, and anesthesiologist and surgeon charges); hospital charges for wound care (based on room charge per day of hospitalization, charges for anti-infective agents used to treat wound infections or for perioperative prophylaxis, dressings, growth factors, topical agents, negative pressure wound therapy, narcotics used to control wound pain or pain from painful procedures performed on the wounds outside of the operating room, and charges for sedation required to decrease wound care related anxiety); and outpatient charges (based on charges for facility fee, physician fees, supplies consumed, dressings [not including visiting nurse charges], negative pressure wound therapy, anti-infective agents used to treat organisms demonstrated by wound culture, narcotics used to control wound pain, growth factors, and charges for topical agents) (Table 1). Some assumptions were utilized. Since there were different surgeons involved in the various cases and discussions of individual charges among surgeons could violate antitrust laws, the charges used for surgeon fees were based on current procedural terminology (CPT) code and the primary author’s billing structure. Essentially, for the purposes of this study, each patient was charged the same rate for the same CPT code. The CPT code was determined based on the description of the operation in the typed operative report. Visiting nurse charges were not obtainable; thus, an assumption was made that visiting nurses were used equally among the groups, and charges could therefore be discarded. It was also assumed that nonwound problems (eg, pneumonia, urinary tract infection, congestive heart failure, renal failure) were not related to the treatment type but to the patient’s medical status and could be disregarded in relation to wound care charges. It should be noted that these assumptions were made prior to data extraction. Table 2 illustrates the extracted case characteristics.

Results

Figure 1 shows the total charges for wound care sorted by case. In an attempt to normalize the charges for size of wound, the total charges for wound care divided by the square surface area of the wound is depicted in Figure 2. Neither shows a significant difference between collagen-glycosaminoglycan biodegradable matrix and STSG. The average charge for a chronic wound treated with collagen-glycosaminoglycan biodegradable matrix was $66,715.71 and for STSG was $91,987.97. The median was $43,127.78 and $60,725.04, respectively. Dividing the total charge by square surface area of the wound yielded an average charge/cm2 of $703.92 for collagen-glycosaminoglycan biodegradable matrix and $693.51 for STSG. The median was $531.92 for collagen-glycosaminoglycan biodegradable matrix and $612.61 for STSG. The average of the total charges divided by the number of days required to completely heal the wound was $709.74 for the patients treated with collagen-glycosaminoglycan biodegradable matrix and $729.88 for patients treated with STSG, with a median of $211.41 and $276.02, respectively, which was again not significantly different. Data for each case is presented in graphic form in Figure 2. Figure 3 shows the charges per day of care. The average of the time it took to heal the wounds divided by the square surface area in cm² is also not significantly different between collagen-glycosaminoglycan biodegradable matrix (2.5 days) and STSG (2.46 days). The facilities’ costs are presented in Figure 4, and again, no significant difference was found. Figures 5 and 6 depict total surgeon charges and total surgeon charges divided by the wound area. The average charges by the surgeons were $2,759.00 for collagen-glycosaminoglycan biodegradable matrix and $7,341.80 for STSG (P = 0.18). The average surgeon’s charge per cm² of wound was $40.22 for collagen-glycosaminoglycan biodegradable matrix and $77.06 for STSG. This was not significantly different (P = 0.07). Figures 7–11 show that there was no significant difference in narcotic use, antibiotic use, hospital days, or healing time.

Discussion

Charges were used instead of cost for the following reasons. First, the hospital and the wound care center consider cost to be proprietary. Second, physicians’ collections differ from surgeon to surgeon and based on their contracts with insurance companies. In order to more accurately compare the economic impact, charges for the hospital, the wound care center, and the physician were used. This study has all the limitations of a retrospective study. The authors also were forced to make several assumptions that may have impacted the charges of one treatment modality over the other, but since there were more dressing changes required by STSG, the assumption that visiting nurse charges were equal would have favored collagen-glycosaminoglycan biodegradable matrix, but the authors concluded that this affect would be small and insignificant. The authors found no statistically significant difference in the charges to patients between those treated with collagen-glycosaminoglycan biodegradable matrix or STSG for chronic wounds. Additionally, there was no significant difference in the time it took to heal the wounds, although there was a trend for the patients treated with collagen-glycosaminoglycan biodegradable matrix to take less time/cm² to heal their wounds. There was no significant difference in the use of narcotics or antibiotics, but there was a trend for more antibiotics to be used with patients treated with collagen-glycosaminoglycan biodegradable matrix. There appeared to be more surgeon charges for patients treated with STSG. This was related to the number of postoperative outpatient debridements required to heal the wounds. Due to the small sample size, the authors do not believe that this was significant, and the P value provided confirmation.

Conclusion

The authors found collagen-glycosaminoglycan biodegradable matrix to be an economically sound alternative to STSG for treatment of chronic wounds. Although this study did not investigate the recurrence rates of wounds or patient satisfaction, it is the authors’ clinical impression that recidivism is less in the collagen-glycosaminoglycan biodegradable matrix-treated patients and that these patients are happier with their outcomes.