Identification and Cost of Diagnostic Tests for Infection in Diabetic Foot Ulcers, Pressure Ulcers, and Venous Leg Ulcers

Purpose: A retrospective analysis of the U.S. Wound Registry was conducted for patients treated from 2005 through 2016 to examine the frequency of culture and sensitivity (C&S) testing in relation to pre-specified patient- and wound-related variables. The cost of C&S testing and rates of antibiotic prescriptions during service and other surrogate indices of infection were calculated.

Methods: The study comprised 82,624 patients with 239,746 wounds (diabetic foot ulcers [DFUs], venous leg ulcers [VLUs], and pressure ulcers [PUs]). On average, 27.3% of wounds had at least one culture test but only 12.7% of wounds received at least one course of antibiotics during service. 

Results: Patients whose wounds had culture tests were consistently sicker than those patients whose wounds did not receive culture tests based on comorbidities. The same pattern was observed for wounds; wounds that had culture tests were older, larger, and had a higher proportion of more severe wounds by Wagner grade for DFUs or stage for PUs.

Frequency of culture testing varied by wound type, with DFUs having significantly higher testing and re-testing rates. When culture testing at the patient level was examined, meaningful and statistically significant differences were seen with increasing number of wounds per patient. While younger patients tended to have high culture testing rates than older patients, there was no meaningful difference comparing how the patient was insured medically. 

Conclusion: The rate of culture testing increased with treatment time although a significant number of wounds that only has 1 or 2 visits (likely “consultation” visits) were tested. Medicare reimbursement cost of testing wounds for culture and sensitivity was about $200 for patients on annual basis.