Diagnosing pedal osteomyelitis: testing choices and their consequences.

Abstract

OBJECTIVE:

To compare the efficacies and cost-effectiveness of four strategies for the management of suspected pedal osteomyelitis in the setting of vascular impairment: 1) therapeutic trial of short-term antibiotics for presumed cellulitis without osteomyelitis (short); 2) technetium bone scanning followed by either short-term therapy if negative or either a biopsy or aggressive long-term intravenous therapy if positive (scan); 3) bone biopsy followed by long-term intravenous therapy if positive or short-term therapy if negative (biopsy); and 4) immediate long-term intravenous antibiotics for presumed osteomyelitis (long).

DESIGN:

Decision analysis and cost-effectiveness analysis with sensitivity analyses. The main outcomes states are amputation and the resource expenditures associated with bone scans, biopsies, and therapies.

DATA SOURCES:

The authors obtained estimates of test accuracy from literature review and summarized them using newly developed meta-analytic techniques.

MAIN RESULTS:

The optimal decision depends heavily on the estimated probability of osteomyelitis at presentation. At very low probabilities, the short-term strategy is preferred. When the probability of osteomyelitis is from 2% to 8%, the lowest amputation rate occurs when one does a diagnostic scan. From 8% to 50%, the best outcomes follow biopsy. At probabilities higher than 50%, the preferred strategy is long-term antibiotics. However, the differences in outcomes are quite small even when osteomyelitis is a virtual certainty.

CONCLUSIONS:

Over the whole range of prior probabilities, the short-term strategy is the least expensive. At very low probabilities, it dominates the other strategies. When the likelihood of osteomyelitis is higher (10-20%), scanning results in outcomes and cost-effectiveness ratios comparable to those of immediate biopsy and is less invasive. When the probability of osteomyelitis is 50%, biopsy is quite cost-effective compared with all the other strategies (cost-effectiveness ratio = $15,502 per amputation averted) and is preferred to the scan strategy. When the confidence that a patient has osteomyelitis is very high (> 90% probability), the improved outcomes associated with long-term antibiotics are achieved with little additional expense and with favorable cost-effectiveness ratios compared with those of the other strategies.

• Authors: A I Mushlin, B Littenberg
• Journal: Journal of general internal medicine (J Gen Intern Med) Vol. 9 Issue 1 Pg. 1-7 (Jan 1994) ISSN: 0884-8734 [Print] United States
• PMID: 7695670 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents

Topics

• Anti-Bacterial Agents (therapeutic use)
• Biopsy
• Bone and Bones (diagnostic imaging)
• Cellulitis (drug therapy)
• Cost-Benefit Analysis
• Decision Support Techniques
• Foot Diseases (diagnosis, economics, epidemiology)
• Humans
• Osteomyelitis (diagnosis, economics, epidemiology)
• Outcome Assessment, Health Care
• Predictive Value of Tests
• Probability
• Radionuclide Imaging
• Sensitivity and Specificity