Person:

Cohen, Jeffrey Marcus

Importance Onychomycosis is the most common disease of the nail in adults. International guidelines urge health care professionals to perform confirmatory diagnostic testing before initiating systemic therapy. This approach was determined to be cost-effective in studies from the late 1990s but has not been evaluated more recently. The effect of testing on the costs of efinaconazole, 10%, topical solution treatment is unknown.

Objective To evaluate the cost and potential harm associated with 3 approaches to onychomycosis evaluation before treatment with oral terbinafine or efinaconazole, 10%.

Design, Setting, and Participants A decision analysis that compared the costs of 3 onychomycosis management algorithms based on recently published data of test statistics, disease prevalence, and relevant costs: (1) empirical therapy without confirmatory testing, (2) pretreatment confirmatory testing with potassium hydroxide (KOH) stain followed by periodic acid–Schiff (PAS) evaluation if KOH testing is negative, and (3) pretreatment testing with PAS. There was no direct patient evaluation. Selection of included studies was based on outcome variables and the quality of study design. The study was conducted from April 1, 2014, to September 1, 2015.

Main Outcomes and Measures Primary outcomes included direct cost of onychomycosis testing and therapy and cost to avoid harm when treating patients with oral terbinafine.

Results At a disease prevalence of 75%, per-patient cost savings of empirical terbinafine therapy without confirmatory testing was $47 compared with the KOH screening model and $135 compared with PAS testing. The cost of testing necessary to prevent a single case of clinically relevant liver toxic effects related to terbinafine at a prevalence of 75% was between $18.2 million and $43.7 million for KOH screening and between $37.6 million and $90.2 million for PAS testing. At a prevalence of 75%, KOH screening and PAS testing before treatment with efinaconazole, 10%, saved $272 and $406 per patient per nail, respectively.

Conclusions and Relevance These results show that empirical treatment with terbinafine for patients with suspected onychomycosis is more cost-effective than confirmatory testing across all prevalence of disease, with minimal effect on patient safety. In contrast, confirmatory testing before treatment with efinaconazole, 10%, is associated with reduced costs. Blanket recommendations for confirmatory testing before systemic therapy should be reconsidered and replaced with recommendations tailored to specific therapies.

Question What is the national health care burden of misdiagnosed lower extremity cellulitis in patients admitted to the hospital from the emergency department?

Findings In this cross-sectional study that included 259 patients, 30% were misdiagnosed with cellulitis, of which 85% did not require hospitalization and 92% received unnecessary antibiotics. Combining these findings with previously published data, cost estimates, and and projections indicate that cellulitis misdiagnosis leads to 50 000 to 130 000 unnecessary hospitalizations in the United States and $195 million to $515 million in avoidable health care spending annually.

Meaning Misdiagnosis of lower extremity cellulitis is common and may lead to unnecessary patient morbidity and considerable health care spending.