Office-based dermatologic diagnostic procedure utilization in the United States Medicare population from 2000-2016.

BACKGROUND: Potassium hydroxide preparations (KOH) and tissue examinations for ova and parasites (O&P) are cost-effective office-based tests. No studies have quantified their utilization and economic impact. METHODS: The objective is to determine the billing patterns and costs of office-based diagnostic procedures in the Medicare population. We conducted a cross sectional study using the Part B National Summary Data File (2000-2016) and the Physician and Other Supplier Public Use File (2012-2015) released by the Centers for Medicare & Medicaid Services. RESULTS: In 2016, the total number of claims among all providers was 28,432 (KOH) and 52,182 (O&P), representing a decrease since 2000 (KOH, -41.8%; O&P, -43.4%). The total claims for in-office procedures by dermatologists per 10,000 beneficiaries decreased between 2012 and 2015 (KOH, -18.8%; O&P, -26.6%). Fewer dermatologists submitted claims for the tests (KOH, -11.3%; O&P, -16.6%). The total single (SB) and multiple (MB) biopsy claims by dermatologists per 10,000 beneficiaries decreased between 2012 and 2015 (SB, -1.8%; MB, -2.7%). The 2016 aggregate payments (% change since 2000) for KOH and O&P were $163,127.75 (-60.4%) and $299,074.18 (-61.6%), respectively; for SB and MB, they were $240,047,487.98 (+142.3%) and $38,214,117.22 (+79.2%), respectively. CONCLUSION: Fewer dermatologists submit claims for KOH and O&P each year. Future studies should evaluate whether this is due to a loss of cost-efficacy, and secondly, if it is related to decreased reimbursement, burdensome in-office laboratory regulations, or changing provider preferences.

Confirmatory Testing Prior to Initiating Onychomycosis Therapy Is Cost-Effective.

BACKGROUND: Onychomycosis can be investigated by sampling. Information gleaned includes nail bed involvement, nail plate penetration, fungal viability, and species identification. Testing samples can confirm a diagnosis. While diagnostic testing is considered useful in directing therapy, a substantial number of clinicians do not confirm diagnosis prior to treatment. OBJECTIVES: The aim of this study is to quantify the benefit of confirmatory testing prior to treating toenail onychomycosis. METHODS: The cost of mycological cure (negative potassium hydroxide and negative culture) and the cost-effectiveness of confirmatory testing were determined using the average cost of potassium hydroxide (KOH), culture, periodic acid-Schiff (PAS), efinaconazole, ciclopirox, terbinafine, and itraconazole. Costs were obtained through literature searches, public domain websites, and telephone surveys to local pharmacies and laboratories. To represent the potential risks of prescribing onychomycosis treatment, the costs associated with liver monitoring, potential life-threatening adverse events, and drug-drug interactions were obtained through public domain websites, published studies, and product inserts. RESULTS: PAS was determined to be the most sensitive confirmatory test and KOH the least expensive. The overall cost of an incorrect diagnosis (no confirmatory test used) ranged between $350 and $1175 CAD per patient for treatment of 3 infected toenails. Comparatively, performing confirmatory testing prior to treatment decreases the overall cost to $320 to $930, depending on the therapy, physician, and test. CONCLUSIONS: It is preferred to diagnose onychomycosis prior to treatment. Furthermore, there are cost savings when confirmatory testing is performed before initiating treatment with both topical and oral antifungals in Canada.

Comparative study of efficacy, rapidity of detection, and cost-effectiveness of potassium hydroxide, calcofluor white, and Chicago sky blue stains in the diagnosis of dermatophytoses.

BACKGROUND: The diagnosis of superficial mycosis such as dermatophytosis is often done clinically. However, in difficult cases, a rapid test with high sensitivity and specificity helps in the immediate confirmation and administration of treatment. METHODS: The efficacy, rapidity of detection, and cost-effectiveness of KOH preparation, calcofluor white (CW) stain, and Chicago sky blue (CSB) stain in the identification of fungal elements were assessed in patients with dermatophytoses attending the dermatology clinic of a tertiary care hospital. All three tests were performed on each sample collected from 73 patients according to standard procedure. The slides were examined after 5 and 30 minutes in × 10 and × 40 magnifications. The sensitivity and specificity of CW and CSB at 5 and 30 minutes were calculated using KOH preparation as the standard test. RESULTS: CSB stain showed highest positivity (94.5%) within 5 minutes when compared to KOH (75.3%) and CW (83.5%). After 30 minutes, positivity increased in KOH (84.9%) and CW stains (89%), but it remained the same in CSB stain. Both CW and CSB stains when compared to 10% KOH are equally sensitive (100%), but CW was more specific (72.7%), particularly at 30 minutes. When cost of performing tests on 100 specimens is considered, KOH, CW, and CSB stains cost Rs 5, 100, and 15, respectively. CONCLUSION: CSB stain is a better stain for rapid diagnosis of dermatophytoses because of ease of performance, rapidity of detection, better appreciation of morphology of fungal elements, and cost effectiveness.

Cost-effectiveness of Confirmatory Testing Before Treatment of Onychomycosis.

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.

A comparison of the contrast stains, Chicago blue, chlorazole black, and Parker ink, for the rapid diagnosis of skin and nail infections.

BACKGROUND: The cheapest, most rapid method for the diagnosis of mycotic skin and nail infections is direct examination of samples using a KOH preparation. The standard KOH wet mount lacks a color contrast. Various contrast dyes are available. Parker ink is one which has been extensively used, however in recent times the stain no longer provides a suitable color contrast. Two other dyes that are available are Chicago blue and chlorazole black. METHODS: 100 samples of skin or nails were prospectively examined using Chicago blue, chlorazole black, and Parker ink-KOH stains. The samples were also cultured, with culture being the diagnostic gold standard. RESULTS: The sensitivities and specificities of the Chicago blue, chlorazole black and Parker ink stains were 78% & 96%; 63% & 97%; and 48% and 96%, respectively. CONCLUSION: The Chicago blue-KOH stain provides a good color contrast and is a suitable replacement for the Parker ink-KOH stain. It is suitable for use in the dermatologist's office or in the laboratory.