Cost-Effectiveness of Laboratory Testing for Uveitis

Research Article

Austin J Clin Ophthalmol. 2015;2(4): 1053.

Cost-Effectiveness of Laboratory Testing for Uveitis

Gupta SK¹, Bajwa A¹*, Wanchek T² and Reddy AK¹

11Department of Ophthalmology, University of Virginia, Charlottesville, USA

22Department of Public Health Sciences, University of Virginia, Charlottesville, USA

*Corresponding author: Asima Bajwa, Department of Ophthalmology, University of Virginia, 1300 Jefferson Park Avenue, Charlottesville, VA 22908, USA

Received: April 24, 2015; Accepted: June 30, 2015; Published: July 07, 2015

Abstract

Purpose: Lab tests are often required to reach a definitive diagnosis in uveitis and guide management. The purpose of this study is to evaluate the diagnostic value of these tests in an incremental cost perspective.

Methods: A revised Bayes’ theorem statistical analysis was performed to determine the most cost-effective testing based on review of the rheumatologic literature of 16 common causes of uveitis for epidemiological data, laboratory testing, sensitivities and specificities, positive and negative predictive values, pretest probability for disease, and Medicare/Medicaid reimbursements. Etiologies were subsequently ranked by Cost-Effectiveness Units (CEU).

Results: For Medicare patients, Rheumatoid Arthritis (RA) was the most cost-effective diagnostic evaluation, average 10.4 CEU, followed by syphilis, Bartonella, granulomatosis with polyangiitis, and polyarteritis nodosa. For Medicaid patients, (HLA-A29) was the most effective initial investigation, average 5.5 CEU, followed by HLA-B27, RA, toxoplasmosis and toxocariasis.

Conclusions: Stepwise process of elimination of lab tests based on CEU may enable the ophthalmologists to arrive at a diagnosis within resource constraints.

Keywords: Uveitis diagnostic tests; Cost effectiveness; Laboratory tests

Abbreviations

CEU: Cost-Effectiveness Units; CMS: Centers for Medicare and Medicaid Services; SLE: Systemic Lupus Erythematosus; ESR: Erythrocyte Sedimentation Rate; CRP: C-reactive Protein; ANA: Antinuclear Antibody; RF: Rheumatoid Factor; GPA: Granulomatosis with Polyangiitis; PAN: Polyarteritis Nodosa; BSCR: Birdshot Choreoretinopathy; RA: Rheumatoid Arthritis

Introduction

Uveitis has an extensive differential, including inflammatory and infectious etiologies [1]. It can be vision-threatening and accounts for an estimated 10% of legal blindness in the United States [1,2]. Significant morbidity exists as children and working young adults are often affected. Some cases of uveitis represent isolated ocular disease, while others may present as ocular manifestations of systemic illnesses [3].

Uveitis can be classified by location, based on the structure(s) of the eye most affected (anterior uveitis, intermediate uveitis, posterior uveitis, or panuveitis) or based on the presence or absence of granulomatous disease [4]. Anterior uveitis constitutes a significant proportion of the morbidity experienced by uveitis patients, with HLA-B27 associated uveitis accounting for the majority of these diagnoses, both in community-based and university referral settings [4,5]. Many of the HLA-B27 associated cases may also present with systemic findings attributable to the seronegative spondyloarthropathies; however, this is not always the case. In certain instances, anterior uveitis may be the sentinel presentation of a seronegative spondyloarthropathy [6]. Less commonly, other autoimmune diseases, such as systemic lupus erythematosus (SLE), sarcoidosis, Sjogren’s syndrome, and juvenile idiopathic arthritis may also be diagnosed based on laboratory testing [4,7,8].

Investigational testing can be useful in determining the etiology of uveitis; however, each test has associated costs, specificity, and sensitivity. In cases without pathognomonic clinical features to guide testing, a costly and inefficient patient work-up may result. Furthermore, non-specific testing practices may result in inaccuracies and false-positives and introduce delay to diagnosis and potential harm to patients [2]. As healthcare providers are increasingly encouraged to approach uveitis efficiently and economically, we developed an interest in evaluating commonly ordered testing in terms of diagnostic value and cost-effectiveness. Based on disease prevalence in the United States, available sensitivity and specificity data for individual tests, pretest likelihood of disease, and available Medicare and Medicaid cost data, we aimed to evaluate the laboratory and imaging investigational methods frequently ordered in the workup of uveitis and create a cost-analysis to determine practices which promote the highest yield and lowest costs for patients [9-12].

Methods

Institutional Review Board approval was not required for this study as it did not involve the examination or treatment of patients or a review of patient records. Diagnostic testing for classic and common etiologies of uveitis was specified by a uveitis specialist (AKR). A systematic literature review for the prevalence of each disease entity in the United States was conducted utilizing MEDLINE, the online bibliographical database, using the search terms “uveitis,” “prevalence,” “United States,” and individual disease entities. The bibliographies of these articles were reviewed and epidemiological data were extracted. A systematic literature review of the diagnostic value of each testing modality as well as sensitivity and specificity, was conducted utilizing the search terms, “uveitis,” “sensitivity,” and “specificity,” for each disease entity and the diagnostic test. English language articles were selected. The bibliographies of these articles were reviewed and diagnostic accuracy and values for tests were recorded [13-51].

A cost determination was made for Medicare and Medicaid reimbursement. Medicare reimbursement cost structures of diagnostic tests in Virginia for fiscal year 2014 were obtained from the 2000 American Medical Association Current Procedural Terminology (CPT) codebook and the Centers for Medicare and Medicaid Services (CMS) Searchable Medicare Physician Fee Schedule via the CMS website [11]. Medicaid reimbursement cost structures were determined using Virginia’s Department of Medical Assistance Services online searchable database [12].

Cost Effectiveness Units (CEU) were determined by dividing the total cost by the total effectiveness. To obtain the CEU, each etiology was paired with its appropriate diagnostic studies. The measure of effectiveness was constructed using each diagnostic test’s sensitivity and specificity for detecting disease as well as the disease prevalence in the United States as a measure of disease probability.

Figure 1 provides an example of one branch of the decision tree used to calculate and compare CEUs. There are two test procedures that could be used to test for Granulomatosis with polyangiitis, C_ANCA (anti neutrophilic cytoplasmic antibody) and PR-3 (anti proteinase-3 antibody). Each test procedure has a sensitivity and specificity and there is also a probability that the patient has granulomatosis with polyangiitis. The end of each branch includes the cost, in this case the Medicare cost is $17.66, and the effectiveness, which is either 1 if the test gave a correct result and 0 if the test gave an incorrect result (Figure 1).