ABSTRACT
BACKGROUND: The diagnostic algorithm for most cancers includes the assessment of a tissue specimen by a surgical pathologist, but if specimen provenance is uncertain, the diagnostic and therapeutic process carries significant risk to the patient. Over the last decade, short tandem repeat (STR) analysis has emerged as a DNA-based method with clinical applicability for specimen identity testing (also known as specimen provenance testing). Although the clinical utility of identity testing using STR-based analysis has been demonstrated in many studies, its economic value has not been established. METHODS: We developed a decision-analytic model of the application of STR-based provenance testing of transrectal prostate biopsy specimens obtained as part of routine clinical care to rule out the presence of adenocarcinoma of the prostate, as compared with no STR-based testing. Using parameter values drawn from the published literature, the cost-effectiveness of STR-based testing was quantified by calculating the incremental cost-effectiveness ratio per quality-adjusted life-year gained. RESULTS: In comparison to the current standard practice of no identity testing, identity testing by STR-based analysis has an incremental cost-effectiveness ratio of $65,570 per quality-adjusted life-year gained at a testing cost of $618 per person. At a cost of $515 per person, identity testing would meet the conservative standard of $50,000 per quality-adjusted life-year. At a test cost of $290 per person, identity testing would be cost saving. CONCLUSION: Given the rapidly declining pricing of STR-based identity testing, it is likely that testing to confirm the identity of positive prostate biopsy samples will be a cost-effective method for preventing treatment errors stemming from misidentification. Studies to formally establish the frequency of specimen provenance errors in routine clinical practice would therefore seem justified.
Subject(s)
Biopsy, Needle/methods , Microsatellite Repeats/genetics , Models, Theoretical , Prostate/pathology , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/genetics , Cost-Benefit Analysis , Diagnostic Techniques and Procedures/economics , Diagnostic Tests, Routine/economics , Humans , MaleABSTRACT
PURPOSE: To create and validate a statistical model predicting progression of primary open-angle glaucoma (POAG) assessed by loss of visual field as measured in mean deviation (MD) using 3 landmark studies of glaucoma progression and treatment. DESIGN: A Markov decision analytic model using patient level data described longitudinal MD changes over 7 years. PARTICIPANTS: Patient-level data from the Collaborative Initial Glaucoma Treatment Study (n = 607), the Ocular Hypertension Treatment Study (OHTS; n = 148; only those who developed POAG in the first 5 years of OHTS) and Advanced Glaucoma Intervention Study (n = 591), the COA model. METHODS: We developed a Markov model with transition matrices stratified by current MD, age, race, and intraocular pressure categories and used a microsimulation approach to estimate change in MD over 7 years. Internal validation compared model prediction for 7 years to actual MD for COA participants. External validation used a cohort of glaucoma patients drawn from university clinical practices. MAIN OUTCOME MEASURES: Change in visual field as measured in MD in decibels (dB). RESULTS: Regressing the actual MD against the predicted produced an R(2) of 0.68 for the right eye and 0.63 for the left. The model predicted ending MD for right eyes of 65% of participants and for 63% of left eyes within 3 dB of actual results at 7 years. In external validation the model had an R(2) of 0.79 in the right eye and 0.77 in the left at 5 years. CONCLUSIONS: The COA model is a validated tool for clinicians, patients, and health policy makers seeking to understand longitudinal changes in MD in people with glaucoma.
Subject(s)
Decision Support Techniques , Glaucoma, Open-Angle/physiopathology , Models, Statistical , Aged , Clinical Trials as Topic , Disease Progression , Female , Glaucoma, Open-Angle/diagnosis , Humans , Intraocular Pressure/physiology , Male , Markov Chains , Middle Aged , Ocular Hypertension/diagnosis , Ocular Hypertension/physiopathology , Vision Disorders/physiopathology , Visual Acuity/physiology , Visual Fields/physiologyABSTRACT
INTRODUCTION: Autologous peripheral stem cell transplantation (ASCT) with high-dose chemotherapy is a preferred treatment for relapsed non- Hodgkin lymphoma (NHL) patients. Estimated failure rates with current stem cell mobilization (SCM) regimens are 5% to 30%. Granulocyte colony-stimulating factor (G-CSF) with plerixafor (G P) is superior to G-CSF alone for SCM in heavily pretreated NHL patients. OBJECTIVES: To conduct a cost-utility evaluation of G P versus G-CSF as a method for SCM in patients with diffuse large B-cell lymphoma (DLBCL), the most common subtype of NHL. METHODS: A Markov model simulated the care process of DLBCL patients undergoing ASCT using data from the Washington University site of the plerixafor phase III study. Other data and utilities were taken from the literature. Costs were Medicare allowable. Using microsimulation we estimated the incremental cost-utility ratio (ICUR) over the patient's remaining lifetime. RESULTS: The expected lifetime cost of providing care for DLBCL patients using G P was $25,567 more than G-CSF, but they accumulated 1.74 more quality-adjusted life-years (QALYs) for an ICUR of $14,735 per QALY. In sensitivity analyses this result was robust to clinically relevant changes in assumptions. CONCLUSIONS: Using G P for SCM in ASCT of patients with DLBCL meets accepted standards of cost-effectiveness, primarily because of its effectiveness in SCM.
