Cost effectiveness analysis: a review.

Medical treatments and strategies are increasingly being subjected to evaluations of economic efficiency. Although the reasons for this are many, it is becoming ever more important for physicians to have an understanding of the uses and limitations of such evaluations. Cost effectiveness analysis (CEA) is a technique that measures the cost of medical technology per unit of a defined health output, usually life years saved with an adjustment for quality of survival. CEA is a popular method of economic evaluation for policy markers, because it can provide direct comparisons among many medical technologies, resulting in a ranked order of procedures based on economic efficiency. The proper interpretation of a CEA requires an understanding of the component parts of the analysis, their theoretical bases, and their limitations. The components of a CEA include the determination of relevant costs, an appropriate analysis viewpoint, the use of discounting for both costs and benefits, and a sensitivity analysis of the assumptions and probabilities that drive the analysis. Marginal and incremental CEAs are techniques that help to address the cost effectiveness of different amounts of a particular treatment and the differential costs and benefits of competing strategies, respectively. A review is presented of the theoretical basis of CEA and its component parts. Emphasis is placed on generating an understanding of the method rather than providing a step-by-step protocol for the undertaking of such studies.

The cost effectiveness of stereotactic radiosurgery versus surgical resection in the treatment of solitary metastatic brain tumors.

Solitary metastatic brain tumors are the most common intracranial neoplasms encountered by neurosurgeons. Surgical resection of brain metastasis with whole brain radiotherapy (WBR) significantly increases survival in comparison with WBR alone. Stereotactic radiosurgery (SR) seems to provide results that are similar to those of surgical resection. To analyze the economic efficiency of these different treatments, we compared the results of surgical resection and SR as reported in the medical literature between 1974 and 1994. We included studies in which: 1) at least 75% of patients received WBR; 2) study dates were in the computed tomography era (after 1975); 3) operative morbidity, mortality, and median survival were reported; 4) study dates were not included in a more recent update or review; 5) tumor histologies were reported; and 6) the cobalt-60 gamma unit was used for SR. Three surgical resection studies and one SR study met all entry requirements. The WBR baseline was developed from two prospective, randomized trials and used for incremental cost effectiveness analysis. We developed a model of typical resource usage for uncomplicated procedures, reported complications, and subsequent craniotomies (for recurrent tumor or radiation necrosis) for both treatment options. Costs were estimated from the societal viewpoint using the 1992 Medicare Provider Analysis and Review database with average cost:charge ratios for surgery and WBR. A survey of capital and operating costs from five sites was used for radiosurgery. Our analysis revealed that radiosurgery had a lower uncomplicated procedure cost ($20,209 versus $27,587), a lower average complication cost per case ($2,534 versus $2,874), and a lower total cost per procedure ($22,743 versus $30,461), was more cost effective ($24,811 versus $32,149 per life year), and had a better incremental cost effectiveness ($40,648 versus $52,384 per life year) than surgical resection. A sensitivity analysis revealed that large changes in key assumptions would be required to change the analysis outcome. Equalization of the incremental cost effectiveness of the two treatments would require one of the following: 1) a 38.7% reduction in SR annual case volume, 2) a 34.7% increase in SR procedure cost, 3) a 18.8% reduction in surgical resection procedure cost, 4) a 240.5% increase in SR morbidity cost, 5) a 12.7% reduction in SR median survival, 6) a 16.8% increase in surgical resection median survival. Elimination of all surgical resection morbidity cost would still result in superior incremental cost effectiveness for SR.(ABSTRACT TRUNCATED AT 400 WORDS)

Single-stage stereotactic diagnosis and radiosurgery: feasibility and cost implications.

We compared the efficacy and the hospital charges of either single-stage or two-stage stereotactic diagnosis and radiosurgery procedures. Twelve patients underwent either one-stage or two-stage diagnosis and management of their brain tumors. Both techniques utilize high-resolution intraoperative stereotactic image-guided technology and rapid touch preparation (imprint) cytopathological techniques to confirm the presence of neoplasm. Following this pathologic diagnosis, six patients immediately underwent stereotactic radiosurgery employing the same frame application and dose planning based on preoperative and intraoperative images. Six patients underwent two-stage procedures, i.e., discharge from the hospital after histopathological diagnosis followed by readmission, reapplication of the stereotactic head frame, and repeat neuroradiological imaging prior to radiosurgery. Requirements for success of the single-stage procedure include intraoperative stereotactic high-resolution imaging, a hospital-wide ethernet system for transferring neurodiagnostic images, and expertise in rapid touch-preparation histopathological technique for accurate diagnosis. Intraoperative computed tomography imaging after biopsy confirmed the target accuracy and lack of movement of the target after brain biopsy. The advantages of the single-stage approach include reduced length of overall hospital stay, simultaneous histopathological diagnosis and therapy in a single hospital admission, and reduced total hospital charges. For patients highly suspected of having brain tumors and for whom stereotactic radiosurgery will be utilized in the treatment, single-stage stereotactic diagnosis immediately followed by radiosurgery is an accurate, effective, and potentially less costly management strategy than a two-stage approach.

Intracranial infantile myofibromatosis.

Infantile myofibromatosis is a proliferative disorder of infancy and early childhood characterized by nodular or diffuse growth of lesions that are comprised of a mixture of mesenchymal elements within the skin, subcutaneous tissues, skeletal muscle, bone, and/or visceral organs. Although these pseudotumors are considered to be the most common fibrous "neoplasm" of infancy, central nervous system involvement is reportedly rare. During the last 7 years, the authors have treated three children with intracranial myofibromas who presented at 6 weeks, 7 months, and 3 3/4 years of age, respectively. Each child had a large calvarial mass that produced significant brain compression despite a paucity of neurological signs. On computerized tomography, these tumors were isodense to brain tissue, enhanced strongly with intravenous contrast material, and showed smoothly marginated bone erosion without surrounding sclerosis. On magnetic resonance imaging, the tumors were hypointense on T1-weighted images, with dense enhancement following the administration of intravenous contrast medium, and hyperintense on T2-weighted images. At operation, the tumors were highly vascular and appeared to arise from within the leaves of the dura, eroding through the overlying bone, but not violating the galeal or arachnoidal layers. Two of the lesions were adherent to major dural venous sinuses. Both of these lesions were completely resected in continuity with the involved dura, and have not recurred 6 years and 1 year, respectively, postoperatively. However, in one patient in whom the involved dura was not resected at the initial procedure, the tumor recurred rapidly. A complete excision of the tumor and involved dura was then performed and the patient is now recurrence-free, 5 1/2 years after the second surgical resection. All patients tolerated resection well, but two have required cranioplasty for persistent calvarial defects. The surgical experience with these lesions is reviewed and the distinctive features of their clinical presentation, radiographic appearance, operative management, and outcome are discussed.

Vasoactive intestinal polypeptide facilitates the late component of the 5-hydroxytryptamine-induced discharge in the cat superior cervical ganglion.

The intra-arterial administration of vasoactive intestinal polypeptide (VIP, 1-10 micrograms, i.a.) to the cat superior cervical ganglion facilitated or unmasked the late component but not the early component of the 5-hydroxytryptamine (5-HT, 0.5-50 micrograms, i.a.)-induced postganglionic discharge. The facilitation occurred in acutely and chronically decentralized ganglia. The early and late 5-HT discharges were blocked by MDL-72222, a 5-HT antagonist, but not by cholinergic antagonists. These data together with previous observations indicate that VIP selectively facilitates slow cholinergic and non-cholinergic excitatory mechanisms in autonomic ganglia.

Vasoactive intestinal polypeptide elicits a discharge in chronically decentralized sympathetic ganglia.

Vasoactive intestinal polypeptide (VIP, 5-50 micrograms) injected intraarterially to the chronically decentralized cat superior cervical ganglion elicited a prolonged (2-5 min) postganglionic discharge which was resistant to cholinergic blocking agents but was blocked by [Leu5]enkephalin and GABA (10-200 micrograms i.a.). VIP did not elicit a discharge in acutely decentralized ganglia. These findings indicate that VIP has direct excitatory effects on ganglion cells and that these excitatory effects are enhanced following degeneration of the preganglionic nerve terminals.