This review seeks to introduce the concept of cost-utility analysis in neurosurgery and to highlight its essential components. It also includes a suggested approach to standardization, which would help bring more credence to this research and potentially affect management choices, reimbursement, and policy.
Jared D. Ament and Kee D. Kim
Jared D. Ament, Krista N. Greenan, Patrick Tertulien, Joseph M. Galante, Daniel K. Nishijima and Marike Zwienenberg
Approximately 475,000 children are treated for traumatic brain injury (TBI) in the US each year; most are classified as mild TBI (Glasgow Coma Scale [GCS] Score 13–15). Patients with positive findings on head CT, defined as either intracranial hemorrhage or skull fracture, regardless of severity, are often transferred to tertiary care centers for intensive care unit (ICU) monitoring. This practice creates a significant burden on the health care system. The purpose of this investigation was to derive a clinical decision rule (CDR) to determine which children can safely avoid ICU care.
The authors retrospectively reviewed patients with mild TBI who were ≤ 16 years old and who presented to a Level 1 trauma center between 2008 and 2013. Data were abstracted from institutional TBI and trauma registries. Independent covariates included age, GCS score, pupillary response, CT characteristics, and Injury Severity Score. A composite outcome measure, ICU-level care, was defined as cardiopulmonary instability, transfusion, intubation, placement of intracranial pressure monitor or other invasive monitoring, and/or need for surgical intervention. Stepwise logistic regression defined significant predictors for model inclusion with p < 0.10. The authors derived the CDR with binary recursive partitioning (using a misclassification cost of 20:1).
A total of 284 patients with mild TBI were included in the analysis; 40 (14.1%) had ICU-level care. The CDR consisted of 5 final predictor variables: midline shift > 5 mm, intraventricular hemorrhage, nonisolated head injury, postresuscitation GCS score of < 15, and cisterns absent. The CDR correctly identified 37 of 40 patients requiring ICU-level care (sensitivity 92.5%; 95% CI 78.5–98.0) and 154 of 244 patients who did not require an ICU-level intervention (specificity 63.1%; 95% CI 56.7–69.1). This results in a negative predictive value of 98.1% (95% CI 94.1–99.5).
The authors derived a clinical tool that defines a subset of pediatric patients with mild TBI at low risk for ICU-level care. Although prospective evaluation is needed, the potential for improved resource allocation is significant.
Jared D. Ament, Kevin R. Greene, Ivan Flores, Fernando Capobianco, Gueider Salas, Maria Ines Uriona, John P. Weaver and Richard Moser
Bolivia, one of the poorest countries in the world, ranks 108th on the 2013 Human Development Index. With approximately 1 neurosurgeon per 200,000 people, access to neurosurgery in Bolivia is a growing health concern. Furthermore, neurosurgery in nonindustrialized countries has been considered both cost-prohibitive and lacking in outcomes evaluation. A non-governmental organization (NGO) supports spinal procedures in Bolivia (Solidarity Bridge), and the authors sought to determine its impact and cost-effectiveness.
In a retrospective review of prospectively collected data, 19 patients were identified prior to spinal instrumentation and followed over 12 months. For inclusion, patients required interviewing prior to surgery and during at least 2 follow-up visits. All causes of spinal pathology were included. Sixteen patients met inclusion criteria and were therefore part of the analysis. Outcomes measured included assessment of activities of daily living, pain, ambulation, return to work/school, and satisfaction. Cost-effectiveness was determined by cost-utility analysis. Utilities were derived using the Health Utilities Index. Complications were incorporated into an expected value decision tree.
Median (± SD) preoperative satisfaction was 2.0 ± 0.3 (on a scale of 0–10), while 6-month postoperative satisfaction was 7 ± 1.4 (p < 0.0001). Ambulation, pain, and emotional disability data suggested marked improvement (56%, 69%, and 63%, respectively; p = 0.035, 0.003, and 0.006). Total discounted incremental quality-adjusted life year (QALY) gain was 0.771. The total discounted cost equaled $9036 (95% CI $8561–$10,740) at 2 years. Computing the incremental cost-effectiveness ratio resulted in a value of $11,720/QALY, ranging from $9220 to $15,473/QALY in a univariate sensitivity analysis.
This NGO-supported spinal instrumentation program in Bolivia appears to be cost-effective, especially when compared with the conventional $50,000/QALY benchmark and the WHO endorsed country-specific threshold of $16,026/QALY. However, with a gross domestic product per capita in Bolivia equaling $4800 per year and 30.3% of the population living on less than $2 per day, this cost continues to appear unrealistic. Additionally, the study has several significant limitations, namely its limited sample size, follow-up period, the assumption that patients not receiving surgical intervention would not make any clinical improvement, the reliance on the NGO for patient selection and sustainable practices such as follow-up care and ancillary services, and the lack of a randomized prospective design. These limitations, as well as an unclear understanding of Bolivian willingness-to-pay data, affect the generalizability of the study findings and impede widespread economic policy reform. Because cost-effectiveness research may inevitably direct care decisions and prove that an effort such as this can be cost saving, a prospective, properly controlled investigation is now warranted.