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Complications and Resource Use Associated With Surgery for Chiari Malformation Type 1 in Adults: A Population
Jacob K Greenberg1, Travis R Ladner, Margaret A Olsen
1Departments of *Neurological Surgery and #Otolaryngology and Divisions of ‖Biostatistics, §Infectious Diseases, and ¶Public Health Sciences, Washington University School of Medicine in St. Louis, St. Louis, Missouri; ‡Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
Insights
Complications following Chiari malformation type 1 (CM-1) surgery are frequent, with surgical issues occurring more often than medical ones. These complications significantly increase hospital costs and patient risk, highlighting the need for careful management.
Area of Science:
- Neurosurgery and Outcomes Research
- Health Services Research
- Medical Economics
Background:
- Outcomes research for Chiari malformation type 1 (CM-1) is limited by small, single-center studies.
- Large-scale data is needed to understand CM-1 surgical outcomes and resource utilization.
Purpose of the Study:
- To investigate complications and resource use in adult CM-1 surgery using administrative data.
- To identify risk factors for morbidity and analyze associated healthcare costs.
Main Methods:
- Retrospective analysis of adult CM-1 surgeries (2004-2010) from State Inpatient Databases in CA, FL, and NY.
- Utilized a validated ICD-9-CM code algorithm to identify patient cohorts and outcomes.
- Employed multivariable logistic regression and negative binomial models for risk factor and cost analysis.
Main Results:
- 1947 CM-1 surgeries were identified; surgical complications (14.3% at 30 days, 18.7% at 90 days) exceeded medical complications.
- Comorbidities like hydrocephalus increased complication risk (OR=4.51 surgical, OR=3.98 medical).
- Older age and male sex increased medical complication risk; risk-adjusted 90-day costs were over double for patients with complications ($46,264-$65,679) versus those without ($18,880).
Conclusions:
- Complications are common after CM-1 surgery, with surgical complications being more prevalent.
- Specific comorbidities and demographic factors are linked to higher complication rates.
- Patient harm and significantly increased hospital costs underscore the importance of these findings for clinical decision-making and patient guidance.
Background:
Outcomes research on Chiari malformation type 1 (CM-1) is impeded by a reliance on small, single-center cohorts.
Objective:
To study the complications and resource use associated with adult CM-1 surgery using administrative data.
Methods:
We used a recently validated International Classification of Diseases, Ninth Revision, Clinical Modification code algorithm to retrospectively study adult CM-1 surgeries from 2004 to 2010 in California, Florida, and New York using State Inpatient Databases. Outcomes included complications and resource use within 30 and 90 days of treatment. We used multivariable logistic regression to identify risk factors for morbidity and negative binomial models to determine risk-adjusted costs.
Results:
We identified 1947 CM-1 operations. Surgical complications were more common than medical complications at both 30 days (14.3% vs 4.4%) and 90 days (18.7% vs 5.0%) postoperatively. Certain comorbidities were associated with increased morbidity; for example, hydrocephalus increased the risk for surgical (odds ratio [OR] = 4.51) and medical (OR = 3.98) complications. Medical but not surgical complications were also more common in older patients (OR = 5.57 for oldest vs youngest age category) and male patients (OR = 3.19). Risk-adjusted hospital costs were $22530 at 30 days and $24852 at 90 days postoperatively. Risk-adjusted 90-day costs were more than twice as high for patients experiencing surgical ($46264) or medical ($65679) complications than for patients without complications ($18880).
Conclusion:
Complications after CM-1 surgery are common, and surgical complications are more frequent than medical complications. Certain comorbidities and demographic characteristics are associated with increased risk for complications. Beyond harming patients, complications are also associated with substantially higher hospital costs. These results may help guide patient management and inform decision making for patients considering surgery.
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