Chester K. Yarbrough, Jacob K. Greenberg, Matthew D. Smyth, Jeffrey R. Leonard, Tae Sung Park and David D. Limbrick Jr.
Historically, assessment of clinical outcomes following surgical management of Chiari malformation Type I (CM-I) has been challenging due to the lack of a validated instrument for widespread use. The Chicago Chiari Outcome Scale (CCOS) is a novel system intended to provide a less subjective evaluation of outcomes for patients with CM-I. The goal of this study was to externally validate the performance of the CCOS.
Patients undergoing surgery for CM-I between 2001 and 2012 were reviewed (n = 292). Inclusion criteria for this study were as follows: 1) patients receiving primary posterior fossa decompression; 2) at least 5.5 months of postoperative clinical follow-up; and 3) patients ≤ 18 years of age at the time of surgery. Outcomes were evaluated using the CCOS, along with a “gestalt” impression of whether patients experienced significant improvement after surgery. A subgroup of 118 consecutive patients undergoing operations between 2008 and 2010 was selected for analysis of interrater reliability (n = 73 meeting inclusion/exclusion criteria). In this subgroup, gestalt and CCOS scores were independently determined by 2 reviewers, and interrater reliability was assessed using the intraclass correlation coefficient (ICC) and kappa (κ) statistic.
The median CCOS score was 14, and 67% of patients had improved gestalt scores after surgery. Overall, the CCOS was effective at identifying patients with improved outcome after surgery (area under curve = 0.951). The interrater reliability of the CCOS (ICC = 0.71) was high, although the reliability of the component scores ranged from poor to good (ICC 0.23–0.89). The functionality subscore demonstrated a low ICC and did not add to the predictive ability of the logistic regression model (likelihood ratio = 1.8, p = 0.18). When analyzing gestalt outcome, there was moderate agreement between raters (κ = 0.56).
In this external validation study, the CCOS was effective at identifying patients with improved outcomes and proved more reliable than the authors' gestalt impression of outcome. However, certain component subscores (functionality and nonpain symptoms) were found to be less reliable, and may benefit from further definition in score assignment. In particular, the functionality subscore does not add to the predictive ability of the CCOS, and may be unnecessary. Overall, the authors found the CCOS to be an improvement over the previously used assessment of outcome at their institution.
Jacob K. Greenberg, Eric Milner, Chester K. Yarbrough, Kim Lipsey, Jay F. Piccirillo, Matthew D. Smyth, Tae Sung Park and David D. Limbrick Jr.
Chiari malformation Type I (CM-I) is a common and often debilitating neurological disease. Efforts to improve treatment of CM-I are impeded by inconsistent and limited methods of evaluating clinical outcomes. To understand current approaches and lay a foundation for future research, the authors conducted a systematic review of the methods used in original published research articles to evaluate clinical outcomes in patients treated for CM-I.
The authors searched PubMed, Embase, the Cumulative Index to Nursing and Allied Health Literature, ClinicalTrials.gov, and Cochrane databases to identify publications between January 2003 and August 2013 that met the following criteria: 1) reported clinical outcomes in patients treated for CM-I; 2) were original research articles; 3) included at least 10 patients or, if a comparative study, at least 5 patients per group; and 4) were restricted to patients with CM-I.
Among the 74 papers meeting inclusion criteria, there was wide variation in the outcome methods used. However, all approaches were broadly grouped into 3 categories: 1) “gestalt” impression of overall symptomatic improvement (n = 45 papers); 2) postoperative change in specific signs or symptoms (n = 20); or 3) results of various standardized assessment scales (n = 22). Among standardized scales, 11 general function measures were used, compared with 6 disease-specific tools. Only 3 papers used scales validated in patients with CM-I. To facilitate a uniform comparison of these heterogeneous approaches, the authors appraised articles in multiple domains defined a priori as integral to reporting clinical outcomes in CM-I. Notably, only 7 articles incorporated patient-response instruments when reporting outcome, and only 22 articles explicitly assessed quality of life.
The methods used to evaluate clinical outcomes in CM-I are inconsistent and frequently not comparable, complicating efforts to analyze results across studies. Development, validation, and incorporation of a small number of disease-specific patient-based instruments will improve the quality of research and care of CM-I patients.
Jacob K. Greenberg, Margaret A. Olsen, Chester K. Yarbrough, Travis R. Ladner, Chevis N. Shannon, Jay F. Piccirillo, Richard C. E. Anderson, John C. Wellons III, Matthew D. Smyth, Tae Sung Park and David D. Limbrick Jr.
Chiari malformation Type I (CM-I) is a common and often debilitating pediatric neurological disease. However, efforts to guide preoperative counseling and improve outcomes research are impeded by reliance on small, single-center studies. Consequently, the objective of this study was to investigate CM-I surgical outcomes using population-level administrative billing data.
The authors used Healthcare Cost and Utilization Project State Inpatient Databases (SID) to study pediatric patients undergoing surgical decompression for CM-I from 2004 to 2010 in California, Florida, and New York. They assessed the prevalence and influence of preoperative complex chronic conditions (CCC) among included patients. Outcomes included medical and surgical complications within 90 days of treatment. Multivariate logistic regression was used to identify risk factors for surgical complications.
A total of 936 pediatric CM-I surgeries were identified for the study period. Overall, 29.2% of patients were diagnosed with syringomyelia and 13.7% were diagnosed with scoliosis. Aside from syringomyelia and scoliosis, 30.3% of patients had at least 1 CCC, most commonly neuromuscular (15.2%) or congenital or genetic (8.4%) disease. Medical complications were uncommon, occurring in 2.6% of patients. By comparison, surgical complications were diagnosed in 12.7% of patients and typically included shunt-related complications (4.0%), meningitis (3.7%), and other neurosurgery-specific complications (7.4%). Major complications (e.g., stroke or myocardial infarction) occurred in 1.4% of patients. Among children with CCCs, only comorbid hydrocephalus was associated with a significantly increased risk of surgical complications (OR 4.5, 95% CI 2.5–8.1).
Approximately 1 in 8 pediatric CM-I patients experienced a surgical complication, whereas medical complications were rare. Although CCCs were common in pediatric CM-I patients, only hydrocephalus was independently associated with increased risk of surgical events. These results may inform patient counseling and guide future research efforts.
Travis R. Ladner, Jacob K. Greenberg, Nicole Guerrero, Margaret A. Olsen, Chevis N. Shannon, Chester K. Yarbrough, Jay F. Piccirillo, Richard C. E. Anderson, Neil A. Feldstein, John C. Wellons III, Matthew D. Smyth, Tae Sung Park and David D. Limbrick Jr.
Administrative billing data may facilitate large-scale assessments of treatment outcomes for pediatric Chiari malformation Type I (CM-I). Validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code algorithms for identifying CM-I surgery are critical prerequisites for such studies but are currently only available for adults. The objective of this study was to validate two ICD-9-CM code algorithms using hospital billing data to identify pediatric patients undergoing CM-I decompression surgery.
The authors retrospectively analyzed the validity of two ICD-9-CM code algorithms for identifying pediatric CM-I decompression surgery performed at 3 academic medical centers between 2001 and 2013. Algorithm 1 included any discharge diagnosis code of 348.4 (CM-I), as well as a procedure code of 01.24 (cranial decompression) or 03.09 (spinal decompression or laminectomy). Algorithm 2 restricted this group to the subset of patients with a primary discharge diagnosis of 348.4. The positive predictive value (PPV) and sensitivity of each algorithm were calculated.
Among 625 first-time admissions identified by Algorithm 1, the overall PPV for CM-I decompression was 92%. Among the 581 admissions identified by Algorithm 2, the PPV was 97%. The PPV for Algorithm 1 was lower in one center (84%) compared with the other centers (93%–94%), whereas the PPV of Algorithm 2 remained high (96%–98%) across all subgroups. The sensitivity of Algorithms 1 (91%) and 2 (89%) was very good and remained so across subgroups (82%–97%).
An ICD-9-CM algorithm requiring a primary diagnosis of CM-I has excellent PPV and very good sensitivity for identifying CM-I decompression surgery in pediatric patients. These results establish a basis for utilizing administrative billing data to assess pediatric CM-I treatment outcomes.