Strengths and limitations of International Classification of Disease Ninth Revision Clinical Modification codes in defining cervical spine surgery.
ABSTRACT Retrospective study.
To evaluate the sensitivity and specificity of International Classification of Disease Ninth Revision Clinical Modification (ICD9-CM) hospital discharge codes to define degenerative cervical spine surgery in comparison to patient operative notes in the medical record.
Population-based studies of spine surgery have often relied on administrative databases as a primary information source, but little is known about the validity of using ICD9-CM codes to identify these operations.
We performed a retrospective study comparing ICD9-CM billing codes to patient operative notes, the gold standard, for patients undergoing spine surgery in 2006 at a single academic center.
We identified 1090 procedures of which 265 were categorized as cervical spine surgery for degenerative indications based on the operative notes. Compared to operative notes, our ICD9-CM algorithm had high sensitivity and specificity for selecting surgery at the cervical spine level and cervical spine surgery for degenerative indications. Categorization of cases by procedure had high sensitivity and specificity for fusion and surgical approach (>95%). Categorization of cases by primary diagnosis was generally less accurate. Cervical spondylosis with myelopathy was the most sensitive primary diagnosis. Categorization of cases by procedure had high sensitivity and specificity for fusion and surgical approach (≥96%). However, diagnoses such as herniated disc and procedures such as laminectomy had low sensitivity but high specificity.
The use of our ICD9-CM algorithm to define spine surgery at the cervical spine level, and degenerative cervical spine surgery is highly accurate. Although specific diagnoses codes are mostly insensitive, an ICD9-CM algorithm can be used to study these procedures with reasonable precision.
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ABSTRACT: Object Venous thromboembolism (VTE) represents a significant complication after spine surgery, with reported rates as high as 2%-4%. Published institutional practices for VTE prophylaxis are highly variable. In 2008, the authors implemented a departmental protocol for early VTE prophylaxis consisting of combined compressive devices and subcutaneous heparin initiated either preoperatively or on the same day of surgery. In this study, the authors compared the incidence of VTE in spine surgery patients before and after implementing this protocol. Methods An institutional review board-approved retrospective review of outcomes in patients undergoing spine surgery 2 years before protocol implementation (representing the preprotocol group) and of outcomes in patients treated 2 years thereafter (the postprotocol group) was conducted. Inclusion criteria were that patients were 18 years or older and had been admitted for 1 or more days. Before 2008 (preprotocol), VTE prophylaxis was variable and provider dependent without any uniform protocol. Since 2008 (postprotocol), a new VTE-prophylaxis protocol was administered, starting either preoperatively or on the same day of surgery and continuing throughout hospitalization. The new protocol consisted of 5000 U heparin administered subcutaneously 3 times daily, except in patients older than 75 years or weighing less than 50 kg, who received this dose twice daily. All patients also received sequential compression devices (SCDs). The incidence of VTE in the 2 protocol phases was identified by codes of the International Classification of Diseases, Ninth Revision (ICD-9) codes for deep vein thrombosis (DVT) and pulmonary embolus (PE). Bleeding complications arising from anticoagulation treatments were evaluated by the Current Procedural Terminology (CPT) code for postoperative epidural hematoma (EDH) requiring evacuation. Results In total, 941 patients in the preprotocol group met the inclusion criteria: 25 had DVT (2.7%), 6 had PE (0.6%), and 6 had postoperative EDH (0.6%). In the postprotocol group, 992 patients met the criteria: 10 had DVT (1.0%), 5 had PE (0.5%), and 4 had postoperative EDH (0.4%). This reduction in DVT after the protocol's implementation was statistically significant (p = 0.009). Despite early aggressive prophylaxis, the incidence of postoperative EDH did not increase and compared favorably to the published literature. Conclusions At a high-volume tertiary center, an aggressive protocol for early VTE prophylaxis after spine surgery decreases VTE incidence without increasing morbidity.Journal of Neurosurgery Spine 08/2014; 21(4):1-8. DOI:10.3171/2014.6.SPINE13447 · 2.36 Impact Factor
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ABSTRACT: Backgrounds The purpose of this study was to investigate the occurrence and factors associated with postoperative shoulder imbalance (PSI) in Lenke type 1A curve. Methods This study included 106 patients with Lenke Type 1A curve who were followed up more than two years after posterior correction surgery. Pedicle screw (PS) constructs were used in 84 patients, and hybrid constructs in 22. The upper instrumented vertebra was rostral to the upper-end vertebra (UEV) in 70 patients, at UEV in 26, and below UEV in 10. The clavicle angle and T1 tilt angle were measured as PSI indicators, and correlations between radiographic parameters of shoulder balance and other radiographic parameters and associations between PSI and clinical parameters were investigated. For statistical analyses, paired and unpaired t-tests were used. Results The mean Cobb angles of the main and proximal thoracic curves were 54.6 ± 9.5 and 26.7 ± 7.9 degrees before surgery, 14.5 ± 7.5, and 14.9 ± 7.1 at follow-up. Clavicle angle and T1 tilt angle were −2.9 ± 2.8 and −2.6 ± 6.3 before surgery, 2.4 ± 2.8 and 4.4 ± 4.3 immediately after surgery, and 1.8 ± 2.1 and 3.4 ± 5.5 at follow-up. Twenty patients developed distal adding-on. Clavicle angle at follow-up correlated weakly but significantly with preoperative clavicle angle (r = 0.34, p = 0.001) and with the correction rates of the main thoracic curve (r = 0.34, p = 0.001); it correlated negatively with the proximal curve spontaneous correction rate (r = −0.21, p = 0.034). The clavicle angle at follow-up was significantly larger in patients with PS-only constructs (PS 2.1 degrees vs. hybrid 0.9, p = 0.02), and tended to be smaller in patients with distal adding-on (adding-on 1.1 vs. non adding-on 2.0, p = 0.09). Conclusions PSI was more common with better correction of the main curve (using PS constructs), in patients with a larger preoperative clavicle angle, and with a larger and more rigid proximal curve. Distal adding-on may compensate for PSI.BMC Musculoskeletal Disorders 11/2014; 15(1):366. DOI:10.1186/1471-2474-15-366 · 1.90 Impact Factor
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ABSTRACT: Object Large administrative databases have assumed a major role in population-based studies examining health care delivery. Lumbar fusion surgeries specifically have been scrutinized for rising rates coupled with ill-defined indications for fusion such as stenosis and spondylosis. Administrative databases classify cases with the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). The ICD-9-CM discharge codes are not designated by surgeons, but rather are assigned by trained hospital medical coders. It is unclear how accurately they capture the surgeon's indication for fusion. The authors first sought to compare the ICD-9-CM code(s) assigned by the medical coder according to the surgeon's indication based on a review of the medical chart, and then to elucidate barriers to data fidelity. Methods A retrospective review was undertaken of all lumbar fusions performed in the Department of Neurosurgery at the authors' institution between August 1, 2011, and August 31, 2013. Based on this review, the indication for fusion in each case was categorized as follows: spondylolisthesis, deformity, tumor, infection, nonpathological fracture, pseudarthrosis, adjacent-level degeneration, stenosis, degenerative disc disease, or disc herniation. These surgeon diagnoses were compared with the primary ICD-9-CM codes that were generated by the medical coders and submitted to administrative databases. A follow-up interview with the hospital's coders and coding manager was undertaken to review causes of error and suggestions for future improvement in data fidelity. Results There were 178 lumbar fusion operations performed in the course of 170 hospital admissions. There were 44 hospitalizations in which fusion was performed for tumor, infection, or nonpathological fracture. Of these, the primary diagnosis matched the surgical indication for fusion in 98% of cases. The remaining 126 hospitalizations were for degenerative diseases, and of these, the primary ICD-9-CM diagnosis matched the surgeon's diagnosis in only 61 (48%) of 126 cases of degenerative disease. When both the primary and all secondary ICD-9-CM diagnoses were considered, the indication for fusion was identified in 100 (79%) of 126 cases. Still, in 21% of hospitalizations, the coder did not identify the surgical diagnosis, which was in fact present in the chart. There are many different causes of coding inaccuracy and data corruption. They include factors related to the quality of documentation by the physicians, coder training and experience, and ICD code ambiguity. Conclusions Researchers, policymakers, payers, and physicians should note these limitations when reviewing studies in which hospital claims data are used. Advanced domain-specific coder training, increased attention to detail and utilization of ICD-9-CM diagnoses by the surgeon, and improved direction from the surgeon to the coder may augment data fidelity and minimize coding errors. By understanding sources of error, users of these large databases can evaluate their limitations and make more useful decisions based on them.Neurosurgical FOCUS 06/2014; 36(6):E2. DOI:10.3171/2014.3.FOCUS1459 · 2.14 Impact Factor