Jennifer Malone

Comparison of ICD-9–based, retrospective, and prospective assessments of perioperative complications: assessment of accuracy in reporting

OBJECT large studies of ICD-9-based complication and hospital-acquired condition (HAC) chart reviews have not been validated through a comparison with prospective assessments of perioperative adverse event occurrence. Retrospective chart review, while generally assumed to underreport complication occurrence, has not been subjected to prospective study. It is unclear whether ICD-9-based population studies are more accurate than retrospective reviews or are perhaps equally susceptible to bias. To determine the validity of an ICD-9-based assessment of perioperative complications, the authors compared a prospective independent evaluation of such complications with ICD-9-based HAC data in a cohort of patients who underwent spine surgery. For further comparison, a separate retrospective review of the same cohort of patients was completed as well. METHODS a prospective assessment of complications in spine surgery over a 6-month period (May to December 2008) was completed using an independent auditor and a validated definition of perioperative complications. The auditor maintained a prospective database, which included complications occurring in the initial 30 days after surgery. All medical adverse events were included in the assessment. All patients undergoing spine surgery during the study period were eligible for inclusion; the only exclusionary criterion used was the availability of the auditor for patient assessment. From the overall patient database, 100 patients were randomly extracted for further review; in these patients ICD-9-based HAC data were obtained from coder data. Separately, a retrospective assessment of complication incidence was completed using chart and electronic medical record review. The same definition of perioperative adverse events and the inclusion of medical adverse events were applied in the prospective, ICD-9-based, and retrospective assessments. RESULTS ninety-two patients had adequate records for the ICD-9 assessment, whereas 98 patients had adequate chart information for retrospective review. The overall complication incidence among the groups was similar (major complications: ICD-9 17.4%, retrospective 19.4%, and prospective 22.4%; minor complications: ICD-9 43.8%, retrospective 31.6%, and prospective 42.9%). However, the ICD-9-based assessment included many minor medical events not deemed complications by the auditor. Rates of specific complications were consistently underreported in both the ICD-9 and the retrospective assessments. The ICD-9 assessment underreported infection, the need for reoperation, deep wound infection, deep venous thrombosis, and new neurological deficits (p = 0.003, p < 0.0001, p < 0.0001, p = 0.0025, and p = 0.04, respectively). The retrospective review underestimated incidences of infection, the need for revision, and deep wound infection (p < 0.0001 for each). Only in the capture of new cardiac events was ICD-9-based reporting more accurate than prospective data accrual (p = 0.04). The most sensitive measure for the appreciation of complication occurrence was the prospective review, followed by the ICD-9-based assessment (p = 0.05). CONCLUSIONS an ICD-9-based coding of perioperative adverse events and major complications in a cohort of spine surgery patients revealed an overall complication incidence similar to that in a prospectively executed measure. In contrast, a retrospective review underestimated complication incidence. The ICD-9-based review captured many medical events of limited clinical import, inflating the overall incidence of adverse events demonstrated by this approach. In multiple categories of major, clinically significant perioperative complications, ICD-9-based and retrospective assessments significantly underestimated complication incidence. These findings illustrate a significant potential weakness and source of inaccuracy in the use of population-based ICD-9 and retrospective complication recording.

Obesity and spine surgery: reassessment based on a prospective evaluation of perioperative complications in elective degenerative thoracolumbar procedures

BACKGROUND CONTEXT The correlation between obesity and incidence of complications in spine surgery is unclear, with some reports suggesting linear relationships between body mass index (BMI) and complication incidence and others noting no relationship. PURPOSE The purpose of this article was to assess the relationship between obesity and occurrence of perioperative complications in an elective thoracolumbar surgery cohort. STUDY DESIGN/SETTING Prospective observational cohort study at a tertiary care facility. PATIENT SAMPLE Cohort of 87 consecutive patients undergoing elective surgery for degenerative thoracolumbar pathologies over a 6-month period (May to December 2008). OUTCOME MEASURES Incidence of perioperative complications (those occurring within 30 days of surgery). METHODS A prospective assessment of perioperative spine surgery complications was completed, and data were prospectively entered into a central database. Two independent auditors assessed for the presence and severity of perioperative complications. Previously validated binary definitions of major and minor complications were used. Patient data and early complications (those occurring within 30 days of index surgery) were analyzed using multivariate regression. RESULTS Mean BMI in this cohort was 31.3; 40.8% of patients were obese (BMI>30) and 10 patients (11.5%) were morbidly obese (BMI>40). The overall complication incidence was 67%. Minor complications occurred in 50% of patients, and major complications occurred in 17.8% of patients. No positioning palsies occurred in this series. Age correlated with an increase in complication risk (p=.006) as did hypertension (p=.004) and performance of a fusion (p<.0001). BMI did not correlate with the incidence of minor, major, or any complications (p=.58). CONCLUSIONS This prospective assessment of perioperative complications in elective degenerative thoracolumbar procedures shows no relationship between patient BMI and the incidence of perioperative minor or major complications. Specific care in perioperative positioning may limit the risk of perioperative positioning palsies in obese patients.

Early Complications Related to Approach in Cervical Spine Surgery: Single-Center Prospective Study

BACKGROUND Surgical intervention is performed on the cervical spine in a heterogeneous number of pathologic conditions in a diverse patient population. Several authors have examined complication prevalence in cervical spine surgery using retrospective analysis. However, few prospective studies have directly examined perioperative complications. Most prospective studies in the spine literature have assessed only specific spinal implants in carefully selected surgical patients, and complication incidence in broader patient populations is limited. OBJECTIVES To prospectively collect data on all patients who underwent cervical spine surgery at a large tertiary care center and to evaluate the effect of the approach and the incidence of early complications. METHODS Data were collected prospectively on 119 patients admitted to the neurosurgical service at Thomas Jefferson University hospital from May to December 2008. Data collected consisted of preoperative diagnosis, medical comorbidities, body mass index, surgical approach, length of stay, and complications, and were analyzed using multivariate regression analysis. Complications occurring within 30 days after each operative procedure were included. Medical adverse events, regardless of their relationship to the operative intervention, were also included as complications. A previously validated binary definition of major and minor complications was used to stratify the data. RESULTS Overall, 53 of 119 patients (44.5%) experienced at least one complication. Eleven of 41 patients (26.8%) undergoing only an anterior cervical procedure had a perioperative complication, compared with 26 of 53 patients (49.0%) undergoing only a posterior cervical procedure (P = .01). In patients undergoing a combined anterior and posterior surgical procedure, 16 of 25 (66%) experienced a complication, a significant difference in comparison with solitary anterior procedures (P = .004). Anterior procedures were associated with postoperative dysphagia and vocal cord paresis, whereas wound infection and C5 palsy was more frequently recorded in the group undergoing surgery via an isolated posterior approach. CONCLUSIONS The incidence of complications or adverse events is not definitely known for most spinal procedures because of the complexity of defining complications and obtaining accurate data. Therefore, to obtain a more accurate assessment of spinal procedures, a prospective algorithm was designed to collect and record complications during the acute perioperative period. Using this technique, a significantly higher complication rate was documented than had been previously reported for cervical spine operative interventions. In addition, use of a broad definition of perioperative complications likely increased the recorded incidence of perioperative adverse events and complications. Complications were more common in patients undergoing posterior and anteroposterior procedures.

Early complications in spine surgery and relation to preoperative diagnosis: a single-center prospective study

OBJECT The reported incidence of complications in spine surgery varies widely. Variable study methodologies may open differing avenues for potential bias, and unclear definitions of perioperative complication make analysis of the literature challenging. Although numerous studies have examined the morbidity associated with specific procedures or diagnoses, no prospective analysis has evaluated the impact of preoperative diagnosis on overall early morbidity in spine surgery. To accurately assess perioperative morbidity in patients undergoing spine surgery, a prospective analysis of all patients who underwent spine surgery by the neurosurgical service at a large tertiary care center over a 6-month period was conducted. The correlation between preoperative diagnosis and the incidence of postoperative complications was assessed. METHODS Data were prospectively collected on 248 consecutive patients undergoing spine surgery performed by the neurosurgical service at the Thomas Jefferson University Hospital from May to December 2008. A standardized definition of minor and major complications was applied to all adverse events occurring within 30 days of surgery. Data on diagnosis, complications, and length of stay were retrospectively assessed using stepwise multivariate analysis. Patients were analyzed by preoperative diagnosis (neoplasm, infection, degenerative disease, trauma) and level of surgery (cervical or thoracolumbar). RESULTS Total early complication incidence was 53.2%, with a minor complication incidence of 46.4% and a major complication incidence of 21.3%. Preoperative diagnosis correlated only with the occurrence of minor complications in the overall cohort (p = 0.02). In patients undergoing surgery of the thoracolumbar spine, preoperative diagnosis correlated with presence of a complication and the number of complications (p = 0.003). Within this group, patients with preoperative diagnoses of infection and neoplasm were more often affected by isolated and multiple complications (p = 0.05 and p = 0.02, respectively). Surgeries across the cervicothoracic and thoracolumbar junctions were associated with higher incidences of overall complication than cervical or lumbar surgery alone (p = 0.04 and p = 0.03, respectively). Median length of stay was 5 days for patients without a complication. Length of stay was significantly greater for patients with a minor complication (10 days, p < 0.0001) and even greater for patients with a major complication (14 days, p < 0.0001). CONCLUSIONS The incidence of complications found in this prospective analysis is higher than that reported in previous studies. This association may be due to a greater accuracy of record-keeping, absence of recall bias via prospective data collection, high complexity of pathology and surgical approaches, or application of a more liberal definition of what constitutes a complication. Further large-scale prospective studies using clear definitions of complication are necessary to ascertain the true incidence of early postoperative complications in spine surgery.

Patient comorbidity score predicting the incidence of perioperative complications: assessing the impact of comorbidities on complications in spine surgery

OBJECT Present attempts to control health care costs focus on reducing the incidence of complications and hospital-acquired conditions (HACs). One approach uses restriction or elimination of hospital payments for HACs. Present approaches assume that all HACs are created equal and that payment restrictions should be applied uniformly. Patient factors, and especially patient comorbidities, likely impact complication incidence. The relationship of patient comorbidities and complication incidence in spine surgery has not been prospectively reported. METHODS The authors conducted a prospective assessment of complications in spine surgery during a 6-month period; an independent auditor and a validated definition of perioperative complications were used. Initial demographics captured relevant patient comorbidities. The authors constructed a model of relative risk assessment based on the presence of a variety of comorbidities. They examined the impact of specific comorbidities and the cumulative effect of multiple comorbidities on complication incidence. RESULTS Two hundred forty-nine patients undergoing 259 procedures at a tertiary care facility were evaluated during the 6-month duration of the study. Eighty percent of the patients underwent fusion procedures. One hundred thirty patients (52.2%) experienced at least 1 complication, with major complications occurring in 21.4% and minor complications in 46.4% of the cohort. Major complications doubled the median duration of hospital stay, from 6 to 12 days in cervical spine patients and from 7 to 14 days in thoracolumbar spine patients. At least 1 comorbid condition was present in 86% of the patients. An increasing number of comorbidities strongly correlated with increased risk of major, minor, and any complications (p = 0.017, p < 0.0001, and p < 0.0001, respectively). Patient factors correlating with increased risk of specific complications included systemic malignancy and cardiac conditions other than hypertension. CONCLUSIONS Comorbidities significantly increase the risk of perioperative complications. An increasing number of comorbidities in an individual patient significantly increases the risk of a perioperative adverse event. Patient factors significantly impact the relative risk of HACs and perioperative complications.

Early Complications Related to Approach in Thoracic and Lumbar Spine Surgery: A Single Center Prospective Study

BACKGROUND Thoracic and lumbar spine surgical procedures are performed for a variety of pathologies. The literature consists of multiple retrospective reviews examining complication prevalence with the surgical treatment of these disorders. However, there is limited direct examination of perioperative complications through a prospective approach. Of the prospective assessments, the majority focuses on specific surgical procedures or provides a limited assessment of certain spinal implants. Prospective assessments of complication incidence in broad patient populations are limited. This article analyzes a prospectively collected database of patients who underwent a thoracic and/or lumbar spine surgery at a large tertiary care center and the effect of surgical approach (anterior or posterior) on the incidence of early complications. METHODS Data collection was performed prospectively on 128 patients on the neurosurgical spine service at Thomas Jefferson University hospital from May to December 2008. Data on preoperative diagnosis, medical comorbidities, body mass index, surgical approach and procedure, length of stay, and complication occurrence was recorded and analyzed. Acute complications or adverse events occurring within the initial 30 days after each operative procedure were included. All medical adverse events were included as complications. A previously circumstantiated binary definition of major and minor complications was used to stratify the data. RESULTS Overall, 76 of 128 patients (59.4%) in this cohort experienced at least one complication. Anterior thoracic and lumbar procedures had an 83.3% (5/6) incidence of complications. Of those patients having solely a posterior thoracic and lumbar procedures, 37 of 75 (49.3%) experienced at least one complication. Combined anterior and posterior surgical procedure had a complication incidence of 34 of 47 (72.3%). The mean number of complications reached significance for the minor and overall complications groups (P = .0076 and .0172, respectively, Poisson regression). Comparing the incidence of complications reveals the overall complications in the posterior alone group compared with the anterior/posterior combined group was significantly lower (P = .0134). Those undergoing instrumented fusions were statistically more likely to encounter complications (P < .001). CONCLUSIONS There is a considerably higher complication incidence than previously reported for thoracic, thoracolumbar, and lumbar spine operations. A prospective approach and a broad definition of perioperative complications increased the recorded incidence of perioperative adverse events and complications. The case complexity of a tertiary referral center may also have escalated the increased incidence. Complications were more common in patients undergoing anterior and anterior/posterior procedures.

Incidence of early complications in cervical spine surgery and relation to preoperative diagnosis: a single-center prospective study.

Study Design Prospective observational cohort study. Objective To determine the incidence of early postoperative complications in patients undergoing cervical spine surgery and its correlation with preoperative diagnosis. Summary of Background Data The reported incidence of complications and adverse events in cervical spine surgery is highly variable. Inconsistent definitions and varying methodologies have made the interpretation of earlier reports difficult. No large study has analyzed the overall early morbidity of cervical spine surgery in a prospective fashion or attempted to correlate preoperative diagnosis and comorbidities with perioperative complications. Methods Data on 121 consecutive patients, who underwent cervical spine surgery at the Thomas Jefferson University Hospital from May to December 2008, was prospectively collected. Complication definition and gradations of complication severity were validated by a survey of spine surgeons and spine surgery patients. An independent assessor prospectively audited complication incidence in the patient cohort. Data on diagnosis, comorbidities, BMI, complications, and length of stay were prospectively collected and assessed using stepwise multivariate analysis. Results The overall incidence of early complications was 47.1% with a 40.5% incidence of minor complications and an 18.2% incidence of major complications. Major complication incidence was greater in cases of infection (20.0%) and spinal oncologic procedures (30.0%), although this difference was not of statistical significance (P=0.07). Total number of complications recorded was greater in cases of infection and neoplasm (P=0.05). Conclusions Complications in cervical spine procedures occurred most frequently in cases involving trauma and spinal oncologic procedures. This study illustrates that the incidence of early complications in cervical spine procedures is greater than appreciated earlier. This difference likely arises owing to the use of a broad definition of perioperative complications, elimination of recall bias through use of a prospective assessment, and overall case complexity. Accurate assessment of the incidence of early complications in cervical spine surgery is important for patient counseling and in design of prospective quality improvement programs.

Preoperative diagnosis and early complications in thoracolumbar spine surgery: a single center prospective study.

Study Design Prospective observational cohort study. Objective To determine the incidence of early complications with thoracolumbar spine surgery and its correlation with preoperative diagnosis. Summary of Background Data The reported incidence of early complications associated with thoracolumbar surgery is highly variable. Varying definitions of what constitutes a “complication” and varying study methodologies make evaluation and comparison of the literature difficult. No large study has investigated the effect of preoperative diagnosis and patient comorbidities on early postoperative complications in thoracolumbar surgery. Methods One-hundred twenty-eight consecutive patients who underwent thoracolumbar surgery by the neurosurgical service at the Thomas Jefferson University Hospital were prospectively entered into a central database from May to December 2008. An earlier-described, binary definition of major and minor complication was used. Data on preoperative diagnosis, comorbidities, body mass index, surgical procedure, length of stay (LOS), and early complication was examined using &khgr;2 and time-to-discharge survival analysis. Results The overall complication incidence was 59.4%, with a minor complication incidence of 52.3% and a major complication incidence of 24.2%. The highest incidences of complications occurred in patients with the diagnosis of infection and tumor, where incidence exceeded 70%; this difference did not achieve statistical significance. The overall median LOS was 7 days; LOS was longer in patients with traumatic pathology (17 d) and patients with neoplastic pathology (14 d) (P<0.05). Conclusions A higher incidence of complications than earlier studies was noted. A trend toward higher complication incidence in patients with infectious or neoplastic disease was observed. The severity of patient pathology, the broader definitions of complication used, and the elimination of recall bias by the use of a prospective study design accounts for the higher incidence of complications reported in this series. However, a large, prospective study using clear definitions is needed to elucidate the true incidence of early complications in thoracolumbar surgery.