Vinita Bahl

A validation study of a retrospective venous thromboembolism risk scoring method.

Objectives:Validate a retrospective venous thromboembolism (VTE) risk scoring method, which was developed at the University of Michigan Health System and based on the Caprini risk assessment model, and assess the confounding effects of VTE prophylaxis. Background:Assessing patients for risk of VTE is essential to initiating appropriate prophylaxis and reducing the mortality and morbidity associated with deep vein thrombosis and pulmonary embolism. Methods:VTE risk factors were identified for 8216 inpatients from the National Surgical Quality Improvement Program using the retrospective scoring method. Logistic regression was used to calculate odds ratios (OR) for VTE within 30 days after surgery for risk factors and risk level. A bivariate probit model estimated the effects of risk while controlling for adherence to prophylaxis guidelines. Results:Distribution of the study population by risk level was highest, 52.1%; high, 36.5%; moderate, 10.4%; and low, 0.9%. Incidence of VTE within 30 days was overall 1.4%; by risk level: highest, 1.94%; high, 0.97%; moderate, 0.70%; low, 0%. Controlling for length of hospitalization (>2 d) and fiscal year, pregnancy or postpartum (OR = 8.3; 1.0–68, P < 0.05), recent sepsis (4.0; 1.4–10.9, P < 0.01), malignancy (2.3; 1.5–3.3, P < 0.01), history of VTE (2.1; 1.1–4.1, P < 0.05), and central venous access (1.8; 1.1–3.0, P < 0.05) were significantly associated with VTE. Risk level was significantly associated with VTE (1.9; 1.3–2.6, P < 0.01). The bivariate probit demonstrated significant correlation between the probability of VTE and lack of adherence to prophylaxis guidelines (&rgr; = 0.299, P = 0.013). Conclusion:The retrospective risk scoring method is valid and supports use of individual patient assessment of risk for VTE within 30 days after surgery.

Identifying patients at high risk for venous thromboembolism requiring treatment after outpatient surgery.

Objective:To identify independent predictors of 30-day venous thromboembolism (VTE) events requiring treatment after outpatient surgery. Background:An increasing proportion of surgical procedures are performed in the outpatient setting. The incidence of VTE requiring treatment after outpatient surgery is unknown. Methods:Prospective observational cohort study using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2009. Adult patients who had outpatient surgery or surgery with subsequent 23-hour observation were included. The main outcome measure was 30-day VTE requiring treatment. Patients were randomly assigned to derivation (N = 173,501) or validation (N = 85,730) cohorts. Logistic regression examined independent risk factors for 30-day VTE. A weighted risk index was created and applied to the validation cohort. Stratified analyses examined 30-day VTE by risk level. Results:Thirty-day incidence of VTE for the overall cohort was 0.15%. Independent risk factors included current pregnancy (adjusted odds ratio [OR] = 7.80, P = 0.044), active cancer (OR = 3.66, P = 0.005), age 41 to 59 years (OR = 1.72, P = 0.008), age 60 years or more (OR = 2.48, P < 0.001), body mass index 40 kg/m2 or higher (OR = 1.81, P = 0.015), operative time 120 minutes or more (OR = 1.69, P = 0.027), arthroscopic surgery (OR = 5.16, P < 0.001), saphenofemoral junction surgery (OR = 13.20, P < 0.001), and venous surgery not involving the great saphenous vein (OR = 15.61, P < 0.001). The weighted risk index identified a 20-fold variation in 30-day VTE between low (0.06%) and highest risk (1.18%) patients. Conclusions:Thirty-day VTE risk after outpatient surgery can be quantified using a weighted risk index. The risk index identifies a high-risk subgroup of patients with 30-day VTE rates of 1.18%.

Stratifying the Risk of Venous Thromboembolism in Otolaryngology

Objective. The consequences of perioperative venous thromboembolism (VTE) are devastating; identifying patients at risk is an essential step in reducing morbidity and mortality. The utility of perioperative VTE risk assessment in otolaryngology is unknown. This study was designed to risk-stratify a diverse population of otolaryngology patients for VTE events. Study Design. Retrospective cohort study. Setting. Single-institution academic tertiary care medical center. Subjects and Methods. Adult patients presenting for otolaryngologic surgery requiring hospital admission from 2003 to 2010 who did not receive VTE chemoprophylaxis were included. The Caprini risk assessment was retrospectively scored via a validated method of electronic chart abstraction. Primary study variables were Caprini risk scores and the incidence of perioperative venous thromboembolic outcomes. Results. A total of 2016 patients were identified. The overall 30-day rate of VTE was 1.3%. The incidence of VTE in patients with a Caprini risk score of 6 or less was 0.5%. For patients with scores of 7 or 8, the incidence was 2.4%. Patients with a Caprini risk score greater than 8 had an 18.3% incidence of VTE and were significantly more likely to develop a VTE when compared to patients with a Caprini risk score less than 8 (P < .001). The mean risk score for patients with VTE (7.4) was significantly higher than the risk score for patients without VTE (4.8) (P < .001). Conclusion. The Caprini risk assessment model effectively risk-stratifies otolaryngology patients for 30-day VTE events and allows otolaryngologists to identify patient subgroups who have a higher risk of VTE in the absence of chemoprophylaxis.

Do the Ahrq Patient Safety Indicators Flag Conditions That Are Present at the Time of Hospital Admission

Objective:The Agency for Healthcare Research and Quality (AHRQ) developed 20 patient safety indicators (PSIs) to identify potentially preventable complications of acute inpatient care based on administrative data. The objective of this patient safety performance study was to assess the impact of cases flagged by each PSI for diagnoses that were actually present on admission on unadjusted PSI rates. Methods:The latest AHRQ PSI software, which allows users to produce 14 of the 20 PSIs for adult inpatients both without and with a “present on admission” (PoA) variable, was applied to administrative data for adult patients discharged from the University of Michigan Health System (UMHS) in 2006. The impact of the PoA values on unadjusted PSI rates was evaluated. Because of concerns about the accuracy of PoA values, results were compared with those of a prior analysis at UMHS that was similar but based on a review of medical records. Findings:Thirteen PSIs had at least 1 case in the numerator. Rates for all but 1 of the 13 were lower using the PoA values and the reduction was statistically significant for 5 PSIs: decubitus ulcer (P < 0.001), foreign body left in (P = 0.033), selected infections due to medical care (P < 0.001), postoperative physiologic and metabolic derangement (P = 0.039), and postoperative pulmonary embolism or deep vein thrombosis (P < 0.001). Results were consistent with those of the analysis of medical records. Conclusions:Unadjusted PSI rates at UMHS are substantially overstated, because the PSIs do not differentiate preexisting conditions from complications and therefore include false positive cases. Because of these findings and the lack of a broader study of the validity of the indicators, PSIs should not be used to profile hospital performance.

Clinical redesign using all patient refined diagnosis related groups.

Objective. Clinical redesign of processes in hospitals that care for children has been limited by a paucity of severity-adjusted indicators that are sensitive enough to identify areas of concern. This is especially true of hospitals that analyze pediatric patient care using standard Centers for Medicare and Medicaid Services (CMS) diagnosis-related groups (DRGs). The objectives of this study were to determine whether 1) utilization of all-patient refined (APR)-DRG severity-adjusted indicators (length of stay, cost per case, readmission rate) from the National Association of Childrens Hospitals and Related Institutions (NACHRI) database could identify areas for improvement at University of Michigan Mott Childrens Hospital (UMMCH) and 2) hospital staff could use the information to implement successful clinical redesign. Methods. The APR-DRG Classification System (version 20) was used with the NACHRI Case Mix Comparative Database by severity level comparison from 1999 to 2002. Indicators include average length of stay (ALOS), case mix index, cost per case, and readmission rate for low acuity asthma (APR-DRG 141.1). UMMCH cases of 141.1 (n = 511) were compared with NACHRI 141.1 (n = 64 312). Although not part of the standard report, mortality rates were calculated by NACHRI for UMMCH and an aggregate of NACHRI member childrens hospitals. Results. Data from 1999 revealed that in noncomplicated asthma cases (level 1 severity), the UMMCH ALOS versus NACHRI ALOS was slightly longer (UMMCH 2.16 days vs NACHRI 2.14 days), and the cost per case was higher (UMMCH

Chemoprophylaxis for Venous Thromboembolism in Otolaryngology

2824 vs NACHRI

Validation of the Caprini Venous Thromboembolism Risk Assessment Model in Critically Ill Surgical Patients

2738), whereas levels 2, 3, and 4 cases (moderate, major, and extreme severity) indicated the ALOS and cost per case were lower than the national aggregate. This showed that the APR-DRG system was sensitive enough to distinguish variances of care within a diagnosis according to severity level. After analysis of internal data and meeting with clinicians to review the indicators, 3 separate clinical processes were targeted: 1) correct documentation of comorbidities and complications, 2) standardized preprinted orders were created with the involvement of the pediatric pulmonologists, and 3) standardized automatic education for parents was started on the first day of admission. Yearly data were reviewed and appropriate adjustments made in the education of both residents and staff. In 2002, the UMMCH ALOS dropped to 1.75 ± .08 days from 2.16 ± .09. In 2002, the NACHRI ALOS was 2.00 days ± 0.01 versus the UMMCH ALOS of 1.75 days ± 0.0845, indicating that the UMMCH ALOS dropped significantly lower than the NACHRI aggregate database over the 3-year period. Cost per case of UMMCH compared with NACHRI after the 3 years indicated that UMMCH increased 12%, whereas the NACHRI aggregate increased 18%. These data show that length of stay and cost per case relative to the national database improved after clinical redesign. Improvements have been sustained throughout the 3-year period. Readmission rates ranged from 2.97% to 0.80% and were less than the national cohort by the third year. There were no mortalities in the UMMCH inpatient asthma program. This demonstrates that clinicians believed that the data from the APR-DRG acuity-adjusted system was useful and that they were then able to apply classical clinical redesign strategies to improve cost-effectiveness and quality that was sustained over 3 years. Conclusions. Severity-adjusted indicators were useful for identifying areas appropriate for clinical redesign and contributed to the improvement in cost-effective patient care without a detriment in quality indicators. This method of using a large comparative database, having measures of severity, and using internal analysis is generalizable for pediatric hospitals and can contribute to ongoing attempts to improve cost-effectiveness and quality in medical care.

Improved outcomes in patients with head and neck cancer using a standardized care protocol for postoperative alcohol withdrawal.

IMPORTANCE Venous thromboembolism (VTE) causes significant morbidity and mortality in surgical patients. Despite strong evidence that thromboprophylaxis reduces the incidence VTE, guidelines for prophylaxis in otolaryngology are not well established. Key to the development of VTE prophylaxis recommendations are effective VTE risk stratification and evaluation of the benefits and harms of prophylaxis. OBJECTIVE To evaluate the effectiveness and safety of VTE chemoprophylaxis among a population of otolaryngology patients stratified by risk. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study of 3498 adult patients admitted for otolaryngologic surgery at a single-institution academic tertiary care medical center between September 1, 2003, and June 30, 2010. INTERVENTIONS Patients were stratified into 2 groups based on whether they received VTE chemoprophylaxis. MAIN OUTCOMES AND MEASURES Incidence of VTE and bleeding-related complications within 30 days after surgery. RESULTS Of 1482 patients receiving VTE chemoprophylaxis, 18 (1.2%) developed a VTE compared with 27 of 2016 patients (1.3%) who did not receive prophylaxis (P = .75). Patients with Caprini VTE risk scores greater than 7 were less likely to have a VTE with perioperative chemoprophylaxis (5.3% vs 10.4%; P = .06). Of patients with VTE chemoprophylaxis, 3.5% developed a bleeding complication compared with 1.2% of patients without prophylaxis (P < .001). Bleeding complications were associated with concomitant use of antiplatelet medications and chemoprophylaxis. Among patients undergoing free tissue transfer, chemoprophylaxis significantly decreased the incidence of VTE (2.1% vs 7.7%; P = .002) and increased bleeding complications (11.9% vs 4.5%; P = .01). In all other patients, VTE chemoprophylaxis did not significantly influence the likelihood of VTE (1.0% vs 0.6%; P = .12) or bleeding (1.5% vs 0.9%; P = .15). CONCLUSIONS AND RELEVANCE Effectiveness and safety of VTE chemoprophylaxis differed between patient subgroups, defined by Caprini risk score and by procedure. Effectiveness was most evident in patients with high Caprini risk scores and microvascular free tissue reconstruction. Bleeding complications were associated with VTE chemoprophylaxis administered in close proximity to potent antiplatelet therapy. The Caprini risk assessment model appears to be an effective tool to stratify otolaryngology patients by risk for VTE. Patients undergoing free tissue reconstruction merit further study before developing recommendations for VTE prophylaxis because of their higher risk of both VTE and bleeding.

Inadequate Venous Thromboembolism Risk Stratification Predicts Venous Thromboembolic Events in Surgical Intensive Care Unit Patients

IMPORTANCE Appropriate risk stratification for venous thromboembolism (VTE) is essential to providing appropriate thromboprophylaxis and avoiding morbidity and mortality. OBJECTIVE To validate the Caprini VTE risk assessment model in a previously unstudied high-risk cohort: critically ill surgical patients. DESIGN, SETTING, AND PARTICIPANTS We performed a retrospective cohort study of 4844 adults (≥18 years old) admitted to a 20-bed surgical intensive care unit in a large tertiary care academic hospital during a 5-year period (July 1, 2007, through June 30, 2012). MAIN OUTCOMES AND MEASURES The main study outcome was VTE (defined as patients with deep vein thrombosis or pulmonary embolism) that occurred during the patients initial hospital admission. RESULTS The study population was distributed among risk levels as follows: low, 5.3%; moderate, 19.9%; high, 31.6%; highest, 25.4%; and superhigh, 14.9%. The overall incidence of inpatient VTE was 7.5% and increased with risk level: 3.5% in low-risk patients, 5.5% in moderate-risk patients, 6.6% in high-risk patients, 8.6% in highest-risk patients, and 11.5% in superhigh-risk patients. Patients with Caprini scores greater than 8 were significantly more likely to develop inpatient VTE events when compared with patients with Caprini scores of 7 to 8 (odds ratio [OR], 1.37; 95% CI, 1.02-1.85; P = .04), 5 to 6 (OR, 1.35; 95% CI, 1.16-1.57; P < .001), 3 to 4 (OR, 1.30; 95% CI, 1.16-1.47; P < .001), or 0 to 2 (OR, 1.37; 95% CI, 1.16-1.64; P < .001). Similarly, patients with Caprini scores of 7 to 8 were significantly more likely to develop inpatient VTE when compared with patients with Caprini scores of 5 to 6 (OR, 1.33; 95% CI, 1.01-1.75; P = .04), 3 to 4 (OR, 1.27; 95% CI, 1.08-1.51; P = .005), or 0 to 2 (OR, 1.38; 95% CI, 1.10-1.74; P = .006). CONCLUSIONS AND RELEVANCE The Caprini VTE risk assessment model is valid. This study supports the use of individual risk assessment in critically ill surgical patients.

Exploratory analyses of the "failure to rescue" measure: evaluation through medical record review.

OBJECTIVE To show clinical benefit in the main outcome measures by the use of a standardized protocol for identification, characterization, and treatment of alcohol withdrawal syndrome (AWS) in postoperative patients with head and neck cancer. DESIGN Prospective cohort study with a retrospective cohort control. SETTING Tertiary care university. PATIENTS A total of 26 consecutive postoperative patients with AWS were selected from among 652 patients with head and neck cancer to be enrolled in the protocol from March 2003 through March 2005. Controls consisted of 14 of 981 consecutive patients with AWS from March 2000 through December 2002. INTERVENTION Application of a standardized care protocol. MAIN OUTCOME MEASURES Sensitivity and specificity of preoperative screening for AWS risk, predictability of outcomes, length of stay, transfers to the intensive care unit (ICU), AWS symptoms, postoperative morbidity and mortality, doses of pharmacotherapy required, and charges. RESULTS Protocol patients demonstrated significantly fewer AWS-related ICU transfers and less delirium and violence than preprotocol patients. Mortality, wound complications, hospital charges, and doses of benzodiazepines, clonidine, and haloperidol were not significantly different between these 2 groups. Preoperative medical history correlated poorly with AWS outcomes. Screening was 87.5% sensitive and 99.7% specific. Late enrollees to the protocol (false-negative screening results) showed many significantly worse outcomes than immediate enrollees. CONCLUSION Use of the standardized AWS symptom-triggered protocol decreased delirium, violence, and AWS-related ICU transfers without significantly increasing hospital charges.