Influence of patient and hospital characteristics on anesthesia time in medicare patients undergoing general and orthopedic surgery

Language Disparity Predicts Poor Patient-Reported Outcome and Follow-Up in Microsurgical Breast Reconstruction

BACKGROUND

 Patients with limited English proficiency (LEP) have starkly different health care experiences compared with their English-proficient counterparts. The authors aim to examine the link between LEP and postoperative outcomes in patients undergoing microsurgical breast reconstruction.

METHODS

 A retrospective review of all patients who underwent abdominal-based microsurgical breast reconstruction at our institution between 2009 and 2019 was performed. Variables collected included patient demographics, language status, interpreter usage, perioperative complications, follow-up visits, and self-reported outcomes (Breast-Q). Pearson's χ 2 test, Student's t-test, odds ratio analysis, and regression modeling were used for analysis.

RESULTS

 A total of 405 patients were included. LEP patients comprised 22.22% of the overall cohort with 80% of LEP patients utilizing interpreter services. LEP patients reported significantly lower satisfaction with an abdominal appearance at the 6-month follow-up and lower physical and sexual well-being scores at the 1-year follow-up (p = 0.05, 0.02, 0.01, respectively). Non-LEP patients had significantly longer operative times (539.6 vs. 499.3 minutes, p = 0.024), were more likely to have postoperative donor site revisions (p = 0.05), and more likely to receive preoperative neuraxial anesthesia (p = 0.01). After adjusting for confounders, LEP stats was associated with 0.93 fewer follow-up visits (p = 0.02). Interestingly, compared with LEP patients who did not receive interpreter services, LEP patients who did had 1.98 more follow-up visits (p = 0.02). There were no significant differences in emergency room visits or complications between the cohorts.

CONCLUSION

 Our findings suggest that language disparities exist within microsurgical breast reconstruction and underscore the importance of effective, language-conscious communication between surgeon and patient.

The Benefit in Patient-Reported Outcomes After Total Knee Arthroplasty was Comparable Across Income Quartiles

BACKGROUND

Few studies have assessed how socioeconomic status (SES) influences patient-reported outcomes (PROMs) after total knee arthroplasty (TKA). This study evaluated the impact of patient median ZIP code income levels on PROMs after TKA.

METHODS

We retrospectively reviewed patients at our institution undergoing primary, unilateral TKA from 2017 to 2020. Patients who did not have one-year postoperative PROMs were excluded. Patients were stratified based on the quartile of their home ZIP code median income from United States Census Bureau data. There were 1,267 patients included: 98 in quartile 1 (median income ≤ $46,308) (7.7%); 126 in quartile 2 (median income $46,309-$57,848) (10.0%); 194 in quartile 3 (median income $57,849-$74,011) (15.7%); and 849 in quartile 4 (median income ≥ $74,012) (66.4%). We collected baseline demographic data, 2-year outcomes, and PROMs preoperatively, as well as at 12 weeks and one year, postoperatively.

RESULTS

The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was significantly higher in quartile 4 preoperatively (P < .001), 12 weeks postoperatively (P < .001), and one year postoperatively (P < .001). There were no significant differences in delta improvements of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement from preoperative to 12 weeks or one year postoperatively. There were no significant differences in lengths of stay, discharge dispositions, readmissions, or revisions.

CONCLUSION

Patients from lower income areas have slightly worse knee function preoperatively and worse outcomes following TKA. However, improvements in PROMs throughout the first year postoperatively are similar across income quartiles, suggesting that patients from lower income quartiles achieve comparable therapeutic benefits from TKA.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Antiemetic Administration and Its Association with Race: A Retrospective Cohort Study

BACKGROUND

Anesthesiologists' contribution to perioperative healthcare disparities remains unclear because patient and surgeon preferences can influence care choices. Postoperative nausea and vomiting is a patient- centered outcome measure and a main driver of unplanned admissions. Antiemetic administration is under the sole domain of anesthesiologists. In a U.S. sample, Medicaid insured versus commercially insured patients and those with lower versus higher median income had reduced antiemetic administration, but not all risk factors were controlled for. This study examined whether a patient's race is associated with perioperative antiemetic administration and hypothesized that Black versus White race is associated with reduced receipt of antiemetics.

METHODS

An analysis was performed of 2004 to 2018 Multicenter Perioperative Outcomes Group data. The primary outcome of interest was administration of either ondansetron or dexamethasone; secondary outcomes were administration of each drug individually or both drugs together. The confounder-adjusted analysis included relevant patient demographics (Apfel postoperative nausea and vomiting risk factors: sex, smoking history, postoperative nausea and vomiting or motion sickness history, and postoperative opioid use; as well as age) and included institutions as random effects.

RESULTS

The Multicenter Perioperative Outcomes Group data contained 5.1 million anesthetic cases from 39 institutions located in the United States and The Netherlands. Multivariable regression demonstrates that Black patients were less likely to receive antiemetic administration with either ondansetron or dexamethasone than White patients (290,208 of 496,456 [58.5%] vs. 2.24 million of 3.49 million [64.1%]; adjusted odds ratio, 0.82; 95% CI, 0.81 to 0.82; P < 0.001). Black as compared to White patients were less likely to receive any dexamethasone (140,642 of 496,456 [28.3%] vs. 1.29 million of 3.49 million [37.0%]; adjusted odds ratio, 0.78; 95% CI, 0.77 to 0.78; P < 0.001), any ondansetron (262,086 of 496,456 [52.8%] vs. 1.96 million of 3.49 million [56.1%]; adjusted odds ratio, 0.84; 95% CI, 0.84 to 0.85; P < 0.001), and dexamethasone and ondansetron together (112,520 of 496,456 [22.7%] vs. 1.0 million of 3.49 million [28.9%]; adjusted odds ratio, 0.78; 95% CI, 0.77 to 0.79; P < 0.001).

CONCLUSIONS

In a perioperative registry data set, Black versus White patient race was associated with less antiemetic administration, after controlling for all accepted postoperative nausea and vomiting risk factors.

EDITOR’S PERSPECTIVE

Alzheimer's Dementia After Exposure to Anesthesia and Surgery in the Elderly: A Matched Natural Experiment Using Appendicitis

OBJECTIVE

The aim of this study was to determine whether surgery and anesthesia in the elderly may promote Alzheimer disease and related dementias (ADRD).

BACKGROUND

There is a substantial conflicting literature concerning the hypothesis that surgery and anesthesia promotes ADRD. Much of the literature is confounded by indications for surgery or has small sample size. This study examines elderly patients with appendicitis, a common condition that strikes mostly at random after controlling for some known associations.

METHODS

A matched natural experiment of patients undergoing appendectomy for appendicitis versus control patients without appendicitis using Medicare data from 2002 to 2017, examining 54,996 patients without previous diagnoses of ADRD, cognitive impairment, or neurological degeneration, who developed appendicitis between ages 68 through 77 years and underwent an appendectomy (the ''Appendectomy'' treated group), matching them 5:1 to 274,980 controls, examining the subsequent hazard for developing ADRD.

RESULTS

The hazard ratio (HR) for developing ADRD or death was lower in the Appendectomy group than controls: HR = 0.96 [95% confidence interval (CI) 0.94-0.98], P < 0.0001, (28.2% in Appendectomy vs 29.1% in controls, at 7.5 years). The HR for death was 0.97 (95% CI 0.95-0.99), P = 0.002, (22.7% vs 23.1% at 7.5 years). The HR for developing ADRD alone was 0.89 (95% CI 0.86-0.92), P < 0.0001, (7.6% in Appendectomy vs 8.6% in controls, at 7.5 years). No subgroup analyses found significantly elevated rates of ADRD in the Appendectomy group.

CONCLUSION

In this natural experiment involving 329,976 elderly patients, exposure to appendectomy surgery and anesthesia did not increase the subsequent rate of ADRD.

Predicting surgical operative time in primary total knee arthroplasty utilizing machine learning models

BACKGROUND

Prolonged surgical operative time is associated with postoperative adverse outcomes following total knee arthroplasty (TKA). Increasing operating room efficiency necessitates the accurate prediction of surgical operative time for each patient. One potential way to increase the accuracy of predictions is to use advanced predictive analytics, such as machine learning. The aim of this study is to use machine learning to develop an accurate predictive model for surgical operative time for patients undergoing primary total knee arthroplasty.

METHODS

A retrospective chart review of electronic medical records was conducted to identify patients who underwent primary total knee arthroplasty at a tertiary referral center. Three machine learning algorithms were developed to predict surgical operative time and were assessed by discrimination, calibration and decision curve analysis. Specifically, we used: (1) Artificial Neural Networks (ANNs), (2) Random Forest (RF), and (3) K-Nearest Neighbor (KNN).

RESULTS

We analyzed the surgical operative time for 10,021 consecutive patients who underwent primary total knee arthroplasty. The neural network model achieved the best performance across discrimination (AUC = 0.82), calibration and decision curve analysis for predicting surgical operative time. Based on this algorithm, younger age (< 45 years), tranexamic acid non-usage, and a high BMI (> 40 kg/m²) were the strongest predictors associated with surgical operative time.

CONCLUSIONS

This study shows excellent performance of machine learning models for predicting surgical operative time in primary total knee arthroplasty. The accurate estimation of surgical duration is important in enhancing OR efficiency and identifying patients at risk for prolonged surgical operative time.

LEVEL OF EVIDENCE

Level III, case control retrospective analysis.

Race/Ethnicity and Duration of Anesthesia for Pediatric Patients in the US: a Retrospective Cohort Study

BACKGROUND

Previous literature has demonstrated adverse patient outcomes associated with racial/ethnic disparities in health services. Because patients/parents and providers care about the duration of anesthesia, this study focuses on this outcome.

OBJECTIVES

To determine the association between race/ethnicity and duration under anesthesia.

RESEARCH DESIGN

In this retrospective cohort study of data from the Multicenter Perioperative Outcomes Group, White non-Latino was the reference and was compared with Black non-Latino children, Latino, Asian, Native American, Other, and "Unknown" race children.

SUBJECTS

Children aged 3 to 17 years.

OUTCOMES

Induction duration (primary outcome), procedure-end duration, and total duration under anesthesia (secondary outcomes).

RESULTS

Of 37,596 eligible cases, 9,610 cases with complete data were analyzed. The sample consisted of 6,894 White non-Latino patients, 1,021 Black non-Latino patients, 50 Latino patients, 287 Asian patients, 26 Native American patients, 57 "Other" race patients, and 1,275 patients of "Unknown" race. The mean induction time was 11.9 min (SD 5.6 min). In adjusted analysis, Black non-Latino patients had 5% longer induction and procedure-end durations than White non-Latino children (exponentiated beta coefficient [Exp (β)] 1.05, 95% CI: 1.02-1.08, p < 0.01 and Exp (β) 1.08, 95% CI 1.04-1.13, p < 0.01 respectively).

CONCLUSIONS

White non-Latino children had shorter induction and procedure-end durations than Black children. The differences in induction and procedure-end time were small but may be meaningful on a population-health level.

Increased Operative Time Impacts Rates of Short-Term Complications After Unicompartmental Knee Arthroplasty

BACKGROUND

Previous evidence has demonstrated an exacerbating effect of increased operative time on short-term complications in total joint arthroplasty. While the same relationship may be expected for unicompartmental knee arthroplasty (UKA), supporting evidence remains sparse. The purpose of this study is to determine the impact of operative time on short-term complication rates after UKA and determine a critical threshold in operative times after which complications may increase.

METHODS

The American College of Surgeons National Surgical Quality Improvement Project was queried from 2007 to 2018 to identify 11,633 UKA procedures that were included in the final analysis. The effect of operative time on complications within 30 days was evaluated using multivariate logistic regression models. Receiver operating characteristics curves and spline regression models were used to identify critical thresholds in operative time that increase the likelihood of short-term complications.

RESULTS

Longer operative times (in minutes) were associated with higher rates of surgical site infection (90.4 ± 26.7 vs 84.8 ± 25.5, P = .003), blood transfusions (94.9 ± 28.6 vs 84.9 ± 25.5, P = .007), as well as reoperation rates (90.8 ± 27.9 vs 84.9 ± 25.5, P = .01), extended hospital length of stay (93.4 ± 29.8 vs 84.5 ± 25.2, P < .001), and mortality (110.4 ± 35.5 vs 84.9 ± 25.5, P = .008). Following multivariate logistic regression, operative time was found to independently predict increased surgical site infection, blood transfusion, myocardial infarction, extended length of stay, and mortality (odds ratio: 1.09 - 1.45, CI: 1.01 - 1.91, all P values <0.02). Receiver operating characteristics curves found an increase in mortality risk during the 30-day postoperative period after 88.5 minutes of operative time, a finding supported by spline regression plots.

CONCLUSION

The present study found a positive correlation between increased operative times and short-term postoperative complication rates after UKA. Despite a statistically significant association with increasing operative time, odds ratios of reported complications are relatively low.

Importance of operating room case scheduling on analyses of observed reductions in surgical site infections from the purchase and installation of capital equipment in operating rooms

BACKGROUND

We review the impact of the consequences of operating room (OR) management decision making on power analyses for observational studies of surgical site infections (SSIs) among patients receiving care in ORs with interventions versus without interventions involving physical changes to ORs. Examples include ventilation systems, bactericidal lighting, and physical alterations to ORs.

METHODS

We performed a narrative review of operating room management and surgical site infection articles. We used 10-years of operating room data to estimate parameters for use in statistical power analyses.

RESULTS

Creating pivot tables or monthly control charts of SSI per case by OR and comparing among ORs with or without intervention is not recommended. This approach has low power to detect a difference in SSI rates among the ORs with or without the intervention. The reason is that appropriate OR case scheduling decision making causes risk factors for SSI to differ among ORs, even when stratifying by surgical specialty. Such risk factors include case duration, urgency, and American Society of Anesthesiologists' Physical Status. Instead, analyze SSI controlling for the OR, where the patient had surgery, and matching patients using these variables is preferable. With α = 0.05, 600 cases per OR, 5 intervention ORs, and 5 or 1 control patients for each intervention patient, reasonable power (≅94% or 78%, respectively) can be achieved to detect reductions (3.6% to 2.4%) in the incidence of SSI between ORs with or without the intervention.

CONCLUSIONS

By using this matched cohort design, the effect of the purchase and installation of capital equipment in ORs on SSI can be evaluated meaningfully.

The Association of Nurse-Physician Teamwork and Mortality in Surgical Patients

In this study we describe nurse-physician teamwork, estimate its association with surgical patient outcomes (30-day mortality and failure-to-rescue), and determine whether these relationships depend upon other modifiable hospital nursing characteristics (nurse staffing and education levels) known to be associated with patient outcomes. This cross-sectional analysis included linked data from 29,391 nurses representing 665 acute care hospitals and 1,321,904 adult patients who underwent a general surgical, vascular, or orthopedic procedure. Surgical patients cared for in hospitals with better nurse-physician teamwork had significantly lower odds of 30-day mortality (odds ratio [OR] = 0.95) and failure-to-rescue (OR = 0.95). In addition, the odds of death and failure-to-rescue were lower for patients in hospitals with both higher nurse-physician teamwork and more favorable patient-to-nurse staffing ratios. Similar trends were observed related to nursing education levels. Improving interprofessional teamwork is one strategy to improve patient outcomes with the added importance of also considering additional features of their nursing workforce.

A Statistical Model-driven Surgical Case Scheduling System Improves Multiple Measures of Operative Suite Efficiency: Findings From a Single-center, Randomized Controlled Trial

OBJECTIVE

We sought to determine whether a data-driven scheduling approach improves Operative Suite (OS) efficiency.

BACKGROUND

Although efficient use of the OS is a critical determinant of access to health care services, OS scheduling methodologies are simplistic and do not account for all the available characteristics of individual surgical cases.

METHODS

We randomly scheduled cases in a single OS by predicting their length using either the historical mean (HM) duration of the most recent 4 years; or a regression modeling (RM) system that accounted for operative and patient characteristics. The primary endpoint was the imprecision in prediction of the end of the operative day. Secondary endpoints included measures of OS efficiency; personnel burnout captured by the Maslach Burnout Inventory; and a composite endpoint of 30-day mortality, myocardial infarction, wound infection, bleeding, amputation, or reoperation.

RESULTS

Two hundred and seven operative days were allocated to scheduling with either the RM or the HM methodology. Mean imprecision in predicting the end of the operative day was higher with the HM approach (30.8 vs 7.2 minutes, P = 0.024). RM was associated with higher throughput (379 vs 356 cases scheduled over the course of the study, P = 0.04). The composite rate of adverse 30-day events was similar (2.2% vs 3.2%, P = 0.44). The mean depersonalization score was higher (3.2 vs 2.0, P = 0.044), and mean personal accomplishment score was lower during HM weeks (37.5 vs 40.5, P = 0.028).

CONCLUSIONS

Compared to the HM scheduling approach, the proposed data-driven RM scheduling methodology improves multiple measures of OS efficiency and OS personnel satisfaction without adversely affecting clinical outcomes.

Longer Operative Time Results in a Higher Rate of Subsequent Periprosthetic Joint Infection in Patients Undergoing Primary Joint Arthroplasty

BACKGROUND

Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA.

METHODS

We retrospectively reviewed 17,342 primary unilateral total knee arthroplasty and total hip arthroplasty performed at a single institution between 2005 and 2016, with a minimum follow-up of 1 year. A multivariate logistic regression model was conducted to identify the association between operative time and the development of SSI within 90 days and PJI within 1 year.

RESULTS

Overall, the incidence of 90-day SSI and 1-year PJI was 1.2% and 0.8%, respectively. Patients with an operative time of >90 minutes had a significantly higher incidence of SSI and PJI (2.1% and 1.4%, respectively) compared to cases lasting between 60 and 90 minutes (1.1% and 0.7%), and those lasting ≤60 minutes (0.9% and 0.7%, P < .01). In the multivariate model, the risk for infection increased by an odds ratio of 1.346 (95% confidential interval 1.114-1.627) for 90-day SSI and 1.253 (95% confidential interval 1.060-1.481) for 1-year PJI for each 20-minute increase in operative time.

CONCLUSION

In patients undergoing primary TJA, each 20-minute increase in operative time was associated with nearly a 25% increased risk of subsequent PJI. We advocate that surgeons pay close attention to this underappreciated risk factor while maintaining safe operative practices, which minimize unnecessary steps and wasted time in the operating room.

Prone positioning in the elderly extends perioperative process times: a retrospective analysis

Objective: Cervical bone fractures describe a predominant trauma in the elderly. With demographic change, prone patient positions might create further stress on personnel resources. Therefore, the aim of this study was to conduct an age-related analysis of pre- and intraoperative process times in patients with cervical fractures. Methods: We reviewed all schedules with cervical spine surgery performed at a tertiary hospital. Two different operative patient positions were specified: prone and supine. We retrospectively analysed three study groups: comparison group (group 1: ≤59 years of age), old patients (group 2: 60-79 years), and very old patients (group 3: ≥80 years). We recorded date and kind of surgery, biometric data, and process times by screening recordings of internal software programs (COPRA^® and SAP 710^®). Group comparisons were conducted using the Kruskal-Wallis test with Dunn's post hoc test and Bonferroni correction, Pearson's chi-square test, and the Mann-Whitney U test, as required. Results: 330 patients (202 male; 128 female) were analysed. The number of patients in the resulting age-dependent groups 1-3 were n=102, n=123, and n=105, respectively. Patients of increasing age and in supine position showed a continuous increase in the time needed for anaesthesia induction (mean between 4 and 8 minutes (p<0.05). When compared to patients in supine position, this time further increased on average by 6 minutes (p<0.05) in old but prone patients. In old and very old patients, getting a patient into a prone position was associated with a time demand between 10 and 12 minutes (p<0.01), respectively. While time for surgery age-dependently decreased in patients that were supine positioned (p<0.001), surgery time was prolonged between 34 and 104 minutes (p<0.05) in patients that were prone. Conclusion: With prone position both anaesthesia-controlled and surgical-controlled times extended in patients of increasing age. With regard to demographic change, this aspect should be considered for future revenue calculations in flat-rate remuneration systems.

Surgical phase modelling in minimal invasive surgery

Background

Surgical Process Modelling (SPM) offers the possibility to automatically gain insight in the surgical workflow, with the potential to improve OR logistics and surgical care. Most studies have focussed on phase recognition modelling of the laparoscopic cholecystectomy, because of its standard and frequent execution. To demonstrate the broad applicability of SPM, more diverse and complex procedures need to be studied. The aim of this study is to investigate the accuracy in which we can recognise and extract surgical phases in laparoscopic hysterectomies (LHs) with inherent variability in procedure time. To show the applicability of the approach, the model was used to automatically predict surgical end-times.

Methods

A dataset of 40 video-recorded LHs was manually annotated for instrument use and divided into ten surgical phases. The use of instruments provided the feature input for building a Random Forest surgical phase recognition model that was trained to automatically recognise surgical phases. Tenfold cross-validation was performed to optimise the model for predicting the surgical end-time throughout the procedure.

Results

Average surgery time is 128 ± 27 min. Large variability within specific phases is seen. Overall, the Random Forest model reaches an accuracy of 77% recognising the current phase in the procedure. Six of the phases are predicted accurately over 80% of their duration. When predicting the surgical end-time, on average an error of 16 ± 13 min is reached throughout the procedure.

Conclusions

This study demonstrates an intra-operative approach to recognise surgical phases in 40 laparoscopic hysterectomy cases based on instrument usage data. The model is capable of automatic detection of surgical phases for generation of a solid prediction of the surgical end-time.

Effect of Individual Surgeons and Anesthesiologists on Operating Room Time

BACKGROUND

Variability in operating room (OR) time causes overutilization and underutilization of the available ORs. There is evidence that for a given type of procedure, the surgeon is the major source of variability in OR time. The primary aim was to quantify the variability between surgeons and anesthesiologists. As illustration, the value of modeling the individual surgeons and anesthesiologist for OR time prediction was estimated.

METHODS

OR data containing 16,480 cases were obtained from a general surgery department. The total amount of variability in OR time accounted for by the type of procedure, first and second surgeon, and the anesthesiologist was determined with the use of linear mixed models. The effect on OR time prediction was evaluated as reduction in overtime and idle time per case.

RESULTS

Differences between first surgeons can account for only 2.9% (2.0%-4.2%) of the variability in OR time. Differences between anesthesiologists can account for 0.1% (0.0%-0.3%) of the variability in OR time. Incorporating the individual surgeons and anesthesiologists led to an average reduction of overtime and idle time of 1.8 (95% confidence interval, 1.7-2.0, 10.5% reduction) minutes and 3.0 (95% confidence interval, 2.8%-3.2, 17.0% reduction) minutes, respectively.

CONCLUSIONS

In comparison with the type of procedure, differences between surgeons account for a small part of OR time variability. The impact of differences between anesthesiologists on OR time is negligible. A prediction model incorporating the individual surgeons and anesthesiologists has an increased precision, but improvements are likely too marginal to have practical consequences for OR scheduling.

Improving the Prediction of Total Surgical Procedure Time Using Linear Regression Modeling

For efficient utilization of operating rooms (ORs), accurate schedules of assigned block time and sequences of patient cases need to be made. The quality of these planning tools is dependent on the accurate prediction of total procedure time (TPT) per case. In this paper, we attempt to improve the accuracy of TPT predictions by using linear regression models based on estimated surgeon-controlled time (eSCT) and other variables relevant to TPT. We extracted data from a Dutch benchmarking database of all surgeries performed in six academic hospitals in The Netherlands from 2012 till 2016. The final dataset consisted of 79,983 records, describing 199,772 h of total OR time. Potential predictors of TPT that were included in the subsequent analysis were eSCT, patient age, type of operation, American Society of Anesthesiologists (ASA) physical status classification, and type of anesthesia used. First, we computed the predicted TPT based on a previously described fixed ratio model for each record, multiplying eSCT by 1.33. This number is based on the research performed by van Veen-Berkx et al., which showed that 33% of SCT is generally a good approximation of anesthesia-controlled time (ACT). We then systematically tested all possible linear regression models to predict TPT using eSCT in combination with the other available independent variables. In addition, all regression models were again tested without eSCT as a predictor to predict ACT separately (which leads to TPT by adding SCT). TPT was most accurately predicted using a linear regression model based on the independent variables eSCT, type of operation, ASA classification, and type of anesthesia. This model performed significantly better than the fixed ratio model and the method of predicting ACT separately. Making use of these more accurate predictions in planning and sequencing algorithms may enable an increase in utilization of ORs, leading to significant financial and productivity related benefits.

Operative Time Affects Short-Term Complications in Total Joint Arthroplasty

BACKGROUND

Increased operative time has been associated with increased complications after total joint arthroplasty (TJA). The purpose of the present study was to investigate the effect of operative time on short-term complications after TJA while also identifying patient and operative factors associated with prolonged operative times.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2011-2013 to identify all patients who underwent primary total hip or knee arthroplasty. Patients were stratified by operative time, and 30-day morbidity and mortality data compared using univariate and multivariable analyses.

RESULTS

We identified 99,444 patients who underwent primary TJA. The overall incidence of complications after TJA was 4.9%. Overall complications were increased in patients with operative times >120 minutes (5.9%) as compared to patients with operative times <60 minutes or 60-120 minutes (4.6% and 4.8%, respectively; P < .001). Wound complications, including surgical site infection, were also increased for procedures lasting >120 minutes. In a multivariable analysis, operative time exceeding 120 minutes remained an independent predictor of any complication and wound complication, with each 30-minute increase in operative time beyond 120 minutes further increasing risk. Patient age ≤65 years, male sex, black race, body mass index ≥30 kg/m², and an American Society of Anesthesiologists classification of 3 or 4, predicted operative times >120 minutes.

CONCLUSION

We found that operative time >120 minutes was associated with increased short-term morbidity and mortality after primary TJA. Younger age, male sex, black race, obesity, and increased comorbidity were risk factors for operative time exceeding 120 minutes.

Indirect Standardization Matching: Assessing Specific Advantage and Risk Synergy

OBJECTIVE

To develop a method to allow a hospital to compare its performance using its entire patient population to the outcomes of very similar patients treated elsewhere.

DATA SOURCES/SETTING

Medicare claims in orthopedics and common general, gynecologic, and urologic surgery from Illinois, New York, and Texas from 2004 to 2006.

STUDY DESIGN

Using two example "focal" hospitals, each hospital's patients were matched to 10 very similar patients selected from 619 other hospitals.

DATA COLLECTION/EXTRACTION METHODS

All patients were used at each focal hospital, and we found the 10 closest matched patients from control hospitals with exactly the same principal procedure as each focal patient.

PRINCIPAL FINDINGS

We achieved exact matches on all procedures and very close matches for other patient characteristics for both hospitals. There were few to no differences between each hospital's patients and their matched control patients on most patient characteristics, yet large and significant differences were observed for mortality, failure-to-rescue, and cost.

CONCLUSION

Indirect standardization matching can produce fair audits of quality and cost, allowing for a comprehensive, transparent, and relevant assessment of all patients at a focal hospital. With this approach, hospitals will be better able to benchmark their performance and determine where quality improvement is most needed.

The nature and sources of variability in pediatric surgical case duration

BACKGROUND

Case time variability confounds surgical scheduling and decreases access to limited operating room resources. Variability arises from many sources and can differ among institutions serving different populations. A rich literature has developed around case time variability in adults, but little in pediatrics.

OBJECTIVE

We studied the effect of commonly used patient and procedure factors in driving case time variability in a large, free-standing, academic pediatric hospital.

METHODS

We analyzed over 40 000 scheduled surgeries performed over 3 years. Using bootstrapping, we computed descriptive statistics for 249 procedures and reported variability statistics. We then used conditional inference regression trees to identify procedure and patient factors associated with pediatric case time and evaluated their predictive power by comparing prediction errors against current practice. Patient and procedure factors included patient's age and weight, medical status, surgeon identity, and ICU request indicator.

RESULTS

Overall variability in pediatric case time, as reflected by standard deviation, was 30% (25.8, 34.7) of the median case time. Relative variability (coefficient of variation), was largest among short cases. For a few procedure types, the regression tree can improve prediction accuracy if extreme behavior cases are preemptively identified. However, for most procedure types, no useful predictive factors were identified and, most notably, surgeon identity was unimportant.

CONCLUSIONS

Pediatric case time variability, unlike adult cases, is poorly explained by surgeon effect or other characteristics that are commonly abstracted from electronic records. This largely relates to the 'long-tailed' distribution of pediatric cases and unpredictably long cases. Surgeon-specific scheduling is therefore unnecessary and similar cases may be pooled across surgeons. Future scheduling efforts in pediatrics should focus on prospective identification of patient and procedural specifics that are associated with and predictive of long cases. Until such predictors are identified, daily management of pediatric operating rooms will require compensatory overtime, capacity buffers, schedule flexibility, and cost.

A hospital-specific template for benchmarking its cost and quality

OBJECTIVE

Develop an improved method for auditing hospital cost and quality tailored to a specific hospital's patient population.

DATA SOURCES/SETTING

Medicare claims in general, gynecologic and urologic surgery, and orthopedics from Illinois, New York, and Texas between 2004 and 2006.

STUDY DESIGN

A template of 300 representative patients from a single index hospital was constructed and used to match 300 patients at 43 hospitals that had a minimum of 500 patients over a 3-year study period.

DATA COLLECTION/EXTRACTION METHODS

From each of 43 hospitals we chose 300 patients most resembling the template using multivariate matching.

PRINCIPAL FINDINGS

We found close matches on procedures and patient characteristics, far more balanced than would be expected in a randomized trial. There were little to no differences between the index hospital's template and the 43 hospitals on most patient characteristics yet large and significant differences in mortality, failure-to-rescue, and cost.

CONCLUSION

Matching can produce fair, directly standardized audits. From the perspective of the index hospital, "hospital-specific" template matching provides the fairness of direct standardization with the specific institutional relevance of indirect standardization. Using this approach, hospitals will be better able to examine their performance, and better determine why they are achieving the results they observe.

Does speed matter? Revision rates and functional outcomes in TKA in relation to duration of surgery

Longer operative times may be required in complex total knee arthroplasty (TKA), however little is known about outcomes in procedures performed rapidly. We analysed 58,009 primary TKAs from the New Zealand National Joint Registry. The mean surgical duration was 89 minutes, and 50% of procedures lasted between 60 and 89 minutes. There was no difference in adjusted revision rates for groups lasting between 40 and 120 minutes, however procedures lasting >120 minutes had significantly higher revision rates. There was a higher revision rate in TKAs lasting <40 minutes (0.71 vs 0.48 revisions per 100 component years) but this was not statistically significant (P = 0.1). For primary TKAs lasting less than 120 minutes, further shortening operative time did not improve outcome, and very rapid procedures (<40 minutes) may lead to an increased risk of revision.

Racial disparities in the use of blood transfusion in major surgery

BACKGROUND

Racial disparities in healthcare in the United States are widespread and have been well documented. However, it is unknown whether racial disparities exist in the use of blood transfusion for patients undergoing major surgery.

METHODS

We used the University HealthSystem Consortium database (2009-2011) to examine racial disparities in perioperative red blood cells (RBCs) transfusion in patients undergoing coronary artery bypass surgery (CABG), total hip replacement (THR), and colectomy. We estimated multivariable logistic regressions to examine whether black patients are more likely than white patients to receive perioperative RBC transfusion, and to investigate potential sources of racial disparities.

RESULTS

After adjusting for patient-level factors, black patients were more likely to receive RBC transfusions for CABG (AOR = 1.41, 95% CI: [1.13, 1.76], p = 0.002) and THR (AOR = 1.39, 95% CI: [1.20, 1.62], p < 0.001), but not for colectomy (AOR = 1.08, 95% CI: [0.90, 1.30], p = 0.40). Black-white disparities in blood transfusion persisted after controlling for patient insurance and hospital effects (CABG: AOR = 1.42, 95% CI: [1.30, 1.56], p < 0.001; THR: AOR = 1.43, 95% CI: [1.29, 1.58], p < 0.001).

CONCLUSIONS

We detected racial disparities in the use of blood transfusion for CABG and THR (black patients tended to receive more transfusions compared with whites), but not for colectomy. Reporting racial disparities in contemporary transfusion practices may help reduce potentially unnecessary blood transfusions in minority patients.

Template matching for auditing hospital cost and quality

OBJECTIVE

Develop an improved method for auditing hospital cost and quality.

DATA SOURCES/SETTING

Medicare claims in general, gynecologic and urologic surgery, and orthopedics from Illinois, Texas, and New York between 2004 and 2006.

STUDY DESIGN

A template of 300 representative patients was constructed and then used to match 300 patients at hospitals that had a minimum of 500 patients over a 3-year study period.

DATA COLLECTION/EXTRACTION METHODS

From each of 217 hospitals we chose 300 patients most resembling the template using multivariate matching.

PRINCIPAL FINDINGS

The matching algorithm found close matches on procedures and patient characteristics, far more balanced than measured covariates would be in a randomized clinical trial. These matched samples displayed little to no differences across hospitals in common patient characteristics yet found large and statistically significant hospital variation in mortality, complications, failure-to-rescue, readmissions, length of stay, ICU days, cost, and surgical procedure length. Similar patients at different hospitals had substantially different outcomes.

CONCLUSION

The template-matched sample can produce fair, directly standardized audits that evaluate hospitals on patients with similar characteristics, thereby making benchmarking more believable. Through examining matched samples of individual patients, administrators can better detect poor performance at their hospitals and better understand why these problems are occurring.

Racial disparities in operative procedure time: the influence of obesity

BACKGROUND

Using Pennsylvania Medicare claims from 1995 to 1996, the authors previously reported that anesthesia procedure length appears longer in blacks than whites. In a new study using a different and larger data set, the authors now examine whether body mass index (BMI), not available in Medicare claims, explains this difference. The authors also examine the relative contributions of surgical and anesthesia times.

METHODS

The Obesity and Surgical Outcomes Study of 47 hospitals throughout Illinois, New York, and Texas abstracted chart information including BMI on elder Medicare patients (779 blacks and 14,596 whites) undergoing hip and knee replacement and repair, colectomy, and thoracotomy between 2002 and 2006. The authors matched all black Medicare patients to comparable whites and compared procedure lengths.

RESULTS

Mean BMI in the black and white populations was 30.24 and 28.96 kg/m, respectively (P<0.0001). After matching on age, sex, procedure, comorbidities, hospital, and BMI, mean white BMI in the comparison group was 30.1 kg/m (P=0.94). The typical matched pair difference (black-white) in anesthesia (induction to recovery room) procedure time was 7.0 min (P=0.0019), of which 6 min reflected the surgical (cut-to-close) time difference (P=0.0032). Within matched pairs, where the difference in procedure times was greater than 30 min between patients, blacks more commonly had longer procedure times (Odds=1.39; P=0.0008).

CONCLUSIONS

Controlling for patient characteristics, BMI, and hospital, elder black Medicare patients experienced slightly but significantly longer procedure length than their closely matched white controls. Procedure length difference was almost completely due to surgery, not anesthesia.

Using mean duration and variation of procedure times to plan a list of surgical operations to fit into the scheduled list time

BACKGROUND AND OBJECTIVE

It is important that a surgical list is planned to utilise as much of the scheduled time as possible while not over-running, because this can lead to cancellation of operations. We wished to assess whether, theoretically, the known duration of individual operations could be used quantitatively to predict the likely duration of the operating list.

METHODS

In a university hospital setting, we first assessed the extent to which the current ad-hoc method of operating list planning was able to match the scheduled operating list times for 153 consecutive historical lists. Using receiver operating curve analysis, we assessed the ability of an alternative method to predict operating list duration for the same operating lists. This method uses a simple formula: the sum of individual operation times and a pooled standard deviation of these times. We used the operating list duration estimated from this formula to generate a probability that the operating list would finish within its scheduled time. Finally, we applied the simple formula prospectively to 150 operating lists, 'shadowing' the current ad-hoc method, to confirm the predictive ability of the formula.

RESULTS

The ad-hoc method was very poor at planning: 50% of historical operating lists were under-booked and 37% over-booked. In contrast, the simple formula predicted the correct outcome (under-run or over-run) for 76% of these operating lists. The calculated probability that a planned series of operations will over-run or under-run was found useful in developing an algorithm to adjust the planned cases optimally. In the prospective series, 65% of operating lists were over-booked and 10% were under-booked. The formula predicted the correct outcome for 84% of operating lists.

CONCLUSION

A simple quantitative method of estimating operating list duration for a series of operations leads to an algorithm (readily created on an Excel spreadsheet, http://links.lww.com/EJA/A19) that can potentially improve operating list planning.

Estimating anesthesia time using the medicare claim: a validation study

INTRODUCTION

Procedure length is a fundamental variable associated with quality of care, though seldom studied on a large scale. The authors sought to estimate procedure length through information obtained in the anesthesia claim submitted to Medicare to validate this method for future studies.

METHODS

The Obesity and Surgical Outcomes Study enlisted 47 hospitals located across New York, Texas, and Illinois to study patients undergoing hip, knee, colon, and thoracotomy procedures. A total of 15,914 charts were abstracted to determine body mass index and initial patient physiology. Included in this abstraction were induction, cut, close, and recovery room times. This chart information was merged to Medicare claims that included anesthesia Part B billing information. Correlations between chart times and claim times were analyzed, models developed, and median absolute differences in minutes calculated.

RESULTS

Of the 15,914 eligible patients, there were 14,369 for whom both chart and claim times were available for analysis. For these 14,369, the Spearman correlation between chart and claim time was 0.94 (95% CI 0.94, 0.95), and the median absolute difference between chart and claim time was only 5 min (95% CI: 5.0, 5.5). The anesthesia claim can also be used to estimate surgical procedure length, with only a modest increase in error.

CONCLUSION

The anesthesia bill found in Medicare claims provides an excellent source of information for studying surgery time on a vast scale throughout the United States. However, errors in both chart abstraction and anesthesia claims can occur. Care must be taken in the handling of outliers in these data.

Are providers more likely to contribute to healthcare disparities under high levels of cognitive load? How features of the healthcare setting may lead to biases in medical decision making

Systematic reviews of healthcare disparities suggest that clinicians' diagnostic and therapeutic decision making varies by clinically irrelevant characteristics, such as patient race, and that this variation may contribute to healthcare disparities. However, there is little understanding of the particular features of the healthcare setting under which clinicians are most likely to be inappropriately influenced by these characteristics. This study delineates several hypotheses to stimulate future research in this area. It is posited that healthcare settings in which providers experience high levels of cognitive load will increase the likelihood of racial disparities via 2 pathways. First, providers who experience higher levels of cognitive load are hypothesized to make poorer medical decisions and provide poorer care for all patients, due to lower levels of controlled processing (H1). Second, under greater levels of cognitive load, it is hypothesized that healthcare providers' medical decisions and interpersonal behaviors will be more likely to be influenced by racial stereotypes, leading to poorer processes and outcomes of care for racial minority patients (H2). It is further hypothesized that certain characteristics of healthcare settings will result in higher levels of cognitive load experienced by providers (H3). Finally, it is hypothesized that minority patients will be disproportionately likely to be treated in healthcare settings in which providers experience greater levels of cognitive load (H4a), which will result in racial disparities due to lower levels of controlled processing by providers (H4b) and the influence of racial stereotypes (H4c).The study concludes with implications for research and practice that flow from this framework.

Patient, hospital, and procedure characteristics influencing total hip and knee arthroplasty procedure duration

Procedure duration is a potential risk factor for total hip arthroplasty (THA) and total knee arthroplasty (TKA) complications. Presently, limited information regarding THA and TKA procedure duration in the United States is available. Patient, hospital, and procedure characteristics that influence procedure duration were determined using Medicare claims data (1997-2004). The median procedure duration decreased from 171.0 to 142.5 minutes for THA and 160.5 to 138.0 minutes for TKA between 1997 and 2004. The median procedure duration decreased as hospital and surgeon volume for both primary THA and TKA increased. Younger patients, males, patients not diagnosed with OA, and patients with more comorbidities generally underwent longer THA and TKA procedures. Larger hospitals (> or =500 beds) were associated with longer THA and TKA procedures, and nonprofit hospitals were associated with shorter procedures. This analysis provides baseline data for future investigation of the influence of procedure duration on total joint arthroplasty outcomes from a national perspective.

Influence of anaesthesia resident training on the duration of three common surgical operations

We investigated the influence of resident training on anaesthesia workflow of three standard procedures--laparoscopic cholecystectomy, diagnostic gynaecological laparoscopy and transurethral prostate gland resection (TURP)--comparing 259 non-emergency resident vs 341 consultant cases from 20 German hospitals. Each hospital provided 10 random cases for each procedure, yielding 600 cases for analysis. Standard time intervals as documented in the hospital information system were: 'Case Time' (the time from the start of anaesthesia induction to discharge of the patient to the recovery area) and 'Anaesthesia Control Time' (which was the Case Time minus the time from the start of surgery to the end of surgical closure). Case Time was significantly shorter for consultants in all three procedures (p < 0.05, analysis of variance) and Anaesthesia Control Time shorter for consultants only in gynaecological laparoscopy and TURP. Patient comorbidity, patient age and geographical location of the hospital were not influential factors in the analysis of variance. We conclude that resident training significantly increases duration of elective operative times.

Hospital teaching intensity, patient race, and surgical outcomes

OBJECTIVES

To determine if the lower mortality often observed in teaching-intensive hospitals is because of lower complication rates or lower death rates after complications (failure to rescue) and whether the benefits at these hospitals accrue equally to white and black patients, since black patients receive a disproportionate share of their care at teaching-intensive hospitals.

DESIGN

A retrospective study of patient outcomes and teaching intensity using logistic regression models, with and without adjusting for hospital fixed and random effects.

SETTING

Three thousand two hundred seventy acute care hospitals in the United States.

PATIENTS

Medicare claims on general, orthopedic, and vascular surgery admissions in the United States for 2000-2005 (N = 4,658,954 unique patients).

MAIN OUTCOME MEASURES

Thirty-day mortality, in-hospital complications, and failure to rescue (the probability of death following complications).

RESULTS

Combining all surgeries, compared with nonteaching hospitals, patients at very major teaching hospitals demonstrated a 15% lower odds of death (P < .001), no difference in complications, and a 15% lower odds of death after complications (failure to rescue) (P < .001). These relative benefits associated with higher resident-to-bed ratio were not experienced by black patients, for whom the odds of mortality and failure to rescue were similar at teaching and nonteaching hospitals, a pattern that is significantly different from that of white patients (P < .001).

CONCLUSIONS

Survival after surgery is higher at hospitals with higher teaching intensity. Improved survival is because of lower mortality after complications (better failure to rescue) and generally not because of fewer complications. However, this better survival and failure to rescue at teaching-intensive hospitals is seen for white patients, not for black patients.

Effect of procedure duration on total hip arthroplasty and total knee arthroplasty survivorship in the United States Medicare population

The effect of procedure duration on joint arthroplasty survivorship in the USA is unknown. We examined the association between procedure duration with primary total hip arthroplasty and total knee arthroplasty survivorship at 8 years in the Medicare population using 1997 to 2004 Medicare claims data. Procedure duration was determined using anesthesia time as a proxy. Kaplan-Meier analysis and Cox regression were used to determine implant survivorship at 8 years and hazard ratios associated with procedure duration. Total knee arthroplasty implant survival was significantly associated with procedure duration (P = .001), in contrast to total hip arthroplasty (P = .127). Total knee arthroplasty procedures shorter than 90 minutes, between 150 and 180 minutes, and more than 240 minutes had significantly higher revision rates than those lasting 120 to 150 minutes. Total hip arthroplasty procedures lasting more than 240 minutes also had a significantly higher revision risk than those lasting 120 to 150 minutes. Our findings support the general belief that longer procedures are associated with the greater probability of complications.