Warren B. Chow

Optimal Preoperative Assessment of the Geriatric Surgical Patient: A Best Practices Guideline from the American College of Surgeons National Surgical Quality Improvement Program and the American Geriatrics Society

The population of the United States (US) is growing and aging.The US Census Bureau projects that the number of Americans age 65 years and older will more than double between 2010 and 2050. The percentage of Americans 65 and older will grow from 13% to more than 20% of the total population by 2030, and the fastest growing segment of this group (individuals 85 years and older) is expected to triple in number over the next 4 decades.These changes in the age demographics of the US population are largely due to people living longer and the “baby boomer” generation

Relevance of the C-Statistic When Evaluating Risk-Adjustment Models in Surgery

BACKGROUND The measurement of hospital quality based on outcomes requires risk adjustment. The c-statistic is a popular tool used to judge model performance, but can be limited, particularly when evaluating specific operations in focused populations. Our objectives were to examine the interpretation and relevance of the c-statistic when used in models with increasingly similar case mix and to consider an alternative perspective on model calibration based on a graphical depiction of model fit. STUDY DESIGN From the American College of Surgeons National Surgical Quality Improvement Program (2008-2009), patients were identified who underwent a general surgery procedure, and procedure groups were increasingly restricted: colorectal-all, colorectal-elective cases only, and colorectal-elective cancer cases only. Mortality and serious morbidity outcomes were evaluated using logistic regression-based risk adjustment, and model c-statistics and calibration curves were used to compare model performance. RESULTS During the study period, 323,427 general, 47,605 colorectal-all, 39,860 colorectal-elective, and 21,680 colorectal cancer patients were studied. Mortality ranged from 1.0% in general surgery to 4.1% in the colorectal-all group, and serious morbidity ranged from 3.9% in general surgery to 12.4% in the colorectal-all procedural group. As case mix was restricted, c-statistics progressively declined from the general to the colorectal cancer surgery cohorts for both mortality and serious morbidity (mortality: 0.949 to 0.866; serious morbidity: 0.861 to 0.668). Calibration was evaluated graphically by examining predicted vs observed number of events over risk deciles. For both mortality and serious morbidity, there was no qualitative difference in calibration identified between the procedure groups. CONCLUSIONS In the present study, we demonstrate how the c-statistic can become less informative and, in certain circumstances, can lead to incorrect model-based conclusions, as case mix is restricted and patients become more homogenous. Although it remains an important tool, caution is advised when the c-statistic is advanced as the sole measure of a model performance.

Validity and Feasibility of the American College of Surgeons Colectomy Composite Outcome Quality Measure.

Objective: To develop a reliable, robust, parsimonious, risk-adjusted 30-day composite colectomy outcome measure. Background: A fundamental aspect in the pursuit of high-quality care is the development of valid and reliable performance measures in surgery. Colon resection is associated with appreciable morbidity and mortality and therefore is an ideal quality improvement target. Methods: From 2010 American College of Surgeons National Surgical Quality Improvement Program data, patients were identified who underwent colon resection for any indication. A composite outcome of death or any serious morbidity within 30 days of the index operation was established. A 6-predictor, parsimonious model was developed and compared with a more complex model with more variables. National caseload requirements were calculated on the basis of increasing reliability thresholds. Results: From 255 hospitals, 22,346 patients were accrued who underwent a colon resection in 2010, most commonly for neoplasm (46.7%). A mortality or serious morbidity event occurred in 4461 patients (20.0%). At the hospital level, the median composite event rate was 20.7% (interquartile range: 15.8%–26.3%). The parsimonious model performed similarly to the full model (Akaike information criterion: 19,411 vs 18,988), and hospital-level performance comparisons were highly correlated (R = 0.97). At a reliability threshold of 0.4, 56 annual colon resections would be required and achievable at an estimated 42% of US and 69% of American College of Surgeons National Surgical Quality Improvement Program hospitals. This 42% of US hospitals performed approximately 84% of all colon resections in the country in 2008. Conclusions: It is feasible to design a measure with a composite outcome of death or serious morbidity after colon surgery that has a low burden for data collection, has substantial clinical importance, and has acceptable reliability.

Reliability of evaluating hospital quality by colorectal surgical site infection type.

Objective: To determine whether risk-adjusted colorectal SSI rates are statistically reliable as hospital quality measures. Background: Policymakers use surgical site infections (SSI) for public reporting of hospital quality and pay-for-performance because they are a relatively common and costly cause of patient morbidity. Methods: Patients who underwent a colorectal procedure in 2009 were identified from the American College of Surgeons National Surgical Quality Improvement Program. We developed hierarchical multivariate logistic models for (1) superficial SSI, (2) deep/organ-space SSI, and (3) “any SSI” and compared how each model ranked hospital-level risk-adjusted performance. Statistical reliability of hospital quality measurements was estimated on a scale from 0 to 1; with 0 indicating that apparent variation between a hospitals quality measurement and the average hospital is statistically unreliable, and 1 indicating that any observed variation is due to a real difference in performance. Results: Mean reliability of hospital-level quality measurements was 0.650 for superficial, 0.404 for deep/organ-space, and 0.586 for “any SSI.” Lower reliability was accounted for by relatively little variation in risk-adjusted SSI rates between hospitals and insufficient numbers of colorectal cases submitted by individual hospitals. In 2009, we estimate that 22.1% of all US hospitals performed a sufficient number of colorectal cases to report superficial SSI rates at a high standard of statistical reliability and 1.0% did for deep/organ-space SSI. Conclusions: As currently constructed, colorectal SSI quality measures might not meet a high standard of statistical reliability for most hospitals, limiting their ability to confidently differentiate high and low performance. Despite an expectation of improving statistical power, combining superficial and deep/organ-space SSI into an “any SSI” measure worsens reliability.

Effect of histologic subtype on treatment and outcomes for esophageal cancer in the United States

Esophageal adenocarcinoma (AC) and squamous cell carcinoma (SCC) have distinct clinico‐pathologic characteristics; however, it is unclear whether treatment patterns differ by histologic subtype. The objective of this study was to examine differences in treatment use and outcomes by histologic subtype for esophageal cancer in the United States.

Variation in Lymph Node Examination After Esophagectomy for Cancer in the United States

OBJECTIVES To evaluate the quality of lymph node examination after esophagectomy for cancer in the United States based on current treatment guidelines (15 nodes) and to assess the association of patient, tumor, and hospital factors with the adequacy of lymph node examination. DESIGN Retrospective observational study from 1998 to 2007. SETTING National cancer database. PATIENTS Patients with stage I through III esophageal cancer undergoing esophagectomy and not treated with neoadjuvant chemoradiotherapy. MAIN OUTCOME MEASURE Rate of adequate lymph node examination (15 nodes). RESULTS A total of 13 995 patients were identified from 639 hospitals. Overall, 4014 patients (28.7%) had at least 15 lymph nodes examined, which increased from 23.5% to 34.4% during the study period. At the hospital level, only 45 centers (7.0%) examined a median of at least 15 lymph nodes. In the most recent period (2005-2007), at least 15 nodes were examined in 38.9% of patients at academic centers vs 28.0% at community hospitals and in 44.1% at high-volume centers vs 29.3% at low-volume centers. On multivariable analysis, hospital type, surgical volume status, and geographic location remained significant predictors of having at least 15 lymph nodes examined. CONCLUSIONS Fewer than one-third of patients and fewer than 1 in 10 hospitals met the benchmark of examining at least 15 lymph nodes. Hospitals should perform internal process improvement activities to improve guideline adherence.

Effect of postoperative complications on adjuvant chemotherapy use in stage III colon cancer.

551 Background: The National Quality Forum has endorsed the use of adjuvant chemotherapy in stage III colon cancer yet a substantial treatment gap exists in the United States. Our objective was to evaluate the contribution of postoperative complications on the use of adjuvant therapy after colectomy for cancer. METHODS Patients from the ACS NSQIP and the NCDB who underwent colon resection for cancer were linked (2006-2008) to create a novel dataset containing robust information on comorbidities, complications, and oncologic variables. The association of complications on adjuvant chemotherapy use was assessed using multivariable regression models. RESULTS From 140 hospitals, 2414 patients underwent resection for stage III colon adenocarcinoma (open colectomy: 64%, laparoscopic colectomy: 36%). Overall, 896 (37.1%) patients were not treated with adjuvant therapy, of which 116 (12.9%) had documented severe comorbidities or advanced age as the reason for no adjuvant therapy receipt. Of the remaining 780 patients, 202 (25.9%) had a potential complication that could account for not receiving adjuvant therapy: 33 perioperative deaths and 169 patients with ≥1 serious complications including organ space infection (n=32), wound dehiscence (n=12), respiratory failure (n=48), pneumonia (n=45), renal failure (n=22) and septic shock (n=38). The remaining 611 patients did not have a documented reason for not receiving adjuvant chemotherapy. Complications independently associated with decreased adjuvant therapy use were renal failure (OR 0.17, 95% CI 0.0-0.59), respiratory failure (OR 0.23, 95% CI 0.11-0.51) and pneumonia (OR 0.36, 95% CI 0.18-0.75). Organ space infection was not associated with decreased use of adjuvant therapy, but significantly increased time to treatment (69 vs. 45 days, P<0.05). Superficial SSI did not decrease adjuvant therapy use or delay treatment. CONCLUSIONS Serious postoperative complications explained one quarter of the adjuvant chemotherapy treatment gap among stage III colon cancer patients and should be considered in quality assessment of colon cancer care. Judging provider performance on quality metrics is challenging without clinical data.

Room for improvement? The adoption of multimodal esophageal cancer care in the United States.

78 Background: Consensus guidelines recommend neoadjuvant chemo- or chemoradiation therapy as the preferred treatment for locally advanced esophageal adenocarcinoma; however, it is unknown if this recommendation has been widely adopted in the U.S. Our objective was to examine esophageal cancer multimodal therapy and identify factors associated with the use of neoadjuvant therapy. METHODS From the National Cancer Data Base, patients with middle third, lower third and GE junction (GEJ) adenocarcinomas were identified. Patients who were clinical stage I-III and underwent surgical resection were included. Separate logistic regression models were developed to identify predictors of neoadjuvant therapy utilization and outcomes. RESULTS From 1998 to 2007, 8,051 patients underwent surgical resection for esophageal cancer: 16.3% stage I, 45.0% stage II and 38.7% stage III. For stage II/III tumors, neoadjuvant use increased (49.0% to 77.8%, p<0.001). After adjustment, factors associated with underuse of neoadjuvant therapy in stage II/III patients were older age, Black or Hispanic ethnicity, more severe comorbidities, tumor location (GEJ and middle vs. lower third), tumor size ≥ 2cm, stage II (vs. III) and geographic region. Stage II/III patients not receiving neoadjuvant had an over two fold increased risk of positive lymph nodes (OR 2.14. 95% CI 1.79 - 2.55, p<0.001). In addition, the positive surgical margin rate increased almost three fold (OR 2.80 95% CI 2.17-3.62, p<0.001) but 30-day postoperative mortality risk was not significantly affected (OR 1.50 95% CI 0.94-2.39; p=0.090). For stage I patients, neoadjuvant therapy decreased over time (38.0% to 11.4%, p<0.001). The overuse of neoadjuvant therapy was associated with higher tumor grade, larger tumor size, and low surgical case volume (all p<0.05). CONCLUSIONS The adoption of neoadjuvant therapy has increased in the past decade; however, opportunity exists to improve guideline treatment for locally advanced esophageal cancer. Registry-based feedback to individual hospitals, such as benchmark comparison tools, could help institutions provide care in concordance with national guidelines. No significant financial relationships to disclose.