Mary T. Hawn

The attributable risk of smoking on surgical complications.

Objective:This study aimed to assess the attributable risk and potential benefit of smoking cessation on surgical outcomes. Summary Background Data:Risk reduction with the implementation of surgical care improvement project process measures has been the primary focus for improving surgical outcomes. Little emphasis has been placed on preoperative risk factor recognition and intervention. Methods:A retrospective cohort analysis of elective operations from 2002 to 2008 in the Veterans Affairs Surgical Quality Improvement Program for all surgical specialties was performed. Patients were stratified by current, prior, and never smokers. Adjusted risk of complication and death was calculated using multilevel, multivariable logistic regression. Results:Of 393,794 patients, 135,741 (34.5%) were current, 71,421 (18.1%) prior, and 186,632 (47.4%) never smokers. A total of 6225 pneumonias, 11,431 deep and superficial surgical-site infections, 2040 thromboembolic events, 1338 myocardial infarctions, and 4792 deaths occurred within 30 days of surgery. Compared with both never and prior smokers individually and controlled for patient and procedure risk factors, current smokers had significantly more postoperative pneumonia, surgical-site infection, and deaths (P < 0.001 for all). There was a dose-dependent increase in pulmonary complications based on pack-year exposure with greater than 20 pack years leading to a significant increase in smoking-related surgical complications. Conclusions:This is the first study to assess the risk of current versus prior smoking on surgical outcomes. Despite being younger and healthier, current smokers had more adverse perioperative events, particularly respiratory complications. Smoking cessation interventions could potentially reduce the occurrence and costs of adverse perioperative events.

Timing of Surgical Antibiotic Prophylaxis and the Risk of Surgical Site Infection

IMPORTANCE Timing of prophylactic antibiotic administration for surgical procedures is a nationally mandated and publicly reported quality metric sponsored by the Centers for Medicare and Medicaid Services Surgical Care Improvement Project. Numerous studies have failed to demonstrate that adherence to the Surgical Care Improvement Project prophylactic antibiotic timely administration measure is associated with decreased surgical site infection (SSI). OBJECTIVE; To determine whether prophylactic antibiotic timing is associated with SSI occurrence. DESIGN Retrospective cohort study using national Veterans Affairs patient-level data on prophylactic antibiotic timing for orthopedic, colorectal, vascular, and gynecologic procedures from 2005 through 2009. SETTING National Veterans Affairs Surgical Care Improvement Project data from 112 Veterans Affairs hospitals and matched Veterans Affairs Surgical Quality Improvement Program data. PATIENTS Patients undergoing hip or knee arthroplasty, colorectal surgical procedures, arterial vascular surgical procedures, and hysterectomy. INTERVENTION Timing of prophylactic antibiotic administration with respect to surgical incision time. MAIN OUTCOMES AND MEASURES Data for prophylactic antibiotic agent, prophylactic antibiotic timing with respect to surgical incision, and patient and procedure risk variables were assessed for their relationship with the occurrence of a composite superficial or deep incisional SSI within 30 days after the procedure. Nonlinear generalized additive models were used to examine the association between antibiotic timing and SSI. RESULTS Of the 32,459 operations, prophylactic antibiotics were administered at a median of 28 minutes (interquartile range, 17-39 minutes) prior to surgical incision, and 1497 cases (4.6%) developed an SSI. Compared with procedures with antibiotic administration within 60 minutes prior to incision, higher SSI rates were observed for timing more than 60 minutes prior to incision (unadjusted odds ratio [OR] = 1.34; 95% CI, 1.08-1.66) but not after incision (unadjusted OR = 1.26; 95% CI, 0.92-1.72). In unadjusted generalized additive models, we observed a significant nonlinear relationship between prophylactic antibiotic timing and SSI when considering timing as a continuous variable (P = .01). In generalized additive models adjusted for patient, procedure, and antibiotic variables, no significant association between prophylactic antibiotic timing and SSI was observed. Vancomycin hydrochloride was associated with higher SSI occurrence for orthopedic procedures (adjusted OR = 1.75; 95% CI, 1.16-2.65). Cefazolin sodium and quinolone in combination with an anaerobic agent were associated with fewer SSI events (cefazolin: adjusted OR = 0.49; 95% CI, 0.34-0.71; quinolone: adjusted OR = 0.55; 95% CI, 0.35-0.87) for colorectal procedures. CONCLUSIONS AND RELEVANCE The SSI risk varies by patient and procedure factors as well as antibiotic properties but is not significantly associated with prophylactic antibiotic timing. While adherence to the timely prophylactic antibiotic measure is not bad care, there is little evidence to suggest that it is better care.

Impact of Obesity on Resource Utilization for General Surgical Procedures

Objective:To determine the impact of the obesity epidemic on workload for general surgeons. Summary Background Data:In 2001, the prevalence of obesity in the United States reached 26%, more than double the rate in 1990. This study focuses on the impact of obesity on surgical practice and resource utilization. Methods:A retrospective analysis was done on patients undergoing cholecystectomy, unilateral mastectomy, and colectomy from January 2000 to December 2003 at a tertiary care center. The main outcome variables were operative time (OT), length of stay (LOS), and complications. The key independent variable was body mass index. We analyzed the association of obesity status with OT, LOS, and complications for each surgery, using multivariate regression models controlling for surgeon time-invariant characteristics. Results:There were 623 cholecystectomies, 322 unilateral mastectomies, and 430 colectomies suitable for analysis from 2000 to 2003. Multivariable regression analyses indicated that obese patients had statistically significantly longer OT (P < 0.01) but not longer LOS (P > 0.05) or more complications (P > 0.05). Compared with a normal-weight patient, an obese patient had an additional 5.19 (95% confidence interval [CI], 0.15–10.24), 23.67 (95% CI, 14.38–32.96), and 21.42 (95% CI, 9.54–33.30) minutes of OT with respect to cholecystectomy, unilateral mastectomy, and colectomy. These estimates were robust in sensitivity analyses. Conclusions:Obesity significantly increased OT for each procedure studied. These data have implications for health policy and surgical resource utilization. We suggest that a CPT modifier to appropriately reimburse surgeons caring for obese patients be considered.

Preoperative oral antibiotics reduce surgical site infection following elective colorectal resections.

BACKGROUND: Surgical site infection is a major cause of morbidity after colorectal resections. Despite evidence that preoperative oral antibiotics with mechanical bowel preparation reduce surgical site infection rates, the use of oral antibiotics is decreasing. Currently, the administration of oral antibiotics is controversial and considered ineffective without mechanical bowel preparation. OBJECTIVE: The aim of this study is to examine the use of mechanical bowel preparation and oral antibiotics and their relationship to surgical site infection rates in a colorectal Surgical Care Improvement Project cohort. DESIGN: This retrospective study used Veterans Affairs Surgical Quality Improvement Program preoperative risk and surgical site infection outcome data linked to Veterans Affairs Surgical Care Improvement Project and Pharmacy Benefits Management data. Univariate and multivariable models were performed to identify factors associated with surgical site infection within 30 days of surgery. SETTINGS: This study was conducted in 112 Veterans Affairs hospitals. PATIENTS: Included were 9940 patients who underwent elective colorectal resections from 2005 to 2009. MAIN OUTCOME MEASURE: The primary outcome measured was the incidence of surgical site infection. RESULTS: Patients receiving oral antibiotics had significantly lower surgical site infection rates. Those receiving no bowel preparation had similar surgical site infection rates to those who had mechanical bowel preparation only (18.1% vs 20%). Those receiving oral antibiotics alone had an surgical site infection rate of 8.3%, and those receiving oral antibiotics plus mechanical bowel preparation had a rate of 9.2%. In adjusted analysis, the use of oral antibiotics alone was associated with a 67% decrease in surgical site infection occurrence (OR=0.33, 95% CI 0.21–0.50). Oral antibiotics plus mechanical bowel preparation was associated with a 57% decrease in surgical site infection occurrence (OR=0.43, 95% CI 0.34–0.55). Timely administration of parenteral antibiotics (Surgical Care Improvement Project-1) had a modest protective effect, with no effect observed for other Surgical Care Improvement Project measures. Hospitals with higher rates of oral antibiotics use had lower surgical site infection rates (R2 = 0.274, p < 0.0001). LIMITATIONS: Determination of the use of oral antibiotics and mechanical bowel preparation is based on retrospective prescription data, and timing of actual administration cannot be determined. CONCLUSIONS: Use and type of preoperative bowel preparation varied widely. These results strongly suggest that preoperative oral antibiotics should be administered for elective colorectal resections. The role of oral antibiotics independent of mechanical bowel preparation should be examined in a prospective randomized trial.

Association of Timely Administration of Prophylactic Antibiotics for Major Surgical Procedures and Surgical Site Infection

BACKGROUND Prophylactic antibiotic (PA) administration 1 to 2 hours before surgical incision (SIP-1) is a publicly reported process measure proposed for performance pay. We performed an analysis of patients undergoing major surgical operations to determine if SIP-1 was associated with surgical site infection (SSI) rates in Department of Veterans Affairs (VA) hospitals. STUDY DESIGN Patients with External Peer Review Program Surgical Care Improvement Project (SCIP)-1 data with matched National Surgical Quality Improvement Program data were included in the study. Patient and facility level analyses comparing SCIP-1 and SSI were performed. We adjusted for clustering effects within hospitals, validated SSI risk score, and procedure type (percentage of colon, vascular, orthopaedic) using generalized estimating equations and linear modeling. RESULTS The study population included 9,195 elective procedures (5,981 orthopaedic, 1,966 colon, and 1,248 vascular) performed in 95 VA hospitals. Timely PA occurred in 86.4% of patients. Untimely PA was associated with a rate of SSI of 5.8%, compared with 4.6% in the timely group (odds ratio = 1.29, 95% CI 0.99, 1.67) in bivariable unadjusted analysis. Patient level risk-adjusted multivariable generalized estimating equation modeling found the SSI risk score was predictive of SSI (p < 0.001); SIP-1 was not associated with SSI. Hospital level multivariable generalized linear modeling found procedure mix (p < 0.0001), but not SIP-1 rate or facility volume, to be associated with facility SSI rate. The study had 80% power to detect a 1.75% difference for patient level SSI rates. CONCLUSIONS Timely PA did not markedly contribute to overall patient or facility SSI rates. These data are important for the ongoing discourse on how to measure and pay for quality of surgical care.

The Relationship Between Timing of Surgical Complications and Hospital Readmission

IMPORTANCE Readmissions after surgery are costly and may reflect quality of care in the index hospitalization. OBJECTIVES To determine the timing of postoperative complications with respect to hospital discharge and the frequency of readmission stratified by predischarge and postdischarge occurrence of complications. DESIGN, SETTING, AND PARTICIPANTS This is a retrospective cohort study of national Veterans Affairs Surgical Quality Improvement Program preoperative risk and outcome data on the Surgical Care Improvement Project cohort for operations performed from January 2005 to August 2009, including colorectal, arthroplasty, vascular, and gynecologic procedures. The association between timing of complication with respect to index hospitalization and 30-day readmission was modeled using generalized estimating equations. MAIN OUTCOME AND MEASURE All-cause readmission within 30 days of the index surgical hospitalization discharge. RESULTS Our study of 59 273 surgical procedures performed at 112 Department of Veterans Affairs (VA) hospitals found an overall complication rate of 22.6% (predischarge complications, 71.9%; postdischarge complications, 28.1%). The proportion of postdischarge complications varied significantly, from 8.7% for respiratory complications to 55.7% for surgical site infection (P < .001). The overall 30-day readmission rate was 11.9%, of which only 56.0% of readmissions were associated with a currently assessed complication. Readmission was predicted by patient comorbid conditions, procedure factors, and the occurrence of postoperative complications. Multivariable generalized estimating equation models of readmission adjusting for patient and procedure characteristics, hospital, and index length of stay found that the occurrence of postdischarge complications had the highest odds of readmission (odds ratio, 7.4-20.8) compared with predischarge complications (odds ratio, 0.9-1.48). CONCLUSIONS AND RELEVANCE More than one-quarter of assessed complications are diagnosed after hospital discharge and strongly predict readmission. Hospital discharge is an insufficient end point for quality assessment. Although readmission is associated with complications, almost half of readmissions are not associated with a complication currently assessed by the Veterans Affairs Surgical Quality Improvement Program.

Long-Term Follow-Up of Technical Outcomes for Incisional Hernia Repair

BACKGROUND Incisional hernia repair (IHR) is plagued by high recurrence rates and lack of long-term outcomes data to guide repair technique. Mesh repair reduces recurrence rates but lacks standardization of technique. We investigated long-term outcomes of elective IHR, focusing on technical predictors of recurrence. STUDY DESIGN This retrospective multicenter cohort study included elective IHR performed at 16 Veterans Affairs hospitals between 1997 and 2002. Hernia characteristics and operative details were abstracted from operative notes, and chart review was performed to identify recurrence and complications. Kaplan-Meier curves and Cox regression models were used to evaluate the effects of hernia characteristics and operative technique on recurrence. RESULTS There were 1,346 elective IHRs, of which 22% were recurrent hernias. Repair technique was primary suture in 31%, open inlay or onlay mesh in 30%, open underlay in 30%, and laparoscopic in 9%. At median follow-up of 73.4 months, there were 383 recurrences (28.5%), 23 mesh removals (1.7%), and 7 enterocutaneous fistulas (ECF) (0.5%). On Cox regression modeling with adjustment for hernia and Veterans Affairs site characteristics, the effectiveness of mesh varied by position. Compared with suture repair, laparoscopic (hazard ratio = 0.49; 95% CI, 0.28-0.84) and open underlay mesh repair (hazard ratio = 0.72; 95% CI, 0.53-0.98) substantially reduced the recurrence risk, but onlay or inlay mesh repair did not. Mesh position did not affect mesh removal or ECF rates. CONCLUSIONS Underlay technique, either laparoscopic or open, for mesh implantation during elective IHR substantially reduces the risk of recurrence, without increasing the risk of serious mesh infection or ECF.

Elective surgical case cancellation in the Veterans Health Administration system: identifying areas for improvement

BACKGROUND This study evaluated elective surgical case cancellation (CC) rates, reasons for these cancellations, and identified areas for improvement within the Veterans Health Administration (VA) system. METHODS CC data for 2006 were collected from the scheduling software for 123 VA facilities. Surveys were distributed to 40 facilities (10 highest and 10 lowest CC rates for high- and low-volume facilities). CC reasons were standardized and piloted at 5 facilities. RESULTS Of 329,784 cases scheduled by 9 surgical specialties, 40,988 (12.4%) were cancelled. CC reasons (9,528) were placed into 6 broad categories: patient (35%), work-up/medical condition change (28%), facility (20%), surgeon (8%), anesthesia (1%), and miscellaneous (8%). Survey results show areas for improvement at the facility level and a standardized list of 28 CC reasons was comprehensive. CONCLUSIONS Interventions that decrease cancellations caused by patient factors, inadequate work-up, and facility factors are needed to reduce overall elective surgical case cancellations.

Smoking as a risk factor for short-term outcomes following primary total hip and total knee replacement in veterans.

To assess the effect of smoking on postoperative complications following elective primary total hip replacement (THR) or primary total knee replacement (TKR).

Oral Antibiotic Bowel Preparation Significantly Reduces Surgical Site Infection Rates and Readmission Rates in Elective Colorectal Surgery.

OBJECTIVE To determine the relationship between oral antibiotic bowel preparation (OABP) and surgical site infection (SSI) rates in a national colectomy cohort. BACKGROUND OABP for elective colorectal surgery has fallen out of favor. Large cohort studies show that OABP is associated with a 50% reduction in SSI after colectomy. METHODS A retrospective analysis of the National Surgical Quality Improvement Program colectomy cohort from 2011 to 2012 was performed to examine the association between use of OABP and outcomes of SSI, length of stay (LOS), and readmission after elective colectomy. Univariate and multivariable analyses for SSI were performed. RESULTS The cohort included 8415 colorectal operations of which 5291 (62.9%) had a minimally invasive surgical (MIS) approach. Overall, 25.6% had no bowel preparation, 44.9% had mechanical bowel preparation (MBP) only, and 29.5% received OABP. The SSI rate was 11.1%, and it varied by preparation type: 14.9% no preparation, 12.0% MBP, and 6.5% OABP (P < 0.001). OABP group had significantly shorter hospital LOS: (median = 4, interquartile range: 3-6) versus other preparations (median LOS = 5) (P < 0.001). Readmission rates were lowest in OABP (8.1%) and highest in the no preparation group (11.8%). Multivariable logistic regressions found OABP associated with lower SSI [adjusted odds ratio (ORadj) = 0.46, 95% confidence interval (CI): 0.36-0.59]. Stratified models found OABP protective for SSI for both open procedures (ORadj = 0.40, 95% CI: 0.30-0.53) and MIS procedures (ORadj = 0.48, 95% CI: 0.36-0.65). CONCLUSIONS OABP is associated with reduced SSI rates, shorter LOS, and fewer readmissions. Adoption of OABP before elective colectomy would reduce SSI without effecting LOS. The practice of MBP alone should be abandoned.