Nancy N. Baxter
St. Michael's Hospital
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Featured researches published by Nancy N. Baxter.
Gastroenterology | 2011
Nancy N. Baxter; Rinku Sutradhar; Shawn S. Forbes; Lawrence Paszat; Refik Saskin; Linda Rabeneck
BACKGROUND & AIMS Most quality indicators for colonoscopy measure processes; little is known about their relationship to patient outcomes. We investigated whether characteristics of endoscopists, determined from administrative data, are associated with development of postcolonoscopy colorectal cancer (PCCRC). METHODS We identified individuals diagnosed with colorectal cancer in Ontario from 2000 to 2005 using the Ontario Cancer Registry. We determined performance of colonoscopy using Ontario Health Insurance Plan data. Patients who had complete colonoscopies 7 to 36 months before diagnosis were defined as having a PCCRC. Patients who had complete colonoscopies within 6 months of diagnosis had detected cancers. We determined if endoscopist factors (volume, polypectomy and completion rate, specialization, and setting) were associated with PCCRC using logistic regression, controlling for potential covariates. RESULTS In the study, 14,064 patients had a colonoscopy examination within 36 months of diagnosis; 584 (6.8%) with distal and 676 (12.4%) with proximal tumors had PCCRC. The endoscopists specialty (nongastroenterologist/nongeneral surgeon) and setting (non-hospital-based colonoscopy) were associated with PCCRC. Those who underwent colonoscopy by an endoscopist with a high completion rate were less likely to have a PCCRC (distal: odds ratio [OR], 0.73; 95% confidence interval [CI], 0.54-0.97; P = .03; proximal: OR, 0.72; 95% CI, 0.53-0.97; P = .002). Patients with proximal cancers undergoing colonoscopy by endoscopists who performed polypectomies at high rates had a lower risk of PCCRC (OR, 0.61; 95% CI, 0.42-0.89; P < .0001). Endoscopist volume was not associated with PCCRC. CONCLUSIONS Endoscopist characteristics derived from administrative data are associated with development of PCCRC and have potential use as quality indicators.
The New England Journal of Medicine | 2014
David R. Urbach; Anand Govindarajan; Refik Saskin; Andrew Wilton; Nancy N. Baxter; Abstr Act
BACKGROUND Evidence from observational studies that the use of surgical safety checklists results in striking improvements in surgical outcomes led to the rapid adoption of such checklists worldwide. However, the effect of mandatory adoption of surgical safety checklists is unclear. A policy encouraging the universal adoption of checklists by hospitals in Ontario, Canada, provided a natural experiment to assess the effectiveness of checklists in typical practice settings. METHODS We surveyed all acute care hospitals in Ontario to determine when surgical safety checklists were adopted. Using administrative health data, we compared operative mortality, rate of surgical complications, length of hospital stay, and rates of hospital readmission and emergency department visits within 30 days after discharge among patients undergoing a variety of surgical procedures before and after adoption of a checklist. RESULTS During 3-month periods before and after adoption of a surgical safety checklist, a total of 101 hospitals performed 109,341 and 106,370 procedures, respectively. The adjusted risk of death during a hospital stay or within 30 days after surgery was 0.71% (95% confidence interval [CI], 0.66 to 0.76) before implementation of a surgical checklist and 0.65% (95% CI, 0.60 to 0.70) afterward (odds ratio, 0.91; 95% CI, 0.80 to 1.03; P=0.13). The adjusted risk of surgical complications was 3.86% (95% CI, 3.76 to 3.96) before implementation and 3.82% (95% CI, 3.71 to 3.92) afterward (odds ratio, 0.97; 95% CI, 0.90 to 1.03; P=0.29). CONCLUSIONS Implementation of surgical safety checklists in Ontario, Canada, was not associated with significant reductions in operative mortality or complications. (Funded by the Canadian Institutes of Health Research.).
Obstetrics & Gynecology | 2006
Patricia L. Judson; Elizabeth B. Habermann; Nancy N. Baxter; Sara Durham; Beth A Virnig
OBJECTIVE: To characterize the incidence of vulvar carcinoma in situ and vulvar cancer over time. METHODS: We used the Surveillance Epidemiology and End Results database to assess trends in the incidence of vulvar cancer over a 28-year period (1973 through 2000) and determined whether there had been a change in incidence over time. Information collected included patient characteristics, primary tumor site, tumor grade, and follow-up for vital status. We calculated the incidence rates by decade of age, used χ2 tests to compare demographic characteristics, and tested for trends in incidence over time. RESULTS: A total of 13,176 in situ and invasive vulvar carcinomas were identified; 57% of the women were diagnosed with in situ, 44% with invasive disease. Vulvar carcinoma in situ increased 411% from 1973 to 2000. Invasive vulvar cancer increased 20% during the same period. The incidence rates for in situ and invasive vulvar carcinomas are distributed differently across the age groups. In situ carcinoma incidence increases until the age of 40–49 years and then decreases, whereas invasive vulvar cancer risk increases as a woman ages, increasing more quickly after 50 years of age. CONCLUSION: The incidence of in situ vulvar carcinoma is increasing. The incidence of invasive vulvar cancer is also increasing but at a much lower rate. LEVEL OF EVIDENCE: III
Diseases of The Colon & Rectum | 2005
Kelli M. Bullard; Judith L. Trudel; Nancy N. Baxter; David A. Rothenberger
PURPOSENeoadjuvant radiation therapy has been used increasingly to downstage rectal cancer and decrease local recurrence. Despite its efficacy, preoperative radiation therapy may inhibit healing and contribute to wound complications. This study was designed to evaluate perineal wound complications after abdominoperineal resection.METHODSThe clinical records of a consecutive series of patients who underwent abdominoperineal resection for rectal carcinoma between 1988 and 2002 were reviewed. Demographic data, disease stage, and use of preoperative radiation therapy were recorded. Major wound complications included delayed wound healing (>1 month), wound infection requiring drainage/debridement, or reoperation.RESULTSA total of 160 patients underwent abdominoperineal resection with primary closure of the perineal wound (mean age, 63 ± 12 years); 117 (73 percent) patients received preoperative radiation therapy; 114 received radiation therapy for rectal cancer (radiation therapy + chemotherapy = 107, radiation therapy alone = 7); 3 received radiation therapy for other pelvic malignancies. Median radiation dose was 5,040 (range, 900–5,400) cGY. Overall wound complication rate was 41 percent. Major wound complication rate was 35 percent. Delayed healing was the most common complication (24 percent), followed by infection (10 percent). Radiation therapy increased the risk of any wound complication (47 vs. 23 percent; P = 0.005), risk of a major wound complication (41 vs. 19 percent; P = 0.021), and risk of infection (14 vs. 0 percent; P = 0.015). Risk of wound complications did not correlate with age, gender, disease stage, smoking, or diabetes.CONCLUSIONSWound complications are frequent after abdominoperineal resection and primary closure of the perineum. Preoperative radiation therapy doubles the rate of total and major perineal wound complications. Alternatives to primary perineal closure should be considered, particularly after radiation therapy.
Journal of Clinical Oncology | 2006
Paul Johnson; Geoff Porter; Rocco Ricciardi; Nancy N. Baxter
PURPOSE The purpose of this study was to examine the impact of the number of negative lymph nodes on survival in patients with stage III colon cancer. PATIENTS AND METHODS Patients who underwent surgery for stage III colon cancer between January 1988 and December 1997 were identified from the Surveillance, Epidemiology and End Results cancer registry. The number of negative and positive nodes was determined for 20,702 eligible patients. Disease-specific survival was examined by substage according to the number of negative nodes identified. A proportional hazards model was constructed to determine the effect of the number of negative nodes on survival. RESULTS For stage IIIB and IIIC patients, there was a significant decrease in disease-specific mortality as the number of negative nodes increased; cumulative 5-year cancer mortality was 27% in stage IIIB patients with 13 or more negative nodes identified versus 45% in those with three or fewer negative lymph nodes evaluated (P < .0001). In patients with stage IIIC cancer, those with 13 or more negative nodes had a 5-year mortality of 42% versus 65% in those with three or fewer negative lymph nodes evaluated (P < .0001). There was no association between the number of negative nodes identified and disease-specific survival for patients with stage IIIA disease. After controlling for the number of positive nodes, a higher number of negative nodes was found to be independently associated with improved disease-specific survival. CONCLUSION The number of negative nodes is an important independent prognostic factor for patients with stage IIIB and IIIC colon cancer.
Annals of Surgery | 2007
Y. Nancy You; Nancy N. Baxter; Andrew K. Stewart; Heidi Nelson
Objective:Determine rates of local excision (LE) over time, and test the hypothesis that LE carries increased oncologic risks but reduced perioperative morbidity when compared with standard resection (SR). Summary Background Data:Despite the lack of level I/level II evidence supporting its oncologic adequacy, LE is performed for stage I rectal cancer. Methods:Surgical therapy for 35,179 patients with stage I rectal cancer diagnosed in 1989 to 2003 was examined over time, utilizing the National Cancer Database. A special study then analyzed perioperative outcomes, local recurrence and survival in 2124 patients diagnosed between 1994 and 1996, including 765 (T1, 601; T2, 164) treated by LE and 1359 (T1, 493; T2, 866) treated by SR. Results:From 1989 to 2003, the use of LE has increased (T1, 26.6–43.7%; T2, 5.8–16.8%; P < 0.001 both). The special study demonstrated significantly lower 30-day morbidity after LE versus SR (5.6% vs. 14.6%; P < 0.001). After adjusting for patient and tumor characteristics, the 5-year local recurrence after LE versus SR was 12.5 versus 6.9% (P = 0.003; hazard ratio = 0.38; 95% CI, 0.23–0.62) for T1 tumors, and 22.1 versus 15.1% (P = 0.01; hazard ratio = 0.69; 95% CI, 0.44–1.07) for T2 tumors. The 5-year overall survival (T1, 77.4% vs. 81.7%, P = 0.09; T2, 67.6% vs. 76.5%, P = 0.01) was influenced by age and comorbidities but not the type of surgery. Conclusions:This study provides the best evidence for both the increasing use and the associated risks of LE versus SR. For each individual patient, the benefits of LE must be balanced against the heightened risk of local failure.
Diseases of The Colon & Rectum | 2004
Alberto Bravo Gutierrez; Robert D. Madoff; Ann C. Lowry; Susan C. Parker; W. Donald Buie; Nancy N. Baxter
PURPOSEThis study was designed to evaluate the outcome of anterior sphincteroplasty in a large series with ten-year follow-up.METHODSThe long-term results in 191 consecutive patients who were a median of ten years from sphincteroplasty were assessed. A questionnaire was administered to assess current bowel function, degree of incontinence, and quality of life as measured by the Fecal Incontinence Quality of Life Scale. Subjective assessment of early outcome was available for most patients at a median follow-up of three years.RESULTSDuring the follow-up period, three patients died and one developed severe dementia. Five patients required further surgery for incontinence and were considered failures. Of the remaining 182 patients, 130 (71 percent) returned a completed questionnaire. At ten years follow-up, 6 percent had no incontinence, 16 percent were incontinent of gas only, 19 percent had soiling only, and 57 percent were incontinent of solid stool. Results worsened significantly between the assessments at three and ten years. The only significant predictors of a poor outcome were older age and fecal incontinence at three years. Preoperative anorectal physiology studies did not predict outcome. Scores on the Fecal Incontinence Quality of Life Scale were lower in those with fecal incontinence, indicating a poorer disease-specific quality of life.CONCLUSIONSOnly 40 percent of patients maintain fecal continence long-term after sphincteroplasty. Older patients and patients with poorer short-term function are more likely to have fecal incontinence at ten years. Incontinence at ten years had a negative effect on quality of life. Further research is needed to develop techniques to improve long-term continence in these patients.
Journal of Clinical Oncology | 2012
Nancy N. Baxter; Joan L. Warren; Michael J. Barrett; Therese A. Stukel; V. Paul Doria-Rose
PURPOSE We designed this study to evaluate the association of colonoscopy with colorectal cancer (CRC) death in the United States by site of CRC and endoscopist specialty. METHODS We designed a case-control study using Surveillance, Epidemiology, and End Results (SEER)-Medicare data. We identified patients (cases) diagnosed with CRC age 70 to 89 years from January 1998 through December 2002 who died as a result of CRC by 2007. We selected three matched controls without cancer for each case. Controls were assigned a referent date (date of diagnosis of the case). Colonoscopy performed from January 1991 through 6 months before the diagnosis/referent date was our primary exposure. We compared exposure to colonoscopy in cases and controls by using conditional logistic regression controlling for covariates, stratified by site of CRC. We determined endoscopist specialty by linkage to the American Medical Association (AMA) Masterfile. We assessed whether the association between colonoscopy and CRC death varied with endoscopist specialty. RESULTS We identified 9,458 cases (3,963 proximal [41.9%], 4,685 distal [49.5%], and 810 unknown site [8.6%]) and 27,641 controls. In all, 11.3% of cases and 23.7% of controls underwent colonoscopy more than 6 months before diagnosis. Compared with controls, cases were less likely to have undergone colonoscopy (odds ratio [OR], 0.40; 95% CI, 0.37 to 0.43); the association was stronger for distal (OR, 0.24; 95% CI, 0.21 to 0.27) than proximal (OR, 0.58; 95% CI, 0.53 to 0.64) CRC. The strength of the association varied with endoscopist specialty. CONCLUSION Colonoscopy is associated with a reduced risk of death from CRC, with the association considerably and consistently stronger for distal versus proximal CRC. The overall association was strongest if colonoscopy was performed by a gastroenterologist.
BMJ | 2004
David R. Urbach; Nancy N. Baxter
Objective: To determine whether the improved outcome of a surgical procedure in high volume hospitals is specific to the volume of the same procedure. Design and setting: Analysis of secondary data in Ontario, Canada. Participants: Patients having an oesophagectomy, colorectal resection for cancer, pancreaticoduodenectomy, major lung resection for cancer, or repair of an unruptured abdominal aortic aneurysm between 1994 and 1999. Main outcome measures: Odds ratio for death within 30 days of surgery in relation to the hospital volume of the same surgical procedure and the hospital volume of the other four procedures. Estimates were adjusted for age, sex, and comorbidity and accounted for hospital level clustering. Results: With the exception of colorectal resection, 30 day mortality seemed to be inversely related not only to the hospital volume of the same procedure but also to the hospital volume of most of the other procedures. In some cases the effect of the volume of a different procedure was stronger than the effect of the volume of the same procedure. For example, the association of mortality from pancreaticoduodenectomy with hospital volume of lung resection (odds ratio for death in hospitals with a high volume of lung resection compared with low volume 0.36, 95% confidence interval 0.23 to 0.57) was much stronger than the association of mortality from pancreaticoduodenectomy with hospital volume of pancreaticoduodenectomy (0.76, 0.44 to 1.32). Conclusion: The inverse association between high volume of procedure and risk of operative death is not specific to the volume of the procedure being studied.
American Journal of Surgery | 1996
Nancy N. Baxter; Robert Cohen; Robin S. McLeod
BACKGROUND The objective of the survey was to examine factors affecting career choice by medical students. METHODS A questionnaire was distributed to the 245 fourth-year students at the University of Toronto, sampling qualities of importance in specialties, the importance of role models, attitudes toward surgery, and specialty match results. RESULTS There was a 69% return rate. Males were more likely to choose a surgical career than were females (27% versus 10%, respectively; P = 0.01). Males were more likely to identify technical challenge, earning potential, and prestige (P < 0.01) whereas females were more likely to identify residency conditions, part-time work, and parental leave availability as important qualities in a specialty (P < 0.01). Females were less likely to take surgical electives (P < 0.001) and more likely to identify a lack of role models (P < 0.003). Students agreed that surgeons have rewarding careers (79%) and earn more (64%); however, they do not agree that surgeons enjoy spending time with patients (10%) or have rewarding family lives (5%). CONCLUSIONS Fewer females than males were found to consider or choose a surgical career, possibly due to differences in qualities of importance in specialties, availability of role models, and exposure through electives.