Chris Vinden

Association of socioeconomic status and receipt of colorectal cancer investigations: a population-based retrospective cohort study

Background: Although the Canadian health care system was designed to ensure equal access, inequities persist. It is not known if inequities exist for receipt of investigations used to screen for colorectal cancer (CRC). We examined the association between socioeconomic status and receipt of colorectal investigation in Ontario. Methods: People aged 50 to 70 years living in Ontario on Jan. 1, 1997, who did not have a history of CRC, inflammatory bowel disease or colorectal investigation within the previous 5 years were followed until death or Dec. 31, 2001. Receipt of any colorectal investigation between 1997 and 2001 inclusive was determined by means of linked administrative databases. Income was imputed as the mean household income of the persons census enumeration area. Multivariate analysis was performed to evaluate the relationship between the receipt of any colorectal investigation and income. Results: Of the study cohort of 1 664 188 people, 21.2% received a colorectal investigation in 1997–2001. Multivariate analysis demonstrated a significant association between receipt of any colorectal investigation and income (p < 0.001); people in the highest-income quintile had higher odds of receiving any colorectal investigation (adjusted odds ratio [OR] 1.38; 95% confidence interval [CI] 1.36–1.40) and of receiving colonoscopy (adjusted OR 1.50; 95% CI 1.48–1.53). Interpretation: Socioeconomic status is associated with receipt of colorectal investigations in Ontario. Only one-fifth of people in the screening-eligible age group received any colorectal investigation. Further work is needed to determine the reason for this low rate and to explore whether it affects CRC mortality.

Hyponatremia and Sodium Picosulfate Bowel Preparations in Older Adults

OBJECTIVES:Bowel preparations are commonly prescribed drugs. Case reports and our clinical experience suggest that sodium picosulfate bowel preparations can precipitate severe hyponatremia in some older adults. At present, this risk is poorly quantified. We investigated the association between sodium picosulfate use and the risk of hyponatremia in older adults.METHODS:We conducted a population-based retrospective cohort study using six linked administrative databases in Ontario, Canada. All Ontario residents over the age of 65 years who filled an outpatient bowel preparation prescription before colonoscopy were eligible. We enrolled new users of either sodium picosulfate (n=99,237) or polyethylene glycol (n=48,595). The primary outcome was hospitalization with hyponatremia within 30 days of the bowel preparation assessed by database codes. The secondary outcomes were hospitalization with urgent head computed tomography (CT) (a proxy for acute central nervous system disturbance) and all-cause mortality.RESULTS:The baseline characteristics of the two groups, including patient demographics, comorbid conditions, and concomitant medications, were nearly identical. Compared with polyethylene glycol, sodium picosulfate was associated with a higher risk of hospitalization with hyponatremia (absolute risk increase: 0.05%, 95% confidence interval (CI): 0.04–0.06%, relative risk (RR): 2.4, 95% CI: 1.5–3.9), but not hospitalization with urgent CT head (RR: 1.1, 95% CI: 0.7–1.4) or mortality (RR: 0.9, 95% CI: 0.7–1.3).CONCLUSIONS:Sodium picosulfate bowel preparations lead to more hyponatremia than polyethylene glycol. There was no evidence of increased risk of acute neurologic symptoms or mortality. The absolute increase in risk of hospitalization with hyponatremia remains low but may be avoidable through appropriate fluid intake or preferential use of polyethylene glycol in some older adults.

Colonoscopy and flexible sigmoidoscopy practice patterns in Ontario: A population-based study

OBJECTIVE To conduct a population-based study on the provision of large bowel endoscopic services in Ontario. METHODS Data from the following databases were analyzed: the Ontario Health Insurance Plan, the Institute for Clinical Evaluative Sciences Physicians Database and Statistics Canada. The flexible sigmoidoscopy and colonoscopy rates per 10,000 persons (50 to 74 years of age) by region between April 1, 2001, and March 31, 2002, were calculated, as well as the numbers and types of physicians who performed each procedure. RESULTS In 2001/2002, a total of 172,108 colonoscopies and 43,400 flexible sigmoidoscopies were performed in Ontario for all age groups. The colonoscopy rate was approximately five times that of flexible sigmoidoscopy; rates varied from 463.1 colonoscopies per 10,000 people in the north to 286.8 colonoscopies per 10,000 people in the east. Gastroenterologists in all regions tended to perform more procedures per physician, but because of the large number of general surgeons, the total number of procedures performed by each group was almost the same. CONCLUSION Population-based rates of colonoscopies and flexible sigmoidoscopies are low in Ontario, as are the procedure volumes of approximately one-quarter of physicians.

Predictors of Missed Colorectal Cancer During Colonoscopy: A Population-Based Analysis

What Is the Clinical Effectiveness of Endoscopy Undertaken By Nurses? Multi-Institution Nurse Endoscopy Trial (MINuET) ISRCTN 82765705 Dharmaraj Durai, John Williams, Ian Russell, W.Y. Cheung, Amanda Farrin Introduction: Nurses are increasingly undertaking gastro-intestinal (GI) endoscopy, but no randomised trial has been undertaken to confirm the clinical effectiveness of this. This study is a UK multicentre, pragmatic randomised controlled trial designed to evaluate clinical effectiveness of upper GI endoscopy (OGD) and lower GI endoscopy (Flexible sigmoidoscopy) undertaken by nurses. Methods: Patients O18 years of age referred for investigation of dyspepsia, weight loss, anaemia, change in bowel habit or bleeding PR were considered for inclusion. Those for a therapeutic procedure were excluded. Randomisation stratified by centre took place before patients were sent for and given an opportunity to request change of endoscopist. 20 centres took part in the flexible sigmoidoscopy sub-trial and 9 in the OGD subtrial. The primary outcome measure was the Gastrointestinal Symptom Rating Questionnaire (GSRQ). Secondary outcome measures were SF36, state trait anxiety inventory (STAI), and Gastrointestinal Endoscopy Satisfaction Questionnaire (GESQ). Patients completed questionnaires at baseline, 1 day, 1 month and 1 year post endoscopy. Primary analysis was by intention to scope. A random sample of OGD video recordings were analysed using a validated objective scale. Results: 1888 patients were recruited and 931 allocated to a doctor for endoscopy and 957 to a nurse. 5 patients requested a change of endoscopist (4 doctor to a nurse, 1 nurse to a doctor). There were no significant difference in the GSRQ, SF-36, and STAI scores between the two groups at 1 month and 1 year. Patients in Nurse Group were more satisfied (p!0.001). On evaluation of OGD videos nurses scored better in thoroughness of examination of stomach (p!.0001). There were no significant differences in new GI diagnosis made at one year. Conclusion: There is no difference in clinical effectiveness of upper and lower GI endoscopies undertaken by doctors and nurses, but patients are more satisfied with nurses. Nurses are more thorough in OGD performance.

Association between day of the week of elective surgery and postoperative mortality

BACKGROUND: In prior studies, higher mortality was observed among patients who had elective surgery on a Friday rather than earlier in the week. We investigated whether mortality after elective surgery was associated with day of the week of surgery in a Canadian population and whether the association was influenced by surgeon experience and volume. METHODS: We conducted a population-based retrospective cohort study in the province of Ontario, Canada. We included adults who underwent 1 of 12 elective daytime surgical procedures from Apr. 1, 2002, to Dec. 31, 2012. The primary outcome was 30-day mortality. We used generalized estimating equations to compare outcomes for surgeries performed on different days of the week, adjusting for patient and surgeon factors. RESULTS: A total of 402 899 procedures performed by 1691 surgeons met our inclusion criteria. The median length of hospital stay was 6 (interquartile range 5–8) days. Surgeon experience varied significantly by day of week (p < 0.001), with surgeons operating on Fridays having the least experience. Nearly all of the patients who had their procedure on a Friday had postoperative care on the weekend, as compared with 49.1% of those whose surgery was on a Monday (p < 0.001). We found no difference in the 30-day mortality between procedures performed on Fridays and those performed on Mondays (adjusted odds ratio 1.08, 95% confidence interval 0.97–1.21). INTERPRETATION: Although surgeon experience differed across days of the week, the risk of 30-day mortality after elective surgery was similar regardless of which day of the week the procedure took place.

Colonoscopic Miss Rates for Colorectal Cancer: A Population Based Analysis

Colonoscopic Miss Rates for Colorectal Cancer: A Population Based Analysis Brian Bressler, Lawrence Paszat, Chris Vinden, Jingsong He, Cindy Li, Linda Rabeneck Background: The gold standard for the diagnosis of colorectal cancer (CRC) is colonoscopy (COL). However, COL does contain an inherent miss rate for CRC. Previous reports evaluated miss rates in patients seen in academic centers or units with endoscopists known for their expertise. The CRC miss rate of COL performed in the course of usual clinical practice is unknown. Objective: To determine the proportion CRCs missed during COL. Methods: Using electronic data from the Canadian Institute for Health Information and the Ontario Health Insurance Program (OHIP), we identified all individuals older than 18 years old, with a new diagnosis of CRC, in the province of Ontario from 1/4/1997 to 31/3/ 2001. We excluded all individuals with synchronous, site unspecified, or location coded as other CRC. We excluded those with CRC in the descending colon and splenic flexure because we are unable to determine the depth of insertion of the instrument for those locations.We also excluded thosewhodid not have aCOL (or flexible sigmoidoscopy in those with rectal or sigmoidCRC)within 3 years prior to their diagnosis. The remaining individuals comprised our study cohort. We separated our cohort into three groups: right-sided (CRC in cecum or ascending colon), transverse CRC, and rectal or sigmoid CRC. We divided each group into two categories. The detected cancers category consisted of individuals who had lower gastrointestinal (GI) endoscopy within 6 months prior to the diagnosis (in this category we assumed the endoscopic procedure identified the cancer); the missed cancers category consisted of those who had lower GI endoscopy 6-36 months prior to the diagnosis (in this category we assumed the endoscopic procedure missed the cancer). Results: We identified 31,553 patients with a new diagnosis of CRC and excluded 21,366 because they were diagnosed with synchronous, site unspecified, location coded as other CRC, descending colon, or splenic flexure CRC, or did not have a COLwithin 3 years of their CRC diagnosis. The remaining 10,187 patients comprised our study cohort, of whom 2,580 had right-sided CRC, 702 had transverse CRC, and 6,905 had rectal or sigmoid CRC. The proportions of missed cancers were: 157 patients (6%) with right-sided CRC, 29 patients (4%) with transverse CRC, and 207 patients (3%) with rectal or sigmoid CRC. Conclusion: The proportion of CRCs missed by colonoscopy in usual clinical practice varies between 3-6% depending on the location of the CRC. When consent is obtained for colonoscopy patients need to be informed of the risk of missing CRC.

Flexible sigmoidoscopy to prevent colorectal cancer

1 Atkin WS, Edwards R, Kralj-Hans I, et al. Onceonly fl exible sigmoidoscopy in prevention of colorectal cancer: a multicentre randomised controlled trial. Lancet 2010; 375: 1624–33. 2 Hewitson P, Glasziou P, Watson E, Towler B, Irwig L. Cochrane systematic review of colorectal cancer screening using fecal occult blood test (hemoccult): an update. Am J Gastroenterol 2008; 103: 1541–49. 3 Atkin W. Options for screening for colorectal cancer. Scand J Gastroenterol 2003; 237 (suppl): 13–16. 4 Hol L, van Leerdam ME, van Ballegooijen M, et al. Screening for colorectal cancer: randomised trial comparing guaiac-based and immunochemical faecal occult blood testing and fl exible sigmoidoscopy. Gut 2010; 59: 62–68. 5 Van Rossum LG, van Rijn AF, Laheij RJ, et al. Random comparison of guaiac and immunochemical fecal occult blood tests for colorectal cancer in a screening population. Gastroenterology 2008; 135: 82–90.

Letter to the Editor: Author Response.

Jude Kornelsen raises several issues, almost all of which are focused on rural obstetrics rather than rural general surgery, which was the focus of the proposed training curricula.1 In response to the concerns regarding volume outcomes, the literature we referenced was not limited to complex major surgery, but included hernia repairs and endoscopy, which are largely elective outpatient procedures wherein distance to care would be irrelevant and system issues are minimized, yet a clear signal of volume to outcome is still seen. We agree that time and distance to emergency care is a determinant to outcome and always will be. The effects are not limited to rural environments nor to obstetrical situations. They also apply to fire, security and policing services. Outcomes of cardiac arrest in Canada’s largest city are worse on the upper floors of high-rise buildings than at street level.2 Unless all people live at equidistant locations from emergency services there will always be inequitable outcomes. The important questions are what high-quality services can be sustainably provided in remote communities, by whom and at what cost, and when should we expect the patient or provider to travel to enable health care services. We reiterate that a comprehensive analysis of geographic and demographic parameters that can support sustainable services analogous to that done in Australia would be helpful in depoliticizing the issue. We disagree that the higher cesarean section (C section) rates when performed by general surgeons in the studies referenced are an argument in favour of family physicians providing the service. The optimal rate of C section is still unclear, but a recent major study3 has suggested that maternal and neonatal mortality are minimized at C section rates of 19%, far higher than previous recommendations. We reiterate that quality outcomes are far more important than travel time or distance and should not be compromised for expediency. Outcomes are measured in lifetimes, whereas travel time is measured in hours. We see absolutely no evidence that supports the premise that training family physicians to do hernia repairs, endoscopy or other minor surgery will enhance obstetrical outcomes in remote communities. The proposed surgical curriculum deviates so substantially from standard surgical curricula that we consider it highly unlikely to result in surgical competency. Solutions to obstetrical issues should not compromise the quality of surgical care.