Effect of Chronic Comorbidities on Follow-up Colonoscopy After Positive Colorectal Cancer Screening Results: A Population-Based Cohort Study.

INTRODUCTION: Fecal occult blood tests (FOBTs) are colorectal cancer screening tests used to identify individuals requiring further investigation with colonoscopy. Delayed colonoscopy after positive FOBT (FOBT+) is associated with poorer cancer outcomes. We assessed the effect of comorbidity on colonoscopy receipt within 12 months after FOBT+. METHODS: Population-based healthcare databases from Ontario, Canada, were linked to assemble a cohort of 50-74-year-old individuals with FOBT+ results between 2008 and 2017. The associations between comorbidities and colonoscopy receipt within 12 months after FOBT+ were examined using multivariable cause-specific hazard regression models. RESULTS: Of 168,701 individuals with FOBT+, 80.5% received colonoscopy within 12 months. In multivariable models, renal failure (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.62-0.82), heart failure (HR 0.77, CI 0.75-0.80), and serious mental illness (HR 0.88, CI 0.85-0.92) were associated with the lowest colonoscopy rates, compared with not having each condition. The number of medical conditions was inversely associated with colonoscopy uptake (≥4 vs 0: HR 0.64, CI 0.58-0.69; 3 vs 0: HR 0.75, CI 0.72-0.78; and 2 vs 0: HR 0.87, CI 0.85-0.89). Having both medical and mental health conditions was associated with a lower colonoscopy uptake relative to no comorbidity (HR 0.88, CI 0.87-0.90). DISCUSSION: Persons with medical and mental health conditions had lower colonoscopy rates after FOBT+ than those without these conditions. Better strategies are needed to optimize colorectal cancer screening and follow-up in individuals with comorbidities.

Periodic screening for breast and cervical cancer in women with diabetes: a population-based cohort study.

PURPOSE: Diabetes is associated with poorer cancer outcomes. Screening for breast and cervical cancer is recommended by clinical guidelines; however, utilization of these tests in people with diabetes has been unclear due to methodological limitations in the evidence base. We used administrative data to determine the association between diabetes and the rates of becoming up-to-date with periodic breast and cervical cancer screening over a 20-year period. METHODS: Healthcare databases from Ontario, Canada, were linked to assemble two population-based cohorts of 50-70 and 21-70 year-olds between 1994 and 2011, eligible for breast and cervical cancer screening, respectively. Using age as the time scale, multivariable recurrent events models were implemented to examine the association between the presence of diabetes and the rates of becoming up-to-date with the recommended cancer screenings. RESULTS: In each of the breast and cervical cancer screening cohorts, there were, respectively, 1,516,302 (16% had diabetes at baseline) and 4,751,220 (9.5% had diabetes at baseline) screen-eligible women. In multivariable models, prevalent diabetes (duration ≥ 2 years) was associated with lower rates of becoming up-to-date with cervical (hazard ratio, HR 0.85, 95% confidence interval, CI 0.84-0.85) and breast (HR 0.94, CI 0.93-0.94) cancer screening, compared to no diabetes. CONCLUSIONS: Having diabetes is associated with decreased rates of becoming up-to-date with two recommended periodic cancer screenings, with a bigger reduction in the rates of becoming up-to-date with cervical cancer screening. Greater attention to cervical cancer preventive services is needed in women with diabetes.

A Pragmatic Randomized Controlled Trial of an Endoscopist Audit and Feedback Report for Colonoscopy.

INTRODUCTION: Variation in endoscopist performance contributes to poor-quality colonoscopy. Audit and feedback (A/F) can be used to improve physician performance, particularly among lower performing physicians. In this large pragmatic randomized controlled trial, we compared A/F to improve endoscopists' colonoscopy performance to usual practice. METHODS: Endoscopists practicing in Ontario, Canada, in 2014 were randomly assigned in October 2015 (index date) to receive (intervention group, n = 417) or not receive (control group, n = 416) an A/F report generated centrally using health administrative data. Colonoscopy performance was measured in both groups over two 12-month periods: prereport and postreport (relative to the index date). The primary outcome was polypectomy rate (PR). Secondary outcomes were cecal intubation rate, bowel preparation, and premature repeat after normal colonoscopy. A post hoc analysis used adenoma detection rate as the outcome. Outcomes were compared between groups for all endoscopists and for lower performing endoscopists using Poisson regression analyses under a difference-in-difference framework. RESULTS: Among all endoscopists, PR did not significantly improve from prereport to postreport periods for those receiving the intervention (relative rate [RR], intervention vs control: 1.07 vs 1.05, P = 0.09). Among lower performing endoscopists, PR improved significantly (RR, intervention vs control 1.34 vs 1.11, P = 0.02) in the intervention group compared with controls. In this subgroup, adenoma detection rate also improved but not significantly (RR, intervention vs control 1.12 vs 1.04, P = 0.12). There was no significant improvement in secondary outcomes between the intervention and control groups. DISCUSSION: A/F reports for colonoscopy improve performance in lower performing endoscopists (ClinicalTrials.gov: NCT02595775).

Clinical and endoscopist factors associated with post-colonoscopy colorectal cancer in a population-based sample.

AIM: Factors associated with verified post-colonoscopy colorectal cancers (PCCRC) have not been well defined and survival for these patients is not well described. We aimed to assess the association of patient, tumour and endoscopist characteristics with PCCRC. METHODS: Using population-based data, we identified individuals diagnosed with CRC from 1 January 2000 to 31 December 2005 who underwent a colonoscopy within 3 years prior to diagnosis. Detected cancers were those diagnosed ≤6 months following colonoscopy; PCCRC were diagnosed >6 months to ≤3 years following colonoscopy. Post-colonoscopy and detected cancers were verified through chart review using a hospital-based simple random sampling frame. We used multivariable conditional logistic regression to determine the association of patient, tumour and endoscopist factors with PCCRC and compared overall survival using Cox proportional hazard models. RESULTS: Using the random sampling frame, we identified 498 patients with PCCRC and 498 with detected CRC; we obtained records and confirmed 367 patients with PCCRC and 412 with detected cancers. In multivariable analysis, patient age (OR 1.01; 95% CI 1.00-1.03) and tumour location (distal vs. proximal OR 0.36; 95% CI 0.25-0.53) were associated with PCCRC; endoscopist quality measures were not significantly associated with PCCRC. We did not find significant differences in overall survival between PCCRC and detected cancers (hazard ratio 1.12; 95% CI 0.92-1.32). CONCLUSION: Although endoscopic quality measures are important for CRC prevention, endoscopist factors were not associated with PCCRC. This study highlights the need for further research into the role of tumour biology in PCCRC development.

Cost-effectiveness of Active Identification and Subsequent Colonoscopy Surveillance of Lynch Syndrome Cases.

BACKGROUND & AIMS: The province of Ontario, Canada is considering immunohistochemical followed by cascade analyses of all patients who received a diagnosis of colorectal cancer (CRC) at an age younger than 70 years to identify individuals with Lynch syndrome. We evaluated the costs and benefits of testing for Lynch syndrome and determined the optimal surveillance interval for first-degree relatives (FDRs) found to have Lynch syndrome. METHODS: We developed a patient flow diagram to determine costs and yield of immunohistochemical testing for Lynch syndrome in CRC cases and, for those found to have Lynch syndrome, their FDRs, accounting for realistic uptake. Subsequently, we used the MISCAN-colon model to compare costs and benefits of annual, biennial, and triennial surveillance in FDRs identified with Lynch syndrome vs colonoscopy screening every 10 years (usual care for individuals without a diagnosis of Lynch syndrome). RESULTS: Testing 1000 CRC cases was estimated to identify 20 CRC index cases and 29 FDRs with Lynch syndrome at a cost of $310,274. Despite the high cost of Lynch syndrome tests, offering the FDRs with Lynch syndrome biennial colonoscopy surveillance was cost-effective at $8785 per life-year gained compared with usual care because of a substantial increase in life-years gained (+122%) and cost savings in CRC care. Triennial surveillance was more costly and less effective, and annual surveillance showed limited additional benefit compared with biennial surveillance. CONCLUSIONS: Immunohistochemical testing for Lynch syndrome in persons younger than 70 years who received a diagnosis of CRC and then testing FDRs of those found to have Lynch syndrome provide a good balance between costs and long-term benefits. Colonoscopy surveillance every 2 years is the optimal surveillance interval for patients with Lynch syndrome.

Anesthesia Assistance in Outpatient Colonoscopy and Risk of Aspiration Pneumonia, Bowel Perforation, and Splenic Injury.

BACKGROUND & AIMS: The increase in use of anesthesia assistance (AA) to achieve deep sedation with propofol during colonoscopy has significantly increased colonoscopy costs without evidence for increased quality and with possible harm. We investigated the effects of AA on colonoscopy complications, specifically bowel perforation, aspiration pneumonia, and splenic injury. METHODS: In a population-based cohort study using administrative databases, we studied adults in Ontario, Canada undergoing outpatient colonoscopy from 2005 through 2012. Patient, endoscopist, institution, and procedure factors were derived. The primary outcome was bowel perforation, defined using a validated algorithm. Secondary outcomes were splenic injury and aspiration pneumonia. Using a matched propensity score approach, we matched persons who had colonoscopy with AA (1:1) with those who did not. We used logistic regression models under a generalized estimating equations approach to explore the relationship between AA and outcomes. RESULTS: Data from 3,059,045 outpatient colonoscopies were analyzed; 862,817 of these included AA. After propensity matching, a cohort of 793,073 patients who had AA and 793,073 without AA was retained for analysis (51% female; 78% were age 50 years or older). Use of AA did not significantly increase risk of perforation (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.84-1.16) or splenic injury (OR, 1.09; 95% CI, 0.62-1.90]. Use of AA was associated with an increased risk of aspiration pneumonia (OR, 1.63; 95% CI, 1.11-2.37). CONCLUSIONS: In a population-based cohort study, AA for outpatient colonoscopy was associated with a significantly increased risk of aspiration pneumonia, but not bowel perforation or splenic injury. Endoscopists should warn patients, especially those with respiratory compromise, of this risk.

Immigration and Adherence to Cervical Cancer Screening: A Provincewide Longitudinal Matched Cohort Study Using Multistate Transitional Models.

OBJECTIVE: Previous studies highlighting inequities in cancer screening between immigrants and non-immigrants have been methodologically limited. This longitudinal matched cohort study used a multistate modelling framework to examine associations between immigration status and cervical cancer screening adherence. METHODS: A 1:1 matched cohort of women aged 25 and older from 1992-2014 who were residing in Ontario was examined. For each woman, the proportion of time spent being non-adherent was determined. Disparities in cervical screening adherence, and specifically the association between immigration status and the rate of becoming adherent, were investigated with a three-state transitional model. The model was adjusted for individual- and physician-level characteristics, which were updated annually and incorporated as time-varying covariates. RESULTS: The matched cohort consisted of 1 156 720 immigrant and non-immigrant women. The median proportion of time spent non-adherent was 38.9% for immigrants and 24.7% for non-immigrants. The rate of becoming adherent among immigrants was lower than that among non-immigrants, after accounting for individual- and physician-level characteristics (relative rate 0.933; 95% CI 0.928-0.937). Other characteristics such as socioeconomic status, immigrant region of origin, presence of primary physician, and physician's sex were found to be significantly associated with cervical screening adherence. CONCLUSION: This study assessed the association between immigration status and adherence to cervical cancer screening. The insights from this work can be used to target groups of women vulnerable to underscreening and to minimize their time spent non-adherent to cancer screening. The methodology serves as a useful framework for examining adherence to other types of cancer screening.

Performance and Cost-Effectiveness of Computed Tomography Lung Cancer Screening Scenarios in a Population-Based Setting: A Microsimulation Modeling Analysis in Ontario, Canada.

BACKGROUND: The National Lung Screening Trial (NLST) results indicate that computed tomography (CT) lung cancer screening for current and former smokers with three annual screens can be cost-effective in a trial setting. However, the cost-effectiveness in a population-based setting with >3 screening rounds is uncertain. Therefore, the objective of this study was to estimate the cost-effectiveness of lung cancer screening in a population-based setting in Ontario, Canada, and evaluate the effects of screening eligibility criteria. METHODS AND FINDINGS: This study used microsimulation modeling informed by various data sources, including the Ontario Health Insurance Plan (OHIP), Ontario Cancer Registry, smoking behavior surveys, and the NLST. Persons, born between 1940 and 1969, were examined from a third-party health care payer perspective across a lifetime horizon. Starting in 2015, 576 CT screening scenarios were examined, varying by age to start and end screening, smoking eligibility criteria, and screening interval. Among the examined outcome measures were lung cancer deaths averted, life-years gained, percentage ever screened, costs (in 2015 Canadian dollars), and overdiagnosis. The results of the base-case analysis indicated that annual screening was more cost-effective than biennial screening. Scenarios with eligibility criteria that required as few as 20 pack-years were dominated by scenarios that required higher numbers of accumulated pack-years. In general, scenarios that applied stringent smoking eligibility criteria (i.e., requiring higher levels of accumulated smoking exposure) were more cost-effective than scenarios with less stringent smoking eligibility criteria, with modest differences in life-years gained. Annual screening between ages 55-75 for persons who smoked ≥40 pack-years and who currently smoke or quit ≤10 y ago yielded an incremental cost-effectiveness ratio of $41,136 Canadian dollars ($33,825 in May 1, 2015, United States dollars) per life-year gained (compared to annual screening between ages 60-75 for persons who smoked ≥40 pack-years and who currently smoke or quit ≤10 y ago), which was considered optimal at a cost-effectiveness threshold of $50,000 Canadian dollars ($41,114 May 1, 2015, US dollars). If 50% lower or higher attributable costs were assumed, the incremental cost-effectiveness ratio of this scenario was estimated to be $38,240 ($31,444 May 1, 2015, US dollars) or $48,525 ($39,901 May 1, 2015, US dollars), respectively. If 50% lower or higher costs for CT examinations were assumed, the incremental cost-effectiveness ratio of this scenario was estimated to be $28,630 ($23,542 May 1, 2015, US dollars) or $73,507 ($60,443 May 1, 2015, US dollars), respectively. This scenario would screen 9.56% (499,261 individuals) of the total population (ever- and never-smokers) at least once, which would require 4,788,523 CT examinations, and reduce lung cancer mortality in the total population by 9.05% (preventing 13,108 lung cancer deaths), while 12.53% of screen-detected cancers would be overdiagnosed (4,282 overdiagnosed cases). Sensitivity analyses indicated that the overall results were most sensitive to variations in CT examination costs. Quality of life was not incorporated in the analyses, and assumptions for follow-up procedures were based on data from the NLST, which may not be generalizable to a population-based setting. CONCLUSIONS: Lung cancer screening with stringent smoking eligibility criteria can be cost-effective in a population-based setting.

Population-based assessment of the outcomes in patients with postcolonoscopy colorectal cancers.

OBJECTIVE: The potential for cancers to not be detected on colonoscopy is increasingly recognised, but little is known about patient outcomes. The objective of this study was to assess the outcomes of patients diagnosed with postcolonoscopy colorectal cancers (PCCRCs). DESIGN: We conducted a population-based retrospective cohort study, including all patients diagnosed with colorectal cancer (CRC) in Ontario, Canada from 2003 to 2009. Patients were categorised into three groups: DETECTED (diagnosed within 6 months of first colonoscopy), PCCRC (diagnosed 6-36 months after first colonoscopy) or NOSCOPE (no colonoscopy within 36 months of diagnosis). Univariate and multivariable analyses were conducted to study overall survival, surgical treatment, emergency presentation and surgical complications. RESULTS: Overall, 45 104 patients were included, with 2804 being classified as having a PCCRC. Compared with the DETECTED group, PCCRC was associated with a significantly higher likelihood of stage IV disease (17.2% vs 12.9%), worse overall survival (5 year OS: 60.8% vs 68.3%, p<0.0001; adjusted HR: 1.25, 95% CI 1.17 to 1.32, p<0.0001), a higher likelihood of emergency presentation (OR: 2.86, 95% CI 2.56 to 3.13, p<0.001) and lower likelihood of surgical resection (OR: 0.61, 95% CI 0.55 to 0.67, p<0.001). However, patients with PCCRC had significantly better outcomes than those in the NOSCOPE group (stage IV: 37.1%, 5 year OS: 38.9%) CONCLUSIONS: Compared with CRC detected by colonoscopy, PCCRCs are associated with a higher risk of emergent presentation, a lower likelihood of surgical resection and most notably, significantly worse oncological outcomes. However, they have better outcomes than patients with no recent colonoscopy.

Beyond the dollar: Influence of sociodemographic marginalization on surgical resection, adjuvant therapy, and survival in patients with pancreatic cancer.

BACKGROUND: The single-payer universal health care system in Ontario, Canada creates a setting with reduced socioeconomic barriers to treatment. Herein, the authors sought to elucidate the influence of sociodemographic marginalization on receipt of pancreatectomy, overall survival (OS), and receipt of adjuvant treatment among patients diagnosed with pancreatic cancer at the population level using an observational cohort study design. METHODS: Patients diagnosed with pancreatic cancer in Ontario between January 2005 and January 2010 were identified using the provincial cancer registry and linked to administrative databases. Census data obtained from each patient's postal code were used as a proxy for that patient's median income, residential instability, material deprivation, ethnic concentration, and dependency (percentage aged <15 years, aged >65 years, and unemployed). Surgical specimen pathology reports were abstracted for histopathology and margin status. Independent predictors of undergoing pancreatectomy, OS after surgical resection, and receipt of adjuvant treatment were identified by logistic regression and Cox proportional hazards analysis. RESULTS: Of the 6296 patients diagnosed with pancreatic cancer, 820 (13%) underwent resection of their tumor. Increasing levels of residential instability (odds ratio [OR], 0.86; 95% confidence interval [95% CI], 0.80-0.94) and material deprivation (OR, 0.86; 95% CI, 0.79-0.94) predicted a decreased likelihood of undergoing surgical resection. Patients living in rural areas (OR, 0.68; 95% CI, 0.51-0.91) and those living in urban areas with lower incomes (OR range, 0.49-0.77) were found to have a lower likelihood of undergoing surgical resection compared with patients in the urban areas with the highest income. After surgical resection, an association between sociodemographic marginalization with OS or receipt of adjuvant treatment was not identified. CONCLUSIONS: Sociodemographic marginalization exerts its influence early in the pancreatic cancer care continuum, and appears to be associated more with which patients undergo surgical resection than the receipt of adjuvant treatment. Cancer 2016;122:3175-82. © 2016 American Cancer Society.

Colorectal cancer mortality reduction is associated with having at least 1 colonoscopy within the previous 10 years among a population-wide cohort of screening age.

BACKGROUND AND AIMS: Colonoscopy has been demonstrated to be effective in colorectal cancer (CRC) mortality reduction, although current screening guidelines have yet to be evaluated. We assessed the protective benefit of colonoscopy within the previous 10 years and whether this effect is maintained with age. METHODS: We used administrative data to compare risk of CRC death (CCD) across colonoscopy utilization among a population-wide cohort comprising individuals aged 60 to 80 years (N = 1,509,423). Baseline and time-dependent colonoscopy exposure models were assessed in the context of competing "other causes of death" (OCDs). Cumulative incidence of CCD and OCD across colonoscopy exposure, over follow-up, was estimated. Relative hazards were computed by age strata (60-69 years, 70-74 years, 75+ years) and proximal and distal cancer subsites. RESULTS: At least 1 colonoscopy during 10 years before baseline was estimated to provide a 51% reduced hazard of CCD (hazard ratio [HR] 0.49; 95% confidence interval [CI], 0.45-0.54) over the following 8 years. When colonoscopy was modeled as a time-dependent covariate, the risk of CCD was further diminished (multivariable-adjusted HR 0.36; 95% CI, 0.33-0.38). Stratified analyses suggested moderately attenuated CCD risk reduction among the oldest age group; however, consideration of OCDs suggest that this is related to competing risks. CCD risk reduction related to colonoscopy was lower for proximal cancers. CONCLUSIONS: Colonoscopy within the previous 10 years provides substantial protective benefit for average-risk individuals over 60 years. CCD risk reduction may be maintained well beyond 74 years, a common upper age limit recommended by screening guidelines.

The impact of stratifying by family history in colorectal cancer screening programs.

In the province-wide colorectal cancer (CRC) screening program in Ontario, Canada, individuals with a family history of CRC are offered colonoscopy screening and those without are offered guaiac fecal occult blood testing (gFOBT, Hemoccult II). We used microsimulation modeling to estimate the cumulative number of CRC deaths prevented and colonoscopies performed between 2008 and 2038 with this family history-based screening program, compared to a regular gFOBT program. In both programs, we assumed screening uptake increased from 30% (participation level in 2008 before the program was launched) to 60%. We assumed that 11% of the population had a family history, defined as having at least one first-degree relative diagnosed with CRC. The programs offered screening between age 50 and 74 years, every two years for gFOBT, and every ten years for colonoscopy. Compared to opportunistic screening (2008 participation level kept constant at 30%), the gFOBT program cumulatively prevented 6,700 more CRC deaths and required 570,000 additional colonoscopies by 2038. The family history-based screening program increased these numbers to 9,300 and 1,100,000, a 40% and 93% increase, respectively. If biennial gFOBT was replaced with biennial fecal immunochemical test (FIT), annual Hemoccult Sensa or five-yearly sigmoidoscopy screening, both the added benefits and colonoscopies required would decrease. A biennial gFOBT screening program that identifies individuals with a family history of CRC and recommends them to undergo colonoscopy screening would prevent 40% (range in sensitivity analyses: 20-51%) additional deaths while requiring 93% (range: 43-116%) additional colonoscopies, compared to a regular gFOBT screening program.

Organized breast screening improves reattendance compared to physician referral: a case control study.

BACKGROUND: The Ontario Breast Screening Program (OBSP) is a population-based breast screening programme, not requiring physician referral. OBSP invites women by mail to book their next screens. However, women who do not participate in the OBSP, may be referred by physicians to non-OBSP mammography facilities, which do not remind women to book their next screen. METHODS: We identified women without breast cancer prior to June 30, 2011, having bilateral mammography (M) during a baseline period at age 50 - 69 at OBSP or non-OBSP facilities, and during a re-exposure period, at the same facility type. We used a case-control design to study the association of facility type and having M during an outcome period. Cases were women failing to receive the outcome M. Controls were matched by age, census tract, and socioeconomic status. Exposure was baseline facility type. Covariates were comorbidity, residential mobility, and primary care physician (PCP) characteristics. Conditional logistic regression analysis was performed. RESULTS: Cases were less likely to have been screened at OBSP facilities. Failure to receive the outcome M was associated with having moved after re-exposure M (OR = 1.61, 95% confidence interval (CI) 1.52, 1.71), having a male PCP (OR = 1.05, 95% CI 1.02, 1.05), or a higher Charlson score (OR = 1.06 per unit increase, 95% CI 1.03, 1.09). Having re-exposure M at an OBSP facility (OR = 0.18, 95% CI 0.18, 0.19)., having a Canadian trained PCP (OR = 0.83, 95% CI 0.8, 0.87), and having a PCP one year after the re-exposure M (OR = 0.81, 95% CI 0.68, 0.97) were protective against failure to receive the outcome M. CONCLUSIONS: The OBSP, not requiring physician referral, and inviting women by mail to book their next screen, is associated with a lower probability of failure to reattend for subsequent screening than screening by PCP referral to non-OBSP facilities.

Patterns of diagnostic imaging and associated radiation exposure among long-term survivors of young adult cancer: a population-based cohort study.

BACKGROUND: Survivors of young adult malignancies are at risk of accumulated exposures to radiation from repetitive diagnostic imaging. We designed a population-based cohort study to describe patterns of diagnostic imaging and cumulative diagnostic radiation exposure among survivors of young adult cancer during a survivorship time period where surveillance imaging is not typically warranted. METHODS: Young adults aged 20-44 diagnosed with invasive malignancy in Ontario from 1992-1999 who lived at least 5 years from diagnosis were identified using the Ontario Cancer Registry and matched 5 to 1 to randomly selected cancer-free persons. We determined receipt of 5 modalities of diagnostic imaging and associated radiation dose received by survivors and controls from years 5-15 after diagnosis or matched referent date through administrative data. Matched pairs were censored six months prior to evidence of recurrence. RESULTS: 20,911 survivors and 104,524 controls had a median of 13.5 years observation. Survivors received all modalities of diagnostic imaging at significantly higher rates than controls. Survivors received CT at a 3.49-fold higher rate (95% Confidence Interval [CI]:3.37, 3.62) than controls in years 5 to 15 after diagnosis. Survivors received a mean radiation dose of 26 miliSieverts solely from diagnostic imaging in the same time period, a 4.57-fold higher dose than matched controls (95% CI: 4.39, 4.81). CONCLUSIONS: Long-term survivors of young adult cancer have a markedly higher rate of diagnostic imaging over time than matched controls, imaging associated with substantial radiation exposure, during a time period when surveillance is not routinely recommended.

Evaluation of a risk index for advanced proximal neoplasia of the colon.

BACKGROUND: A clinical risk index that uses distal colorectal findings at flexible sigmoidoscopy (FS) in conjunction with easily determined risk factors for advanced proximal neoplasia (APN) may be useful for tailoring or prioritizing screening with colonoscopy. OBJECTIVE: To conduct an external evaluation of a previously published risk index in a large, well-characterized cohort. DESIGN: Cross-sectional. SETTING: Teaching hospital and colorectal cancer screening center. PATIENTS: A total of 5139 asymptomatic persons aged 50 to 74 (54.9% women) with a mean age (±SD) of 58.3 (±6.2) years. INTERVENTIONS: Between 2003 and 2011, all participants underwent a complete screening colonoscopy and removal of all polyps. MAIN OUTCOME MEASUREMENTS: Participants were classified as low, intermediate, or high risk for APN, based on their composite risk index scores. The concordance or c-statistic was used to measure discriminating ability of the risk index. RESULTS: A total of 167 persons (3.2%) had APN. The prevalence of those with APN among low-, intermediate-, and high-risk categories was 2.1%, 2.9%, and 6.5%, respectively. High-risk individuals were 3.2 times more likely to have APN compared with those in the low-risk category. The index did not discriminate well between those in the low- and intermediate-risk categories. The c-statistic for the overall index was 0.62 (95% confidence interval, 0.58-0.66). LIMITATIONS: Distal colorectal findings were derived from colonoscopies and not FS itself. CONCLUSION: The risk index discriminated between those at low risk and those at high risk, but it had limited ability to discriminate between low- and intermediate-risk categories for prevalent APN. Information on other risk factors may be needed to tailor, or prioritize, access to screening colonoscopy.

Lack of follow-up colonoscopy after positive FOBT in an organized colorectal cancer screening program is associated with modifiable health care practices.

BACKGROUND: ColonCancerCheck (CCC), Ontario's organized colorectal cancer (CRC) screening program, uses guaiac fecal occult blood testing (gFOBT). To reduce CRC-related mortality, persons with a positive gFOBT must have colonoscopy. We identified factors associated with failure to have colonoscopy within 6months of a positive gFOBT. METHODS: Population-based, retrospective cohort analysis of CCC participants with positive gFOBT (April 2008 to December 2009) using health administrative data. Patient, physician and health care utilization factors associated with a lack of follow-up colonoscopy were identified using descriptive and multivariate analyses. RESULTS: There were 21,839 participants with a positive gFOBT; 14,091 (64%) had colonoscopy within 6months. The strongest factors associated with failure to follow-up were recent colonoscopy (in 2years prior vs. >10years or never, OR: 4.31, 95% C.I.: 3.82, 4.86), as well as repeat gFOBT (OR: 6.08, 95% C.I.: 5.46, 6.78) and hospital admission (OR: 4.35, 95% C.I.: 3.57, 5.26) in the follow-up period. CONCLUSION: In the first 18months of the CCC Program, 1/3 of those with a positive gFOBT did not have colonoscopy within 6months. Identification of potentially modifiable factors associated with failure to follow up lay the groundwork for interventions to address this critical quality gap.

Evaluation of a clinical risk index for advanced colorectal neoplasia among a North American population of screening age.

BACKGROUND: A clinical risk index employing age, sex, family history of colorectal cancer (CRC), smoking history and body mass index (BMI) may be useful for prioritizing screening with colonoscopy. The aim of this study was to conduct an external evaluation of a previously published risk index for advanced neoplasia (AN) in a large, well-characterized cohort. METHODS: Five thousand one hundred thirty-seven asymptomatic persons aged 50 to 74 (54.9 % women) with a mean age (SD) of 58.3 (6.2) years were recruited for the study from a teaching hospital and colorectal cancer screening centre between 2003 and 2011. All participants underwent a complete screening colonoscopy and removal of all polyps. AN was defined as cancer or a tubular adenoma, traditional serrated adenoma (TSA), or sessile serrated adenoma (SSA) with villous characteristics (≥25% villous component), and/or high-grade dysplasia and/or diameter ≥10 mm. Risk scores for each participant were summed to derive an overall score (0-8). The c-statistic was used to measure discriminating ability of the risk index. RESULTS: The prevalence of AN in the study cohort was 6.8 %. The likelihood of detecting AN increased from 3.6 to 13.1 % for those with a risk score of 1 to 6 respectively. The c-statistic for the multivariable logistic model in our cohort was 0.64 (95 % CI = 0.61-067) indicating modest overlap between risk scores. CONCLUSIONS: The risk index for AN using age, sex, family history, smoking history and BMI was found to be of limited discriminating ability upon external validation. The index requires further refinement to better predict AN in average risk persons of screening age.

Sessile serrated polyps at screening colonoscopy: have they been under diagnosed?

OBJECTIVES: The sessile serrated adenoma/polyp (SSA/P) is increasingly recognized as an important precursor to colorectal cancer (CRC) and may contribute to proximal postcolonoscopy CRCs. Hyperplastic polyps (HPs) generally follow a more benign course than do SSA/Ps, but they have a similar histologic appearance. Our aims were to identify patient and polyp factors associated with reclassification of HPs as SSA/Ps during a central pathology review and to characterize and compare their subsequent clinical management with other polyps. METHODS: From 2003 to 2008, we prospectively enrolled asymptomatic persons aged 50-74 years in a study of screening colonoscopy. Because criteria for SSA/P diagnosis evolved over our study period, we initiated a second review of all HPs >5 mm in size in 2011, with reclassification of polyps if indicated. Rates of subsequent colonoscopies, polypectomies, and CRCs were identified. RESULTS: We enrolled 2,527 persons who underwent colonoscopy in whom 111 had HPs >5 mm. Thirty-two of the 111 participants (28.8%) with HPs >5 mm had their polyps reclassified as SSA/Ps. There were no significant differences in patient characteristics between those with reclassified SSA/Ps and those who had HPs >5 mm. SSA/Ps were more likely to be proximal (P<0.001) and larger (P<0.007) than the HPs. In all, 48.3% of those with high-risk adenomas received appropriate follow-up compared with 26.1% of those with high-risk SSA/Ps. CONCLUSIONS: Almost 1/3 of recently diagnosed HPs >5 mm were reclassified as SSA/Ps. Patients previously diagnosed with larger HPs in the proximal colon may benefit from a pathologic review to ensure appropriate diagnosis and follow-up.

Evaluating the impact of public health initiatives on trends in fecal occult blood test participation in Ontario.

BACKGROUND: Since the publication of two randomized controlled trials (RCT) in 1996 demonstrating the effectiveness of fecal occult blood test (FOBT) in reducing colorectal cancer (CRC) mortality, several public health initiatives have been introduced in Ontario to promote FOBT participation. We examined the effect of these initiatives on FOBT participation and evaluated temporal trends in participation between 1994 and 2012. METHOD: Using administrative databases, we identified 18 annual cohorts of individuals age 50 to 74 years eligible for CRC screening and identified those who received FOBT in each quarter of a year. We used negative binomial segmented regression to examine the effect of initiatives on trends and Joinpoint regression to evaluate temporal trends in FOBT participation. RESULTS: Quarterly FOBT participation increased from 6.5 per 1000 in quarter 1 to 41.6 per 1000 in quarter 72 (January-March 2012). Segmented regression indicated increases following the publication of the RCTs in 1996 (Δ slope = 6%, 95% CI = 4.3-7.9), the primary care physician financial incentives announcement in 2005 (Δ slope = 2.2%, 95% CI = 0.68-3.7), the launch of the ColonCancerCheck (CCC) Program (Δ intercept = 35.4%, 95% CI = 18.3 -54.9), and the CCC Program 2-year anniversary (Δ slope = 7.2%, 95% CI = 3.9 - 10.5). Joinpoint validated these findings and identified the specific points when changes occurred. CONCLUSION: Although observed increases in FOBT participation cannot be definitively attributed to the various initiatives, the results of the two statistical approaches suggest a causal association between the observed increases in FOBT participation and most of these initiatives.