Robert J Hilsden

The University of Calgary, Calgary, Alberta, Canada

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Publications (120)801.78 Total impact

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    ABSTRACT: 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.
    BMC Gastroenterology 12/2015; 15(1). DOI:10.1186/s12876-015-0395-y · 2.37 Impact Factor
  • Rachid Mohamed · Robert J Hilsden · Catherine Dube · Alaa Rostom ·


  • 06/2015;
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    ABSTRACT: Although several quality indicators of colonoscopy have been defined, quality assurance activities should be directed at the measurement of quality indicators that are predictive of key screening colonoscopy outcomes. The goal of this study was to examine the association among established quality indicators and the detection of screen-relevant lesions (SRLs), adverse events, and postcolonoscopy cancers. Historical cohort study. Canadian colorectal cancer screening center. A total of 18,456 asymptomatic men and women ages 40 to 74, at either average risk or increased risk for colorectal cancer because of a family history, who underwent a screening colonoscopy from 2008 to 2010. Using univariate and multivariate analyses, we explored the association among procedural quality indicators and 3 colonoscopy outcomes: detection of SRLs, adverse events, and postcolonoscopy cancers. The crude rates of SRLs, adverse events, and postcolonoscopy cancers were 240, 6.44, and .54 per 1000 colonoscopies, respectively. Several indicators, including endoscopist withdrawal time (OR, 1.3; 95% CI, 1.2-1.4) and cecal intubation rate (OR, 13.9; 95% CI, 1.9-96.9), were associated with the detection of SRLs. No quality indicator was associated with the risk of adverse events. Endoscopist average withdrawal time over 6 minutes (OR, .12; 95% CI, .002-.85) and SRL detection rate over 20% (OR, .17; 95% CI, .03-.74) were associated with a reduced risk of postcolonoscopy cancers. Single-center study. Quality assurance programs should prioritize the measurement of endoscopist average withdrawal time and adenoma (SRL) detection rate. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.
    Gastrointestinal endoscopy 05/2015; DOI:10.1016/j.gie.2015.03.1914 · 5.37 Impact Factor

  • Gastroenterology 04/2015; 148(4):S-204. DOI:10.1016/S0016-5085(15)30681-8 · 16.72 Impact Factor
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    ABSTRACT: 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. To conduct an external evaluation of a previously published risk index in a large, well-characterized cohort. Cross-sectional. Teaching hospital and colorectal cancer screening center. A total of 5139 asymptomatic persons aged 50 to 74 (54.9% women) with a mean age (± SD) of 58.3 (± 6.2) years. Between 2003 and 2011, all participants underwent a complete screening colonoscopy and removal of all polyps. 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. 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). Distal colorectal findings were derived from colonoscopies and not FS itself. 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. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.
    Gastrointestinal Endoscopy 03/2015; 81(6). DOI:10.1016/j.gie.2014.12.028 · 5.37 Impact Factor
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    ABSTRACT: Screening for hepatitis C virus (HCV) is recommended in patients born between 1945 and 1965 ("baby boomers") in the United States. Because these patients are often screened for colorectal cancer, dual screening for HCV may enhance case identification. Our objectives were to assess the acceptability and yield of screening for HCV among patients undergoing screening for colorectal cancer. Patients referred for a colonoscopy to screen for colorectal cancer completed an anonymous survey regarding the acceptability of screening for HCV, risk factors and prior testing. The impacts of demographics and risk factors for HCV on willingness to be screened were determined using logistic regression, and the stored sera of 483 patients who had undergone screening for colorectal cancer between February 2011 and August 2012 were tested for HCV antibodies. Among 1012 survey respondents (median age 56 yr; 911 [90.0%] were baby boomers, 880 [87.0%] were white and 223 [22.0%] were born outside Canada), 123 patients (12.2%) reported prior testing for HCV. HCV was previously diagnosed in 9 of these patients (0.9%, representing 1.0% of the patients who were baby boomers): 5 (55.6% of those diagnosed) reported risk factors. Excluding patients diagnosed with HCV, 903 (90.0%) respondents indicated that they would consent to testing of blood or saliva for HCV. After adjusting for age, sex and status of immigration, patients who were white (odds ratio [OR] 3.38, 95% confidence interval [CI] 1.81-6.32) and patients with risk factors (> 1 v. 0: OR 3.67, 95% CI 1.12-12.02) had a greater acceptance of screening. Among 483 patients screened for colorectal cancer, 3 were anti-HCV positive (0.6%, 95% CI 0.1%-1.8%), representing 0.8% (95% CI 0.2%-2.4%) of the patients who were baby boomers. Acceptance of screening for HCV is high among patients undergoing screening for colorectal cancer in the Calgary area. However, the low prevalence of HCV suggests that the cost-effectiveness of birth-cohort screening in this population warrants evaluation.
    01/2015; 3(1):E62-E67. DOI:10.9778/cmajo.20140024
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    ABSTRACT: 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.
    The American Journal of Gastroenterology 07/2014; 109(11). DOI:10.1038/ajg.2014.78 · 10.76 Impact Factor

  • Gastroenterology 05/2014; 146(5):S-408. DOI:10.1016/S0016-5085(14)61475-X · 16.72 Impact Factor
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    Gastrointestinal Endoscopy 05/2014; 79(5):AB322. DOI:10.1016/j.gie.2014.02.307 · 5.37 Impact Factor
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    ABSTRACT: Estimating risk for advanced proximal neoplasia (APN) based on distal colon findings can help identify asymptomatic persons who should undergo examination of the proximal colon after flexible sigmoidoscopy (FS) screening. We aimed to determine the risk of APN by most advanced distal finding among an average-risk screening population. Prospective, cross-sectional study. Teaching hospital and colorectal cancer screening center. A total of 4651 asymptomatic persons at average risk for colorectal cancer aged 50 to 74 years (54.4% women [n = 2529] with a mean [± standard deviation] age of 58.4 ± 6.2 years). All participants underwent a complete colonoscopy, including endoscopic removal of all polyps. We explored associations between several risk factors and APN. Logistic regression was used to identify independent predictors of APN. A total of 142 persons (3.1%) had APN, of whom 85 (1.8%) had isolated APN (with no distal findings). APN was associated with older age, a BMI >27 kg/m(2), smoking, distal advanced adenoma and/or cancer, and distal non-advanced tubular adenoma. Those with a distal advanced neoplasm were more than twice as likely to have APN compared with those without distal lesions. Distal findings used to estimate risk of APN were derived from colonoscopy rather than FS itself. In persons at average risk for colorectal cancer, the prevalence of isolated APN was low (1.8%). Use of distal findings to predict APN may not be the most effective strategy. However, incorporating factors such as age (>65 years), sex, BMI (>27 kg/m(2)), and smoking status, in addition to distal findings, should be considered for tailoring colonoscopy recommendations. Further evaluation of risk stratification approaches in other asymptomatic screening populations is warranted.
    Gastrointestinal endoscopy 03/2014; 80(4). DOI:10.1016/j.gie.2014.02.001 · 5.37 Impact Factor
  • Robert J. Hilsden · Gisela Macphail · Jason Grebely · Brian Conway · Samuel S. Lee ·
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    ABSTRACT: Background: This study investigated the efficacy and safety of directly observed pegylated interferon (peg-IFN) alfa-2a plus self-administered ribavirin (RBV) for the treatment of hepatitis C virus (HCV) among people with active drug use. Methods: A randomized, open-label, parallel group trial of immediate vs delayed treatment with peg-IFN alfa-2a plus RBV in participants with recent injection drug and/or crack cocaine use (prior 3 months). The primary end point was sustained virologic response (SVR). Results: Sixty-six participants were randomized (immediate treatment, n = 48; delayed treatment, n = 18). Loss to follow-up was comparable among those randomized to immediate and delayed treatment (23% vs 33%, P = .389). In a post hoc intent-to-treat analysis of all randomized individuals, the SVR was 65% (95% confidence interval [CI], 49%-78%; 31/48) in those randomized to immediate treatment as compared to 39% (95% CI, 17%-64%; 7/18) in those randomized to delayed treatment (P = .060). Among those who received delayed treatment (12/18), SVR was 58% (7/12). Among 60 participants who received at least 1 dose of study medication, SVR was 63% (95% CI, 50%-75%, n = 38). Recent drug use at baseline (past month) did not impact completion or SVR. Discontinuation due to adverse events occurred in 7%. The HCV reinfection rate was 2.8 per 100 person-years (95% CI, 0.0-14.5 person-years) with 1 reinfection observed among 23 remaining in follow-up post-SVR (median, 1.8 years; range, 0.5-1.8 years). Conclusions: Among people actively using drugs treated with directly observed peg-IFN alfa-2a plus self-administered RBV, SVR is comparable to that seen in clinical trials of non-drug users, and the rate of HCV reinfection is low.
    Clinical Infectious Diseases 07/2013; 57(suppl 2):S90-S96. DOI:10.1093/cid/cit327 · 8.89 Impact Factor
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    Steven J Heitman · Elizabeth Mackay · Robert J Hilsden · Alaa Rostom ·

    Gastroenterology 05/2013; 145(1). DOI:10.1053/j.gastro.2013.05.025 · 16.72 Impact Factor
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    ABSTRACT: Background Some studies have shown that endoscopist specialty is associated with colorectal cancers missed by colonoscopy. We sought to examine the relationship between endoscopist specialty and polypectomy rate, a colonoscopy quality indicator. Polypectomy rate is defined as the proportion of colonoscopies that result in the removal of one or more polyps. Methods A cross-sectional study was conducted of endoscopists and their patients from 7 Montreal and 2 Calgary endoscopy clinics. Eligible patients were aged 50–75 and covered by provincial health insurance. A patient questionnaire assessed family history of colorectal cancer, history of large bowel conditions and symptoms, and previous colonoscopy. The outcome, polypectomy status, was obtained from provincial health administrative databases. For each city, Bayesian hierarchical logistic regression was used to estimate the odds ratio for polypectomy comparing surgeons to gastroenterologists. Model covariates included patient age, sex, family history of colorectal cancer, colonoscopy indication, and previous colonoscopy. Results In total, 2,113 and 538 colonoscopies were included from Montreal and Calgary, respectively. Colonoscopies were performed by 38 gastroenterologists and 6 surgeons in Montreal, and by 31 gastroenterologists and 5 surgeons in Calgary. The adjusted odds ratios comparing surgeons to gastroenterologists were 0.48 (95% CI: 0.32–0.71) in Montreal and 0.73 (95% CI: 0.43–1.21) in Calgary. Conclusions An association between endoscopist specialty and polypectomy was observed in both cities after adjusting for patient-level covariates. Results from Montreal suggest that surgeons are half as likely as gastroenterologists to remove polyps, while those from Calgary were associated with a wide, non-significant Bayesian credible interval. However, residual confounding from patient-level variables is possible, and further investigation is required.
    BMC Gastroenterology 05/2013; 13(1):78. DOI:10.1186/1471-230X-13-78 · 2.37 Impact Factor
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    Maida J Sewitch · Mengzhu Jiang · Lawrence Joseph · Robert J Hilsden · Alain Bitton ·
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    ABSTRACT: Background Algorithms to identify screening colonoscopies in administrative databases would be useful for monitoring colorectal cancer (CRC) screening uptake, tracking health resource utilization, and quality assurance. Previously developed algorithms based on expert opinion were insufficiently accurate. The purpose of this study was to develop and evaluate the accuracy of model-based algorithms to identify screening colonoscopies in health administrative databases. Methods Patients aged 50-75 were recruited from endoscopy units in Montreal, Quebec, and Calgary, Alberta. Physician billing records and hospitalization data were obtained for each patient from the provincial administrative health databases. Indication for colonoscopy was derived using Bayesian latent class analysis informed by endoscopist and patient questionnaire responses. Two modeling methods were used to fit the data, multivariate logistic regression and recursive partitioning. The accuracies of these models were assessed. Results 689 patients from Montreal and 541 from Calgary participated (January to March 2007). The latent class model identified 554 screening exams. Multivariate logistic regression predictions yielded an area under the curve of 0.786. Recursive partitioning using the latent outcome had sensitivity and specificity of 84.5% (95% CI: 81.5-87.5) and 63.3% (95% CI: 59.7-67.0), respectively. Conclusions Model-based algorithms using administrative data failed to identify screening colonoscopies with sufficient accuracy. Nevertheless, the approach of constructing a latent reference standard against which model-based algorithms were evaluated may be useful for validating administrative data in other contexts where there lacks a gold standard.
    BMC Medical Informatics and Decision Making 04/2013; 13(1):45. DOI:10.1186/1472-6947-13-45 · 1.83 Impact Factor
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    ABSTRACT: Current quality improvement tools for endoscopy services, such as the Global Rating Scale (GRS), emphasize the need for patient-centred care. However, there are no studies that have investigated patient expectations and⁄or perceptions of quality indicators in endoscopy services. To identify quality indicators for colonoscopy services from the patient perspective; to rate indicators of importance; to determine factors that influence indicator ratings; and to compare the identified indicators with those of the GRS. A two-phase mixed methods study was undertaken in Montreal (Quebec), Calgary (Alberta) and Hamilton (Ontario) among patients ≥18 years of age who spoke and read English or French. In phase 1, focus group participants identified quality indicators that were then used to construct a survey questionnaire. In phase 2, survey questionnaires, which were completed immediately after colonoscopy, prompted respondents to rate the 20 focus group-derived indicators according to their level of importance (low, medium, high) and to list up to nine additional items. Multiple logistic regression analysis was used to determine the factors that influenced focus group-derived indicator ratings. Patient-identified indicators were compared with those used in the GRS to identify novel indicators. Three quality indicator themes were identified by 66 participants in 12 focus groups: communication, comfort and service environment. Of the 828 surveys distributed, 402 (48.6%) were returned and 65% of focus group-derived indicators were rated highly important by at least 55% of survey respondents. Indicator ratings differed according to age, sex, site and perceived colorectal cancer risk. Of the 29 patient-identified indicators, 17 (58.6%) were novel. Patients identified 17 novel quality indicators, suggesting that patients and health professionals differ in their perspectives with respect to quality in colonoscopy services.
    Canadian journal of gastroenterology = Journal canadien de gastroenterologie 02/2013; 27(1):25-32. · 1.98 Impact Factor
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    ABSTRACT: Comfort during colonoscopy is a critical component of safety and quality. To develop and validate the Nurse-Assessed Patient Comfort Score (NAPCOMS). Prospective scale validation. Colorectal cancer screening centers in the United Kingdom and Canada. A total of 300 consecutive patients undergoing colonoscopy at participating colorectal cancer screening centers. The NAPCOMS was developed by using a modified Delphi process. During colonoscopy, two endoscopy room nurses independently observed and rated patient comfort and tolerability by using NAPCOMS. In addition, endoscopists reported global comfort scores and patients' reported global comfort by using visual 4-point Likert and National Health Service-United Kingdom Global Rating Scales. Reliability and validity of NAPCOMS was measured by using intraclass correlations (ICC) between nurse ratings of colonoscopies and between NAPCOMS, endoscopist ratings, and patient ratings of global comfort. The ICC for the overall NAPCOMS was 0.84 (95% confidence interval [CI], 0.80-0.87). There was high agreement between the NAPCOMS and endoscopist ratings of comfort (ICC = 0.77; 95% CI, 0.72-0.81), moderate agreement between the NAPCOMS and patient ratings (ICC = 0.61; 95% CI, 0.53-0.67), and moderate agreement between the endoscopist and patient ratings (ICC = 0.52; 95% CI, 0.43-0.60). NAPCOMS was validated in outpatients who received colonoscopy with minimal to moderate sedation as part of a screening and surveillance program, so performance among inpatients or those requiring deep sedation was not tested. NAPCOMS is a reliable and valid tool for assessing patient comfort in the setting of outpatient colonoscopy performed with minimal to moderate sedation.
    Gastrointestinal endoscopy 02/2013; 77(2):255-61. DOI:10.1016/j.gie.2012.10.003 · 5.37 Impact Factor
  • Catherine Dubé · Robert J Hilsden ·

    Canadian journal of gastroenterology = Journal canadien de gastroenterologie 12/2012; 26(12):869. · 1.98 Impact Factor
  • Ali Rezaie · Hude Quan · Richard N Fedorak · Remo Panaccione · Robert J Hilsden ·
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    ABSTRACT: A population-based database of inflammatory bowel disease (IBD) patients is invaluable to explore and monitor the epidemiology and outcome of the disease. In this context, an accurate and validated population-based case definition for IBD becomes critical for researchers and health care providers. IBD and non-IBD individuals were identified through an endoscopy database in a western Canadian health region (Calgary Health Region, Calgary, Alberta). Subsequently, using a novel algorithm, a series of case definitions were developed to capture IBD cases in the administrative databases. In the second stage of the study, the criteria were validated in the Capital Health Region (Edmonton, Alberta). A total of 150 IBD case definitions were developed using 1399 IBD patients and 15,439 controls in the development phase. In the validation phase, 318,382 endoscopic procedures were searched and 5201 IBD patients were identified. After consideration of sensitivity, specificity and temporal stability of each validated case definition, a diagnosis of IBD was assigned to individuals who experienced at least two hospitalizations or had four physician claims, or two medical contacts in the Ambulatory Care Classification System database with an IBD diagnostic code within a two-year period (specificity 99.8%; sensitivity 83.4%; positive predictive value 97.4%; negative predictive value 98.5%). An alternative case definition was developed for regions without access to the Ambulatory Care Classification System database. A novel scoring system was developed that detected Crohn disease and ulcerative colitis patients with a specificity of >99% and a sensitivity of 99.1% and 86.3%, respectively. Through a robust methodology, a reproducible set of criteria to capture IBD patients through administrative databases was developed. The methodology may be used to develop similar administrative definitions for chronic diseases.
    Canadian journal of gastroenterology = Journal canadien de gastroenterologie 10/2012; 26(10):711-7. · 1.98 Impact Factor

  • Gastroenterology 05/2012; 142(5). DOI:10.1016/S0016-5085(12)60858-0 · 16.72 Impact Factor

Publication Stats

2k Citations
801.78 Total Impact Points


  • 1998-2015
    • The University of Calgary
      • • Department of Medicine
      • • Department of Community Health Sciences
      Calgary, Alberta, Canada
  • 2011
    • Sunnybrook Health Sciences Centre
      Toronto, Ontario, Canada
  • 2007
    • Aga Khan University Hospital, Karachi
      Kurrachee, Sindh, Pakistan