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Background Clinical trials are important but extremely costly. Utilization of routinely collected administrative data may simplify and enhance clinical trial data collection. Purpose The aim of this study was to test the feasibility of use of administrative databases in Ontario, Canada, for long-term clinical trial follow-up, specifically (a) to determine whether limited patient identifiers held by the Canadian Cancer Trials Group can be used to probabilistically link with individuals in the Institute for Clinical Evaluative Sciences databases and if so, (b) the level of concordance between the two data sets. Methods This retrospective study was conducted through collaboration of established health service (Institute for Clinical Evaluative Sciences) and clinical trial (Canadian Cancer Trials Group) research groups in the province of Ontario, Canada, where healthcare is predominantly funded by the government. Adults with pre-treated metastatic colorectal cancer previously enrolled in the Canadian Cancer Trials Group CO.17 and CO.20 randomized phase III trials were included, limited to those in Ontario. The main outcomes were rate of successful probabilistic linkage and concordance of survival data, stated a priori. Results Probabilistic linkage was successful in 266/293 (90.8%) participants. In those patients for whom linkage was successful, the Canadian Cancer Trials Group (trial) and the Institute for Clinical Evaluative Sciences (administrative) data sets were concordant with regard to the occurrence of death during the period of clinical trial follow-up in 206/209 (98.6%). Death was recorded in the Institute for Clinical Evaluative Sciences, but not the Canadian Cancer Trials Group, for 57 cases, where the event occurred after the clinical trial cut-off dates. The recorded date of death matched closely between both databases. During the period of clinical trial conduct, administrative databases contained details of hospitalizations and emergency room visits not captured in the clinical trial electronic database. Conclusion Prospective use of administrative data could enhance clinical trial data collection, both for long-term follow-up and resource utilization for economic analyses and do so less expensively than current primary data collection. Recording a unique identifier (e.g. health insurance number) in trial databases would allow deterministic linkage for all participants.

This paper reviews the first NTIRE challenge on perceptual image enhancement with the focus on proposed solutions and results. The participating teams were solving a real-world photo enhancement problem, where the goal was to map low-quality photos from the iPhone 3GS device to the same photos captured with Canon 70D DSLR camera. The considered problem embraced a number of computer vision subtasks, such as image denoising, image resolution and sharpness enhancement, image color/contrast/exposure adjustment, etc. The target metric used in this challenge combined PSNR and SSIM scores with solutions' perceptual results measured in the user study. The proposed solutions significantly improved baseline results, defining the state-of-the-art for practical image enhancement.

IntroductionThe importance of Indigenous data sovereignty and Indigenous-led research processes is increasingly being recognized in Canada and internationally. For First Nations in Ontario, Canada, access to routinely-collected demographic and health systems data is critical to planning and measuring health status and outcomes in their populations. Linkage of this data with the Indian Register (IR), under First Nations data governance, has unlocked data for use by First Nations organizations and communities. ObjectivesTo describe the linkage of the IR database to the Ontario Registered Persons Database (RPDB) within the context of Indigenous data sovereignty principles. MethodsDeterministic and probabilistic record linkage methods were used to link the IR to the RPDB. There is no established population of First Nations people living in Ontario with which we could establish a linkage rate. Accordingly, several approaches were taken to determine a denominator that would represent the total population of First Nations we would hope to link to the RPDB. ResultsOverall, 201,678 individuals in the national IR database matched to Ontario health records by way of the RPDB, of which 98,562 were female and 103,116 were male. Of those First Nations individuals linked to the RPDB, 90.2% (n=181,915) lived in Ontario when they first registered with IR, or were affiliated with an Ontario First Nation Community. The proportion of registered First Nations people linking to the RPDB improved across time, from 62.8% in the 1960s to 94.5% in 2012. Conclusions This linkage of the IR and RPDB has resulted in the creation of the largest First Nations health research study cohort in Canada. The linked data are being used by First Nations communities to answer questions that ultimately promote wellbeing, effective policy, and healing.

We used record linkage to create a data repository of health information of persons who were federally incarcerated in Ontario and Canada. We obtained records from 56,867 adults who were federally incarcerated between January 1, 1998 and December 31, 2011 from the Correctional Service of Canada; 15,248 records belonged to individuals residing in Ontario, Canada. We linked these records to the Registered Persons Database (RPDB) which contained records from 18,116,996 individuals eligible for health care in Ontario. Out of 56,867 OMS records, 22,844 (40.2%) were linked to the RPDB. Looking only at those incarcerated in Ontario, 98%, (14 953 of 15248) records were linked to RPDB. Most records of persons in Ontario-based facilities were linked deterministically. Linkage rates were lower for women, minority groups, and substance users. In conclusion, record linkage enabled the creation of a valuable data repository: there are no electronic medical records for correctional populations in Canada, making it more difficult to profile their health.

PURPOSE: To assess the risk of fatal and nonfatal myocardial infarction (MI) after breast-conserving surgery (BCS) and radiation therapy (RT) for left-sided breast cancer. PATIENTS AND METHODS: A hospital-based retrospective cohort linkage study of all breast cancer patients registered at the Princess Margaret Hospital (PMH), Toronto, Canada, between 1982 and 1988 who were treated with postlumpectomy RT was performed. Available identifiers for the study cohort were linked to two province-wide health files: the Canadian Institute for Health Information Hospitalization File and the Ontario Mortality Database. Admissions to hospital for MI and deaths attributable to MI were identified. The relevant original health records were abstracted to verify the diagnosis of MI according to diagnostic criteria used in the World Health Organization multinational monitoring of trends and determinants in cardiovascular disease (MONICA) project. We compared incidence of MI in the study cohort with the general population and incidence of MI after therapy for left- versus right-sided breast cancer. RESULTS: A cohort of 2,128 patients was identified. The median length of follow-up was 10.2 years. The incidence of MI in the study cohort was comparable to that in an age-matched general population of women in Ontario. There were 70 coronary events among 56 patients after breast irradiation. According to MONICA criteria, 53 and six events were characterized as definite and possible MIs, respectively. Eleven events did not satisfy MONICA criteria for MI. Twenty-six patients treated for left-sided and 23 patients treated for right-sided breast cancer experienced at least one definite or possible MI (log-rank test, P = .66). There were eight fatal MIs among the left-sided group and six among the right-sided group. There was no excess of other cardiac diseases among patients who received left-sided radiotherapy compared to the right-sided group. CONCLUSION: We have found no evidence for excess morbidity and mortality from coronary artery disease among women treated with RT to the left breast after BCS at 10.2 years of follow-up. Longer follow-up is required to confirm that excess cardiac disease has been completely avoided.

Background Longer times from diagnosis to breast cancer treatment are associated with poorer prognosis. This study examined factors associated with wait times by phase in the breast cancer treatment pathway. Methods There were 1760 women eligible for the study, aged 50–69 diagnosed in Ontario with invasive breast cancer from 1995–2003. Multivariate logistic regression examined factors associated with greater than median wait times for each phase of the treatment pathway; from diagnosis to definitive surgery; from final surgery to radiotherapy without chemotherapy and from final surgery to chemotherapy. Results The median wait times were 17 days (Inter Quartile Range (IQR) = 0–31) from diagnosis to definitive surgery, 44 days (IQR = 34–56) from final surgery to postoperative chemotherapy and 75 days (IQR = 57–97) from final surgery to postoperative radiotherapy. Diagnosis during 2000–2003 compared to 1995–1999 was associated with significantly longer wait times for each phase of the treatment pathway. Higher income quintile was associated with longer wait time from diagnosis to surgery (OR = 1.47, 95% CI = 1.05-2.06) and shorter wait times from final surgery to radiotherapy (OR = 0.60, 95% CI = 0.37-0.96). Greater stage at diagnosis was associated with shorter wait times from diagnosis to definitive surgery (stage III vs I: OR = 0.49, 95% CI = 0.34-0.71). Conclusions While diagnosis during the latter part of the study period was associated with significantly longer wait times for all phases of the treatment pathway, there were variations in the associations of stage and income quintile with wait times by treatment phase. Continued assessment of factors associated with wait times across the breast cancer treatment pathway is important, as they indicate areas to be targeted for quality improvement with the ultimate goal of improving prognosis.

Most studies reporting more favourable biological features of screen-detected breast cancers compared with symptomatic or interval cancers include initial or prevalent screens and therefore may not indicate the real benefit of screening on breast cancer mortality. We conducted case-case comparisons within a cohort of eligible women (N=771 715) who were aged 50-69 between 1 January 1995 and 31 December 2003. A randomly selected sample of breast cancers (N=1848) diagnosed among these women were compared by detection method. Tumour characteristics of interval cancers (N=362) diagnosed after 6-24 months of a negative screen or symptomatic breast cancers (N=491) were compared with subsequent screen-detected breast cancers diagnosed within 6 months of a positive screen (N=995) using polytomous logistic regression. Tumours were evaluated for clinical presentation, histology and expression of hormone receptors. Women with symptomatic detected [odds ratio (OR)=7.48, 95% confidence interval (CI)=5.38-10.38] and interval cancers (OR=2.20, 95% CI=1.56-3.10) were more often diagnosed at stage III-IV versus I than women with rescreen-detected cancers. After adjusting for tumour size, women with symptomatic cancers had tumours of higher grade (OR=1.50, 95% CI=1.05-2.15) and mitotic score (OR=1.69, 95% CI=1.15-2.49) and women with interval cancers had tumours of higher mitotic score (OR=1.52, 95% CI=1.01-2.28) compared with women diagnosed at screening. Subsequent screen-detected cancers are not only detected at an earlier stage but are also less aggressive, leading to a better prognosis. As long-term mortality reduction for breast screening may depend on subsequent screens, our study indicates that mammography screening can be effective in women aged 50-69.

In a recent study involving 27,500 women who had breast reduction surgery in Ontario, Canada, 17 women who were diagnosed as having breast cancer at the time of their breast reduction surgery were identified. The aims of this study were to (1) describe a population-based series of patients who had breast cancer diagnosed at the time of breast reduction, (2) describe the treatment of these cancers, and (3) compare their survival rate with survival in patients in the general population who had breast cancer. Information about these women, their treatment, and outcome was extracted from hospital records, pathology reports, and reports from regional cancer centers. The chance of finding an invasive breast cancer at the time of breast reduction was 0.06 percent, which is lower than what has been reported previously. Sixty-seven percent of these women were treated with total mastectomy. In the remaining 33 percent, who were treated with partial mastectomy, the entire tumor was removed at the time of breast reduction. Fifty percent of the women were treated with radiation, and 25 percent were treated with chemotherapy or hormonal therapy. Compared with women in the general population of Ontario who have breast cancer, women whose breast cancer is discovered during breast reduction surgery are more likely to be treated with complete mastectomy and less likely to be treated with radiotherapy or chemotherapy. Seventy-one percent of the breast reduction group were axillary node-negative at diagnosis, compared with 58 percent in the general population of women with breast cancer. Survival from breast cancer in women diagnosed at the time of breast reduction (88 percent, 5-year survival) was better than survival from breast cancer in the general population (77 percent). These findings suggest that cancers found in women at the time of breast reduction are less advanced, possibly because they are diagnosed at an earlier stage.

Reduction mammaplasty is one of the most common procedures performed by plastic surgeons in Canada. In a recent study of 27,500 women in the province of Ontario who underwent breast reduction surgery, 105 women were identified who developed breast cancer after reduction mammaplasty. The purpose of this study was to compare women who had breast cancer and had a previous breast reduction with women who had breast cancer but did not have a breast reduction. Specifically, we wanted to document patient demographics, cancer type, surgical and nonsurgical treatment, and eventual outcome. A comparison group of non-breast reduction women was taken from the cohort of breast cancer patients in the province of Ontario, and the two groups were matched for age, year of diagnosis, and place of diagnosis. It was found that (1) the average age at diagnosis of breast cancer is significantly younger for women who have had previous breast reduction surgery than for those who have not; (2) the median interval between breast reduction and cancer is 5 years; (3) the type, location, and side of breast cancers are similar in the two groups of women; (4) breast reduction does not significantly increase or decrease survival rate from breast cancer; and (5) women who have had breast reduction receive the same treatment for their breast cancer as women who have not had reduction mammaplasty.

To ascertain the extent of prostate-specific antigen (PSA) testing in patients with prostate cancer (PC), with other cancers (OC), and with no cancer (NC) in two clinical laboratory databases.PSA test records were obtained from a tertiary care hospital, Sunnybrook Health Science Centre (SHSC) and from a private laboratory, Gamma-Dynacare Medical Laboratories (GDL), during the period 1988 to 1995. These records were linked with the Ontario Cancer Registry (OCR) to establish a diagnosis of PC, OC, or NC. Trends in PSA testing according to diagnostic category, testing laboratory, patient age (by decade), and PSA value (in microgram/L) were determined.Major cancer sites identified in the patients tested for PSA were prostate (60%), bladder and colon (7% each), lung (5%), kidney (3%), and rectum (3%). There were 11,867 patients (8.5%) with PC, 8,002 (5.9%) with OC, and 118,954 (86%) with NC. The total number of PSA tests performed on these patients was 230,756, of which 21% were on PC, 5% on OC, and 74% on NC; of these tests, 64% were performed through GDL and 36% through SHSC. The mean (median) number of tests per patient was: PC, 4.0 (2); OC, 1.4 (1); and NC, 1.5 (1). For PC 89% and for OC 72% of all tests occurred after diagnosis. Between 1990 and 1995 the number of PSA tests increased two-fold in PC and OC, and 20-fold in NC. We estimate that about one-half of the PSA tests in the NC group were for screening purposes. The proportion of PSA tests occurring in PC, OC, and NC for patients 50 to 70 years of age was 41%, 50%, and 63%, respectively; for patients over 70 years of age, this proportion was 58%, 46%, and 22% respectively; and for patients under 50 it was 1%, 4%, and 15%, respectively. Between 1990 and 1995, the largest increase in testing frequency was in the NC group, particularly in patients 50 to 70 years of age, which was accompanied by a decrease in patients over 70. Less than 10% of testing occurred in patients under 50 in all diagnostic groups. We estimate that about 26% of PSA screening tests in NC occurred outside the guidelines for patient age. Between 1988 and 1995, the proportion of PSA results below our detection limit (0.2 micrograms/L) showed a steady rise in the PC group, as did the proportion between 0.2 and 3.9 micrograms/L; these were accompanied by a fall in the proportion20.0 micrograms/L. However, the proportion of PSA results within these ranges did not change much during the same time period for the OC and NC groups. At cutoffs of PSA = 4.0 micrograms/L (or PSA = 10.0 micrograms/L), estimates of clinical specificity were 84.0% (or 96.3%), and of clinical sensitivity were 83.4% (or 47.1%).Most (86%) PSA testing occurred in men with NC, consistent with diagnosis or screening. There were more PSA tests per patient in PC than in OC, and most testing occurred after diagnosis. PSA testing in the NC group continues to increase rapidly. The proportion of PSA tests in patients over age 70 decreased in the order of PCNCOC. Between 1990 and 1995, there was an increase in the proportion of patients tested who were between 50 and 70 in the NC group, which may suggest more screening in this group. Over this same time period, there was an increase in the proportion of undetectable PSA values, possibly suggesting increased use of radical therapy; there was also a decrease in the proportion of PSA20 micrograms/L, possibly suggesting a decrease in the prevalence of advanced stage PC.

Introduction Although prognostic differences between screen-detected, interval and symptomatic breast cancers are known, factors associated with wait times to diagnosis among these three groups have not been studied. Methods Of the 16,373 invasive breast cancers diagnosed between January 1, 1995 and December 31, 2003 in a cohort of Ontario women aged 50 to 69, a random sample (N = 2,615) were selected for chart abstraction. Eligible women were classified according to detection method; screen-detected (n = 1181), interval (n = 319) or symptomatic (n = 406). Diagnostic wait time was calculated from the initial imaging or biopsy to breast cancer diagnosis. Logistic regression analysis examined associations between diagnostic wait times dichotomized as greater or less than the median and demographic, clinical and prognostic factors separately for each detection cohort. Results Women who underwent an open biopsy had significantly longer than median wait times to diagnosis, compared to women who underwent a fine needle aspiration or core biopsy; (screen-detected OR = 2.76, 95% CI = 2.14-3.56; interval OR = 2.56, 95% CI = 1.50-4.35; symptomatic OR = 5.56, 95% CI = 3.33-9.30). Additionally, screen-detected breast cancers diagnosed with stage II and symptomatic cancers diagnosed at stage III or IV had significantly shorter diagnostic wait times compared to those diagnosed at stage 1 (OR = 0.66 95% CI = 0.50-0.87 and OR = 0.46, 95% CI = 0.25-0.85 respectively). Conclusions Our study is consistent with expedited diagnostic work-up for breast cancers with more advanced prognostic features. Furthermore, women who had an open surgical biopsy had a greater than the median diagnostic wait time, irrespective of detection method.