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dc.contributor.authorCohen, Lucasen
dc.description.abstractPurpose: The breast cancer diagnostic process is complex. Patients can receive various tests including mammograms, ultrasounds, MRI scans and biopsies. A protracted time to diagnosis can affect a patient’s prognosis and mental well-being. This thesis examined the association between high diagnostic testing and diagnostic delay and described high testing differences across Ontario Local Health Integration Networks (LHINs). Methods: This was a cross-sectional study of symptom-detected patients diagnosed in Ontario from 2007 to 2015 (N=38,590) using data from linked administrative datasets. Patients diagnosed from 2012 to 2015 were included in the LHIN-specific analyses. High testing was defined as patients having received > 2 days of mammogram appointments, > 2 days of ultrasound appointments, > 1 day of MRI appointments, or > 2 days of biopsy appointments. The outcome studied was whether patients had a specialist interval (time from first specialist test or consultation to diagnosis) longer than 30 or 90 days. Hierarchical logistic regression controlled for potential confounders and clustering by diagnosing institution. Results: High diagnostic testing occurred in 13.4% of patients. Patients with high testing had higher odds of having a specialist interval longer than 30 days (adjusted OR=9.9; 95% CI: 9.2-10.7) and 90 days (adjusted OR=8.0; 95% CI: 7.4-8.7) compared to patients who received standard testing. High diagnostic testing varied by LHIN, ranging from 4.0% to 31.6%. Studying the LHINs indicated variation in high testing after controlling for potential confounders and that repeat breast ultrasound appeared to be driving the high testing rate. Conclusions: This thesis provides evidence that there is a strong association between receiving a high amount of diagnostic testing and the time to a breast cancer diagnosis in symptomatic patients. Additionally, ultrasound is the diagnostic test repeated most often and the test that explains high test variation across LHINs. This information could help Ontario and other health care jurisdictions develop models of high-quality breast cancer care that also aim to reduce repeat diagnostic testing with the goal of shortening the time to diagnosis.en
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.rightsAttribution-NonCommercial 3.0 United Statesen
dc.subjectBreast Canceren
dc.subjectDiagnostic Delayen
dc.subjectDiagnostic Intervalen
dc.subjectRepeat Testingen
dc.subjectDiagnostic Testingen
dc.subjectSymptomatic Breast Canceren
dc.subjectBreast Neoplasmen
dc.titleFrequency of High Diagnostic Testing and its Association With the Specialist Interval in Ontario Symptomatic Breast Cancer Patientsen
dc.contributor.supervisorGroome, Pattien
dc.contributor.departmentPublic Health Sciencesen
dc.embargo.termsI want to have this thesis restricted so that together with my supervisor, we can seek journal publications before the methodology and results of the thesis are disseminated through this thesis. This is to reduce the possibility of someone copying the work within this thesis and publishing in a journal before we do.en
dc.embargo.liftdate2024-12-20T16:16:00Z's University at Kingstonen

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Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
Except where otherwise noted, this item's license is described as Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada