Tolu Sajobi

Tolu Sajobi
The University of Calgary | HBI · Department of Community Health Sciences

PhD

About

200
Publications
25,834
Reads
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7,726
Citations
Introduction
Dr. Tolu Sajobi is associate professor of biostatistics in the Department of Community Health Sciences at the University of Calgary and a member of the O'Brien Institute for Public Health and the Hotchkiss Brain Institute. His program of research focuses on development and application of novel statistical methods in clinical and population health studies. Dr. Sajobi's areas of expertise include measurement and analysis of behavioral and patient-reported outcomes, robust statistical methods for prediction in repeated measures designs, and design of randomized controlled trials.
Additional affiliations
January 2013 - present
The University of Calgary
Position
  • Professor (Associate)
March 2012 - December 2012
Phenomenome Discoveries Inc
Position
  • Statistician
September 2008 - March 2012
University of Saskatchewan
Position
  • Research Assistant
Education
September 2008 - June 2012
University of Saskatchewan
Field of study
  • Biostatistics, Health Outcomes
January 2007 - April 2008
University of Windsor
Field of study
  • Queueing Theory , Mathematical Epidemiology
January 1999 - April 2004
Obafemi Awolowo University
Field of study
  • Statistics, Mathematics

Publications

Publications (200)
Article
Background: Intravenous thrombolysis with alteplase bolus followed by infusion is a global standard of care for patients with acute ischaemic stroke. We aimed to determine whether tenecteplase given as a single bolus might increase reperfusion compared with this standard of care. Methods: In this multicentre, open-label, parallel-group, registry...
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Purpose Mixture item response theory (MixIRT) models can be used to uncover heterogeneity in responses to items that comprise patient-reported outcome measures (PROMs). This is accomplished by identifying relatively homogenous latent subgroups in heterogeneous populations. Misspecification of the number of latent subgroups may affect model accuracy...
Article
Objectives Improving diet quality among low-income populations remains a public health priority. In Canada, the British Columbia (BC) Farmers’ Market Nutrition Coupon Program (FMNCP) aims to improve the diet quality of low-income households by providing coupons to purchase healthy foods from BC farmers’ markets. This randomized controlled trial, co...
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Objectives Our objective was to validate a Social Vulnerabilities Survey that was developed to identify patient barriers in the following domains: (1) salience or priority of health; (2) social support; (3) transportation; and (4) finances. Design Cross-sectional psychometric study. Questions for one domain (health salience) were developed de novo...
Article
Background Patients with coronary artery disease (CAD) are at risk for developing atrial fibrillation (AF). Whether attending a cardiac rehabilitation (CR) program can attenuate this risk is unclear. Methods This retrospective cohort study included patients who were free of pre-existing AF and referred to CR after coronary revascularization betwee...
Article
The AcT trial (Alteplase Compared to Tenecteplase) compares alteplase or tenecteplase for patients with acute ischemic stroke. All eligible patients are enrolled by deferral of consent. Although the use of deferral of consent in the AcT trial meets the requirements of Canadian policy, we sought to provide a more explicit and rigorous approach to th...
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Full-text available
Background : Intravenous thrombolysis with alteplase is widely used in acute ischemic stroke patients presenting early after symptom onset. Recent phase II trials have suggested that intravenous tenecteplase may be safer and associated with higher early reperfusion rates as compared to alteplase. This study investigates whether intravenous tenectep...
Article
Background Cerebral amyloid angiopathy (CAA) is associated with cognitive decline. CAA has diverse impacts on brain structure and function; however, the brain lesions that mediate the association of CAA with cognition are not understood well. Aims To determine the degree to which CAA neuroimaging biomarkers mediate the association of CAA with cogni...
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Purpose Item non-response (i.e., missing data) may mask the detection of differential item functioning (DIF) in patient-reported outcome measures or result in biased DIF estimates. Non-response can be challenging to address in ordinal data. We investigated an unsupervised machine-learning method for ordinal item-level imputation and compared it wit...
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PurposeThe Seattle Angina Questionnaire (SAQ) is a widely used patient-reported measure of health status in patients with coronary artery disease. Comparisons of SAQ scores amongst population groups and over time rely on the assumption that its factorial structure is invariant. This study evaluates the measurement invariance of the SAQ across diffe...
Article
Background Individuals with type 2 diabetes should engage in ≥150 minutes of moderate-to-vigorous-physical activity (MVPA) weekly, but most do not meet this guideline. Understanding how social determinants correlate with physical activity in adults with type 2 diabetes may improve development and delivery of physical activity interventions. This st...
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BACKGROUND In light of evidence from recent trials that endovascular thrombectomy (EVT) alone may potentially be noninferior to combined treatment, that is, with intravenous thrombolysis (IVT) with alteplase and EVT, we sought to understand physician and patient preferences around this issue. METHODS We conducted a 2‐stage mixed methods study that...
Article
Background: Trials’ data are increasingly re-analyzed to identify treatment effect heterogeneity: that is, subgroups of patients who have either enhanced or adverse effects in a trial. This study investigates the robustness of subgroup identification methods in an acute stroke trial. Methods and Analysis: The Model-based recursive partitioning (MOB...
Article
Background: Efficient healthcare workflow leads to faster reperfusion and better functional outcomes of stroke in the early-time window. We investigated the impact of care delays on the outcomes of stroke patients treated with endovascular thrombectomy (EVT) in the late window. Methods: Pooled data from seven randomized clinical trials and registri...
Article
Objective: We aimed to assess the reliability and validity of single-item global ratings (GR) of satisfaction with epilepsy surgery. Methods: We recruited 240 patients from four centers in Canada and Sweden who underwent epilepsy surgery ≥1 year earlier. Participants completed a validated questionnaire on satisfaction with epilepsy surgery (the...
Preprint
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Background An unplanned extubation is the uncontrolled and accidental removal of a breathing tube. The health impact of an unplanned extubation ranges from minimal to life-threatening, but this is an important quality indicator in pediatric critical care. Objective To comprehensively synthesize literature published on quality improvement (QI) prac...
Article
Objective The relationship between antiseizure medications (ASMs), which improve health outcomes by controlling seizures, and health-related quality of life (HRQOL) is poorly understood and may involve intermediate variables. We evaluated the potential mediators of the association between ASMs and HRQOL. Methods Data are from an outpatient registr...
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Discriminant analysis procedures that assume parsimonious covariance and/or means structures have been proposed for distinguishing between two or more populations in multivariate repeated measures designs. However, these procedures rely on the assumptions of multivariate normality which is not tenable in multivariate repeated measures designs which...
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Purpose The Working Group undertook a critical, comprehensive synthesis of the response shift work to date. We aimed to (1) describe the rationale for this initiative; (2) outline how the Working Group operated; (3) summarize the papers that comprise this initiative; and (4) discuss the way forward. Methods Four interdisciplinary teams, consisting...
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Purpose This work is part of an international, interdisciplinary initiative to synthesize research on response shift in results of patient-reported outcome measures. The objective is to critically examine current response shift methods. We additionally propose advancing new methods that address the limitations of extant methods. Methods Based on l...
Article
Background Cerebral amyloid angiopathy (CAA) causes cognitive decline, but it is not known whether it is associated with neuropsychiatric symptoms (NPS). Methods and Results Participants with CAA, mild cognitive impairment, mild dementia due to Alzheimer's disease, and normal cognition were recruited from stroke and dementia clinics and community...
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Introduction To date, there is no broadly accepted dementia risk score for use in individuals with mild cognitive impairment (MCI), partly because there are few large datasets available for model development. When evidence is limited, the knowledge and experience of experts becomes more crucial for risk stratification and providing MCI patients wit...
Article
Importance Enzyme-inducing antiseizure medications (eiASMs) have been hypothesized to be associated with long-term risks of cardiovascular disease. Objective To quantify and model the putative hazard of cardiovascular disease secondary to eiASM use. Design, Setting, and Participants This cohort study covered January 1990 to March 2019 (median [IQ...
Article
Introduction: Patients with colorectal cancer are at risk of malnutrition before surgery. Multimodal prehabilitation (nutrition, exercise, stress reduction) readies patients physically and mentally for their operation. However, it is unclear whether extent of malnutrition influences prehabilitation outcomes. Methods: We conducted a pooled analys...
Article
Focus of Presentation Multivariable regression models can be used to answer a variety of clinical questions. The two main objectives of regression models are to either 1) understand an association between one or more exposures and an outcome; or 2) predict future outcomes based on certain exposures or variables. To simplify this, we will consider t...
Article
Electroencephalography (EEG) is used to prognosticate recovery in comatose patients with hypoxic ischemic brain injury (HIBI) secondary to cardiac arrest. We sought to determine the prognostic use of specific EEG patterns for predicting disability and death following HIBI secondary to cardiac arrest. This systematic review searched Medline, Embase,...
Article
Background Several clinical and demographic factors relate to anatomic spread of adult-onset isolated dystonia, but a predictive model is still lacking. Objectives 1) To develop and validate a predictive model of anatomic spread of adult-onset isolated dystonia; 2) to evaluate whether presence of tremor associated with dystonia influences model pr...
Article
Objective The 19-item Epilepsy Surgery Satisfaction Questionnaire (ESSQ-19) is a validated and reliable post hoc means of assessing patient satisfaction with epilepsy surgery. Prediction models building on these data can be used to counsel patients. Methods The ESSQ-19 was derived and validated on 229 patients recruited from Canada and Sweden. We...
Article
Objective This study was undertaken to identify clusters of adult onset epilepsy with distinct comorbidities and risks of early and late death. Methods This was a retrospective open cohort study that included all adults meeting a case definition for epilepsy after the Acceptable Mortality Recording date in the Health Improvement Network database f...
Article
Objectives Patient-reported outcome measures (PROMs) are used widely to elicit patient's self-appraisal of their health status and quality of life. One fundamental assumption when measuring PROMs is that all individuals interpret questions about their health status in a consistent manner. However, subgroups of patients with a similar health conditi...
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Full-text available
Background There remains no effective intervention capable of reversing most cases of dementia. Current research is focused on prevention by addressing risk factors that are shared between cardiovascular disease and dementia (e.g., hypertension) before the cognitive, functional, and behavioural symptoms of dementia manifest. A promising preventive...
Article
Objectives Morbidity and mortality from cardiovascular diseases (CVDs) are higher among individuals with a lower, compared to those with a higher socioeconomic position (SEP). However, the contribution of modifiable risk factors to these inequities is not known. This study aimed to examine whether and to what extent modifiable risk factors mediate...
Article
Objectives Socioeconomic inequities in cardiovascular diseases (CVDs) are greater in females than males. However, the mechanisms underpinning the excess CVD risk conferred by low socioeconomic position (SEP) in females remain unclear. This study aimed to quantify the mediating effects of modifiable risk factors to associations between SEP and CVD m...
Article
Introduction Transient ischemic attack (TIA) and minor ischemic stroke (IS) is associated with a increased risk of late life dementia. In this study we aim to study the extent to which the rates of hippocampal atrophy in TIA/IS differ from healthy controls, and how they are correlated to neuropsychological measurements. Methods TIA or minor stroke...
Article
Background: To determine whether there is an association between preoperative nutritional status and preoperative physical function, patient-reported quality of life, and body composition in colorectal cancer patients awaiting elective surgery. Methods: We conducted a pooled analysis of individual baseline patient data (n = 266) collected from 5...
Article
Importance The benefits of endovascular thrombectomy (EVT) are time dependent. Prior studies may have underestimated the time-benefit association because time of onset is imprecisely known. Objective To assess the lifetime outcomes associated with speed of endovascular thrombectomy in patients with acute ischemic stroke due to large-vessel occlusi...
Article
Background Compared with those with a higher socio-economic position (SEP), individuals with a lower SEP have higher cancer morbidity and mortality. However, the contribution of modifiable risk factors to these inequities is not known. This study aimed to quantify the mediating effects of modifiable risk factors to associations between SEP and canc...
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Importance Several real-world oncology studies have produced findings that contradict those from randomized clinical trials. Such disparities may be associated with methodological shortcomings. Objective To examine the association between a shortened duration of adjuvant chemotherapy among individuals with stage III colon cancer using real-world d...
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Full-text available
Objectives Agitation and aggression are common in dementia and pre‐dementia. The dementia risk syndrome mild behavioral impairment (MBI) includes these symptoms in the impulse dyscontrol domain. However, the neural circuitry associated with impulse dyscontrol in neurodegenerative disease is not well understood. The objective of this work was to inv...
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Background Administrative data have limited sensitivity for case finding of atrial fibrillation/atrial flutter (AF/AFL). Linkage with clinical repositories of interpreted ECGs may enhance diagnostic yield of AF/AFL. Methods and Results We retrieved 369 ECGs from the institutional Marquette Universal System for Electrocardiography (MUSE) repository...
Preprint
Full-text available
PurposeThe Seattle Angina Questionnaire (SAQ) is a widely used patient-reported measure of health status in patients with coronary artery disease. Comparisons of SAQ scores amongst population groups and over time rely on the assumption that its factorial structure is invariant (i.e., equivalent). This study evaluates the measurement invariance of t...
Article
Full-text available
Background Chronic kidney disease is associated with a high incidence of acute coronary syndrome and related morbidity and mortality. Treatment choices for patients with chronic kidney disease involve trade-offs in the potential benefits and harms of invasive management options. Objective The objective was to quantify preferences of patients with...
Preprint
Full-text available
Background: Clinicians and decision-makers are mostly interested in how the overall effect in a randomized controlled trial impact patient differently due to differential treatment effects. Subgroup analyses of randomized trials examine if the overall treatment effect is consistent among the subgroup or to identify groups that modify the interventi...
Article
Objective To use clinically informed machine learning to derive prediction models for early and late premature death in epilepsy. Methods This was a population‐based primary care observational cohort study. All patients meeting a case definition for incident epilepsy in the Health Improvement Network database for inclusive years 2000‐2012 were inc...
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Full-text available
Background The Seattle Angina Questionnaire (SAQ) is a widely-used patient-reported outcomes measure in patients with heart disease. This study assesses the validity and reliability of the SAQ in a Canadian cohort of individuals with stable angina. Methods and results Data are from the Alberta Provincial Project for Outcome Assessment in Coronary...
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Introduction: Early Supported Discharge (ESD) is a clinical flow management service offering interdisciplinary rehabilitation, wherein patients are provided supported in-home rehabilitation treatment; in comparison to conventional hospital-based rehabilitation model of service delivery. There has been little research into the functional outcomes fo...
Article
Introduction: Cardiorespiratory fitness (CRF) is an independent risk factor for cardiovascular morbidity and mortality. Cardiac rehabilitation (CR) can reduce cardiovascular risk factors and improve CRF. However, the relationship between CR, CRF, and risk of incident atrial fibrillation (AF) in patients with cardiovascular disease is less clear. Ob...
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Aging is associated with subjective memory complaints. Approximately half of those with subjective memory complaints have objective cognitive impairment. Previous studies have provided evidence of an association between genetic risk for Alzheimer’s disease (AD) and dementia progression. Also, aging is a significant risk factor for vascular patholog...
Article
Objective To identify research gaps and inform implementation we systematically reviewed the literature evaluating cost-effectiveness of recommended treatments (education, exercise and diet) for the management of hip and/or knee OA. Methods We searched Medline, Embase, Cochrane Central Register of Controlled Trials, National Health Services Econom...
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Background and purpose Patients with transient ischemic attack (TIA) show evidence of cognitive impairment but the reason is not clear. Measurement of microstructural changes in white matter (WM) using diffusion tensor imaging (DTI) may be a useful outcome measure. We report WM changes using DTI and the relationship with neuropsychological performa...
Preprint
Full-text available
Background: Agitation and aggression are common in dementia and pre-dementia. The dementia risk syndrome mild behavioral impairment (MBI) includes these symptoms in the impulse dyscontrol domain. However, the neural circuitry associated with impulse dyscontrol in neurodegenerative disease is not well understood. The aim of this work is to investiga...
Article
Objective No validated tools exist to assess satisfaction with epilepsy surgery. We aimed to develop and validate a new measure of patient satisfaction with epilepsy surgery, the 19‐item Epilepsy Surgery Satisfaction Questionnaire (ESSQ‐19). Methods An initial 31‐item measure was developed based on literature review, patient focus groups, thematic...
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Full-text available
Background International guidelines recommend education, exercise, and dietary weight management as core treatments to manage osteoarthritis (OA) regardless of disease severity or co-morbidity. Evidence supports the clinical effectiveness of OA management programs, but the cost-effectiveness of core treatments remains unclear. We will systematicall...
Article
Prehabilitation is a new field of research that aims to optimize modifiable surgical risk factors before surgery to improve patient-oriented outcomes preoperatively and postoperatively. As with any new intervention, the pressing questions that arise include what interventions work, for whom they work, and when do they work best? Given that prehabil...
Article
PURPOSE To develop a tool that can be used to predict early discontinuation of adjuvant chemotherapy among patients with stage III colon cancer. PATIENTS AND METHODS Through record linkage of Alberta administrative and tumor registry databases, we identified a cohort of individuals age ≥ 18 years who were diagnosed with stage III colon cancer and...
Article
Objective: Thirty percent to sixty-four percent of patients experience poorly controlled pain following spine surgery, leading to patient dissatisfaction and poor outcomes. Identification of at-risk patients before surgery could facilitate patient education and personalized clinical care pathways to improve postoperative pain management. According...
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Full-text available
Background and Purpose: Stroke-related functional risk scores are used to predict patients' functional outcomes following a stroke event. We evaluate the predictive accuracy of machine-learning algorithms for predicting functional outcomes in acute ischemic stroke patients after endovascular treatment.Methods: Data were from the Precise and Rapid A...
Preprint
Full-text available
Background: There remains no effective intervention capable of reversing most cases of dementia. Current research is focused on prevention, by addressing risk factors that are shared between cardiovascular disease and dementia (e.g., hypertension) before the cognitive, functional, and behavioural symptoms of dementia manifest. A promising preventiv...
Article
Objective: To assess the use of Ketotifen Fumarate (KF) to reduce post-traumatic contractures following elbow fractures and/or dislocations. Design: Randomized clinical trial. Setting: Three hospitals in Calgary, Canada including one Level 1 trauma center. Participants: Adults (n=151) sustaining operative or non-operatively managed isolated...
Article
Objective To apply unsupervised machine learning to patient‐reported outcomes to identify clusters of epilepsy patients exhibiting unique psychosocial characteristics. Methods Consecutive outpatients seen at the Calgary Comprehensive Epilepsy Program outpatient clinics with complete patient‐reported outcome measures on quality of life, health stat...
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Full-text available
Introduction Low-income populations have poorer diet quality and lower psychosocial well-being than their higher-income counterparts. These inequities increase the burden of chronic disease in low-income populations. Farmers’ market subsidies may improve diet quality and psychosocial well-being among low-income populations. In Canada, the British C...
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Full-text available
Background: Injuries and resulting stiffness around joints, especially the elbow, have huge psychological effects by reducing quality of life through interference with normal daily activities such as feeding, dressing, grooming, and reaching for objects. Over the last several years and through numerous research results, the myofibroblast-mast cell...
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Background: Factors that are prognostic of early discontinuation of adjuvant chemotherapy among stage III colon cancer patients have yet to be described. To address this gap, a survey of medical oncologists and a systematic review and meta-analysis were conducted. Methods: A survey was distributed in March 2019 to medical oncologists who treat c...
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Full-text available
Objective There is growing evidence that the well-being of childcare workers has important implications for the care provided to children attending childcare centers. To add to the growing body of research in this area and to lay the groundwork for further research, we report the results of a pilot study examining factors that are associated with t...
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INTRODUCTION Approximately, 30% to 64% of people suffer from poorly controlled pain following spine surgery leading to patient dissatisfaction and poor outcomes. The ability to identify these patients before surgery may be useful to facilitate patient education and the development of personalized clinical-care pathways to improve postoperative pain...
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Full-text available
Background: Contrast-induced acute kidney injury (CI-AKI) is a common and serious complication of invasive cardiac procedures. Quality improvement programs have been associated with a lower incidence of CI-AKI over time, but there is a lack of high-quality evidence on clinical decision support for prevention of CI-AKI and its impact on processes o...