Browsing by Author "Ronksley, Paul Everett"
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Item Open Access Association between Severity of Obstructive Sleep Apnea and Health Care Utilization(2008) Ronksley, Paul Everett; Hemmelgarn, Brenda; Tsai, WillisItem Open Access Association between Severity of Obstructive Sleep Apnea and Health Care Utilization(2008) Ronksley, Paul Everett; Hemmelgarn, Brenda; Tsai, WillisItem Open Access The Cost-Effectiveness of a Prevention Strategy for Clostridioides difficile Infections in Alberta Health Services(2019-04-30) Leal, Jenine Rocha; Manns, Braden; Henderson, Elizabeth Ann; Conly, John M.; Ronksley, Paul Everett; Loeb, Mark; Noseworthy, Tom W.The clinical and economic burden of hospital-acquired Clostridioides difficile infection (HA-CDI) is significant, however there is uncertainty in the cost-effectiveness of implementing probiotics for the primary prevention of HA-CDI among hospitalized patients prescribed antibiotics. In this thesis we examined the predictors of mortality and length of stay among this patient population in Alberta. We determined the attributable cost of HA-CDI and applied these estimates in a cost-effectiveness analysis of probiotics for the primary prevention of HA-CDI in Alberta from the perspective of a publicly-funded healthcare system. We conducted three studies: a population-based, retrospective cohort study using clinical surveillance, administrative and laboratory databases to determine the predictors of 30-day all-cause and attributable mortality and length of stay; a propensity score-matched study to compare patients with HA-CDI to patients without CDI to determine the attributable cost of HA-CDI in Alberta; and a cost-effectiveness analysis using decision analytic modelling to evaluate the costs and consequences related to probiotic use for the primary prevention of CDI. We found that the incidence and mortality rates of HA-CDI are declining, though the latter was not statistically significant. Advancing age was associated with all outcomes after adjusting for a number of baseline factors. Increased baseline white blood cell counts were associated with a lower risk of mortality. Hospital-acquired CDI total adjusted costs were 27% higher and length of stay was 13% higher than non-cases of CDI. Oral probiotics as a preventive strategy for CDI resulted in a lower risk of CDI and cost-savings. Previous studies on the burden of HA-CDI have been limited in their size and scope. Our first study was the largest population-based cohort study evaluating predictors of mortality; while our second study was the first to use propensity score-matching and a micro-costing approach for the estimation of costs associated with HA-CDI. We were the first to conduct an economic evaluation of probiotics for the primary prevention of CDI. This work will be presented to Alberta Health Services to support the evaluation of probiotics as a preventive strategy against CDI and whether to scale up probiotics to all provincial hospitals.Item Open Access Derivation and Internal Validation of a Prediction Model for Hand Fracture Referral Among Pediatric Patients(2019-06-18) Hartley, Rebecca Lauren; Ronksley, Paul Everett; Faris, Peter D.; Fraulin, Frankie O. G.; Harrop, Alan RobertsonPediatric hand fractures are common however, which fractures should be referred for specialist care remains unclear. This thesis aimed to develop a prediction model to identify which acute pediatric hand fractures required referral to a hand surgeon. Data was collected on consecutively referred pediatric hand fractures to a plastic surgery clinic over two years. The primary outcome was necessary referral, defined as fractures that required surgery, closed reduction or more than four appointments. Multivariable logistic regression with bootstrapping was used to derive and internally validate a model, which was then translated into a risk index. Of 1,173 fractures, 417 (35.6%) met criteria for a necessary referral. The multivariable model identified six significant predictors: angulation, condylar involvement, dislocation or subluxation, displacement, open fractures, and rotation and had strong performance (C-statistic 0.88). The risk index, with a threshold 1 point, had a sensitivity of 96.4% and specificity of 45.5%. A simple prediction model was developed to identify which acute pediatric hand fractures required referral to a hand surgeon. While these results require external validation prior to clinical use, this tool may help identify high risk patients and allow for targeted referral.Item Open Access Development of a Clinical Care Pathway for Patients with Suspected Acute Coronary Syndromes in the Emergency Department(2020-04-30) O'Rielly, Connor M.; McRae, Andrew D.; Ronksley, Paul Everett; Andruchow, James E.; Sajobi, Tolulope T.Chest pain is a predominant reason for emergency department (ED) visits and hospitalizations in Canada. ED physicians use diagnostic tools (e.g., biomarkers) to identify patients with myocardial infarction (MI) requiring intervention, and prognostic tools (e.g., risk scores) to determine which patients without MI are eligible for discharge. While clinical guidelines recommend that these two portions of the assessment occur sequentially, the evidence for each has emerged in isolation. There is also a paucity of evidence on risk score use in the era of high-sensitivity cardiac troponin (hs-cTn) assays, adverse event risk factors for patients without MI, and appropriate timelines for follow-up. This project had three complimentary objectives: (1) Synthesize available evidence on prognostic prediction score performance when hs-cTn assays are incorporated; (2) Quantify the time course of major adverse cardiac events (MACE) in patients without index MI and identify characteristics with potential predictive value for MACE, and; (3) Develop a sequential clinical pathway for the assessment of chest pain in the ED and measure the impacts on diagnostic and prognostic accuracy as well as ED patient flow. A systematic review was conducted to synthesize evidence on the chest pain risk scores to be prioritized for integration into the clinical pathway. A time-to-event analysis was then conducted to measure timing of MACE in patients without index MI, as well as a stratified analysis to identify characteristics with predictive value for 30-day MACE to be used in the pathway for clinical stratification. Trial clinical pathways were developed and quantitatively compared. Pathways combined a validated 2-hour hs-cTn diagnostic algorithm with variable clinical pre-stratification, risk score types, and low-risk cut-offs. A sequential clinical pathway using a validated hs-cTn algorithm and the HEART score can identify nearly 40% of ED chest pain patients as eligible for discharge without the need for further testing with no missed MI or 30-day MACE. This thesis project contributed evidence necessary for the updating and advancing of the ED chest pain assessment and presents an evidence-based sequential clinical pathway that maximizes the efficiency of the ED chest pain assessment.Item Open Access The Development of Patient Safety Indicators for Critically Ill Patients Admitted to the Intensive Care Unit(2020-07-09) Wu, Guosong; Stelfox, Henry Thomas; Wu, Qunhong; Quan, Hude; Ronksley, Paul Everett; Holroyd-Leduc, Jayna M.Patient safety is a top priority in critical care. Patient safety indicators (PSIs) have been developed to measure critical care safety. Despite several approaches have been used to develop PSIs (deductive, inductive, and joint approach), PSIs are widely applied to measure the care performance in Intensive Care Units (ICUs). The overall objective of this thesis was to use a joint approach to develop a PSI that can be used to evaluate the safety of critical care and to assess the reliability and validity of this PSI. Three studies were conducted to achieve this objective. In the first study, we systematically reviewed the literature of PSIs proposed for patients admitted to an ICU. Heterogeneity of PSI definitions were observed. Among 44 unique PSIs identified from 21 studies, reliability and validity of four PSIs was only reported in one study. In the second study, a panel of ICU experts evaluated the 44 unique PSIs identified in our systematic review. The expert panel proposed an additional 20 PSIs and, during a second round, evaluated and prioritized the 64 PSIs using a modified RAND Appropriateness Method. The top ten ranked PSIs included clinically important concepts that had data available in a local electronic database. This included patient falls, which we investigated in our final study. In the third study, we constructed a fall risk predictive model leveraging provincial electronic medical record (EMR) and examined its reliability and validity. Overall, fall incidence rate was 1.55 (95% CI 1.36-1.76) per 1,000 patient days. The model displayed an excellent discrimination (AUC 0.82) and calibration. We propose the definition of Risk-adjusted Standardized Fall Rate (RSFR) to compared critical care performance across sites and overtime in order to test effectiveness of quality improvement strategies. RSFR demonstrates good test re-test reliability (r=0.662) and construct validity (r=0.533). The study proposed PSI for patient falls was developed from a comprehensive systematic review of the literature, structured expert panel review of candidate PSIs, and validated using a local EMR database. The main findings of this thesis support RSFR could be measured and monitored provincially or nationally to benchmark critical care safety performance.Item Open Access Enhancing Self-management Support for Adults with Chronic Kidney Disease: A Person-centered, Theory-informed Approach(2019-11) Donald, Maoliosa; Hemmelgarn, Brenda; Beanlands, Heather J.; Ronksley, Paul Everett; Straus, Sharon E.Strategies to support patients to self-manage their chronic kidney disease (CKD) have been identified as one of the top 10 kidney research priorities internationally. Recognizing that this research priority is key to delivering person-centered care, this thesis examines enhancing adult CKD self-management support using patient-centered and theoretical approaches. We conducted three sequential studies: a scoping review to identify and describe self-management interventions for adult patients with CKD; a descriptive qualitative study to identify the needs of adults with CKD and their caregivers based on their experiences with managing CKD; and a one-day consensus workshop using personas to determine the preferences for content and features for a CKD patient self-management electronic health (eHealth) tool. We found a lack of patient engagement and application of behaviour change theories in the development of CKD self-management interventions. In addition, we identified the needs of patients and their caregivers regarding areas of knowledge, information sharing, and relevant supports for self-management in early stages of CKD. Patients, caregivers, health care professionals, and policy makers provided detailed subject matter for CKD topic areas, as well as preferred features to consider for a novel approach to supporting CKD self-management. This thesis work is pragmatic, as well as innovative in nature. To our knowledge, this is the first multi-phase study to meaningfully engage patients with CKD and caregivers as patient partners. Their involvement went beyond the role of consultation, where they actively participated in informing all phases of the research. To enhance CKD self-management support, our work offers evidence to inform the co-development of a tailored self-management support intervention for adults with CKD and their informal caregivers in Canada.Item Open Access Hospitalization Costs of Canadian Cystic Fibrosis Patients(2020-09-29) Skolnik, Kate; Williamson, Tyler S.; Quon, Bradley S.; Pendharkar, Sachin R.; Ronksley, Paul EverettIntroduction: Cystic fibrosis (CF) is a genetic disease that can lead to significant morbidity. As the CF population increases and treatment regimens escalate in complexity, CF care costs are expected to rise and could put tremendous strain on health care systems. Our aim was to examine the hospitalization costs of Canadian CF patients. Methods: We performed an analysis of annual CF hospital costs for the 2014 fiscal year using a public payer perspective. Secondary objectives were to examine differences in annual hospital costs for Canadian CF patients (1) by patient characteristics, (2) between provinces, and (3) over time (from 2010 to 2014). Record level data were obtained from the Canadian Institute for Health Information databases. CF patients were defined based on at least one hospital admission with an ICD-10 code of E84. Costs were estimated using a case-mix aggregate costing strategy. Results: In 2014, 953 of 2,702 (35%) Canadians with CF had 1,705 hospitalizations resulting in a total cost of $32.1 million. Mean hospital cost per patient and mean cost per hospitalization were $34,982 and $19,782, respectively. There were no differences in mean cost per hospitalization by age or sex. Mean cost per hospitalization was highest among those admitted for pneumothorax ($22,685), followed by CF pulmonary exacerbation ($21,130) and distal intestinal obstruction syndrome ($18,816). The mean cost per hospitalization was highest for Alberta ($25,229) and lowest for NB ($10,734). Between 2010 and 2014, the total cost of all hospitalizations for CF patients increased by 17% ($27.4 to $32.1 million). Conclusion: Canadian CF hospitalizations are costly; these costs vary by type of admitting diagnosis and are increasing over time. These national estimates will inform health care planning as well as future cost effectiveness analyses for CF interventions.Item Open Access The Human Microbiome: Implications for Health and Disease(2018-09-10) Missaghi, Bayan; Barkema, Herman Wildrik; Kaplan, Gilaad G.; Ronksley, Paul EverettThe human microbiome is the collective genome of native microbial flora that have evolved with us over millennia and which are typically consistent, despite geographic, ethnic and dietary differences around the globe. Studies have revealed that agitation to the normal development of the microbiome during the first year of life, such as with antimicrobial use, can lead to atrophy later on, resulting in the development of autoimmune diseases such as inflammatory bowel disease (IBD). Moreover, dysbioses, such as those seen with Clostridium difficile infection (CDI), have an accelerated deleterious effect on patients who have already developed inflammatory bowel disease, potentially resulting in life-threatening complications, including ileus, toxic megacolon, and death. We composed a review article which presents an outline of the loss of a normal microbiome as an etiology of immune dysregulation and IBD pathogenesis initiation. Moreover, we summarized the knowledge base with respect to the role of a healthy microbiome in terms of its diversity and important functional elements, and synopsized some of the therapeutic interventions and modalities that are being explored as potential applications of microbiome-host interactions. Additionally, we conducted a systematic review of the literature and a meta-analysis in order to clarify the risk of colectomy among the subset of IBD patients with ulcerative colitis (UC) subsequent to their development of CDI. We determined that UC patients with CDI are indeed at an increased risk of colectomy relative to their counterparts without CDI, but that future better quality prospective studies, ideally with a population-based approach and with long term follow-up of outcomes, would be helpful to better evaluate this potential relationship under different circumstances.Item Open Access Trajectories of Kidney Function in Children with Reduced Kidney Function(2018-05-18) Kahlon, Bhavneet Kaur; Samuel, Susan M.; James, Matthew T.; Pacaud, Danièle Le; Ronksley, Paul Everett; Hagel, Brent EdwardLittle is known about the progression of chronic kidney disease (CKD) during the emerging adulthood period in patients with pediatric onset CKD cared for in primary care. We performed a retrospective cohort study using administrative data from The Health Improvement Network Database to determine the natural history of CKD, the impact of the emerging adulthood period, and the effects of comorbidities including mental health disorders, substance use, and pregnancy on CKD progression. We identified 15,679 patients who met cohort inclusion criteria. We found that kidney function measured using the estimated glomerular filtration rate (eGFR) increased with increasing age. Emerging adulthood was associated with an attenuation in this increase in eGFR. Finally, the presence of mental health disorders, substance use, and pregnancy modified the relationship between age and eGFR resulting in a small, but statistically significant acceleration in the eGFR increase over age, but were associated with lower baseline eGFR.Item Open Access Unmet Health Care Needs and Adverse Outcomes for Patients with Chronic Disease(2013-03-06) Ronksley, Paul Everett; Hemmelgarn, BrendaChronic medical conditions such as diabetes, hypertension, and heart disease are common in Canada and often occur together. Despite the availability of effective treatments, many Canadians do not receive optimal care for these conditions. This may be due to a number of factors, including reduced access to health services. The overall objective of this thesis was to improve knowledge of barriers to care and their association with adverse outcomes among patients with chronic disease. We conducted three independent studies to address this objective. Our first study provides a national perspective on the potential gaps in care for Canadians with chronic disease. Using population-based survey data we found that 1 in 7 adults with chronic disease report a perceived unmet health care need – a commonly used indicator of limited access to care. Participants with multiple chronic conditions (multi-morbidity) were more likely to report a barrier to care. Furthermore, the most commonly reported reasons for an unmet need were related to service wait times and resource availability. By linking national survey and administrative data, our second study explored whether these perceived barriers to care were associated with adverse health outcomes. Unmet health care need was not associated with an increased risk of hospitalization when studied in aggregate form. However, when stratified by unmet need type, adults reporting barriers related to resource availability had an increased risk of all-cause hospitalization compared to those without. Our final study examined factors related to health system use and their association with adverse outcomes. Using provincial administrative data, specific patterns of health resource use and discharge disposition were associated with increased risk of subsequent hospitalization after discharge among patients with diabetes. Despite a universal health care system, gaps in care for patients with chronic medical conditions remain. Although our findings highlight a number of potentially modifiable gaps in chronic disease care, further understanding of the concept of unmet health care need and the various factors that influence it are required. This may inform areas for future intervention aimed at enhancing and improving management for those living with chronic medical conditions.Item Open Access Using machine learning methods to improve chronic disease case definitions in primary care electronic medical records(2018-04-23) Lethebe, Brendan Cord; Williamson, Tyler S.; Sajobi, Tolulope T.; Quan, Hude; Ronksley, Paul EverettBackground: Chronic disease surveillance at the primary care level is becoming more feasible with the increased use of electronic medical records (EMRs). However, the quality of surveillance information is directly dependent on the quality of the case definitions that identify the conditions of interest. Purpose: To determine whether machine learning algorithms can produce chronic disease case definitions comparable to committee created case definitions in a primary care EMR setting. Methods: A chart review was conducted for the presence of hypertension, diabetes, osteoarthritis, and depression in a cohort of 1920 patients from the Canadian Primary Care Sentinel Surveillance Network database. The results of this chart review were used as training data. The C5.0, Classification and Regression Tree, Chi-Squared Automated Interaction Detection decision trees, Forward Stepwise logistic regression, Least Absolute Shrinkage and Selection Operator penalized logistic regression were compared using 10-fold cross validation. Sensitivity, specificity, positive predictive value and negative predictive value were estimated and compared for the four chronic conditions of interest. Results: Validity measures were similar across algorithms. For hypertension, sensitivity ranged between 93.1-96.7%, while specificity ranged from 88.8-93.2%. For diabetes, sensitivities ranged from 93.5-96.3% with specificities between 97.1-99.0%. For osteoarthritis, sensitivities ranged from 82.0-84.4% with specificities between 92.7-94.0%. For depression, sensitivities went from 81.4-88.3%, and specificities ranged from 93.4-94.9%. Compared with the committee-created case definitions, these metrics were equivalent or better using the machine learning method. Conclusions: Machine learning algorithms produced accurate case definitions comparable to committee-created case definitions. It is possible to use machine learning techniques to develop high quality case definitions from EMR data.