Browsing by Author "de Koning, Lawrence"

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    A pragmatic randomized controlled trial of rapid on-site influenza and respiratory syncytial virus PCR testing in paediatric and adult populations
    (2022-11-16) Bibby, Helen L.; de Koning, Lawrence; Seiden-Long, Isolde; Zelyas, Nathan; Church, Deirdre L.; Berenger, Byron M.
    Abstract Background Rapid/point-of-care respiratory virus nucleic acid tests (NAT) may improve oseltamivir, antibiotic, diagnostic test, and hospital bed utilization. Previous randomized controlled trials (RCT) on this topic have not used standard procedures of an accredited healthcare and laboratory system. Methods We conducted a parallel RCT at two hospitals [paediatric = Alberta Children’s Hospital (ACH); primarily adult = Peter Lougheed Centre (PLC)]. Patients with a respiratory viral testing order were randomized to testing at either a central accredited laboratory (standard arm) or with a rapid polymerase chain reaction test at an on-site accredited laboratory followed by standard testing [rapid on-site test (ROST) arm] based on day of specimen receipt at the laboratory. Patients and clinicians were blinded to assignment. The primary outcome for ACH was inpatient length of stay (LOS) and for PLC was the proportion of inpatients prescribed oseltamivir. Results 706 patient encounters were included at ACH; 322 assigned to ROST (181 inpatients) and 384 to the standard arm (194 inpatients). 422 patient encounters were included at PLC; 200 assigned to ROST (157 inpatients) and 222 to the standard arm (175 inpatients). The rate of oseltamivir prescription and number of doses given was reduced in PLC inpatients negative for influenza in the ROST arm compared to standard arm [mean 14.9% (95% CI 9.87–21.9) vs. 27.5% (21.0–35.2), p = 0.0135; mean 2.85 doses (SEM 2.39–3.32) vs. 4.17 doses (3.85–4.49) p = 0.022, respectively]. ROST also significantly reduced oseltamivir use at ACH, reduced chest radiographs (ACH), and laboratory test ordering (PLC), but not antibiotic prescriptions. ROST also reduced the median turnaround time by > 24 h (ACH and PLC). The LOS at ACH was not significantly different between the ROST and standard arms [median 4.05 days (SEM 1.79–18.2) vs 4.89 days (2.07–22.9), p = 0.062, respectively]. No adverse events were reported. Conclusions In a RCT representing implementation of ROST in an accredited laboratory system, we found that a ROST improved oseltamivir utilization and is the first RCT to show reduced ancillary testing in both paediatric and adult populations. A larger study is required to assess reduction in paediatric LOS as ACH was underpowered. These findings help justify the implementation of rapid on-site respiratory virus testing for inpatients. Trial registration ISRCTN, number 10110119, Retrospectively Registered, 01/12/2021.
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    Refined Prognostication in Coronary Artery Disease Using Routine Laboratory Test Data
    (2016) Gerling, Michael; de Koning, Lawrence; James, Matthew; Naugler, Christopher; Wilton, Stephen
    Coronary artery disease (CAD) is a leading cause of morbidity and mortality. Numerous prognostic scores have been developed that rely on clinical information to predict risk of adverse outcomes and subsequently aid clinicians in determining appropriate intervention strategies. This thesis examines the ability of laboratory test data, including the complete blood count (CBC), electrolytes, estimated glomerular filtration rate (eGFR), and 25-OH vitamin D, to improve prognostic assessment in CAD patients beyond existing clinical risk factors. Although 25-OH vitamin D status was found to be inversely associated with mortality, it was neither associated with nor predictive of hospital readmission, and provided little additional prognostic information beyond existing risk factors. Conversely, a risk score derived from components of the CBC, electrolytes, and eGFR, in conjunction with age and sex, was strongly predictive of mortality, and led to considerable improvement in the ability to identify high-risk patients beyond existing risk factors.
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    Risk Prediction of Acute Kidney Injury Following, Major, Non-Cardiac Surgery
    (2016) Wilson, Todd; James, Matthew; de Koning, Lawrence; Quinn, Rob; Zarnke, Kelly
    Acute kidney injury (AKI) is a serious complication of major, non-cardiac surgery. Risk prediction models for AKI may be useful for informed consent processes and to identify high-risk patients to target with perioperative prevention and early intervention strategies. This thesis includes a systematic review of published prediction models for AKI following, major, non-cardiac surgery. Although seven models were identified, most were derived in small, single center cohorts, and none were externally validated. The second part of the thesis reports derivation and internal validation of five risk prediction models and a risk index based on readily available preoperative variables for predicting severe AKI requiring dialysis after major, non-cardiac surgery. The final risk index showed excellent discrimination (c-statistic 0.89) and was well calibrated. Further research to externally validate this risk index and evaluate the clinical impact of its use is needed to establish its role in perioperative care.
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    Survey of the initial management of celiac disease antibody tests by ordering physicians
    (2019-07-19) Potter, Kathryn; de Koning, Lawrence; Butzner, J. D; Gidrewicz, Dominica
    Abstract Background Appropriate interpretation of a positive celiac antibody test by an ordering physician is important in order to institute proper management. We evaluated why children with an initial positive celiac serology were not referred for diagnostic biopsy or followed with serial testing by the ordering physician. Methods Consecutive celiac serologies in all patients less than 18 years of age were evaluated over 3.5 years and 775 children with a positive tissue transglutaminase antibody (TTG) were identified. If no management of a positive TTG could be identified, a survey was sent to the ordering physician. Responses were categorized as appropriate or inappropriate management. Results Of the 775 patients with a positive TTG, 193 (24.9%, 95% CI 21.9–28.1%) received no follow-up management. We contacted 173 ordering physicians and 120 (69%) responded. Of the 120 responses, 55 patients (45.8%, 95% CI 36.8–55.1%) were managed appropriately and 46 (38.3%, 95% CI 29.7–47.7%) were considered to be inappropriately managed when no repeat TTG was obtained within 18 months. Reasons for inappropriate management included: screen considered to be false positive (44.7%), patient was not experiencing symptoms of celiac disease (31.6%), symptoms had resolved (15.8%), results were not indicative of celiac disease (26.3%) and patients started a gluten-free diet with no evaluation of response (15.8%). In 19 patients the TTG was not acted upon for technical reasons. Conclusions Positive TTGs require appropriate interventions. These include: subspecialist referral for further evaluation and/or repeat testing to evaluate: 1) treatment response or 2) patients with minimal or no symptoms.