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1.  Simulation as a New Tool to Establish Benchmark Outcome Measures in Obstetrics 
PLoS ONE  2015;10(6):e0131064.
There are not enough clinical data from rare critical events to calculate statistics to decide if the management of actual events might be below what could reasonably be expected (i.e. was an outlier).
In this project we used simulation to describe the distribution of management times as an approach to decide if the management of a simulated obstetrical crisis scenario could be considered an outlier.
Twelve obstetrical teams managed 4 scenarios that were previously developed. Relevant outcome variables were defined by expert consensus. The distribution of the response times from the teams who performed the respective intervention was graphically displayed and median and quartiles calculated using rank order statistics.
Only 7 of the 12 teams performed chest compressions during the arrest following the ‘cannot intubate/cannot ventilate’ scenario. All other outcome measures were performed by at least 11 of the 12 teams. Calculation of medians and quartiles with 95% CI was possible for all outcomes. Confidence intervals, given the small sample size, were large.
We demonstrated the use of simulation to calculate quantiles for management times of critical event. This approach could assist in deciding if a given performance could be considered normal and also point to aspects of care that seem to pose particular challenges as evidenced by a large number of teams not performing the expected maneuver. However sufficiently large sample sizes (i.e. from a national data base) will be required to calculate acceptable confidence intervals and to establish actual tolerance limits.
PMCID: PMC4480859  PMID: 26107661
2.  Infectious Disease Exposures and Contact Tracing in Homeless Shelters 
An outbreak among homeless shelter users of a communicable disease with a short generation time would pose serious public health challenges. Data from Toronto were used to examine the number of shelter residents potentially exposed in the event of such an outbreak. A shelter user had contact with a mean of 97 other residents (range, 1–292) in one day and a mean of 120 (range, 2–624) in eight days. After a single week, contact tracing becomes difficult due to the challenge of locating homeless people who have left the shelter system. Over an 8-day period, individuals who used more than one shelter had contact with an average of 98 more other shelter residents than those who stayed in a single shelter had. At the onset of a serious outbreak, it may be desirable to institute policies that strongly encourage individuals to remain at their current shelter for the duration of the outbreak.
PMCID: PMC4465825  PMID: 19029743 CAMSID: cams4738
Homeless people; disease outbreaks; contact tracing
3.  Normal Values for Segmental Bioimpedance Spectroscopy in Pediatric Patients 
PLoS ONE  2015;10(4):e0126268.
Localized limb edema is a clinically relevant sign in diseases such as post-thrombotic syndrome and lymphedema. Quantitative evaluation of localized edema in children is mainly done by measuring the absolute difference in limb circumference, which includes fat and fat-free mass. Bioimpedance spectroscopy (BIS) provides information on the fluid volume of a body segment. Our objective was to determine normal ranges for segmental (arm and leg) BIS measurements in healthy children. Additionally, we determined the normal ranges for the difference in arm and ankle circumference and explored the influence of handedness and the correlation between techniques.
Healthy children aged 1-18 years were recruited. The ratio of extracellular fluid content between contralateral limbs (estimated as the inter-arm and inter-leg extracellular impedance ratio), and the ratio of extracellular to intracellular fluid content for each limb (estimated as the intracellular to extracellular impedance ratio) were determined with a bioimpedance spectrometer. Arm and ankle circumference was determined with a Gulick II tape.
We recruited 223 healthy children (48 infants, 54 preschoolers, 66 school-aged children, and 55 teenagers). Normal values for arm and leg BIS measurements, and for the difference in arm and ankle circumference were estimated for each age category. No influence of handedness was found. We found a statistically significant correlation between extracellular impedance ratio and circumference difference for arms among teenagers.
We determined normal BIS ranges for arms and legs and for the difference in circumference between arms and between ankles in children. There was no statistically significant correlation between extracellular impedance ratio and difference in circumference, except in the case of arms in adolescents. This may indicate that limb circumference measures quantities other than fluid, challenging the adequacy of this technique to determine the presence of localized edema in most age groups.
PMCID: PMC4395226  PMID: 25875618
4.  Surveillance patterns after curative-intent colorectal cancer surgery in Ontario 
Despite improvements in screening, diagnosis, treatment and surveillance follow-up of colorectal cancer patients over the past 20 years, a significant proportion of individuals who undergo curative-intent treatment experience recurrence within five years. However, due to existing guideline differences and limited supporting data, postoperative surveillance is variably performed. This retrospective cohort study, performed in Toronto, Ontario, used information from several databases and provides insight to the care patients receive in the presence of conflicting guidelines and the mixed results reported in similar studies.
Postoperative surveillance following curative-intent resection of colorectal cancer (CRC) is variably performed due to existing guideline differences and to the limited data supporting different strategies.
To examine population-based rates of surveillance imaging and endoscopy in patients in Ontario following curative-intent resection of CRC with no evidence of recurrence, as well as patient or disease factors that may predispose certain groups to more frequent versus less frequent surveillance; to provide insight to the care patients receive in the presence of conflicting guidelines, in efforts to help improve care of CRC survivors by identifying any potential underuse or overuse of particular surveillance modalities, or inequalities in access to surveillance.
A retrospective cohort study was conducted using data from the Ontario Cancer Registry and several linked databases. Ontario patients undergoing curative-intent CRC resection from 2003 to 2007 were identified, excluding patients with probable disease relapse. In the five-year period following surgery, the number of imaging and endoscopic examinations was determined.
There were 4960 patients included in the study. Over the five-year postoperative period, the highest proportion of patients who underwent postoperative surveillance received the following number of tests for each modality examined: one to three abdominopelvic computed tomography (CT) scans (n=2073 [41.8%]); one to three abdominal ultrasounds (n=2443 [49.3%]); no chest CTs, one to three chest x-rays (n=2385 [48.1%]); and two endoscopies (n=1845 [37.2%]). Odds of not receiving any abdominopelvic imaging (CT or abdominal ultrasound) were higher in those who did not receive adjuvant chemo-therapy (OR 6.99 [95% CI 5.26 to 9.35]) or those living in certain geographical areas, but were independent of age, sex and income. Nearly all patients (n=4473 [90.2%]) underwent ≥1 endoscopy at some point during the follow-up period.
In contrast to findings from similar studies in other jurisdictions, most Ontario CRC survivors receive postoperative surveillance with imaging and endoscopy, and care is equitable across sociodemographic groups, although unexplained geographical variation in practice exists and warrants further investigation.
PMCID: PMC4210233  PMID: 25014181
Colorectal adenocarcinoma; Curative-intent surgery; Postoperative imaging; Surgery; Surveillance
5.  Expanding Paramedicine in the Community (EPIC): study protocol for a randomized controlled trial 
Trials  2014;15:473.
The incidence of chronic diseases, including diabetes mellitus (DM), heart failure (HF) and chronic obstructive pulmonary disease (COPD) is on the rise. The existing health care system must evolve to meet the growing needs of patients with these chronic diseases and reduce the strain on both acute care and hospital-based health care resources. Paramedics are an allied health care resource consisting of highly-trained practitioners who are comfortable working independently and in collaboration with other resources in the out-of-hospital setting. Expanding the paramedic’s scope of practice to include community-based care may decrease the utilization of acute care and hospital-based health care resources by patients with chronic disease.
This will be a pragmatic, randomized controlled trial comparing a community paramedic intervention to standard of care for patients with one of three chronic diseases. The objective of the trial is to determine whether community paramedics conducting regular home visits, including health assessments and evidence-based treatments, in partnership with primary care physicians and other community based resources, will decrease the rate of hospitalization and emergency department use for patients with DM, HF and COPD. The primary outcome measure will be the rate of hospitalization at one year. Secondary outcomes will include measures of health system utilization, overall health status, and cost-effectiveness of the intervention over the same time period. Outcome measures will be assessed using both Poisson regression and negative binomial regression analyses to assess the primary outcome.
The results of this study will be used to inform decisions around the implementation of community paramedic programs. If successful in preventing hospitalizations, it has the ability to be scaled up to other regions, both nationally and internationally. The methods described in this paper will serve as a basis for future work related to this study.
Trial registration NCT02034045. Date: 9 January 2014.
Electronic supplementary material
The online version of this article (doi:10.1186/1745-6215-15-473) contains supplementary material, which is available to authorized users.
PMCID: PMC4289358  PMID: 25467772
Randomized controlled trial; Community health services; Primary health care; Allied health personnel
6.  A Comprehensive Assessment of Health Care Utilization among Homeless Adults under a System of Universal Health Insurance 
American journal of public health  2013;103(0 2):S294-S301.
To comprehensively assess health care utilization in a population-based sample of homeless adults compared to matched controls under a system of universal health insurance.
Health care utilization was assessed for 1,165 homeless single adult men, single adult women, and adults in families and their age- and sex-matched low-income controls in Toronto, Canada from 2005-2009. Repeated measures general linear models (GLM) were used to calculate risk ratios and 95% confidence intervals.
Homeless participants had mean rates of 9.1 ambulatory care encounters (maximum=141.1), 2.0 emergency department encounters (maximum=104.9), 0.2 medical/surgical hospitalizations (maximum=14.9), and 0.1 psychiatric hospitalizations per person-year (maximum=4.8). Rate ratios comparing homeless participants to matched controls were 1.76 (95% CI: 1.58-1.96) for ambulatory care encounters, 8.48 (95% CI: 6.72-10.70) for emergency department encounters, 4.22 (95% CI: 2.99-5.94) for medical/surgical hospitalizations, and 9.27 (95% CI: 4.42-19.43) for psychiatric hospitalizations.
Within a system of universal health insurance, homeless people have substantially higher rates of emergency department and hospital use compared to general population controls. These differences are largely driven by the subset of homeless persons who are extremely high-intensity users of health services.
PMCID: PMC3969141  PMID: 24148051
Health care utilization; Homeless persons; Matched controls; Ambulatory care; Hospitalization
7.  Predictors of Medical/surgical and Psychiatric Hospitalizations among a Population-based Cohort of Homeless Adults 
American journal of public health  2013;103(0 2):S380-S388.
To identify factors associated with inpatient hospitalizations among a population-based cohort of homeless adults in Toronto, Canada.
Participants were linked to administrative databases to capture hospital admissions during the study period (2005–2009). Logistic regression was used to identify predictors of medical/surgical and psychiatric hospitalizations.
Among 1,165 homeless adults, 20% had a medical/surgical hospitalization and 12% had a psychiatric hospitalization during the study period. These individuals contributed a total of 921 hospitalizations, of which 548 were medical/surgical and 373 were psychiatric. Independent predictors of medical/surgical hospitalization included birth in Canada, having a primary care provider, higher perceived external health locus of control, and lower health status. Independent predictors of psychiatric hospitalization included being a current smoker, having a recent mental health problem, and having a lower perceived internal health locus of control. Being accompanied by a partner or dependent children was protective for hospitalization.
Health care need was a strong predictor of medical/surgical and psychiatric hospitalizations. Some hospitalizations among homeless adults are potentially avoidable, while others represent an unavoidable use of health services.
PMCID: PMC3969145  PMID: 24148040
Hospitalization; Homeless persons; Health care utilization
8.  High Utilizers of Emergency Health Services in a Population-based Cohort of Homeless Adults 
American journal of public health  2013;103(0 2):S302-S310.
To identify predictors of emergency department (ED) use among a population-based prospective cohort of homeless adults in Toronto, Canada.
ED visit rates were assessed using administrative data (2005-2009). Logistic regression was used to identify predictors of ED use. Frequent users were defined as participants with rates in the top decile (≥4.7 visits per person-year).
Among 1,165 homeless adults, 892 (77%) had at least one ED visit during the study period. The average rate of ED visits was 2.0 visits/person-year, while frequent users averaged 12.1 visits/person-year. Frequent users accounted for 10% of the sample but contributed over 60% of visits. Predictors of frequent use in adjusted analyses included birth in Canada, higher monthly income, lower health status, perceived unmet mental health needs, and perceived external health locus of control from powerful others; being accompanied by a partner and/or dependent children had a protective effect on frequent use.
Among homeless adults with universal health insurance, a small subgroup accounts for the majority of visits to emergency services. Frequent use was driven by multiple predisposing, enabling, and need factors.
PMCID: PMC3969147  PMID: 24148033
Health care utilization; Emergency department; Homeless persons
9.  Eight years later: outcomes of CBT-treated versus untreated anxious children 
Brain and Behavior  2014;4(5):765-774.
Anxiety disorders are the most common psychiatric disorders of childhood, generate significant distress, are considered precursors to diverse psychiatric disorders, and lead to poor social and employment outcomes in adulthood. Although childhood anxiety has a significant impact on a child's developmental trajectory, only a handful of studies examined the long-term impact of treatment and none included a control group. The aim of this study was to conduct a long-term follow-up (LTFU) of anxious children who were treated with Cognitive–Behavioral Therapy (CBT) compared to a matched group of children who were not.
Subjects comprised 120 children: a treatment group which included the first 60 consecutive consenting children who were diagnosed with an anxiety disorder and treated with CBT between the years 1997 and 2003 and a control group, 60 matched children who were assessed but not treated with CBT. An “ex-post-facto” design was used to compare the two groups.
Children showed lower rates of anxiety diagnosis (about 50% for both groups) and significantly improved functioning at LTFU (time effect P < 0.0001; no group difference). Anxiety levels were significantly lower in the nontreatment group at LTFU as compared to initial assessment (P = 0.02), but not in the treatment group, and a significant between-group difference was found (P = 0.01) according to child. An inverse relationship was found between self-efficacy/self-esteem and anxiety outcome ([P = 0.0008] and [P = 0.04], respectively).
This study supports the assumption that childhood anxiety disorders may improve without treatment and highlights self-efficacy/self-esteem as potential factors in recovery.
PMCID: PMC4188368  PMID: 25328851
Adolescents; anxiety; children; cognitive–behavioral therapy; long-term follow-up; youth
10.  Medial open transversus abdominis plane (MOTAP) catheters for analgesia following open liver resection: study protocol for a randomized controlled trial 
Trials  2014;15:241.
The current standard for pain control following liver surgery is intravenous, patient-controlled analgesia (IV PCA) or epidural analgesia. We have developed a modification of a regional technique called medial open transversus abdominis plane (MOTAP) catheter analgesia. The MOTAP technique involves surgically placed catheters through the open surgical site into a plane between the internal oblique muscle and the transverse abdominis muscle superiorly. The objective of this trial is to assess the efficacy of this technique.
This protocol describes a multicentre, prospective, blinded, randomized controlled trial. One hundred and twenty patients scheduled for open liver resection through a subcostal incision will be enrolled. All patients will have two MOTAP catheters placed at the conclusion of surgery. Patients will be randomized to one of two parallel groups: experimental (local anaesthetic through MOTAP catheters) or placebo (normal saline through MOTAP catheters). Both groups will also receive IV PCA. The primary endpoint is mean cumulative postoperative opioid consumption over the first 2 postoperative days (48 hours). Secondary outcomes include pain intensity, patient functional outcomes, and the incidence of complications.
This trial has been approved by the ethics boards at participating centres and is currently enrolling patients. Data collection will be completed by the end of 2014 with analysis mid-2015 and publication by the end of 2015.
Trial registration
The study is registered with ( NCT01960049; 23 September 2013)
PMCID: PMC4078361  PMID: 24950773
Liver surgery; Analgesia; Transversus abdominis plane; Randomized controlled trial
11.  A Direct Morphometric Comparison of Five Labeling Protocols for Multi-Atlas Driven Automatic Segmentation of the Hippocampus in Alzheimer’s Disease 
NeuroImage  2012;0:50-70.
Hippocampal volumetry derived from structural MRI is increasingly used to delineate regions of interest for functional measurements, assess efficacy in therapeutic trials of Alzheimer’s disease (AD) and has been endorsed by the new AD diagnostic guidelines as a radiological marker of disease progression. Unfortunately, morphological heterogeneity in AD can prevent accurate demarcation of the hippocampus. Recent developments in automated volumetry commonly use multitemplate fusion driven by expert manual labels, enabling highly accurate and reproducible segmentation in disease and healthy subjects. However, there are several protocols to define the hippocampus anatomically in vivo, and the method used to generate atlases may impact automatic accuracy and sensitivity – particularly in pathologically heterogeneous samples. Here we report a fully automated segmentation technique that provides a robust platform to directly evaluate both technical and biomarker performance in AD among anatomically unique labeling protocols. For the first time we test head-to-head the performance of five common hippocampal labeling protocols for multi-atlas based segmentation, using both the Sunnybrook Longitudinal Dementia Study and the entire Alzheimer’s Disease Neuroimaging Initiative 1 (ADNI-1) baseline and 24-month dataset. We based these atlas libraries on the protocols of (Haller et al., 1997; Killiany et al., 1993; Malykhin et al., 2007; Pantel et al., 2000; Pruessner et al., 2000), and a single operator performed all manual tracings to generate de facto “ground truth” labels. All methods distinguished between normal elders, mild cognitive impairment (MCI), and AD in the expected directions, and showed comparable correlations with measures of episodic memory performance. Only more inclusive protocols distinguished between stable MCI and MCI-to-AD converters, and had slightly better associations with episodic memory. Moreover, we demonstrate that protocols including more posterior anatomy and dorsal white matter compartments furnish the best voxel-overlap accuracies (Dice Similarity Coefficient = 0.87–0.89), compared to expert manual tracings, and achieve the smallest sample sizes required to power clinical trials in MCI and AD. The greatest distribution of errors was localized to the caudal hippocampus and alveus-fimbria compartment when these regions were excluded. The definition of the medial body did not significantly alter accuracy among more comprehensive protocols. Voxel-overlap accuracies between automatic and manual labels were lower for the more pathologically heterogeneous Sunnybrook study in comparison to the ADNI-1 sample. Finally, accuracy among protocols appears to significantly differ the most in AD subjects compared to MCI and normal elders. Together, these results suggest that selection of a candidate protocol for fully automatic multi-template based segmentation in AD can influence both segmentation accuracy when compared to expert manual labels and performance as a biomarker in MCI and AD.
PMCID: PMC3606906  PMID: 23142652
Automatic Hippocampal Segmentation; Multi-atlas; Alzheimer’s disease; Hippocampal Tracing Protocol
12.  Implementing wait-time reductions under Ontario government benchmarks (Pay-for-Results): a Cluster Randomized Trial of the Effect of a Physician-Nurse Supplementary Triage Assistance team (MDRNSTAT) on emergency department patient wait times 
Internationally, emergency departments are struggling with crowding and its associated morbidity, mortality, and decreased patient and health-care worker satisfaction. The objective was to evaluate the addition of a MDRNSTAT (Physician (MD)-Nurse (RN) Supplementary Team At Triage) on emergency department patient flow and quality of care.
Pragmatic cluster randomized trial. From 131 weekday shifts (8:00–14:30) during a 26-week period, we randomized 65 days (3173 visits) to the intervention cluster with a MDRNSTAT presence, and 66 days (3163 visits) to the nurse-only triage control cluster. The primary outcome was emergency department length-of-stay (EDLOS) for patients managed and discharged only by the emergency department. Secondary outcomes included EDLOS for patients initially seen by the emergency department, and subsequently consulted and admitted, patients reaching government-mandated thresholds, time to initial physician assessment, left-without being seen rate, time to investigation, and measurement of harm.
The intervention’s median EDLOS for discharged, non-consulted, high acuity patients was 4:05 [95th% CI: 3:58 to 4:15] versus 4:29 [95th% CI: 4:19–4:38] during comparator shifts. The intervention’s median EDLOS for discharged, non-consulted, low acuity patients was 1:55 [95th% CI: 1:48 to 2:05] versus 2:08 [95th% CI: 2:02–2:14]. The intervention’s median physician initial assessment time was 0:55 [95th% CI: 0:53 to 0:58] versus 1:21 [95th% CI: 1:18 to 1:25]. The intervention’s left-without-being-seen rate was 1.5% versus 2.2% for the control (p = 0.06). The MDRNSTAT subgroup analysis resulted in significant decreases in median EDLOS for discharged, non-consulted high (4:01 [95th% CI: 3:43–4:16]) and low acuity patients (1:10 95th% CI: 0:58–1:19]), as well as physician initial assessment time (0:25 [95th% CI: 0:23–0:26]). No patients returned to the emergency department after being discharged by the MDRNSTAT at triage.
The intervention reduced delays and left-without-being-seen rate without increased return visits or jeopardizing urgent care of severely ill patients.
Trial registration number
PMCID: PMC4225765  PMID: 24207160
13.  Diabetic status and the relation of the three domains of glycemic control to mortality in critically ill patients: an international multicenter cohort study 
Critical Care  2013;17(2):R37.
Hyperglycemia, hypoglycemia, and increased glycemic variability have each been independently associated with increased risk of mortality in critically ill patients. The role of diabetic status on modulating the relation of these three domains of glycemic control with mortality remains uncertain. The purpose of this investigation was to determine how diabetic status affects the relation of hyperglycemia, hypoglycemia, and increased glycemic variability with the risk of mortality in critically ill patients.
This is a retrospective analysis of prospectively collected data involving 44,964 patients admitted to 23 intensive care units (ICUs) from nine countries, between February 2001 and May 2012. We analyzed mean blood glucose concentration (BG), coefficient of variation (CV), and minimal BG and created multivariable models to analyze their independent association with mortality. Patients were stratified according to the diagnosis of diabetes.
Among patients without diabetes, mean BG bands between 80 and 140 mg/dl were independently associated with decreased risk of mortality, and mean BG bands >140 mg/dl, with increased risk of mortality. Among patients with diabetes, mean BG from 80 to 110 mg/dl was associated with increased risk of mortality and mean BG from 110 to 180 mg/dl with decreased risk of mortality. An effect of center was noted on the relation between mean BG and mortality. Hypoglycemia, defined as minimum BG <70 mg/dl, was independently associated with increased risk of mortality among patients with and without diabetes and increased glycemic variability, defined as CV >20%, was independently associated with increased risk of mortality only among patients without diabetes. Derangements of more than one domain of glycemic control had a cumulative association with mortality, especially for patients without diabetes.
Although hyperglycemia, hypoglycemia, and increased glycemic variability is each independently associated with mortality in critically ill patients, diabetic status modulates these relations in clinically important ways. Our findings suggest that patients with diabetes may benefit from higher glucose target ranges than will those without diabetes. Additionally, hypoglycemia is independently associated with increased risk of mortality regardless of the patient's diabetic status, and increased glycemic variability is independently associated with increased risk of mortality among patients without diabetes.
See related commentary by Krinsley,
See related commentary by Finfer and Billot,
PMCID: PMC3733432  PMID: 23452622
14.  Enhancing breast milk production with Domperidone in mothers of preterm neonates (EMPOWER trial) 
The use of mother’s own breast milk during initial hospitalization has a positive impact not only in reducing potential serious neonatal morbidities but also contribute to improvements in neurodevelopmental outcomes. Mothers of very preterm infants struggle to maintain a supply of breast milk during their infants’ prolonged hospitalization. Galactogogues are medications that induce lactation by exerting its effects through oxytocin or prolactin enhancement. Domperidone is a potent dopamine D2 receptor antagonist which stimulates the release of prolactin. Small trials have established its ability in enhancing breast milk production. EMPOWER was designed to determine the safety and efficacy of domperidone in mothers experiencing an inadequate milk supply.
EMPOWER is a multicenter, double masked, randomized controlled phase-II trial to evaluate the safety and effectiveness of domperidone in those mothers identified as having difficulty in breast milk production. Eligible mothers will be randomized to one of two allocated groups: Group A: domperidone 10 mg orally three times daily for 28 days; and Group B: identical placebo 10 mg orally three times daily for 14 days followed by domperidone 10 mg orally three times daily for 14 days. The primary outcome will be determined at the completion of the first 2-week period; the second 2-week period will facilitate answering the secondary questions regarding timing and duration of treatment. To detect an estimated 30% change between the two groups (from 40% to 28%, corresponding to an odds ratio of 0.6), a total sample size of 488 mothers would be required at 80% power and alpha = 0.05. To account for a 15% dropout, this number is increased to 560 (280 per group). The duration of the trial is expected to be 36–40 months.
The use of a galactogogue often becomes the measure of choice for mothers in the presence of insufficient breast milk production, particularly when the other techniques are unsuccessful. EMPOWER is designed to provide valuable information in guiding the practices for this high-risk group of infants and mothers. The results of this trial will also inform both mothers and clinicians about the choices available to increase and maintain sufficient breast milk.
Trial registration
Clinical Identifier: NCT01512225
PMCID: PMC3532128  PMID: 22935052
Domperidone; Galactogogues; Mothers of preterm infants; Breast milk
15.  Emergency department length of stay for patients requiring mechanical ventilation: a prospective observational study 
Recommendations for acceptable emergency department (ED) length of stay (LOS) vary internationally with ≤ 8 h generally considered acceptable. Protracted ED LOS may place critically ill patients requiring mechanical ventilation at increased risk of adverse events as most EDs are not resourced for longitudinal delivery of critical care. Our objective was to quantify the ED LOS for mechanically ventilated patients (invasive and/or non-invasive ventilation [NIV]) and to explore patient and system level predictors of prolonged ED LOS. Additionally, we aimed to describe delivery and monitoring of ventilation in the ED.
Prospective observational study of ED LOS for all patients receiving mechanical ventilation at four metropolitan EDs in Toronto, Canada over two six-month periods in 2009 and 2010.
We identified 618 mechanically ventilated patients which represented 0.5% (95% CI 0.4%–0.5%) of all ED visits. Of these, 484 (78.3%) received invasive ventilation, 118 (19.1%) received NIV; 16 received both during the ED stay. Median Kaplan-Meier estimated duration of ED stay for all patients was 6.4 h (IQR 2.8–14.6). Patients with trauma diagnoses had a shorter median (IQR) LOS, 2.5 h (1.3–5.1), compared to ventilated patients with non-trauma diagnoses, 8.5 h (3.3–14.0) (p <0.001). Patients requiring NIV had a longer ED stay (16.6 h, 8.2–27.9) compared to those receiving invasive ventilation exclusively (4.6 h, 2.2–11.1) and patients receiving both (15.4 h, 6.4–32.6) (p <0.001). Longer ED LOS was associated with ED site and lower priority triage scores. Shorter ED LOS was associated with intubation at another ED prior to transfer.
While patients requiring mechanical ventilation represent a small proportion of overall ED visits these critically ill patients frequently experienced prolonged ED stay especially those treated with NIV, assigned lower priority triage scores at ED presentation, and non-trauma patients.
PMCID: PMC3466156  PMID: 22494785
Mechanical ventilation; Emergency department; Non-invasive ventilation, critical illness; Acute respiratory failure
16.  Genetic predictors of response to treatment with citalopram in depression secondary to traumatic brain injury 
Brain injury : [BI]  2010;24(7-8):959-969.
To determine which serotonergic system-related single nucleotide polymorphisms (SNPs) predicted variation in treatment response to citalopram in depression following a traumatic brain injury (TBI).
Ninety (50 M/40 F, aged 39.9, SD = 18.0 years) post-TBI patients with a major depressive episode (MDE) were recruited into a 6-week open-label study of citalopram (20 mg/day). Six functional SNPs in genes related to the serotonergic system were examined: serotonin transporter (5HTTLPR including rs25531), 5HT1A C-(1019)G and 5HT2A T-(102)C, methylene tetrahydrofolate reductase (MTHFR) C-(677)T, brain-derived neurotrophic factor (BDNF) val66met and tryptophan hydroxylase-2 (TPH2) G-(703)T. Regression analyses were performed using the six SNPs as independent variables: Model 1 with response (percentage Hamilton Depression (HAMD) change from baseline to endpoint) as the dependent variable and Model 2 with adverse event index as the dependent variable (Bonferroni corrected p-value <0.025).
MTHFR and BDNF SNPs predicted greater treatment response (R2= 0.098, F = 4.65, p = 0.013). The 5HTTLPR predicted greater occurrence of adverse events (R2= 0.069, F = 5.72, p = 0.020).
Results suggest that polymorphisms in genes related to the serotonergic system may help predict short-term response to citalopram and tolerability to the medication in patients with MDE following a TBI.
PMCID: PMC3142269  PMID: 20515362 CAMSID: cams1807
Traumatic brain injury; serotonin receptors; serotonin transporter; brain derived neurotrophic factor (BDNF); methylenetetrahydrofolate reductase (MTHFR); tryptophan hydroxylase (TPH)
17.  Anxiety As a Predictor of Treatment Outcome in Children and Adolescents with Depression 
The aim of this study was to examine the impact of co-morbid illnesses on treatment outcomes in depressed children and adolescents aged 7–17 who were treated with fluoxetine.
This data set was drawn from two large clinical trials involving children and adolescents with depression. Subjects with a diagnosis of major depressive disorder and depressive symptoms of at least moderate severity as defined by a Children's Depression Rating Score, Revised (CDRS-R) total score ≥40 and a Clinical Global Impressions–Severity (CGI-S) rating ≥4 were included. Subjects were randomized to receive fluoxetine or placebo over an 8-week period. Predictor analyses examining two primary outcomes were conducted: (1) Response based on Clinical Global Impressions–Improvement (CGI-I) score of 1 or 2, and (2) remission based on CDRS-R score of ≤28. Logistic regression models were run to assess whether anxiety disorders were a predictor of response or remission.
A total of 309 study participants were included. The only factor found to influence response was treatment with fluoxetine (p = 0.022, odds ratio [OR] = 2.08, 95% confidence interval [CI] 1.30, 3.31). Several factors were found to influence remission: Treatment with fluoxetine (p < 0.0001, OR = 3.17, 95% CI 1.80, 5.57), gender (p = 0.024, OR = 1.90, 95% CI 1.09, 3.30), and number of co-morbid diagnoses (p = 0.026, OR 0.73, 95% CI 0.55, 0.96).
Anxiety disorders alone did not predict response or remission, but the total number of co-morbid illnesses was associated with remission in depressed children and adolescents treated with fluoxetine.
PMCID: PMC2936256  PMID: 20578934
18.  Informed decision-making in elective major vascular surgery: analysis of 145 surgeon–patient consultations 
Canadian Journal of Surgery  2011;54(3):173-178.
Prior studies show significant gaps in the informed decision-making process, a central goal of surgical care. These studies have been limited by their focus on low-risk decisions, single visits rather than entire consultations, or both. Our objectives were, first, to rate informed decision-making for major elective vascular surgery based on audiotapes of actual physician–patient conversations and, second, to compare ratings of informed decision-making for first visits to ratings for multiple visits by the same patient over time.
We prospectively enrolled patients for whom vascular surgical treatment was a potential option at a tertiary care outpatient vascular surgery clinic. We audio-taped all surgeon–patient conversations, including multiple visits when necessary, until a decision was made. Using an existing method, we evaluated the transcripts for elements of decision-making, including basic elements (e.g., an explanation of the clinical condition), intermediate elements (e.g., risks and benefits) and complex elements (e.g., uncertainty around the decision).
We analyzed 145 surgeon–patient consultations. Overall, 45% of consultations contained complex elements, whereas 23% did not contain the basic elements of decision-making. For the 67 consultations that involved multiple visits, ratings were significantly higher when evaluating all visits (50% complex elements) compared with evaluating only the first visit (33% complex elements, p < 0.001.)
We found that 45% of consultations contained complex elements, which is higher than prior studies with similar methods. Analyzing decision-making over multiple visits yielded different results than analyzing decision-making for single visits.
PMCID: PMC3104311  PMID: 21443835
19.  Feedback GAP: study protocol for a cluster-randomized trial of goal setting and action plans to increase the effectiveness of audit and feedback interventions in primary care 
Audit and feedback to physicians is commonly used alone or as part of multifaceted interventions. While it can play an important role in quality improvement, the optimal design of audit and feedback is unknown. This study explores how feedback can be improved to increase acceptability and usability in primary care. The trial seeks to determine whether a theory-informed worksheet appended to feedback reports can help family physicians improve quality of care for their patients with diabetes and/or ischemic heart disease.
Two-arm cluster trial was conducted with participating primary care practices allocated using minimization to simple feedback or enhanced feedback group. The simple feedback group receives performance feedback reports every six months for two years regarding the proportion of their patients with diabetes and/or ischemic heart disease who are meeting quality targets. The enhanced feedback group receives these same reports as well as a theory-informed worksheet designed to facilitate goal setting and action plan development in response to the feedback reports. Participants are family physicians from across Ontario who use electronic medical records; data for rostered patients are used to produce the feedback reports and for analysis.
The primary disease outcomes are the blood pressure (BP), and low-density lipoprotein cholesterol (LDL) levels. The primary process measure is a composite score indicating the number of recommended activities (e.g., tests and prescriptions) conducted by the family physicians for their patients with diabetes and/or ischemic heart disease within the appropriate timeframe. Secondary outcomes are the proportion of patients whose results meet targets for glucose, LDL, and BP as well as the percent of patients receiving relevant prescriptions. A qualitative process evaluation using semi-structured interviews will explore perceived barriers to behaviour change in response to feedback reports and preferences with regard to feedback design.
Intention-to-treat approach will be used to analyze the trial. Analysis will be performed on patient-level variables using generalized estimating equation models to adjust for covariates and account for the clustered nature of the data. The trial is powered to show small, but clinically important differences of 7 mmHG in systolic BP and 0.32 mmol/L in LDL.
Trial Registration NCT00996645
PMCID: PMC3161381  PMID: 21167034
20.  Pan-Canadian Evaluation of Irreversible Compression Ratios (“Lossy” Compression) for Development of National Guidelines 
New technological advancements including multislice CT scanners and functional MRI, have dramatically increased the size and number of digital images generated by medical imaging departments. Despite the fact that the cost of storage is dropping, the savings are largely surpassed by the increasing volume of data being generated. While local area network bandwidth within a hospital is adequate for timely access to imaging data, efficiently moving the data between institutions requires wide area network bandwidth, which has a limited availability at a national level. A solution to address those issues is the use of lossy compression as long as there is no loss of relevant information. The goal of this study was to determine levels at which lossy compression can be confidently used in diagnostic imaging applications. In order to provide a fair assessment of existing compression tools, we tested and compared the two most commonly adopted DISCOM compression algorithms: JPEG and JPEG-2000. We conducted an extensive pan-Canadian evaluation of lossy compression applied to seven anatomical areas and five modalities using two recognized techniques: objective methods or diagnostic accuracy and subjective assessment based on Just Noticeable Difference. By incorporating both diagnostic accuracy and subjective evaluation techniques, enabled us to define a range of compression for each modality and body part tested. The results of our study suggest that at low levels of compression, there was no significant difference between the performance of lossy JPEG and lossy JPEG 2000, and that they are both appropriate to use for reporting on medical images. At higher levels, lossy JPEG proved to be more effective than JPEG 2000 in some cases, mainly neuro CT. More evaluation is required to assess the effect of compression on thin slice CT. We provide a table of recommended compression ratios for each modality and anatomical area investigated, to be integrated in the Canadian Association of Radiologists standard for the use of lossy compression in medical imaging.
PMCID: PMC3043739  PMID: 18931879
Compression; JPEG2000; digital imaging; lossy compression; JPEG
21.  The health of homeless immigrants 
This study examined the association between immigrant status and current health in a representative sample of 1,189 homeless people in Toronto, Canada.
Multivariate regression analyses were performed to examine the relationship between immigrant status and current health status (assessed using the SF-12) among homeless recent immigrants (≤10 years since immigration), non-recent immigrants (>10 years since immigration), and Canadian-born individuals recruited at shelters and meal programs (response rate 73%).
After adjusting for demographic characteristics and lifetime duration of homelessness, recent immigrants were significantly less likely to have chronic conditions (RR 0.7, 95% CI 0.5 to 0.9), mental health problems (OR 0.4, 95% CI 0.2 to 0.7), alcohol problems (OR 0.2, 95% CI 0.1 to 0.5), and drug problems (OR 0.2, 95% CI 0.1 to 0.4) compared to non-recent immigrants and Canadian-born individuals. Recent immigrants were also more likely to have better mental health status (+3.4 points, SE ±1.6) and physical health status (+2.2 points, SE ±1.3) on scales with a mean of 50 and a standard deviation of 10 in the general population.
Homeless recent immigrants are a distinct group who are generally healthier and may have very different service needs compared to other homeless people.
PMCID: PMC2773541  PMID: 19654122
homelessness; migration and health
22.  Multidimensional Social Support and the Health of Homeless Individuals 
Homeless individuals often suffer from serious health problems. It has been argued that the homeless are socially isolated, with low levels of social support and social functioning, and that this lack of social resources contributes to their ill health. These observations suggest the need to further explore the relationship between social networks, social support, and health among persons who are homeless. The purpose of this study was to examine the association between multidimensional (cognitive/perceived and behavioral/received) social support and health outcomes, including physical health status, mental health status, and recent victimization, among a representative sample of homeless individuals in Toronto, Canada. Multivariate regression analyses were performed on social support and health outcome data from a subsample of 544 homeless adults, recruited from shelters and meal programs through multistage cluster sampling procedures. Results indicated that participants perceived moderately high levels of access to financial, emotional, and instrumental social support in their social networks. These types of perceived social supports were related to better physical and mental health status and lower likelihood of victimization. These findings highlight a need for more services that encourage the integration of homeless individuals into social networks and the building of specific types of social support within networks, in addition to more research into social support and other social contextual factors (e.g., social capital) and their influence on the health of homeless individuals.
PMCID: PMC2729873  PMID: 19629703
Homelessness; Social support; Physical health; Mental health; Victimization; Canada
23.  Drug problems among homeless individuals in Toronto, Canada: prevalence, drugs of choice, and relation to health status 
BMC Public Health  2010;10:94.
Drug use is believed to be an important factor contributing to the poor health and increased mortality risk that has been widely observed among homeless individuals. The objective of this study was to determine the prevalence and characteristics of drug use among a representative sample of homeless individuals and to examine the association between drug problems and physical and mental health status.
Recruitment of 603 single men, 304 single women, and 284 adults with dependent children occurred at homeless shelters and meal programs in Toronto, Canada. Information was collected on demographic characteristics and patterns of drug use. The Addiction Severity Index was used to assess whether participants suffered from drug problems. Associations of drug problems with physical and mental health status (measured by the SF-12 scale) were examined using regression analyses.
Forty percent of the study sample had drug problems in the last 30 days. These individuals were more likely to be single men and less educated than those without drug problems. They were also more likely to have become homeless at a younger age (mean 24.8 vs. 30.9 years) and for a longer duration (mean 4.8 vs. 2.9 years). Marijuana and cocaine were the most frequently used drugs in the past two years (40% and 27%, respectively). Drug problems within the last 30 days were associated with significantly poorer mental health status (-4.9 points, 95% CI -6.5 to -3.2) but not with poorer physical health status (-0.03 points, 95% CI -1.3 to 1.3)).
Drug use is common among homeless individuals in Toronto. Current drug problems are associated with poorer mental health status but not with poorer physical health status.
PMCID: PMC2841106  PMID: 20181248
24.  The Toronto prehospital hypertonic resuscitation-head injury and multi organ dysfunction trial (TOPHR HIT) - Methods and data collection tools 
Trials  2009;10:105.
Clinical trials evaluating the use of hypertonic saline in the treatment of hypovolemia and head trauma suggest no survival superiority over normal saline; however subgroup analyses suggest there may be a reduction in the inflammatory response and multiorgan failure which may lead to better survival and enhanced neurocognitive function. We describe a feasibility study of randomizing head injured patients to hypertonic saline and dextran vs. normal saline administration in the out of hospital setting.
This feasibility study employs a randomized, placebo-controlled design evaluating normal saline compared with a single dose of 250 ml of 7.5% hypertonic saline in 6% dextran 70 in the management of traumatic brain injuries. The primary feasibility endpoints of the trial were: 1) baseline survival rates for the treatment and control group to aid in the design of a definitive multicentre trial, 2) randomization compliance rate, 3) ease of protocol implementation in the out-of-hospital setting, and 4) adverse event rate of HSD infusion.
The secondary objectives include measuring the effect of HSD in modulating the immuno-inflammatory response to severe head injury and its effect on modulating the release of neuro-biomarkers into serum; evaluating the role of serum neuro-biomarkers in predicting patient outcome and clinical response to HSD intervention; evaluating effects of HSD on brain atrophy post-injury and neurocognitive and neuropsychological outcomes.
We anticipate three aspects of the trial will present challenges to trial success; ethical demands associated with a waiver of consent trial, challenging follow up and comprehensive accurate timely data collection of patient identifiers and clinical or laboratory values. In addition all the data collection tools had to be derived de novo as none existed in the literature.
Trial registration number
PMCID: PMC2788534  PMID: 19930566
25.  DreamTel; Diabetes risk evaluation and management tele-monitoring study protocol 
The rising prevalence of type 2 diabetes underlines the importance of secondary strategies for the prevention of target organ damage. While access to diabetes education centers and diabetes intensification management has been shown to improve blood glucose control, these services are not available to all that require them, particularly in rural and northern areas. The provision of these services through the Home Care team is an advance that can overcome these barriers. Transfer of blood glucose data electronically from the home to the health care provider may improve diabetes management.
Methods and design
The study population will consist of patients with type 2 diabetes with uncontrolled A1c levels living on reserve in the Battlefords region of Saskatchewan, Canada. This pilot study will take place over three phases. In the first phase over three months the impact of the introduction of the Bluetooth enabled glucose monitor will be assessed. In the second phase over three months, the development of guidelines based treatment algorithms for diabetes intensification will be completed. In the third phase lasting 18 months, study subjects will have diabetes intensification according to the algorithms developed.
The first phase will determine if the use of the Bluetooth enabled blood glucose devices which can transmit results electronically will lead to changes in A1c levels. It will also determine the feasibility of recruiting subjects to use this technology. The rest of the Diabetes Risk Evaluation and Management Tele-monitoring (DreamTel) study will determine if the delivery of a diabetes intensification management program by the Home Care team supported by the Bluetooth enabled glucose meters leads to improvements in diabetes management.
Trial Registration
Protocol NCT00325624
PMCID: PMC2689225  PMID: 19426530

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