John S. Sampalis
McGill University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by John S. Sampalis.
Annals of Surgery | 2004
Nicolas V. Christou; John S. Sampalis; Moishe Liberman; Didier Look; Stephane Auger; A. P. H. Mclean; Lloyd D. MacLean
Objective:This study tested the hypothesis that weight-reduction (bariatric) surgery reduces long-term mortality in morbidly obese patients. Background:Obesity is a significant cause of morbidity and mortality. The impact of surgically induced, long-term weight loss on this mortality is unknown. Methods:We used an observational 2-cohort study. The treatment cohort (n = 1035) included patients having undergone bariatric surgery at the McGill University Health Centre between 1986 and 2002. The control group (n = 5746) included age- and gender-matched severely obese patients who had not undergone weight-reduction surgery identified from the Quebec provincial health insurance database. Subjects with medical conditions (other then morbid obesity) at cohort-inception into the study were excluded. The cohorts were followed for a maximum of 5 years from inception. Results:The cohorts were well matched for age, gender, and duration of follow-up. Bariatric surgery resulted in significant reduction in mean percent excess weight loss (67.1%, P < 0.001). Bariatric surgery patients had significant risk reductions for developing cardiovascular, cancer, endocrine, infectious, psychiatric, and mental disorders compared with controls, with the exception of hematologic (no difference) and digestive diseases (increased rates in the bariatric cohort). The mortality rate in the bariatric surgery cohort was 0.68% compared with 6.17% in controls (relative risk 0.11, 95% confidence interval 0.04–0.27), which translates to a reduction in the relative risk of death by 89%. Conclusions:This study shows that weight-loss surgery significantly decreases overall mortality as well as the development of new health-related conditions in morbidly obese patients.
Medicine | 1991
Pouchot J; John S. Sampalis; Beaudet F; Carette S; Décary F; Salusinsky-Sternbach M; Hill Ro; Gutkowski A; Harth M; Myhal D
Clinical and laboratory manifestations, disease course, outcome, and HLA associations were studied in an inception cohort of 62 subjects with adult Stills disease (ASD) from 5 Canadian universities. Twenty-eight patients (45%) were female and the median age at disease onset was 24 years. In general, the clinical features observed in our patients were identical to those in other published series. However, significantly higher frequencies of sore throat (92%), weight loss (76%), lymphadenopathy (74%), pleuritis (53%), pneumonitis (27%), and abdominal pain (48%) were noted in our patients compared to those in a recent literature review. Liver involvement with hepatomegaly (44%) or abnormal liver function tests (LFTs) (76%) was common and was responsible for the 2 deaths attributed to Stills disease in our series. Severe liver failure always occurred in conjunction with aspirin or NSAID therapy. Therefore, whether or not aspirin or other NSAIDs are used, we recommend close monitoring of LFTs in patients with ASD, especially early in the disease course. Laboratory manifestations were similar to those already reported. Leukocytosis (greater than or equal to 15,000/mm3) was present in 50 patients (81%), a normochromic, normocytic anemia (hemoglobin less than or equal to 10 g/dl) in 42 (68%), and an elevated ESR in all. The mean follow-up of the 62 patients was 70 months (range, 2-163). Twenty-one patients (34%) had a self-limited disease course, 15 (24%) an intermittent course, and 22 (36%) a chronic disease course. Four patients (6%) died, and 2 of these deaths were attributed to Stills disease. For those patients who experienced a recurrence of ASD, the flares were usually of shorter duration and milder in severity than the initial episode. No initiating factor for disease exacerbation was identified in our patients. Although 22 of 62 patients (36%) had a chronic disease course, 52 (90%) were in ARA Functional Class I, and only 4 and 2 patients were in ARA Functional Class II and III, respectively. Patients with Stills disease had higher scores than the controls on the Pain (P less than 0.01) and Physical Disability (P less than 0.05) subscales of Arthritis Impact Measurement Scales health status questionnaire. Joint radiographs performed at the follow-up evaluation disclosed typical carpometacarpal and intercarpal involvement in 16 of 39 patients. In our series, HLA-B17, B18, B35, and DR2 were significantly associated with ASD. Three significant predictors of an unfavorable outcome, either a chronic disease course or a longer time to clinical remission, were identified.(ABSTRACT TRUNCATED AT 400 WORDS)
American Journal of Surgery | 1993
Lloyd D. MacLean; Barbara M. Rhode; John S. Sampalis; R. Armour Forse
A prospective, randomized trial comparing vertical banded gastroplasty (VBG) and vertical gastric bypass (GB) for obesity was completed in 106 patients who did not differ in baseline body mass index (BMI = kg/m2) or length of follow-up. The goal of this surgery was to return patients to within 50% of their ideal weight, i.e., a body mass index less than 35 kg/m2, and to accomplish this while maintaining a low risk for malnutrition as well as other morbidity and mortality. Success was defined as a BMI less than 35 kg/m2 because the mortality risk increases rapidly above this degree of obesity. Surgical failures were encountered in 43% of the 54 patients in the VBG group, all of whom had division between the vertical staple lines. The main causes of failure were stenosis and enlargement of the gastroplasty orifice. Surgery failed in 23% of the GB-treated patients, due to perforation of the vertical staple line. An isolated gastric bypass (IGB) not dependent on staples was performed as the remedial operation for the failures of both VBG and GB. IGB was significantly better than VBG or GB, with a success rate of 83% compared with 39% for VBG and 58% for GB. Subsequent experience since completion of this randomized trial in 54 consecutive patients supports IGB for primary, as well as remedial, operations for the morbidly obese (BMI = 40 to 50 kg/m2), as well as for patients who are super obese (BMI greater than 50 kg/m2).
Journal of Trauma-injury Infection and Critical Care | 1999
John S. Sampalis; Ronald Denis; André Lavoie; Pierre Frechette; Stella Boukas; Andreas Nikolis; Daniel Benoit; David Fleiszer; Rea A. Brown; Micheal Churchill-Smith; David S. Mulder
BACKGROUND Regionalization of trauma care services in our region was initiated in 1993 with the designation of four tertiary trauma centers. The process continued in 1995 with the implementation of patient triage and transfer protocols. Since 1995, the network of trauma care has been expanded with the designation of 33 secondary, 30 primary, and 32 stabilization trauma centers. In addition, during this period emergency medical personnel have been trained to assess and triage trauma victims within minimal prehospital time. The objective of the present study was to evaluate the impact of trauma care regionalization on the mortality of major trauma patients. METHODS This was a prospective study in which patients were entered at the time of injury and were followed to discharge from the acute-care hospital. The patients were identified from the Quebec Trauma Registry, a review of the records of acute-care hospitals that treat trauma, and records of the emergency medical services in the region. The study sample consisted of all patients fulfilling the criteria of a major trauma, defined as death, or Injury Severity Score (ISS) > 12, or Pre-Hospital Index > 3, or two or more injuries with Abbreviated Injury Scale scores > 2, or hospital stay of more than 3 days. Data collection took place between April 1, 1993, and March 31, 1998. During this period, four distinct phases of trauma care regionalization were defined: pre-regionalization (phase 0), initiation (phase I), intermediate (phase II), and advanced (phase III). RESULTS A total of 12,208 patients were entered into the study cohort, and they were approximately evenly distributed over the 6 years of the study. During the study period, there was a decline in the mean age of patients from 54 to 46 years, whereas the male/female ratio remained constant at 2:1. There was also an increase in the mean ISS, from 25.5 to 27.5. The proportion of patients injured in motor vehicle collisions increased from less than 45% to more than 50% (p < 0.001). The mortality rate during the phases of regionalization were: phase 0, 52%; phase I, 32%; phase II, 19%; and phase III, 18%. These differences were clinically important and statistically significant (p < 0.0001). Stratified analysis showed a significant decline in mortality among patients with ISS between 12 and 49. The change in mortality for patients with fatal injuries (ISS > or = 50) was not significant. During the study period, the mean prehospital time decreased significantly, from 62 to 44 minutes. The mean time to admission after arrival at the hospital decreased from 151 to 128 minutes (p < 0.001). The latter decrease was primarily attributable to changes at the tertiary centers. The proportion of patients with ISS between 12 and 24 and between 25 and 49 who were treated at tertiary centers increased from 56 to 82% and from 36 to 84%, respectively (p < 0.001). Compared with the secondary and primary centers, throughout the course of the study the mortality rate in the secondary and tertiary centers showed a consistent decline (p < 0.001). In addition, the mortality rate in the tertiary centers remained consistently lower (p < 0.001). The results of multivariate analyses showed that after adjusting for injury severity and patient age, the primary factors contributing to the reduced mortality were treatment at a tertiary center, reduced prehospital time, and direct transport from the scene to tertiary centers. CONCLUSION This study produced empirical evidence that the integration of trauma care services into a regionalized system reduces mortality. The results showed that tertiary trauma centers and reduced prehospital times are the essential components of an efficient trauma care system.
Journal of Trauma-injury Infection and Critical Care | 2000
Moishe Liberman; David S. Mulder; John S. Sampalis
BACKGROUND The question of whether to use advanced life support (ALS) or basic life support (BLS) for trauma patients in the prehospital setting has been much debated and still lacks a clear answer. The purpose of this study was to conduct a comprehensive critical review of the literature regarding this controversy METHODS A total of 174 articles on prehospital ALS or BLS for trauma were reviewed. Fifteen of these studies were found to involve mortality statistics for both ALS- and BLS-treated patients. Odds ratios were calculated for survival in ALS versus BLS and summarized across studies on the basis of multivariate scoring systems that incorporated both design and methodological assessment. Overall odds ratios for all studies were calculated on the basis of both raw data from the papers, and weighted odds ratios were calculated from the scoring systems. RESULTS Six studies were scored as being methodologically average (5 favoring BLS and 1 favoring ALS), two were scored as good (1 favoring BLS and 1 favoring ALS), seven as excellent (6 favoring BLS and 1 favoring ALS). Ten studies had an average study design score (6 favoring BLS and 4 favoring ALS) and seven had a good study design score (6 favoring BLS and 1 favoring ALS). Weighted odds ratio for dying was 2.59 for patients receiving ALS compared with those receiving BLS. The crude odds ratio was 2.92. CONCLUSION The aggregated data in the literature have failed to demonstrate a benefit for on-site ALS provided to trauma patients and support the scoop and run approach.
Journal of Trauma-injury Infection and Critical Care | 1997
John S. Sampalis; Ronald Denis; Pierre Frechette; Rea A. Brown; David Fleiszer; David S. Mulder
BACKGROUND The purpose of the study was to compare the outcome of severely injured patients who were transported directly to a Level I, tertiary trauma center with those who were transferred after being first transported to less specialized hospitals. METHODS The data were based on all patients treated at three tertiary trauma centers in Quebec between April 1, 1993, and December 31, 1995. There were 1,608 patients (37%) transferred and 2,756 patients (63%) transported directly. RESULTS The mean age of the patients was approximately 45 years, and more than 60% were males. The predominant mechanisms of injury were falls and motor vehicle crashes. The transfer and direct transport groups were similar with respect to age, gender, and mechanism of injury. Body regions injured were also similar with the exception of head or neck injuries (transfer, 56%; direct, 28%; p < 0.0001). The mean Injury Severity Score was 14, the mean Pre-Hospital Index score was 5.5, and the mean Revised Trauma Score was 7.5. The two groups were similar with respect to these injury severity measures. The primary outcome of interest was mortality described as overall death rate, death rate in the emergency room, and death rate after admission. Other outcomes studied were hospital length of stay and duration of treatment in an intensive care unit. When compared with the direct transport group, transferred patients were at increased risk for overall mortality (transfer, 8.9%; direct, 4.8%; odds ratio, 1.96; 95% confidence interval (CI) = 1.53-2.50), emergency room mortality (transfer, 3.4%; direct, 1.2%; odds ratio, 2.96; 95% CI = 1.90-4.6), and mortality after admission (transfer, 5.5%; direct, 3.6%; odds ratio, 1.57; 95% CI = 1.17-2.11). All of these differences were statistically significant (p < 0.003). Stratified and multiple logistic regression analysis did not alter these results and failed to identify a patient subgroup for which transfer was associated with a reduced risk of mortality. After adjusting for patient age, Injury Severity Score, and presence of injuries to the head or neck and extremities, transferred patients stayed significantly longer in the hospital and the intensive care unit as indicated by the mean length of stay (transfer, 16.0 days; direct, 13.2 days; p = 0.02) and the mean intensive care unit stay (transfer, 2.0 days; direct, 0.95 days; p = 0.001). CONCLUSION The results of this study have shown that transportation of severely injured patients from the scene directly to Level I trauma centers is associated with a reduction in mortality and morbidity. Further studies are required for the evaluation of transport protocols for rural trauma. Economic and cost-effectiveness considerations of patient triage are also essential.
Journal of Trauma-injury Infection and Critical Care | 1993
John S. Sampalis; André Lavoie; Jack I. Williams; David S. Mulder; Mathias Kalina
A sample of 360 severely injured patients was selected from a cohort of 8007 trauma victims followed prospectively from the time of injury to death or discharge. A case referent study was used to test the association between on-site care, total prehospital time, and level of care at the receiving hospital with short-term survival. Multiple logistic regression analyses showed that use of Advanced Life Support (ALS) at the scene was not associated with survival, whereas treatment at a level I compatible hospital was associated with a 38% reduction in the odds of dying, which approached statistical significance. Total prehospital time over 60 minutes was associated with a statistically significant adjusted relative odds of dying (OR = 3.0). The results of this study support the need for regionalization of trauma care and fail to show a benefit associated with ALS.
Surgery for Obesity and Related Diseases | 2008
Nicolas V. Christou; Moishe Lieberman; Fotini Sampalis; John S. Sampalis
BACKGROUND To assess the effect of bariatric surgery on the cancer risk of patients with morbid obesity because evidence is mounting of an association between obesity and cancer. METHODS We performed an observational 2-cohort study. The treatment cohort (n = 1035) included patients who had undergone bariatric surgery from 1986 to 2002. The control group (n = 5746) included age- and gender-matched morbidly obese patients who had not undergone weight-reduction surgery and who were identified from a single-payor administrative database. The subjects with physician or hospital visits for a cancer-related diagnosis or treatment within the 6 months previous to the beginning of the study were excluded. The cohorts were followed up for a maximum of 5 years from study inception. RESULTS Bariatric surgery resulted in a significant reduction in the mean percentage of excess weight loss (67.1%, P <.001). The surgery patients had significantly fewer physician/hospital visits for all cancer diagnoses (n = 21, 2.0%) compared with the controls (n = 487, 8.45%; relative risk .22, 95% confidence interval .143-.347; P = .001). The physician/hospital visits for common cancers such as breast cancer were significantly reduced in the surgery group (P = .001). For all other cancers, the physician/hospital visits showed a trend toward being lower in the surgery group. Because of the low frequencies, statistical significance could not be demonstrated for individual cancer diagnoses. CONCLUSION The data suggest that bariatric surgery improves the cancer outcomes in some morbidly obese patients.
Journal of Trauma-injury Infection and Critical Care | 2004
André Lavoie; Lynne Moore; Natalie LeSage; Moishe Liberman; John S. Sampalis
OBJECTIVE The purpose of this study was to determine whether the New Injury Severity Score (NISS) is a better predictor of mortality than the Injury Severity Score (ISS) in general and in subgroups according to age, penetrating trauma, and body region injured. METHODS The study population consisted of 24,263 patients from three urban Level I trauma centers in the province of Quebec, Canada. Discrimination and calibration of NISS and ISS models were compared using receiver operator characteristic (ROC) curves and Hosmer-Lemeshow statistics. RESULTS NISS showed better discrimination than ISS (area under the ROC curve = 0.827 vs. 0.819; p = 0.0006) and improved calibration (Hosmer-Leme-show = 62 vs. 112). The advantage of the NISS over the ISS was particularly evident among patients with head/neck injuries (area under the ROC curve = 0.819 vs. 0.784; p < 0.0001; Hosmer-Lemeshow = 59 vs. 350). CONCLUSION The NISS is a more accurate predictor of in-hospital death than the ISS and should be chosen over the ISS for case-mix control in trauma research, especially in certain subpopulations such as head/neck-injured patients.
Archives of Medical Science | 2011
Paul S. Aisen; Serge Gauthier; Steven H. Ferris; Daniel Saumier; Denis Haine; D. Garceau; Anh Duong; Joyce Suhy; Joonmi Oh; Wan C. Lau; John S. Sampalis
Introduction The aim of the study was to assess the clinical efficacy, safety, and disease-modification effects of tramiprosate (homotaurine, ALZHEMEDTM) in mild-to-moderate Alzheimer’s disease (AD). Material and methods Double-blind, placebo-controlled, randomized trial in 67 clinical centres across North America. Patients aged ≥ 50 years, with mild-to-moderate AD (Mini-Mental State Examination score between 16 and 26) and on stable doses of cholinesterase inhibitors, alone or with memantine. Intervention: 78-week treatment with placebo, tramiprosate 100 mg or tramiprosate 150 mg BID. Measurements: Alzheimer Disease Assessment Scale – cognitive subscale (ADAS-cog) and Clinical Dementia Rating – Sum of Boxes (CDR-SB) assessments were performed at baseline and every 13 weeks. Baseline and 78-week magnetic resonance imaging (MRI) hippocampus volume (HV) measurements were conducted in a subgroup of patients. Results A total of 1,052 patients were enrolled and 790 (75.1%) completed the 78-week trial. Patient discontinuation and reasons for withdrawal were similar across groups. Planned analyses did not reveal statistically significant between-group differences. Lack of adequate statistical validity of the planned analysis models led to the development of revised predictive models. These adjusted models showed a trend toward a treatment effect for ADAS-cog (P = 0.098) and indicated significantly less HV loss for tramiprosate 100 mg (P = 0.035) and 150 mg (P = 0.009) compared to placebo. The incidence of adverse events was similar across treatment groups. Conclusions The primary planned analyses did not show a significant treatment effect, but were confounded by unexplained variance. Post-hoc analyses showed a significant treatment-related reduction in HV loss. However, there was only a trend towards slowing of decline on the ADAS-cog and no slowing of decline on the CDR-SB. These results must be interpreted in consideration of the limitations of clinical and disease-modification outcome measures and their relationship, the heterogeneity of the disease and the impact of confounding demographic and clinical variables.