2024-03-29T06:57:30Z
http://ir.lib.uwo.ca/do/oai/
oai:ir.lib.uwo.ca:surgerypub-1026
2010-03-26T21:14:59Z
publication:stats
publication:rwkex
publication:rwkex_researcharticles
publication:surgerypub
publication:pmid
publication:surgery
publication:statspub
publication:faculties
17943900
Cholecystectomy Deferral in Patients with Endoscopic Sphincterotomy
McAlister, Vivian
Davenport, Eric
Renouf, Elizabeth
Article
2007-01-01T08:00:00Z
Cholecystectomy
Choledocholithiasis
Humans
Randomized Controlled Trials as Topic
Sphincterotomy
Endoscopic
Cochrane Database of Systematic Reviews
4
CD006233
http://dx.doi.org/10.1002/14651858.CD006233.pub2
Statistics and Probability
Surgery
BACKGROUND: Cholecystectomy is not required in up to 64% of patients who adopt a wait-and-see policy after endoscopic clearance of common bile duct stones. Although reports of retrospective cohort series have shown a higher mortality among patients who defer cholecystectomy, it is not known if this is due to the patients' premorbid health status or due to the deferral of cholecystectomy. Randomised clinical trials of prophylactic cholecystectomy versus wait-and-see have not had sufficient power to demonstrate differences in survival.
OBJECTIVES: To evaluate the beneficial and harmful effects of cholecystectomy deferral (wait-and-see) versus elective (prophylactic) cholecystectomy in patients who have had an endoscopic biliary sphincterotomy.
SEARCH STRATEGY: We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Controlled Trials Register (CENTRAL) in The Cochrane Library, MEDLINE (1966 to 2007), EMBASE (1980 to 2007), and Science Citation Index Expanded without language restrictions until April 2007.
SELECTION CRITERIA: Randomised clinical trials comparing patients whose gallbladder was left in-situ after endoscopic sphincterotomy (wait-and-see group) versus patients who had cholecystectomy with either endoscopic sphincterotomy or common bile duct exploration (prophylactic cholecystectomy group), irrespective of blinding, language, or publication status.
DATA COLLECTION AND ANALYSIS: We assessed the impact of a wait-and-see policy on mortality. Secondary outcomes assessed were the incidence of biliary pain, cholangitis, pancreatitis, need for cholangiography, need for cholecystectomy, and the rate of difficult cholecystectomy. We pooled data using relative risk with fixed-effect and random-effects models.
MAIN RESULTS: We included 5 randomised trials with 662 participants out of 93 publications identified through the literature searches. The number of deaths was 47 in the wait-and-see group (334 patients) compared to 26 in the prophylactic cholecystectomy group (328 patients) for a 78% increased risk of mortality (RR 1.78, 95% CI 1.15 to 2.75, P = 0.010). The survival benefit of prophylactic cholecystectomy was independent of trial design, inclusion of high risk patients or inclusion of any one of the five trials. Patients in the wait-and-see group had higher rates of recurrent biliary pain (RR 14.56, 95% CI 4.95 to 42.78, P < 00001), jaundice or cholangitis (RR 2.53, 95% CI 1.09 to 5.87, P = 0.03), and of repeat ERCP or other forms of cholangiography (RR 2.36, 95% CI 1.29 to 4.32, P = 0.005). Cholecystectomy was eventually performed in 35% (115 patients) of the wait-and-see group.
AUTHORS' CONCLUSIONS: Prophylactic cholecystectomy should be offered to patients whose gallbladders remain in-situ after endoscopic sphincterotomy and common bile duct clearance.
This review is published as a Cochrane review in the Cochrane Database of Systematic Reviews 2007, Issue 4. Cochrane reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and the Cochrane Database of Systematic Reviews should be consulted for the most recent version of the Review.
https://ir.lib.uwo.ca/surgerypub/28
oai:ir.lib.uwo.ca:surgerypub-1027
2010-03-26T21:19:32Z
publication:stats
publication:rwkex
publication:epidem
publication:rwkex_researcharticles
publication:oncpub
publication:surgerypub
publication:pmid
publication:surgery
publication:statspub
publication:faculties
publication:onc
publication:epidempub
16827858
Cyclosporin versus Tacrolimus for Liver Transplanted Patients
Haddad, Elizabeth
McAlister, Vivian
Renouf, Elizabeth
Malthaner, Richard
Kjaer, Mette S.
Gluud, Lise Lotte
Article
2006-01-01T08:00:00Z
Acute Disease
Cyclosporine
Follow-Up Studies
Graft Rejection
Humans
Immunosuppressive Agents
Liver Transplantation
Risk Factors
Tacrolimus
Cochrane Database of Systematic Reviews
4
CD005161
http://dx.doi.org/10.1002/14651858.CD005161.pub2
Epidemiology
Oncology
Statistics and Probability
Surgery
A systematic review of randomized clinical trials (RCT) was undertaken to evaluate the beneficial and harmful effects of immunosuppression with cyclosporin versus tacrolimus for liver transplanted patients. MEDLINE, EMBASE, Cochrane Central and Hepato-Biliary Group Controlled Trials Registers were searched. Using fixed and random effects model, relative risk (RR), values <1 favoring>tacrolimus, with 95% confidence intervals (CI) were calculated. Of 717 potentially relevant references, 16 RCTs were eligible for inclusion. Mortality and graft loss at 1 year were significantly reduced in tacrolimus-treated recipients (Death: RR 0.85, 95% CI 0.73-0.99; graft loss: RR 0.73, 95% CI 0.61-0.86). Tacrolimus reduced the number of recipients with acute rejection (RR 0.81, 95% CI 0.75-0.88) and steroid-resistant rejection (RR 0.54, 95% CI 0.47-0.74) in the first year. Lymphoproliferative disorder or dialysis rates were not different but more de novo diabetes (RR 1.38, 95% CI 1.01-1.86) occurred with tacrolimus. More patients stopped cyclosporin than tacrolimus (RR 0.57, 95% CI 0.49-0.66). Treating 100 recipients with tacrolimus instead of cyclosporin would avoid rejection and steroid-resistant rejection in nine and seven patients respectively, graft loss and death in five and two patients respectively, but four additional patients would develop diabetes after liver transplantation.
This review is published as a Cochrane review in the Cochrane Database of Systematic Reviews 2006, Issue 4. Cochrane reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and the Cochrane Database of Systematic Reviews should be consulted for the most recent version of the Review.
https://ir.lib.uwo.ca/surgerypub/29
oai:ir.lib.uwo.ca:statspub-1000
2010-07-07T21:12:24Z
publication:stats
publication:rwkex
publication:rwkex_researcharticles
publication:pmid
publication:statspub
publication:faculties
20470408
How Old Is This Mutation? A Study of Three Ashkenazi Jewish Founder Mutations
Greenwood, Celia M. T.
Sun, Shuying
Veenstra, Justin
Hamel, Nancy
Niell, Bethany
Gruber, Stephen
Foulkes, William D.
Article
2010-05-14T07:00:00Z
Mutations
Ashkenazi Jewish
Genetics
BMC Genetics
BMC Genetics
11
39
http://dx.doi.org/10.1186/1471-2156-11-39
Genetics and Genomics
Statistics and Probability
BACKGROUND: Several founder mutations leading to increased risk of cancer among Ashkenazi Jewish individuals have been identified, and some estimates of the age of the mutations have been published. A variety of different methods have been used previously to estimate the age of the mutations. Here three datasets containing genotype information near known founder mutations are reanalyzed in order to compare three approaches for estimating the age of a mutation. The methods are: (a) the single marker method used by Risch et al., (1995); (b) the intra-allelic coalescent model known as DMLE, and (c) the Goldgar method proposed in Neuhausen et al. (1996), and modified slightly by our group. The three mutations analyzed were MSH2*1906 G->C, APC*I1307K, and BRCA2*6174delT.
RESULTS: All methods depend on accurate estimates of inter-marker recombination rates. The modified Goldgar method allows for marker mutation as well as recombination, but requires prior estimates of the possible haplotypes carrying the mutation for each individual. It does not incorporate population growth rates. The DMLE method simultaneously estimates the haplotypes with the mutation age, and builds in the population growth rate. The single marker estimates, however, are more sensitive to the recombination rates and are unstable. Mutation age estimates based on DMLE are 16.8 generations for MSH2 (95% credible interval (13, 23)), 106 generations for I1037K (86-129), and 90 generations for 6174delT (71-114).
CONCLUSIONS: For recent founder mutations where marker mutations are unlikely to have occurred, both DMLE and the Goldgar method can give good results. Caution is necessary for older mutations, especially if the effective population size may have remained small for a long period of time.
https://ir.lib.uwo.ca/statspub/1
oai:ir.lib.uwo.ca:surgerypub-1068
2010-08-23T00:30:02Z
publication:stats
publication:rwkex
publication:rwkex_researcharticles
publication:surgerypub
publication:pmid
publication:surgery
publication:statspub
publication:faculties
16827858
Cyclosporin versus Tacrolimus as Primary Immunosuppressant after Liver Transplantation: A Meta-analysis
McAlister, Vivian C.
Haddad, E.
Renouf, E.
Malthaner, R. A.
Kjaer, M. S.
Gluud, L. L.
Article
2006-07-01T07:00:00Z
Cyclosporine
Graft Rejection
Immunosuppressive Agents
Liver Transplantation
Risk Factors
Tacrolimus
American Journal of Transplantation
6
7
1578
1585
http://dx.doi.org/10.1111/j.1600-6143.2006.01360.x
Statistics and Probability
Surgery
A systematic review of randomized clinical trials (RCT) was undertaken to evaluate the beneficial and harmful effects of immunosuppression with cyclosporin versus tacrolimus for liver transplanted patients. MEDLINE, EMBASE, Cochrane Central and Hepato-Biliary Group Controlled Trials Registers were searched. Using fixed and random effects model, relative risk (RR), values <1 favoring>tacrolimus, with 95% confidence intervals (CI) were calculated. Of 717 potentially relevant references, 16 RCTs were eligible for inclusion. Mortality and graft loss at 1 year were significantly reduced in tacrolimus-treated recipients (Death: RR 0.85, 95% CI 0.73-0.99; graft loss: RR 0.73, 95% CI 0.61-0.86). Tacrolimus reduced the number of recipients with acute rejection (RR 0.81, 95% CI 0.75-0.88) and steroid-resistant rejection (RR 0.54, 95% CI 0.47-0.74) in the first year. Lymphoproliferative disorder or dialysis rates were not different but more de novo diabetes (RR 1.38, 95% CI 1.01-1.86) occurred with tacrolimus. More patients stopped cyclosporin than tacrolimus (RR 0.57, 95% CI 0.49-0.66). Treating 100 recipients with tacrolimus instead of cyclosporin would avoid rejection and steroid-resistant rejection in nine and seven patients respectively, graft loss and death in five and two patients respectively, but four additional patients would develop diabetes after liver transplantation.
https://ir.lib.uwo.ca/surgerypub/66
oai:ir.lib.uwo.ca:statspub-1002
2012-03-22T00:37:04Z
publication:stats
publication:rwkex_technicalreports
publication:rwkex
publication:statspub
publication:faculties
A Greedy Algorithm for Unimodal Kernel Density Estimation by Data Sharpening
Wolters, Mark A
Report
2009-01-01T08:00:00Z
Shape constrained estimation
Heuristic optimization
Statistics and Probability
<p>Nonparametric methods for smoothing, regression, and density estimation produce estimators with great shape flexibility. Although this flexibility is an advantage, the practical value of nonparametric methods would be increased if qualitative constraints—natural-language shape restrictions—could also be imposed on the estimator. In density estimation, the most common such constraints are monotonicity (the density must be nondecreasing or nonincreasing) and unimodality (the density must have only one peak). The work presented here takes unimodal kernel density estimation as a representative problem in constrained nonparametric estimation. The method proposed for handling the constraint is data sharpening. A greedy algorithm is described for achieving the unimodality constraint. The algorithm is deterministic and runs quickly. It can find solutions that are competitive with the incumbent method, sequential quadratic programming.</p>
<p>This is a technical report from the Department of Statistical and Actuarial Sciences. The posting of it was recommended by Dr. John Braun. </p>
https://ir.lib.uwo.ca/statspub/2
oai:ir.lib.uwo.ca:statspub-1011
2023-05-29T17:41:40Z
publication:stats
publication:statspub
publication:faculties
A Conceptual Framework for Knowledge Exchange in a Wildland Fire Research and Practice Context
McFayden, Colin B.
Johnston, Lynn M.
Woolford, Douglas G.
George, Colleen
Boychuk, Den
Johnston, Daniel
Wotton, B. Mike
Johnston, Joshua M.
Book Chapter
2023-01-01T08:00:00Z
knowledge exchange
knowledge transfer
knowledge broker
wildfire
forest fire
technical transfer
fire management
pedagogy
data translator
data translation
Statistics and Probability
<p>This is a preprint of the following chapter: McFayden CB, Johnston LM, Woolford DG, George C, Johnston D, Boychuk D, Wotton BM, & Johnston JM, A Conceptual Framework for Knowledge Exchange in a Wildland Fire Research and Practice Context, published in Applied Data Science: Data Translators Across the Disciplines, edited by D Woolford, D Kotsopoulos, & B Samuels, 2023, Springer reproduced with permission of Springer Nature. The final authenticated version is available online at: <a href="http://dx.doi.org/10.1007/978-3-031-29937-7_12">http://dx.doi.org/10.1007/978-3-031-29937-7_12</a> </p>
http://creativecommons.org/licenses/by-nc-nd/4.0/
https://ir.lib.uwo.ca/statspub/3
oai:ir.lib.uwo.ca:statspub-1012
2023-12-05T16:45:29Z
publication:stats
publication:statspub
publication:faculties
Invasion dynamics of the European Collared-Dove in North America are explained by combined effects of habitat and climate
Shao, Yiran
Ethier, Danielle
Bonner, Simon
Article
2023-01-01T08:00:00Z
Bayesian modelling
Citizen science
Habitat condition
Invasive species
Managment planning
Range expansion
Streptopelia decaocto
Ornithological Applications
Ornithological Applications
https://doi.org/10.1093/ornithapp/duad052
Statistics and Probability
<p>Global biodiversity is increasingly threatened by the spread of invasive species. Understanding the mechanisms influencing the initial colonization and persistence of invaders is therefore needed if conservation actions are to prevent new invasions or strive to slow their spread. The Eurasian Collared-Dove (Streptopelia decaocto, EUCO) is one of the most successful avian invasive species in North America; however, to our knowledge, no study has simultaneously examined the role that climate-matching, human activity, directional propagation, and local density have in this invasion process. Our research expands upon a cellular-automata-based hierarchical model developed to assess directional invasion dynamics to further quantify the impacts of climate, elevation, and land cover type on the spread of EUCO in North America. Our results suggest that EUCO’s dispersal patterns can largely be explained by the effects of habitat, climate, and environmental conditions at different stages of the invasion process rather than some innate preferred north-westerly spread. Specifically, EUCO initially colonized warm and wet grassland habitats and tended to persist in urban areas. We also found that while EUCO were more likely to spread to the northeast of existing habitats, directional preference did not drive persistence and recolonization events. These findings highlight the importance of incorporating both neighborhood effects and environmental factors in the modelling of range-expanding species, adding to the toolset available to researchers to model invasive species spread. Further, our research demonstrates that historical records of invasive species occurrences can provide the data resources needed to disentangle the characteristics driving species invasion and enable predictions that are of critical importance to resource managers.</p>
<p>This is a pre-copyedited, author-produced PDF of an article accepted for publication in Ornithological Applications following peer review. The version of record [Invasion dynamics of the European Collared-Dove in North America are explained by combined effects of habitat and climate. Ornithological Applications (2023)] is available online at: <a href="https://doi.org/10.1093/ornithapp/duad052">https://doi.org/10.1093/ornithapp/duad052</a>.</p>
http://creativecommons.org/licenses/by/4.0/
https://ir.lib.uwo.ca/statspub/4