Fixed-effect versus random-effect models for evaluating therapeutic preferences

2002 ◽  
Vol 21 (16) ◽  
pp. 2325-2330 ◽  
Author(s):  
Y. Lee
Keyword(s):  
Random Effect ◽  
Fixed Effect ◽  
Therapeutic Preferences ◽  
Random Effect Models

Abstract 005: A Comparison of Methods for Identifying Hospital Performance Outliers in Cardiac Surgery

2017 ◽  
Vol 10 (suppl_3) ◽  
Author(s):  
Xiaoting Wu ◽  
Min Zhang ◽  
Richard L Prager ◽  
Donald S Likosky
Keyword(s):  
Logistic Regression ◽  
Regression Models ◽  
Random Effect ◽  
Hospital Performance ◽  
Fixed Effect ◽  
Logistic Regression Models ◽  
Indirect Standardization ◽  
Statistical Approaches ◽  
Random Effect Models ◽  
Direct Standardization

Introduction: A number of statistical approaches have been advocated and implemented to estimate adjusted hospital outcomes for public reporting or reimbursement. Nonetheless, the ability of these methods to identify hospital performance outliers in support of quality improvement has not yet been fully investigated. Methods: We leveraged data from patients undergoing coronary artery bypass grafting surgery between 2012-2015 at 33 hospitals participating in a statewide quality collaborative. We applied 5 different statistical approaches (1: indirect standardization with standard logistic regression models, 2: indirect standardization with fixed effect models, 3: indirect standardization with random effect models, 4: direct standardization with fixed effect models, 5: direct standardization with random effect models) to estimate hospital post-operative pneumonia rates adjusting for patients’ risk. Unlike the standard logistic regression models, both fixed effect and random effect models accounted for hospital effect. We applied each method to each year, and subsequently compared methods in their ability to identify hospital performance outliers. Results: Pneumonia rates ranged from 0 % to 24 %. The standard logistic regression models for 2013-2015 had c-statistics of 0.73-0.75, fixed effect models had c-statistics of 0.81-0.83, and random effect models had c-statistics of 0.80-0.83. Each method differed in its ability to identify performance outliers (Figure 1). In direct standardization, random effect models stabilized the hospital rates by moving the estimated rates toward the average rate, fixed effect models produced larger standard errors of hospital effect (particularly for hospitals with low case volumes). In indirect standardization, the three models showed high agreement on their derived observed: expected ratio (intraclass correlation =0.95). Indirect standardization with fixed effect or random effect models, identified similar hospital performance outliers in each year. Conclusion: The five statistical approaches varied in their ability to identify performance outliers. Given its higher sensitivity to outlier hospitals, indirect standardization methods with fixed or random effect models, may be best suited to support quality improvement activities.

Fixed-effect or Random-effect Models

Medical Care ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 25-27 ◽  
Author(s):  
Claude M. Setodji ◽  
Michael Shwartz
Keyword(s):  
Random Effect ◽  
Fixed Effect ◽  
Random Effect Models

scholarly journals 263 Effects of soybean meal level on growth performance of 11- to 25-kg nursery pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 87-88
Author(s):  
Henrique S Cemin ◽  
Mike D Tokach ◽  
Steve S Dritz ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Growth Performance ◽  
Soybean Meal ◽  
Random Effect ◽  
Fixed Effect ◽  
Nursery Pigs ◽  
Energy Value ◽  
Caloric Efficiency ◽  
Main Effects

Abstract Four experiments were conducted to determine the effects of increasing soybean meal (SBM) in diets with or without 25% DDGS on growth performance of nursery pigs. Treatments were arranged in a 2 × 3 factorial with main effects of SBM (27.5, 32.5, or 37.5%) and DDGS (0 or 25%). A total of 296, 2,502, 4,118, and 711 pigs, initially 10.6, 11.7, 12.5, and 12.3 kg, were used and there were 10, 16, 13, and 12 replicates per treatment in Exp. 1, 2, 3, and 4, respectively. Experimental diets were fed for 21 d. Pigs were weighed and feed disappearance measured to calculate ADG, ADFI, G:F, and caloric efficiency (CE). Data were analyzed using the GLIMMIX procedure of SAS with block as random effect and treatment as fixed effect. The average cull rate was 0.7, 0.5, 0.2, and 0% and the mortality rate was 0.7, 0.3, 0.4, and 0% in Exp. 1 to 4, respectively. There were interactions (P ≤ 0.039) between SBM and DDGS for G:F and CE in Exp. 2 and for ADG and ADFI in Exp. 3. These were mostly driven by increasing SBM negatively affecting performance in a greater magnitude when diets contained DDGS compared to diets without DDGS. The main effects of DDGS and SBM were more consistent across experiments. Pigs fed diets with 25% DDGS had decreased (P ≤ 0.001) ADG and ADFI in all experiments as well as poorer (P ≤ 0.028) G:F and CE except for Exp. 3. Feeding increasing amounts of SBM generally did not result in any major impact in ADG, but consistently improved (linear, P ≤ 0.078) G:F and CE across experiments. The mechanism for this response is unclear but could be driven by intrinsic components of SBM or underestimating the energy value of SBM.

scholarly journals LO84: The incidence of fall-related intracranial bleeding in older adults taking anticoagulants, antiplatelets and neither medication: a meta-analysis

CJEM ◽  
2020 ◽  
Vol 22 (S1) ◽  
pp. S38-S38
Author(s):  
K. de Wit ◽  
D. Nishijima ◽  
S. Mason ◽  
R. Jeanmonod ◽  
S. Parpia ◽  
...  
Keyword(s):  
Older Adults ◽  
Meta Analysis ◽  
Grey Literature ◽  
Random Effect ◽  
Intracranial Bleeding ◽  
Inclusion Criteria ◽  
Antiplatelet Medication ◽  
Cochrane Database ◽  
Random Effect Models ◽  
Anticoagulant Medication

Introduction: It is unclear whether anticoagulant or antiplatelet medications increase the risk for intracranial bleeding in older adults after a fall. Our aim was to report the incidence of intracranial bleeding among older adults presenting to the emergency department (ED) with a fall, among patients taking anticoagulants, antiplatelet medications, both medications and neither medication. Methods: This was a systematic review and meta-analysis, PROSPERO reference CRD42019122626. Medline, EMBASE (via OVID 1946 - July 2019), Cochrane, Database of Abstracts of Reviews of Effects databases and the grey literature were searched for studies reporting on older adults who were evaluated after a fall. We included prospective studies conducted in the ED where more than 80% of the cohort were 65 years or older and had fallen. We contacted study authors for aggregate data on intracranial bleeding in patients prescribed anticoagulant medication, antiplatelet medication and neither medication. Incidences of intracranial bleeding were pooled using random effect models, and I2 index was used to assess heterogeneity. Results: From 7,240 publication titles, 10 studies met inclusion criteria. The authors of 8 of these 10 studies provided data (on 9,489 patients). All studies scored low or moderate risk of bias. The pooled incidence of intracranial bleeding among patients taking an anticoagulant medication was 5.1% (n = 5,016, 95% Confidence Interval (CI): 4.1 to 6.3%) I2 = 42%, a single antiplatelet 6.4% (n = 2,148, 95% CI: 5.4 to 7.6%) I2 = 75%, both anticoagulant and antiplatelet medications 5.9% (n = 212, 95% CI: 1.3 to 13.5%) I2 = 72%, and neither of these medications 4.8% (n = 1,927, 95% CI: 3.5 to 6.2%) I2 = 50%. A sensitivity analysis restricted to patients who had a head CT in the ED reported incidences of 6.1% (n = 3,561, 95% CI: 3 to 8.3%), 8.4% (n = 1,781, 95% CI: 5.5 to 11.8%), 6.7% (n = 206, 95% CI 1.5 to 15.2%) and 6.6% (n = 1,310, 95% CI: 5.0 to 8.4%) respectively. Conclusion: The incidence of fall-related intracranial bleeding in older ED patients was similar among patients who take anticoagulant medication, antiplatelet medication, both and neither medication, although there was heterogeneity between study findings.

Correlation between Methylenetetrahydrofolate Reductase Polymorphisms and Hepatocellular Carcinoma: A Meta-Analysis

2019 ◽  
Vol 74 (3) ◽  
pp. 251-256 ◽  
Author(s):  
Hailong Su ◽  
Guo Zhang
Keyword(s):  
Hepatocellular Carcinoma ◽  
Gene Polymorphisms ◽  
Methylenetetrahydrofolate Reductase ◽  
Meta Analysis ◽  
Random Effect ◽  
Recessive Model ◽  
Mthfr Gene ◽  
Systematic Research ◽  
The Relationship ◽  
Random Effect Models

Background: The correlation between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and hepatocellular carcinoma (HCC) remains controversial. Objectives: We performed this study to better assess the relationship between MTHFR gene polymorphisms and the likelihood of HCC. Methods: A systematic research of PubMed, Medline, and Embase was performed to retrieve relevant articles. ORs and 95% CIs were calculated. Results: A total of 15 studies with 8,378 participants were analyzed. In overall analyses, a significant association with the likelihood of HCC was detected for the rs1801131 polymorphism with fixed-effect models (FEMs) in recessive comparison (p = 0.002, OR 0.62, 95% CI 0.43–0.82). However, no positive results were detected for the rs1801133 polymorphism in any comparison. Further subgroup analyses revealed that the rs1801131 polymorphism was significantly associated with the likelihood of HCC in Asians with both FEMs (recessive model: p < 0.0001, OR 0.42, 95% CI 0.29–0.62; allele model: p = 0.004, OR 1.20, 95% CI 1.06–1.35) and random-effect models (recessive model: p = 0.002, OR 0.47, 95% CI 0.29–0.75). Nevertheless, we failed to detect any significant correlation between the rs1801133 polymorphism and HCC. Conclusions: Our findings indicated that the rs1801131 polymorphism may serve as a genetic biomarker of HCC in Asians.

scholarly journals Multivariate random effect models with complete and incomplete data

2012 ◽  
Vol 109 ◽  
pp. 146-155 ◽  
Author(s):  
James O. Chipperfield ◽  
David G. Steel
Keyword(s):  
Incomplete Data ◽  
Random Effect ◽  
Random Effect Models
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