scholarly journals Estimating the causal effects of modifiable, non-genetic factors on Huntington disease progression using propensity score weighting

2021 ◽  
Vol 83 ◽  
pp. 56-62
Author(s):  
Beth Ann Griffin ◽  
Marika Suttorp Booth ◽  
Monica Busse ◽  
Edward J. Wild ◽  
Claude Setodji ◽  
...  
Keyword(s):  
Propensity Score ◽  
Disease Progression ◽  
Huntington Disease ◽  
Genetic Factors ◽  
Causal Effects ◽  
Propensity Score Weighting

Genetically adjusted propensity score matching: Closing the gap between non-experimental designs and true experiments in the social sciences.

2018 ◽  
Author(s):  
Ian A Silver
Keyword(s):  
Social Sciences ◽  
Propensity Score ◽  
Propensity Score Matching ◽  
Genetic Factors ◽  
Difference Score ◽  
Causal Effects ◽  
Risk Scores ◽  
Statistical Techniques ◽  
Point Estimates ◽  
The Social

Objectives: Social scientists employ various statistical techniques to approximate the causal association between two interrelated constructs. Although these methodologies have proven particularly useful for the advancement of knowledge, the limitations associated with preceding statistical techniques limit the ability of scholars to approximate causal associations within some conditions. As such, the current manuscript provides a new statistical technique designed to approximate causal associations.Methods: Genetically adjusted propensity score matching (GAPSM) represents an innovative iteration of propensity score matching (PSM) designed to integrate environmental and genetic factors into the matching process. As proposed, through the implementation of polygenic risk scores, future scholars can estimate genetically adjusted propensity scores (GAPS) through the implementation of two distinct statistical processes. To demonstrate the validity of the GAPSM approach, the current study employs simulation analyses to compare the point estimates derived from a post-GAPSM model, to the point estimates derived from a post-PSM model and a MZ difference score model. Results: The results of the simulation analyses demonstrated that when more robust environmental measures are introduced into the GAPSM approach and a larger amount of the variance in a treatment condition is explained by environmental factors, post-GAPSM models approach the true point estimate more closely than the point estimates derived from post-PSM models and MZ difference score models. Conclusions: Overall, the findings demonstrate that the GAPSM approach can prove useful when assessing the causal effects of treatment conditions on subsequent phenotypes by adjusting for observed environmental and genetic factors. Within the social sciences, this method could provide substantive advancements in our understanding of causal effects.

scholarly journals Switching antifibrotics in patients with idiopathic pulmonary fibrosis: a multi-center retrospective cohort study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuzo Suzuki ◽  
Kazutaka Mori ◽  
Yuya Aono ◽  
Masato Kono ◽  
Hirotsugu Hasegawa ◽  
...  
Keyword(s):  
Cohort Study ◽  
Propensity Score ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Disease Progression ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Survival Times ◽  
Antifibrotic Therapy ◽  
Median Period

Abstract Background Currently, there are two antifibrotics used to treat idiopathic pulmonary fibrosis (IPF): pirfenidone and nintedanib. Antifibrotics slow disease progression by reducing the annual decline of forced vital capacity (FVC), which possibly improves outcomes in IPF patients. During treatment, patients occasionally switch antifibrotic treatments. However, prognostic implication of changing antifibrotics has not yet been evaluated. Methods This multi-center retrospective cohort study examined 262 consecutive IPF patients who received antifibrotic therapy. Antifibrotic agents were switched in 37 patients (14.1%). The prognoses were compared between the patient cohort that switched antifibrotics (Switch-IPF) and those without (Non-Switch-IPF) using propensity-score matched analyses. Results The median period between the initiation of antifibrotic therapy and the drug switch was 25.8 (12.7–35.3) months. The most common reasons for the switch were disease progression (n = 17) followed by gastrointestinal disorders (n = 12). Of the 37 patients that switched antifibrotics, only eight patients disrupted switched antifibrotics by their adverse reactions. The overall prognosis of the Switch-IPF cohort was significantly better than the Non-Switch-IPF cohort (median periods: 67.2 vs. 27.1 months, p < 0.0001). In propensity-score matched analyses that were adjusted to age, sex, FVC (%), history of acute exacerbation, and usage of long-term oxygen therapy, the Switch-IPF cohort had significantly longer survival times than the Non-Switch-IPF group (median 67.2 vs. 41.3 months, p = 0.0219). The second-line antifibrotic therapy showed similar survival probabilities than those in first-line antifibrotic therapy in multistate model analyses. Conclusion Switching antifibrotics is feasible and may improve prognosis in patients with IPF. A further prospective study will be required to confirm clinical implication of switching the antifibrotics.

Association of Body Mass Index With Clinical Outcomes in Patients With Heart Failure With Reduced Ejection Fraction Treated With Sacubitril/Valsartan

2021 ◽  
pp. 107424842110244
Author(s):  
Kazuhiko Kido ◽  
Christopher Bianco ◽  
Marco Caccamo ◽  
Wei Fang ◽  
George Sokos
Keyword(s):  
Heart Failure ◽  
Body Mass Index ◽  
Propensity Score ◽  
Ejection Fraction ◽  
Clinical Outcomes ◽  
Body Mass ◽  
Normal Weight ◽  
Reduced Ejection Fraction ◽  
Propensity Score Weighting ◽  
Patients With Heart Failure

Background: Only limited data are available that address the association between body mass index (BMI) and clinical outcomes in patients with heart failure with reduced ejection fraction who are receiving sacubitril/valsartan. Methods: We performed a retrospective multi-center cohort study in which we compared 3 body mass index groups (normal, overweight and obese groups) in patients with heart failure with reduced ejection fraction receiving sacubitril/valsartan. The follow-up period was at least 1 year. Propensity score weighting was performed. The primary outcomes were hospitalization for heart failure and all-cause mortality. Results: Of the 721 patients in the original cohort, propensity score weighting generated a cohort of 540 patients in 3 groups: normal weight (n = 78), overweight (n = 181), and obese (n = 281). All baseline characteristics were well-balanced between 3 groups after propensity score weighting. Among our results, we found no significant differences in hospitalization for heart failure (normal weight versus overweight: average hazard ratio [AHR] 1.29, 95% confidence interval [CI] = 0.76-2.20, P = 0.35; normal weight versus obese: AHR 1.04, 95% CI = 0.63-1.70, P = 0.88; overweight versus obese groups: AHR 0.81, 95% CI = 0.54-1.20, P = 0.29) or all-cause mortality (normal weight versus overweight: AHR 0.99, 95% CI = 0.59-1.67, P = 0.97; normal weight versus obese: AHR 0.87, 95% CI = 0.53-1.42, P = 0.57; overweight versus obese: AHR 0.87, 95% CI = 0.58-1.32, P = 0.52). Conclusion: We identified no significant associations between BMI and clinical outcomes in patients diagnosed with heart failure with a reduced ejection fraction who were treated with sacubitril/valsartan. A large-scale study should be performed to verify these results.

scholarly journals Varicella zoster virus infections increase the risk of disease flares in patients with SLE: a matched cohort study

2019 ◽  
Vol 6 (1) ◽  
pp. e000339 ◽  
Author(s):  
Fangfang Sun ◽  
Yi Chen ◽  
Wanlong Wu ◽  
Li Guo ◽  
Wenwen Xu ◽  
...  
Keyword(s):  
Propensity Score ◽  
Varicella Zoster Virus ◽  
Cox Regression ◽  
Control Period ◽  
Cox Regression Analysis ◽  
Varicella Zoster ◽  
Propensity Score Weighting ◽  
Kaplan Meier ◽  
Increased Risk ◽  
Risk Of Disease

ObjectiveTo explore whether varicella zoster virus (VZV) infection could increase the risk of disease flares in patients with SLE.MethodsPatients who had VZV reactivations between January 2013 and April 2018 were included from the SLE database (n=1901) of Shanghai Ren Ji Hospital, South Campus. Matched patients with SLE were selected as background controls with a 3:1 ratio. Patients with SLE with symptomatic bacterial infections of the lower urinary tract (UTI) were identified as infection controls. Baseline period and index period were defined as 3 months before and after infection event, respectively. Control period was the following 3 months after the index period. Flare was defined by SELENA SLEDAI Flare Index. Kaplan-Meier analysis, Cox regression model and propensity score weighting were applied.ResultsPatients with VZV infections (n=47), UTI controls (n=28) and matched SLE background controls (n=141) were included. 16 flares (34%) in the VZV group within the index period were observed, as opposed to only 7.1% in UTI controls and 9.9% in background controls. Kaplan-Meier curve revealed that patients with a VZV infection had a much lower flare-free survival within the index period compared with the controls (p=0.0003). Furthermore, after adjusting for relevant confounders including baseline disease activity and intensity of immunosuppressive therapy, Cox regression analysis and propensity score weighting confirmed that VZV infection within 3 months was an independent risk factor for SLE flares (HR 3.70 and HR 4.16, respectively).ConclusionsIn patients with SLE, recent VZV infection within 3 months was associated with increased risk of disease flares.

Impact of resection and ablation for single hypovascular hepatocellular carcinoma ≤2 cm analysed with propensity score weighting

2018 ◽  
Vol 38 (3) ◽  
pp. 484-493 ◽  
Author(s):  
Kenichi Takayasu ◽  
Shigeki Arii ◽  
Michiie Sakamoto ◽  
Yutaka Matsuyama ◽  
Masatoshi Kudo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Propensity Score ◽  
Propensity Score Weighting
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