Michele L Jonsson Funk

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Doubly robust estimation combines a form of outcome regression with a model for the exposure (i.e., the propensity score) to estimate the causal effect of an exposure on an outcome. When used individually to estimate a causal effect, both outcome regression and propensity score methods are unbiased only if the statistical model is correctly specified. The(More)
CONTEXT Patients with chronic heart failure have impaired long-term survival, but their own expectations regarding prognosis have not been well studied. OBJECTIVES To quantify expectations for survival in patients with heart failure, to compare patient expectations to model predictions, and to identify factors associated with discrepancies between(More)
To estimate the risk of repeat surgery for recurrent prolapse or mesh removal after vaginal mesh versus native tissue repair for anterior vaginal wall prolapse. We utilized longitudinal, adjudicated, healthcare claims from 2005 to 2010 to identify women ≥18 years who underwent an anterior colporrhaphy (CPT 57420) with or without concurrent vaginal mesh (CPT(More)
Hepatitis B is a serious disease that is endemic in many parts of the world. A significant proportion of patients with chronic hepatitis B (CHB) are infected with a variant form of the hepatitis B virus (HBV) which decreases or abolishes the production of hepatitis B e-antigen (HBeAg). The purpose of this literature review is to describe the epidemiology of(More)
OBJECTIVE Propensity scores for the analysis of observational data are typically estimated using logistic regression. Our objective in this review was to assess machine learning alternatives to logistic regression, which may accomplish the same goals but with fewer assumptions or greater accuracy. STUDY DESIGN AND SETTING We identified alternative methods(More)
The applied literature on propensity scores has often cited the c-statistic as a measure of the ability of the propensity score to control confounding. However, a high c-statistic in the propensity model is neither necessary nor sufficient for control of confounding. Moreover, use of the c-statistic as a guide in constructing propensity scores may result in(More)
OBJECTIVE To assess the practice of adjuvant radiation (RT) for endometrial cancer in the United States following the publication of the Post Operative Radiation Therapy in Endometrial Carcinoma (PORTEC1), and Gynecologic Oncology Group-Adjuvant Radiation for Intermediate Risk Endometrial Cancers (GOG99). METHODS A retrospective cohort study using the NCI(More)
We compared an assay using signal amplification of a heat-dissociated p24 antigen (HDAg) with the Roche Monitor human immunodeficiency virus (HIV) RNA assay. The two assays gave comparable results when 130 specimens from 130 patients were tested (r = 0.60, P < 0.0001). The HDAg assay was almost as sensitive (85%) as the Roche HIV RNA kit (95%), just as(More)
A high-pressure liquid chromatographic method was developed for the separation and quantitation of salicylsalicylic acid (I), aspirin (II), and salicylic acid (III) in human plasma and urine. The method for plasma involves the selective extraction of I--III and an internal standard, alpha-phenylcinnamic acid, into methylene chloride from acidified plasma,(More)
OBJECTIVE While some observational studies have suggested a protective effect of metformin on incident cancer, concerns about potential bias remain. We compared the incidence of endometrial cancer in metformin versus sulfonylurea initiators. Research design and methods We conducted a retrospective cohort analysis using US healthcare claims (MarketScan®),(More)