Zhen Chen
ORCID: 0000-0001-5299-7365
· 40 papers in corpus
other
2013
Inter-rater reliability is usually assessed by means of the intraclass correlation coefficient. Using two-way analysis of variance to model raters and subjects as random effects, we derive group sequential testing procedures for the design …
other
2013
Analysis of human urine is commonly used in biomonitoring studies to assess exposure to essential (e.g., Cu, Zn, Se) and non-essential (Pb, Cd, Pt) trace elements. These data are also used in epidemiological studies to evaluate potential as…
observational
2013
There has been limited study of trace elements and endometriosis. Using a matched cohort design, 473 women aged 18-44 years were recruited into an operative cohort, along with 131 similarly aged women recruited into a population cohort. End…
other
2012
BACKGROUND: Obesity is a growing public health problem among reproductive-aged women, with consequences for chronic disease risk and reproductive and obstetric morbidities. Evidence also suggests that body shape (i.e., regional fat distribu…
other
2012
In diagnostic medicine, estimating the diagnostic accuracy of a group of raters or medical tests relative to the gold standard is often the primary goal. When a gold standard is absent, latent class models where the unknown gold standard te…
diagnostic-accuracy
2012
OBJECTIVE: To estimate the interrater and intrarater reliability of endometriosis diagnosis and severity of disease among gynecologic surgeons viewing operative digital images. METHODS: The study population comprised a random sample (n=148…
observational
2012
OBJECTIVE: To assess in utero exposures and the odds of an endometriosis diagnosis. DESIGN: Matched cohort design. SETTING: Fourteen participating clinical centers in geographically defined areas in Utah and California. PATIENT(S): Opera…
other
2012
High-dimensional biomarker data are often collected in epidemiological studies when assessing the association between biomarkers and human disease is of interest. We develop a latent class modeling approach for joint analysis of high-dimens…
other
2012
We propose efficient nonparametric statistics to compare medical imaging modalities in multi-reader multi-test data and to compare markers in longitudinal ROC data. The proposed methods are based on the weighted area under the ROC curve, wh…
observational
2012
BACKGROUND: Environmental chemicals may be associated with endometriosis. No published research has focused on the possible role of perfluorochemicals (PFCs) despite their widespread presence in human tissues. METHODS: We formulated two sa…
observational
2012
BACKGROUND: An equivocal literature exists regarding the relation between persistent organochlorine pollutants (POPs) and endometriosis in women, with differences attributed to methodologies. OBJECTIVES: We assessed the association between…
observational
2012
Benzophenone (BP)-type UV filters are widely used in a variety of personal care products for the protection of skin and hair from UV irradiation. Despite the estrogenic potencies of BP derivatives, few studies have examined the occurrence o…
observational
2011
OBJECTIVE: To estimate the incidence of endometriosis in an operative cohort of women seeking clinical care and in a matched population cohort to delineate more fully the scope and magnitude of endometriosis in the context of and beyond cli…
2011
observational
2011
Background and Aims: Persistent organic pollutants (POPs) have been associated with endometriosis, though with equivocal results possibly reflecting choice of biospecimen. We sought to assess this ...