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Dive into the research topics where Katherine T. Chen is active.

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Featured researches published by Katherine T. Chen.


Obstetrics & Gynecology | 2006

Prevalence of methicillin-sensitive and methicillin-resistant Staphylococcus aureus in pregnant women.

Katherine T. Chen; Richard C. Huard; Phyllis Della-Latta; Lisa Saiman

OBJECTIVE: To estimate the extent of Staphylococcus aureus vaginal-rectal colonization among pregnant women as severe S aureus infections have emerged in pregnant and postpartum women and infants. METHODS: We conducted a prospective surveillance study for methicillin-sensitive S aureus and methicillin-resistant S aureus on all routine de-identified vaginal-rectal prenatal group B streptococcus (GBS) screening cultures submitted to the microbiology laboratory of a tertiary-care facility from January to July 2005. Standard microbiologic techniques and molecular analyses were used to detect community-associated methicillin-resistant S aureus strains. As opposed to health care–associated methicillin-resistant S aureus isolates, community-associated methicillin-resistant S aureus isolates were defined as those possessing the type IV or type V staphylococcal chromosomal cassette mec element and usually lacking a multidrug-resistant phenotype. RESULTS: A total of 2,963 GBS screening cultures were analyzed, from which 743 (25.1%, 95% confidence interval [CI] 23.5–26.7%) GBS isolates and 507 (17.1%, 95% CI 15.7–18.5%) S aureus isolates were identified. Group B streptococcus colonization was significantly associated with S aureus colonization (prevalence odds ratio 2.1, 95% CI 1.7–2.5, P<.001). Of the S aureus isolates, 14 (2.8%, 95% CI 1.4–4.2%) were methicillin-resistant, and 13 of these were determined to be community-associated methicillin-resistant S aureus. CONCLUSION: The prevalence of S aureus colonization identified in GBS screening cultures from pregnant women was substantial and associated with GBS co-colonization. Although we do not advocate routine screening of pregnant women for methicillin-sensitive S aureus and methicillin-resistant S aureus colonization, we recommend continued monitoring of both methicillin-sensitive S aureus and methicillin-resistant S aureus infections in this population and their infants. LEVEL OF EVIDENCE: II-3


Obstetrics & Gynecology | 2005

Genital herpes simplex virus infection and perinatal transmission of human immunodeficiency virus

Katherine T. Chen; Marta Segu; L. H. Lumey; Louise Kuhn; Rosalind J. Carter; Marc Bulterys; Elaine J. Abrams

OBJECTIVE: To assess the risk of perinatal human immunodeficiency virus (HIV) transmission in HIV-infected women clinically diagnosed with genital herpes simplex virus (HSV) infection during pregnancy. METHODS: This retrospective analysis included 402 HIV-infected pregnant women who enrolled from 1994–1999 in a multicenter prospective cohort study in New York City, who delivered a liveborn singleton infant with known HIV infection status, and who had information on diagnosis of genital HSV infection during pregnancy. Study participants were determined to have genital HSV infection during pregnancy by documentation of clinical diagnosis. RESULTS: Forty-six (11.4%) of the study participants delivered HIV-infected infants. Twenty-one (5.2%) had clinical diagnosis of genital HSV infection in pregnancy. Six (28.6%) of the 21 HIV-infected women with a clinical diagnosis of genital HSV infection delivered an HIV-infected infant. In univariate analyses, HIV-infected pregnant women with clinical diagnosis of genital HSV infection during pregnancy had a significantly increased risk of perinatal HIV transmission (odds ratio 3.4, 95% confidence interval 1.3–9.3; P = .02). When other factors associated with perinatal HIV transmission were included in a logistic regression model (lack of zidovudine therapy during pregnancy or delivery, prolonged rupture of membranes, and preterm delivery), clinical diagnosis of genital HSV infection during pregnancy remained a significant independent predictor of perinatal HIV transmission (adjusted odds ratio 4.8, 95% confidence interval 1.3–17.0; P = .02). CONCLUSION: Clinical diagnosis of genital HSV infection during pregnancy in HIV-infected women may be a risk factor for perinatal HIV transmission. If future studies confirm this association, therapy to suppress genital HSV reactivation during pregnancy may be a strategy to reduce perinatal HIV transmission. LEVEL OF EVIDENCE: II-3


Clinical Infectious Diseases | 2005

Hepatitis C Virus Coinfection and HIV Load, CD4+ Cell Percentage, and Clinical Progression to AIDS or Death among HIV-Infected Women: Women and Infants Transmission Study

Ronald C. Hershow; Peter T. O'Driscoll; Ed Handelsman; Jane Pitt; George V. Hillyer; Leslie Serchuck; Ming Lu; Katherine T. Chen; Sigal Yawetz; Susan E. Pacheco; Katherine Davenny; Samuel Adeniyi-Jones; David L. Thomas

BACKGROUND Despite previous study, it remains unclear whether hepatitis C virus (HCV) coinfection affects the progression of human immunodeficiency virus (HIV) type 1 infection. The Women and Infants Transmission Study provided an opportunity to assess this issue. METHODS Longitudinal data on 652 HIV-1-infected women enrolled in the study before the availability of highly active antiretroviral therapy (HAART; 1989-1995) were analyzed. Random effects models were used to determine whether HCV coinfection was associated with different CD4+ cell percentages and HIV-1 RNA levels over time, and Cox proportional hazards models were used to compare the rates of clinical progression to acquired immunodeficiency syndrome (AIDS) or death. RESULTS Of 652 women, 190 (29%) were HCV infected. During follow-up, 19% of women were exposed to HAART. After controlling for indicators of disease progression (CD4+ cell percentages and HIV-1 RNA levels determined closest to the time of delivery in pregnant women), ongoing drug use, receipt of antiretroviral therapy, and other important covariates, no differences were detected in the HIV-1 RNA levels, but the CD4+ cell percentages were slightly higher in HCV-infected women than in HCV-uninfected women. During follow-up, 48 women had progression to a first clinical AIDS-defining illness (ADI), and 26 died with no documented antecedent ADI. In multivariable analyses, HCV-infected participants did not have faster progression to a first class C AIDS-defining event or death (relative hazard, 0.75; 95% confidence interval, 0.37-1.53). CONCLUSIONS In this cohort, the rate of clinical progression of HIV-1 infection was not greater for HCV-infected women.


Obstetrics & Gynecology | 2001

Cost-effectiveness of elective cesarean delivery in human immunodeficiency virus–infected women

Katherine T. Chen; Randall L Sell; Ruth Tuomala

Objective To evaluate the cost-effectiveness of an elective cesarean delivery strategy in human immunodeficiency virus (HIV)-infected women receiving zidovudine therapy to prevent perinatal transmission. Methods A decision-analysis model was constructed to compare two delivery strategies in HIV-infected women: usual care and recommendation for elective cesarean delivery. The model followed a hypothetical cohort of 7000 HIV-infected pregnant women in the United States who were receiving zidovudine therapy for 1 year. The third-party payer perspective was taken. Cost of delivery method with and without complications and lifetime medical care cost for pediatric HIV infection were considered. The main outcome measure was cases of perinatal HIV transmission prevented. Results Compared with the usual care strategy, the elective cesarean delivery strategy resulted in an additional 3486 cesarean deliveries each year, prevented 142 cases (52.4%) of perinatal HIV transmission, and resulted in incremental overall cost savings to society of


Obstetrics & Gynecology | 2014

Identification of iPhone and iPad applications for obstetrics and gynecology providers.

Sara Farag; Kathy Chyjek; Katherine T. Chen

5.3 million per year (


Obstetrics & Gynecology | 2016

Evaluation of Smartphone Menstrual Cycle Tracking Applications Using an Adapted APPLICATIONS Scoring System.

Michelle L. Moglia; Henry V. Nguyen; Kathy Chyjek; Katherine T. Chen; Paula M. Castaño

37,284 saved per case of perinatal transmission prevented). With other estimates held constant, the elective cesarean delivery strategy would not be cost saving when the baseline perinatal HIV transmission rates were all reduced by 43.3%. Conclusions Elective cesarean delivery in HIV-infected women receiving zidovudine is one management strategy for prevention of perinatal HIV transmission and can be cost saving. However, if other strategies, such as use of combination antiretroviral therapy and/or measurement of viral load, result in at least 50% reduction of the baseline perinatal HIV transmission rates, elective cesarean delivery will not be cost saving.


Obstetrics & Gynecology | 2015

Rating Pregnancy Wheel Applications Using the APPLICATIONS Scoring System.

Kathy Chyjek; Sara Farag; Katherine T. Chen

OBJECTIVE: To systematically identify the number of applications (“apps”) compatible with the iPhone and the iPad that are potentially useful to obstetrician–gynecologists (ob-gyns). METHODS: Obstetrics and gynecology MeSH terms were searched in the Apple iTunes Store. A master list of unique apps was created and the apps were divided into categories and subcategories. RESULTS: A total of 1,816 unique apps using 55 different obstetrics and gynecology MeSH terms were found. Of these unique apps, 242 apps (13.3%) were considered potentially useful to ob-gyns. The MeSH terms that yielded the highest number of potentially useful apps were “gynecology” (23%), “breast cancer” (17%), “obstetrics” (14%), and “pregnancy” (12%). CONCLUSION: Less than 15% of apps found were considered potentially useful to ob-gyns. Thus, the obstetrics and gynecology community is in need of an organized effort to identify, review, and determine the accuracy of apps that can potentially improve the performance of health care providers and lead to better patient outcomes. We propose the formation of a committee to guide in this important task. LEVEL OF EVIDENCE: III


American Journal of Obstetrics and Gynecology | 2008

No association between antepartum serologic and genital tract evidence of herpes simplex virus-2 coinfection and perinatal HIV-1 transmission.

Katherine T. Chen; Ruth Tuomala; Clara Chu; Meei Li Huang; D. Heather Watts; Carmen D. Zorrilla; Mary E. Paul; Ron Hershow; Philip LaRussa

OBJECTIVE: To identify smartphone menstrual cycle tracking applications (apps) and evaluate their accuracy, features, and functionality. METHODS: In this systematic evaluation, we searched the Apple iTunes store for free menstrual cycle tracking apps for patient use. We considered an application accurate if menstrual cycle predictions were based on average cycle lengths of at least three previous cycles, ovulation (when included) was predicted at 13–15 days before the start of the next cycle, and the application contained no misinformation. We modified the APPLICATIONS Scoring System to evaluate the features and functionality of accurate apps. RESULTS: Our search criteria yielded 1,116 apps; 108 remained after excluding duplicate, non-English, nonmenstrual cycle tracking, and priced apps. We further eliminated 88 that did not meet inclusion or accuracy criteria. Of the 20 accurate, free apps, 80% contained information for conception and 50% for contraception. Common features and functionality included password protection (55%); no requirement for Internet connectivity (80%); no advertisements (65%); in-application technical support (70%); medical disclaimers (65%); health education (55%); tracking of menstrual flow (70%), symptoms (70%), and intercourse (75%); alerts for next menses (65%) and fertility (55%); and cycle length information (75%). Forty percent were available for Android. Usefulness for fertility medications (15%), professional involvement (5%), and cited literature (5%) were rare. CONCLUSION: Most free smartphone menstrual cycle tracking apps for patient use are inaccurate. Few cite medical literature or health professional involvement. We list accurate apps to aid health care providers in understanding the key components they can use to evaluate and recommend apps for patients.


AIDS | 2012

Small for Gestational Age Birth Outcomes in Pregnant Women with Perinatally Acquired HIV

Jennifer Jao; Keith Sigel; Katherine T. Chen; Gabriela Rodriguez-Caprio; Roberto Posada; Gail Shust; Juan P. Wisnivesky; Elaine J. Abrams; Rhoda S. Sperling

OBJECTIVE: To identify the top-rated pregnancy wheel applications (apps) using a newly developed APPLICATIONS scoring system. METHODS: A list of pregnancy wheel apps was identified. Consumer-based and inaccurate apps were excluded. The APPLICATIONS scoring system was developed to rate the remaining apps. Application comprehensiveness was evaluated. Objective rating components included price, paid subscription, literature used, in-app purchases, connectivity to the Internet, advertisements, text search field, interdevice compatibility, and other components such as images or figures, videos, and special features. Subjective rating components were ease of navigation and subjective presentation. RESULTS: A complete list of 55 pregnancy wheel apps was created from three sources. Thirty-nine (71%) were consumer-based, inaccurate, or both, leaving 16 (29%) for analysis using the APPLICATIONS scoring system. CONCLUSION: More than two thirds of pregnancy wheel apps were excluded from our study secondary to being consumer-based, inaccurate, or both. This highlights the importance of identifying systematically, reviewing critically, and rating the thousands of available apps to health care providers to ensure accuracy and applicability. We propose that our APPLICATIONS scoring system be used to rate apps in all specialties with the goal of improving health care provider performance and thereby patient outcomes. LEVEL OF EVIDENCE: III


Journal of Perinatology | 2002

The role of intrapartum fever in identifying asymptomatic term neonates with early-onset neonatal sepsis.

Katherine T. Chen; Steven A. Ringer; Amy Cohen; Ellice Lieberman

OBJECTIVE The purpose of this study was to assess the risk of perinatal HIV-1 transmission in women who are coinfected with herpes simplex virus-2 (HSV-2). STUDY DESIGN We performed a nested case-control study of 26 women whose HIV-1 was transmitted to their infants and 52 control subjects whose HIV-1 was not transmitted. We assessed antepartum serologic evidence of HSV-2 by HSV-2 serostatus and genital tract evidence of HSV-2 by presence of HSV-2 DNA. RESULTS There was no significant association between antepartum serologic evidence of HSV-2 coinfection and the risk of perinatal HIV-1 transmission. There was also no association between antepartum genital tract evidence of HSV-2 coinfection and risk of perinatal HIV-1 transmission. CONCLUSION Women who were infected with HIV-1 with antepartum serologic and genital tract evidence of HSV-2 coinfection did not appear to have an increased risk of perinatal HIV-1 transmission. However, further investigations are needed to assess HSV-2 reactivation and the risk of perinatal HIV-1 transmission at the time of delivery.

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Britt Lunde

University of Illinois at Chicago

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Ellice Lieberman

Brigham and Women's Hospital

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Sara Farag

Icahn School of Medicine at Mount Sinai

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Phyllis Della-Latta

Columbia University Medical Center

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Ruth Tuomala

Brigham and Women's Hospital

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Adam Jacobs

Icahn School of Medicine at Mount Sinai

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