Filters








16,473 Hits in 6.3 sec

Yield and bias in defining a cohort study baseline from electronic health record data

Jason L. Vassy, Yuk-Lam Ho, Jacqueline Honerlaw, Kelly Cho, J. Michael Gaziano, Peter W.F. Wilson, David R. Gagnon
2018 Journal of Biomedical Informatics  
We aimed to examine the yield and potential for these healthcare process biases in defining a study baseline using EHR data, using the example of cholesterol and blood pressure (BP) measurements.  ...  Aims-Despite growing interest in using electronic health records (EHR) to create longitudinal cohort studies, the distribution and missingness of EHR data might introduce selection bias and information  ...  JLV is supported by NIH L30-DK089597, KL2-TR001100, and Career Development Award IK2-CX001262 from the United States Department of Veterans Affairs Clinical Sciences Research and Development Service.  ... 
doi:10.1016/j.jbi.2017.12.017 pmid:29305952 pmcid:PMC5846098 fatcat:m5xigkdywzdtxdpixhq6kper7y

Statins and Risk of Lower Limb Revision Surgery: The Influence of Differences in Study Design Using Electronic Health Records From the United Kingdom and Denmark

Arief Lalmohamed, Tjeerd P. van Staa, Peter Vestergaard, Hubertus G. M. Leufkens, Anthonius de Boer, Pieter Emans, Cyrus Cooper, Frank de Vries
2016 American Journal of Epidemiology  
Our study base consisted of patients with a primary total joint replacement in Denmark and the United Kingdom (n = 189,286; 1987-2012).  ...  In contrast, both time-fixed cohort designs yielded substantially lower risk estimates (IRR = 0.36 (95% CI: 0.34, 0.38) and IRR = 0.65 (95% CI: 0.63, 0.68), respectively).  ...  ACKNOWLEDGMENTS The funders had no role in the design and conduct of the study; the collection, management, analysis, and interpretation of the data; or the preparation, review, or approval of the manuscript  ... 
doi:10.1093/aje/kwv311 pmid:27317693 pmcid:PMC5860554 fatcat:oawq5zyhhjavvl4x5v7s6ktydu

Design choices for observational studies of the effect of exposure on disease incidence

Mitchell H Gail, Douglas G Altman, Suzanne M Cadarette, Gary Collins, Stephen JW Evans, Peggy Sekula, Elizabeth Williamson, Mark Woodward
2019 BMJ Open  
We discuss cohort studies, sub-samples from cohorts (case-cohort and nested case-control designs), and population-based or hospital-based case-control studies.  ...  Appropriate study design is the foundation of a scientifically valid observational study. Mistakes in design are often irremediable.  ...  Acknowledgements The authors are members of the Topic Group 5 (Study Design) of the STRATOS (STRrengthening Analytical Thinking for Observational Studies) Initiative (http://www. stratos-initiative. org  ... 
doi:10.1136/bmjopen-2019-031031 pmid:31822541 pmcid:PMC6924819 fatcat:g4ibtxzsnzczrktgtqbwhrx35e

Use and Customization of Risk Scores for Predicting Cardiovascular Events Using Electronic Health Record Data

Julian Wolfson, David M. Vock, Sunayan Bandyopadhyay, Thomas Kottke, Gabriela Vazquez‐Benitez, Paul Johnson, Gediminas Adomavicius, Patrick J. O'Connor
2017 Journal of the American Heart Association : Cardiovascular and Cerebrovascular Disease  
on electronic health data (EHD) face 4 questions. (1) Do published risk scores applied to EHD yield accurate estimates of cardiovascular risk?  ...  Methods and Results--Data were extracted from the EHD of 84 116 adults aged 40 to 79 years who received care at a large healthcare delivery and insurance organization between 2001 and 2011.  ...  this evaluation is performed using data derived from longitudinal cohort studies or electronic health records.  ... 
doi:10.1161/jaha.116.003670 pmid:28438733 pmcid:PMC5532984 fatcat:kgzc44fwlfcofbnjghldk22jtm

Conducting real-world evidence studies on the clinical outcomes of diabetes treatments

Sebastian Schneeweiss, Elisabetta Patorno
2021 Endocrine reviews  
Imagining the randomized trial we would ideally perform before designing an RWE study in its likeness reduces bias; the new-user active comparator cohort design has proven useful in many RWE studies of  ...  RWE studies follow a structured approach: (1) A design layer decides on the study design, which is driven by the study question and refined by a medically informed target population, patient-informed outcomes  ...  Figure 3 : 3 From longitudinal electronic healthcare data to a causal cohort study design Adapted from: Schneeweiss S.  ... 
doi:10.1210/endrev/bnab007 pmid:33710268 pmcid:PMC8476933 fatcat:3mdfu7wpxffndex24al333rune

Physical inactivity, cardiometabolic disease, and risk of dementia: an individual-participant meta-analysis

Mika Kivimäki, Archana Singh-Manoux, Jaana Pentti, Séverine Sabia, Solja T Nyberg, Lars Alfredsson, Marcel Goldberg, Anders Knutsson, Markku Koskenvuo, Aki Koskinen, Anne Kouvonen, Maria Nordin (+17 others)
2019 BMJ (Clinical Research Edition)  
of physical inactivity at study entry, and were linked to electronic health records.  ...  strategy was designed to retrieve individual-participant data from prospective cohort studies.  ...  Dementia ascertainment was based on electronic health records.  ... 
doi:10.1136/bmj.l1495 pmid:30995986 pmcid:PMC6468884 fatcat:onl2p7lb4nbypip77lsna7yica

Self-report versus electronic medical record recorded healthcare utilisation in older community-dwelling adults: Comparison of two prospective cohort studies

Emma Wallace, Frank Moriarty, Christine McGarrigle, Susan M. Smith, Rose-Anne Kenny, Tom Fahey, Sarah A. Arias
2018 PLoS ONE  
The aim of this study is to compare healthcare utilisation rates using patient self-report and manual extraction from the general practice (GP) electronic medical record (EMR).  ...  Methods Study population: Two prospective cohort studies (n = 806 and n = 1,377, aged �70 years) conducted in the Republic of Ireland were compared.  ...  A detailed review of and data extraction from each participant's electronic GP EMR was undertaken by researchers at baseline (2010) and again at https://doi.org/10.1371/journal.pone.0206201.g001 Self-report  ... 
doi:10.1371/journal.pone.0206201 pmid:30365518 pmcid:PMC6203362 fatcat:h5mh2wtlqze6dkqelyhijsfdea

Using Primary Care Data to Report Real-World Pancreatic Cancer Survival and Symptomatology [chapter]

Nathan Jeffreys, Hajira Dambha-Miller, Xuejuan Fan, Filipa Ferreira, Harshana Liyanage, Julian Sherlock, John Williams, Rebecca Rice, Ali Stunt, Sara Faithfull, Piers Gatenby, Agnieszka Lemanska (+1 others)
2021 Studies in Health Technology and Informatics  
In this study we extracted a pancreatic cancer cohort from a nationally representative English primary care database of electronic health records (EHRs) and reported on their symptom and mortality data  ...  All-cause mortality data was recorded for 4623 (39.69%). Mean age at recording of cancer diagnosis was 71.4 years (SD 12.0 years). 1-year and 5-year survival was 22.06% and 3.27% respectively.  ...  Acknowledgements This work was supported by a grant from Pancreatic Cancer Action, a registered Charity in England & Wales (1137689) and Scotland (SC049777).  ... 
doi:10.3233/shti210142 pmid:34042727 fatcat:o5id3ot6ozg7fhrrq2nrx3ocoy

Cohort Studies: Marching Forward

R. Thadhani
2006 American Society of Nephrology. Clinical Journal  
Acknowledgments This study was supported by grants DK71674 and HD39223 (R.T.) and Alberta Heritage Foundation for Medical Research and Canadian Institutes for Health Research (M.T.).  ...  Even in cases in which a randomized trial is not feasible, the possibility of biased results from a cohort study remains.  ...  Basic design of prospective cohort study in which a population at risk is identified, exposures are defined at baseline, and the cohort is followed forward in time.  ... 
doi:10.2215/cjn.00080106 pmid:17699334 fatcat:l6bxcmymrnc5tctvdm4ytbnwv4

Cancer risk among insulin users: comparing analogues with human insulin in the CARING five-country cohort study

Anna But, Marie L. De Bruin, Marloes T. Bazelier, Vidar Hjellvik, Morten Andersen, Anssi Auvinen, Jakob Starup-Linde, Marjanka K. Schmidt, Kari Furu, Frank de Vries, Øystein Karlstad, Nils Ekström (+1 others)
2017 Diabetologia  
By using a common data model and semi-aggregate approach, we pooled individual-level records from five cohorts and applied Poisson regression models.  ...  used to conduct a cohort study on new insulin users (N = 327,112).  ...  The study protocol, where data sources and study cohorts are described in more detail, was registered in the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCePP) electronic  ... 
doi:10.1007/s00125-017-4312-5 pmid:28573394 pmcid:PMC5552833 fatcat:iojkpgxfajbixhwtxif4c2croq

Electronic cigarettes for smoking cessation

Jamie Hartmann-Boyce, Hayden McRobbie, Chris Bullen, Rachna Begh, Lindsay F Stead, Peter Hajek
2016 The Cochrane library  
We used a fixed-effect Mantel-Haenszel model to calculate the risk ratio (RR) with a 95% confidence interval (CI) for each study, and where appropriate we pooled data from these studies in meta-analyses  ...  Our searches identified over 1700 records, from which we include 24 completed studies (three RCTs, two of which were eligible for our cessation meta-analysis, and 21 cohort studies).  ...  We offer a narrative synthesis of data from cohort studies.  ... 
doi:10.1002/14651858.cd010216.pub3 pmid:27622384 pmcid:PMC6457845 fatcat:xwjwbxeyqjafjgcbv4ppehca2a

Automated data-adaptive analytics for electronic healthcare data to study causal treatment effects

Sebastian Schneeweiss
2018 Clinical Epidemiology  
This work was funded in part by the Patient-centered Outcomes Research Institute. SS was also funded by the National Institutes of Health and the US Food and Drug Administration.  ...  Acknowledgments The author is grateful for numerous valuable discussions with his colleagues Jeremy A Rassen, Robert J Glynn, Jessica M Franklin, and Richie Wyss as well as most helpful insights from Mark  ...  This study did not adjust for health care utilization markers such as the numbers of visits, which could have improved the estimation. • Toh et al 57 used UK electronic health records from primary care  ... 
doi:10.2147/clep.s166545 pmid:30013400 pmcid:PMC6039060 fatcat:ryp6oybswbbwfllnvivlfcur44

A Naive Bayes machine learning approach to risk prediction using censored, time-to-event data

Julian Wolfson, Sunayan Bandyopadhyay, Mohamed Elidrisi, Gabriela Vazquez-Benitez, David M. Vock, Donald Musgrove, Gediminas Adomavicius, Paul E. Johnson, Patrick J. O'Connor
2015 Statistics in Medicine  
Modern observational databases such as electronic health records (EHRs) provide an alternative to the longitudinal cohort studies traditionally used to construct risk models, bringing with them both opportunities  ...  Predicting an individual's risk of experiencing a future clinical outcome is a statistical task with important consequences for both practicing clinicians and public health experts.  ...  This work was partially supported by NHLBI grant #R01HL102144-01 and AHRQ grant #R21HS017622-01.  ... 
doi:10.1002/sim.6526 pmid:25980520 pmcid:PMC4523419 fatcat:kxocrn36sbgwhdr4fpaz4jxnsi

Use of predicted vital status to improve survival analysis of multidrug-resistant tuberculosis cohorts

Meredith B. Brooks, Salmaan Keshavjee, Irina Gelmanova, Nataliya A. Zemlyanaya, Carole D. Mitnick, Justin Manjourides
2018 BMC Medical Research Methodology  
To address this problem, we develop a tool to predict vital status at the end of a cohort period using the initial treatment outcome and assess its ability to reduce bias in treatment effect estimates.  ...  Multidrug-resistant tuberculosis (MDR-TB) cohorts often lack long-term survival data, and are summarized instead by initial treatment outcomes.  ...  Funding This work was supported by a pilot study grant (U19 OH008861) from the Harvard T.H.  ... 
doi:10.1186/s12874-018-0637-0 pmid:30537944 pmcid:PMC6290510 fatcat:4cgsk5uoenctddand2lyfqiyci

The effects of decentralising antiretroviral therapy care delivery on health outcomes for adolescents and young adults in low- and middle-income countries: a systematic review

Roxanna Haghighat, Janina Steinert, Lucie Cluver
2019 Global Health Action  
The studies and abstracted data were insufficiently homogenous in implementation and study design to justify meta-analysis.  ...  Results: Of 11 potentially eligible studies, two studies from sub-Saharan Africa met inclusion criteria after data disaggregation by age.  ...  We also thank both Florian Scheibe and Adrienne Chan for responding to requests for additional information and age-disaggregated data from their studies.  ... 
doi:10.1080/16549716.2019.1668596 pmid:31558145 pmcid:PMC6781195 fatcat:imcia4cw3rf4tfy742scpnsoky
« Previous Showing results 1 — 15 out of 16,473 results