1,845 results match your criteria BMC Medical Research Methodology [Journal]


A co-produced method to involve service users in research: the SUCCESS model.

BMC Med Res Methodol 2019 Feb 15;19(1):34. Epub 2019 Feb 15.

Centre for Innovative Ageing, College of Human and Health Science, Swansea University, Swansea, UK.

Background: Public and patient involvement is a routine element of health services research methods to produce better designed and reported studies. Although co-production is recommended when involving people in research, methods for involving people are usually designed and managed by researchers and there is little evidence about methods to co-produce models for effective public and patient involvement. We report the method used by a group of patient and carer service users to develop and implement a model for involving public members in research. Read More

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http://dx.doi.org/10.1186/s12874-019-0671-6DOI Listing
February 2019

Assessment of reporting quality of abstracts of systematic reviews with meta-analysis using PRISMA-A and discordance in assessments between raters without prior experience.

BMC Med Res Methodol 2019 Feb 14;19(1):32. Epub 2019 Feb 14.

Center for Evidence-Based Medicine and Health Care, Catholic University of Croatia, Ilica 242, 10000, Zagreb, Croatia.

Background: Reporting quality of systematic reviews' (SRs) abstracts is important because this is often the only information about a study that readers have. The aim of this study was to assess adherence of SR abstracts in the field of anesthesiology with the reporting checklist PRISMA extension for Abstracts (PRISMA-A) and to analyze to what extent will the use of PRISMA-A yield concordant ratings in two raters without prior experience with the checklist.

Methods: We analyzed reporting quality of SRs with meta-analysis of randomized controlled trials of interventions published in the field of anesthesiology from 2012 to 2016 by using 12-item PRISMA-A checklist. Read More

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http://dx.doi.org/10.1186/s12874-019-0675-2DOI Listing
February 2019

Dynamic prediction of repeated events data based on landmarking model: application to colorectal liver metastases data.

BMC Med Res Methodol 2019 Feb 14;19(1):31. Epub 2019 Feb 14.

Department of Biostatistics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Background: In some clinical situations, patients experience repeated events of the same type. Among these, cancer recurrences can result in terminal events such as death. Therefore, here we dynamically predicted the risks of repeated and terminal events given longitudinal histories observed before prediction time using dynamic pseudo-observations (DPOs) in a landmarking model. Read More

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http://dx.doi.org/10.1186/s12874-019-0677-0DOI Listing
February 2019

Efficient two-step multivariate random effects meta-analysis of individual participant data for longitudinal clinical trials using mixed effects models.

BMC Med Res Methodol 2019 Feb 14;19(1):33. Epub 2019 Feb 14.

Department of Health Promotion and Human Behavior, Kyoto University Graduate School of Medicine / School of Public Health, Kyoto, Japan.

Background: Mixed effects models have been widely applied in clinical trials that involve longitudinal repeated measurements, which possibly contain missing outcome data. In meta-analysis of individual participant data (IPD) based on these longitudinal studies, joint synthesis of the regression coefficient parameters can improve efficiency, especially for explorations of effect modifiers that are useful to predict the response or lack of response to particular treatments.

Methods: In this article, we provide a valid and efficient two-step method for IPD meta-analyses using the mixed effects models that adequately addresses the between-studies heterogeneity using random effects models. Read More

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http://dx.doi.org/10.1186/s12874-019-0676-1DOI Listing
February 2019

Chronic Headache Education and Self-management Study (CHESS) - a mixed method feasibility study to inform the design of a randomised controlled trial.

BMC Med Res Methodol 2019 Feb 11;19(1):30. Epub 2019 Feb 11.

Headache Group, UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.

Background: Self-management support programmes are effective in a range of chronic conditions however there is limited evidence for their use in the treatment of chronic headaches. The aim of this study was to test the feasibility of four key aspects of a planned, future evaluative trial of a new education and self-management intervention for people with chronic headache: 1) recruiting people with chronic headache from primary care; 2) a telephone interview for the classification of chronic headaches; 3) the education and self-management intervention itself; and 4) the most appropriate patient reported outcomes (PROMS).

Methods: Participants were identified and recruited from general practices in the West Midlands of the UK. Read More

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http://dx.doi.org/10.1186/s12874-019-0672-5DOI Listing
February 2019

Spurious interaction as a result of categorization.

Authors:
Magne Thoresen

BMC Med Res Methodol 2019 Feb 7;19(1):28. Epub 2019 Feb 7.

Centre for Biostatistics and Epidemiology, Department of Biostatistics, University of Oslo, P.O. Box 1122, Blindern, N-0317, Oslo, Norway.

Background: It is common in applied epidemiological and clinical research to convert continuous variables into categorical variables by grouping values into categories. Such categorized variables are then often used as exposure variables in some regression model. There are numerous statistical arguments why this practice should be avoided, and in this paper we present yet another such argument. Read More

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http://dx.doi.org/10.1186/s12874-019-0667-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6367751PMC
February 2019

Concurrent validity of the Fitbit for assessing sedentary behavior and moderate-to-vigorous physical activity.

BMC Med Res Methodol 2019 Feb 7;19(1):29. Epub 2019 Feb 7.

Department of Health, Kinesiology, and Recreation, University of Utah, Salt Lake City, UT, 84112, USA.

Background: Recent advances in sensor technologies have promoted the use of consumer-based accelerometers such as Fitbit Flex in epidemiological and clinical research; however, the validity of the Fitbit Flex in measuring sedentary behavior (SED) and physical activity (PA) has not been fully determined against previously validated research-grade accelerometers such as ActiGraph GT3X+. Therefore, the purpose of this study was to examine the concurrent validity of the Fitbit Flex against ActiGraph GT3X+ in a free-living condition.

Methods: A total of 65 participants (age: M = 42, SD = 14 years, female: 72%) each wore a Fitbit Flex and GT3X+ for seven consecutive days. Read More

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http://dx.doi.org/10.1186/s12874-019-0668-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6367836PMC
February 2019

Challenges and benefits of integrating diverse sampling strategies in the observation of cardiovascular risk factors (ORISCAV-LUX 2) study.

BMC Med Res Methodol 2019 Feb 4;19(1):27. Epub 2019 Feb 4.

Ministry of Health, Directorate of Health, Luxembourg City, Luxembourg.

Background: It is challenging to manage data collection as planned and creation of opportunities to adapt during the course of enrolment may be needed. This paper aims to summarize the different sampling strategies adopted in the second wave of Observation of Cardiovascular Risk Factors (ORISCAV-LUX, 2016-17), with a focus on population coverage and sample representativeness.

Methods: Data from the first nationwide cross-sectional, population-based ORISCAV-LUX survey, 2007-08 and from the newly complementary sample recruited via different pathways, nine years later were analysed. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-019-0669-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360765PMC
February 2019
2 Reads

Improving reporting of meta-ethnography: the eMERGe reporting guidance.

BMC Med Res Methodol 2019 Jan 31;19(1):25. Epub 2019 Jan 31.

Bangor University, Bangor, UK.

Aims: The aim of this study was to provide guidance to improve the completeness and clarity of meta-ethnography reporting.

Background: Evidence-based policy and practice require robust evidence syntheses which can further understanding of people's experiences and associated social processes. Meta-ethnography is a rigorous seven-phase qualitative evidence synthesis methodology, developed by Noblit and Hare. Read More

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http://dx.doi.org/10.1186/s12874-018-0600-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359764PMC
January 2019

Purposive sampling in a qualitative evidence synthesis: a worked example from a synthesis on parental perceptions of vaccination communication.

BMC Med Res Methodol 2019 Jan 31;19(1):26. Epub 2019 Jan 31.

Cochrane EPOC group and the Informed Health Choices Research Centre, Norwegian Institute of Public Health, Postboks 222 Skøyen, Sandakerveien 24C, inngang D11, 0213, Oslo, Norway.

Background: In a qualitative evidence synthesis, too much data due to a large number of studies can undermine our ability to perform a thorough analysis. Purposive sampling of primary studies for inclusion in the synthesis is one way of achieving a manageable amount of data. The objective of this article is to describe the development and application of a sampling framework for a qualitative evidence synthesis on vaccination communication. Read More

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http://dx.doi.org/10.1186/s12874-019-0665-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6357413PMC
January 2019

Does the provision of a DVD-based audio-visual presentation improve recruitment in a clinical trial? A randomised trial of DVD trial invitations.

BMC Med Res Methodol 2019 Jan 30;19(1):24. Epub 2019 Jan 30.

Medicines Monitoring Unit (MEMO) and Hypertension Research Centre Division of Cardiovascular and Diabetes Medicine, University of Dundee Ninewells Hospital and Medical School, Dundee, United Kingdom.

Background: Recruitment to clinical trials can be challenging. Methods that improve the efficiency of trial recruitment are needed to increase successful study completions. The aim of this study was to ascertain whether sending an audio-visual presentation on a digital versatile disc (DVD), along with usual study invitation materials, would improve recruitment to the Febuxostat versus Allopurinol Streamlined Trial (FAST), a clinical trial in patients with established gout. Read More

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http://dx.doi.org/10.1186/s12874-019-0663-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6354366PMC
January 2019
1 Read

Estimating the loss of lifetime function using flexible parametric relative survival models.

BMC Med Res Methodol 2019 Jan 28;19(1):23. Epub 2019 Jan 28.

Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, Aalborg, 9000, Denmark.

Background: Within cancer care, dynamic evaluations of the loss in expectation of life provides useful information to patients as well as physicians. The loss of lifetime function yields the conditional loss in expectation of life given survival up to a specific time point. Due to the inevitable censoring in time-to-event data, loss of lifetime estimation requires extrapolation of both the patient and general population survival function. Read More

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http://dx.doi.org/10.1186/s12874-019-0661-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6350283PMC
January 2019

Re-formulating Gehan's design as a flexible two-stage single-arm trial.

BMC Med Res Methodol 2019 Jan 28;19(1):22. Epub 2019 Jan 28.

MRC Biostatistics Unit, University of Cambridge, Cambridge, CB2 0SR, UK.

Background: Gehan's two-stage design was historically the design of choice for phase II oncology trials. One of the reasons it is less frequently used today is that it does not allow for a formal test of treatment efficacy, and therefore does not control conventional type-I and type-II error-rates.

Methods: We describe how recently developed methodology for flexible two-stage single-arm trials can be used to incorporate the hypothesis test commonly associated with phase II trials in to Gehan's design. Read More

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http://dx.doi.org/10.1186/s12874-019-0659-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6350340PMC
January 2019

Migraine day frequency in migraine prevention: longitudinal modelling approaches.

BMC Med Res Methodol 2019 Jan 23;19(1):20. Epub 2019 Jan 23.

Economic Modelling Center of Excellence, Amgen Europe GmbH, Suurstoffi 22, P.O. Box 94, CH-6343, Rotkreuz, Switzerland.

Background: Health economic models are critical tools to inform reimbursement agencies on health care interventions. Many clinical trials report outcomes using the frequency of an event over a set period of time, for example, the primary efficacy outcome in most clinical trials of migraine prevention is mean change in the frequency of migraine days (MDs) per 28 days (monthly MDs [MMD]) relative to baseline for active treatment versus placebo. Using these cohort-level endpoints in economic models, accounting for variation among patients is challenging. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-019-0664-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6343253PMC
January 2019
1 Read

Psychometric properties of the Chinese version of the spiritual care-giving scale (C-SCGS) in nursing practice.

BMC Med Res Methodol 2019 Jan 23;19(1):21. Epub 2019 Jan 23.

School of Nursing, Jilin University, Changchun, China.

Background: Spiritual care is defined as recognizing and responding to the needs of the human spirit when the individual is facing trauma, illness, or sadness. Providing spiritual care is one of the core aspects of holistic care, as it is significantly associated with patients' quality of life. The provision of optimal spiritual care requires good understanding by the nurses. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-019-0662-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6343288PMC
January 2019
3 Reads

Comparison of logistic-regression based methods for simple mediation analysis with a dichotomous outcome variable.

BMC Med Res Methodol 2019 Jan 21;19(1):19. Epub 2019 Jan 21.

Department of Epidemiology and Biostatistics, Amsterdam UMC, Location VU University Medical Center, P.O. Box 7057, 1007, MB, Amsterdam, The Netherlands.

Background: Logistic regression is often used for mediation analysis with a dichotomous outcome. However, previous studies showed that the indirect effect and proportion mediated are often affected by a change of scales in logistic regression models. To circumvent this, standardization has been proposed. Read More

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http://dx.doi.org/10.1186/s12874-018-0654-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6341620PMC
January 2019

How to design a dose-finding study using the continual reassessment method.

BMC Med Res Methodol 2019 Jan 18;19(1):18. Epub 2019 Jan 18.

MRC Biostatistics Unit Hub for Trials Methodology Research, University of Cambridge, Cambridge Institute of Public Health, Forvie Site, Robinson Way, Cambridge Biomedical Campus, Cambridge, CB2 0SR, UK.

Introduction: The continual reassessment method (CRM) is a model-based design for phase I trials, which aims to find the maximum tolerated dose (MTD) of a new therapy. The CRM has been shown to be more accurate in targeting the MTD than traditional rule-based approaches such as the 3 + 3 design, which is used in most phase I trials. Furthermore, the CRM has been shown to assign more trial participants at or close to the MTD than the 3 + 3 design. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0638-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6339349PMC
January 2019
5 Reads
2.270 Impact Factor

The triple variable index combines information generated over time from common monitoring variables to identify patients expressing distinct patterns of intraoperative physiology.

BMC Med Res Methodol 2019 Jan 14;19(1):17. Epub 2019 Jan 14.

Department of Anesthesiology, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA, 15261, USA.

Background: Mean arterial pressure (MAP), bispectral index (BIS), and minimum alveolar concentration (MAC) represent valuable, yet dynamic intraoperative monitoring variables. They provide information related to poor outcomes when considered together, however their collective behavior across time has not been characterized.

Methods: We have developed the Triple Variable Index (TVI), a composite variable representing the sum of z-scores from MAP, BIS, and MAC values that occur together during surgery. Read More

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http://dx.doi.org/10.1186/s12874-019-0660-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6332613PMC
January 2019
2 Reads

Likelihood-based random-effects meta-analysis with few studies: empirical and simulation studies.

BMC Med Res Methodol 2019 Jan 11;19(1):16. Epub 2019 Jan 11.

Department of Medical Statistics, University Medical Center Göttingen, Humboldtallee 32, Göttingen, 37073, Germany.

Background: Standard random-effects meta-analysis methods perform poorly when applied to few studies only. Such settings however are commonly encountered in practice. It is unclear, whether or to what extent small-sample-size behaviour can be improved by more sophisticated modeling. Read More

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http://dx.doi.org/10.1186/s12874-018-0618-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6330405PMC
January 2019
1 Read

Reliability of patient-reported complications following hip or knee arthroplasty procedures.

BMC Med Res Methodol 2019 Jan 11;19(1):15. Epub 2019 Jan 11.

South Western Sydney Clinical School, UNSW Sydney, Level 2, Clinical Building, Liverpool Hospital, Cnr Elizabeth and Goulburn Sts, Liverpool NSW, 2170, Australia.

Background: Patient reported outcomes are increasingly used to assess the success of surgical procedures. Patient reported complications are often included as an outcome. However, these data must be validated to be accurate and useful in clinical practice. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0645-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6330452PMC
January 2019
5 Reads

Multiple imputation methods for handling missing values in a longitudinal categorical variable with restrictions on transitions over time: a simulation study.

BMC Med Res Methodol 2019 Jan 10;19(1):14. Epub 2019 Jan 10.

Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia.

Background: Longitudinal categorical variables are sometimes restricted in terms of how individuals transition between categories over time. For example, with a time-dependent measure of smoking categorised as never-smoker, ex-smoker, and current-smoker, current-smokers or ex-smokers cannot transition to a never-smoker at a subsequent wave. These longitudinal variables often contain missing values, however, there is little guidance on whether these restrictions need to be accommodated when using multiple imputation methods. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0653-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6329074PMC
January 2019
7 Reads

A semi-parametric mixed models for longitudinally measured fasting blood sugar level of adult diabetic patients.

BMC Med Res Methodol 2019 Jan 10;19(1):13. Epub 2019 Jan 10.

Arthritis Research UK Centre for Epidemiology, Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Manchester, UK.

Background: At the diabetic clinic of Jimma University Specialized Hospital, health professionals provide regular follow-up to help people with diabetes live long and relatively healthy lives. Based on patient condition, they also provide interventions in the form of counselling to promote a healthy diet and physical activity and prescribing medicines. The main purpose of this study is to estimate the rate of change of fasting blood sugar (FBS) profile experienced by patients over time. Read More

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http://dx.doi.org/10.1186/s12874-018-0648-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327398PMC
January 2019
4 Reads

The current use of feasibility studies in the assessment of feasibility for stepped-wedge cluster randomised trials: a systematic review.

BMC Med Res Methodol 2019 Jan 10;19(1):12. Epub 2019 Jan 10.

Department of Health Sciences, University of Leicester, Leicester, UK.

Background: Stepped-wedge cluster randomised trials (SW-CRTs) are a pragmatic trial design, providing an unprecedented opportunity to increase the robustness of evidence underpinning implementation and quality improvement interventions. Given the complexity of the SW-CRT, the likelihood of trials not delivering on their objectives will be mitigated if a feasibility study precedes the definitive trial. It is not currently known if feasibility studies are being conducted for SW-CRTs nor what the objectives of these studies are. Read More

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http://dx.doi.org/10.1186/s12874-019-0658-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327386PMC
January 2019
1 Read

Methods of sample size calculation in descriptive retrospective burden of illness studies.

BMC Med Res Methodol 2019 Jan 9;19(1). Epub 2019 Jan 9.

Broadstreet Health Economics and Outcomes Research, 343 Railway St Vancouver BC, Vancouver, V6A 1A4, Canada.

Background: Observational burden of illness studies are used in pharmacoepidemiology to address a variety of objectives, including contextualizing the current treatment setting, identifying important treatment gaps, and providing estimates to parameterize economic models. Methodologies such as retrospective chart review may be utilized in settings for which existing datasets are not available or do not include sufficient clinical detail. While specifying the number of charts to be extracted and/or determining whether the number that can feasibly extracted will be clinically meaningful is an important study design consideration, there is a lack of rigorous methods available for sample size calculation in this setting. Read More

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http://dx.doi.org/10.1186/s12874-018-0657-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6325730PMC
January 2019
1 Read

Self-reported and routinely collected electronic healthcare resource-use data for trial-based economic evaluations: the current state of play in England and considerations for the future.

BMC Med Res Methodol 2019 Jan 9;19(1). Epub 2019 Jan 9.

School of Social and Community Medicine, University of Bristol Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK.

Background: Randomised controlled trials (RCTs) are generally regarded as the "gold standard" for providing quantifiable evidence around the effectiveness and cost-effectiveness of new healthcare technologies. In order to perform the economic evaluations associated with RCTs, there is a need for accessible and good quality resource-use data; for the purpose of discussion here, data that best reflect the care received. Traditionally, researchers have developed questionnaires for resource-use data collection. Read More

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http://dx.doi.org/10.1186/s12874-018-0649-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6325715PMC
January 2019
1 Read

An application of a pattern-mixture model with multiple imputation for the analysis of longitudinal trials with protocol deviations.

BMC Med Res Methodol 2019 Jan 9;19(1):10. Epub 2019 Jan 9.

Department of Statistical Sciences, University of Cape Town, Cape Town, Rondebosch7701, South Africa.

Background: The benefit of a given treatment can be evaluated via a randomized clinical trial design. However, protocol deviations may severely compromise treatment effect since such deviations often lead to missing values. The assumption that methods of analysis can account for the missing data cannot be justified and hence methods of analysis based on plausible assumptions should be used. Read More

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http://dx.doi.org/10.1186/s12874-018-0639-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327569PMC
January 2019
1 Read

Modelling reassurances of clinicians with hidden Markov models.

BMC Med Res Methodol 2019 Jan 9;19(1):11. Epub 2019 Jan 9.

School of Medicine, University of St Andrews, North Haugh, St Andrews, KY16 9TF, UK.

Background: A key element in the interaction between clinicians and patients with cancer is reassurance giving. Learning about the stochastic nature of reassurances as well as making inferential statements about the influence of covariates such as patient response and time spent on previous reassurances are of particular importance.

Methods: We fit Hidden Markov Models (HMMs) to reassurance type from multiple time series of clinicians' reassurances, decoded from audio files of review consultations between patients with breast cancer and their therapeutic radiographer. Read More

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http://dx.doi.org/10.1186/s12874-018-0629-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327545PMC
January 2019
1 Read

The power of the group: comparison of interviews and group concept mapping for identifying patient-important outcomes of care.

BMC Med Res Methodol 2019 Jan 8;19(1). Epub 2019 Jan 8.

School of Medicine, Department of Family and Community Medicine, Thomas Jefferson University, Philadelphia, PA, USA.

Background: Data are limited regarding how to effectively and efficiently identify patient priorities for research or clinical care. Our goal was to compare the comprehensiveness and efficiency of group concept mapping (GCM), a group participatory method, to interviews for identifying patient goals when seeking care.

Methods: We engaged patients with moderately- to poorly-controlled diabetes mellitus in either GCM or an individual interview. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0656-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323717PMC
January 2019
5 Reads

Providing quality data in health care - almost perfect inter-rater agreement in the Norwegian tonsil surgery register.

BMC Med Res Methodol 2019 Jan 7;19(1). Epub 2019 Jan 7.

Department of Medical Quality Registries, St. Olav's University Hospital, MTFS, Torgarden, P.O. Box 3250, 7006, Trondheim, Norway.

Background: The Norwegian Tonsil Surgery Register (NTSR) was launched in January 2017. The purpose of the register is to present data on tonsil surgery to facilitate improvements in patient care. Data used for evaluating the quality of medical care needs to be of high reliability. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0651-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323706PMC
January 2019
6 Reads

A scoping review of the problems and solutions associated with contamination in trials of complex interventions in mental health.

BMC Med Res Methodol 2019 Jan 7;19(1). Epub 2019 Jan 7.

Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, 16 De Crespigny Park, London, SE5 8AF, United Kingdom.

Background: In a randomised controlled trial, contamination is defined as the receipt of active intervention amongst participants in the control arm. This review assessed the processes leading to contamination, its typical quantity, methods used to mitigate it, and impact of use of cluster randomisation to prevent it on study findings in trials of complex interventions in mental health.

Methods: This is a scoping review of trial design approaches and methods of study conduct to address contamination. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0646-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323722PMC
January 2019
4 Reads

Population-based assessment of health, healthcare utilisation, and specific needs of Syrian migrants in Germany: what is the best sampling method?

BMC Med Res Methodol 2019 Jan 7;19(1). Epub 2019 Jan 7.

Occupational and Environmental Epidemiology & NetTeaching Unit, Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, Ziemssenstr. 1, 80336, Munich, Germany.

Background: Studies elucidating health-related information and special needs of Syrian migrants living in Germany are urgently required. However, data is scarce and finding appropriate sampling strategies to obtain representative results is challenging. In order to increase survey response in hard-to-reach populations, new methods were developed. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0652-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323854PMC
January 2019
8 Reads

Evidence-based sizing of non-inferiority trials using decision models.

BMC Med Res Methodol 2019 Jan 7;19(1). Epub 2019 Jan 7.

Statistical Research and Applications Branch, Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, 9609 Medical Center Drive, Room 4E534, Bethesda, MD, 20892-9765, USA.

Background: There are significant challenges to the successful conduct of non-inferiority trials because they require large numbers to demonstrate that an alternative intervention is "not too much worse" than the standard. In this paper, we present a novel strategy for designing non-inferiority trials using an approach for determining the appropriate non-inferiority margin (δ), which explicitly balances the benefits of interventions in the two arms of the study (e.g. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0643-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6322228PMC
January 2019
6 Reads

Tests of trend between disease outcomes and ordinal covariates discretized from underlying continuous variables: simulation studies and applications to NHANES 2007-2008.

BMC Med Res Methodol 2019 Jan 5;19(1). Epub 2019 Jan 5.

Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

Background: Many epidemiological studies test trends when investigating the association between a risk factor and a disease outcome. Continuous exposures are commonly discretized when the outcome is nonlinearly related to exposure as well as to facilitate interpretation and reduce measurement error. Guidance is needed regarding statistically valid trend tests for epidemiological data of this nature. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0630-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6321711PMC
January 2019
2 Reads

Use of saliva to monitor meningococcal vaccine responses: proposing a threshold in saliva as surrogate of protection.

BMC Med Res Methodol 2019 Jan 5;19(1). Epub 2019 Jan 5.

Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Postbaknummer 41, Postbus 1, 3720, BA, Bilthoven, The Netherlands.

Background: Mucosal antibodies against capsular polysaccharides offer protection against acquisition and carriage of encapsulated bacteria like Neisseria meningitidis serogroup C. Measurements of salivary antibodies as replacement for blood testing has important (cost-effective) advantages, particular in studies that assess the impact of large-scale vaccination or in populations in which blood sampling is difficult. This study aimed to estimate a threshold for meningococcal IgG salivary antibody levels to discriminate between unprotected and protected vaccinated individuals. Read More

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http://dx.doi.org/10.1186/s12874-018-0650-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6321721PMC
January 2019
1 Read

Machine learning methodologies versus cardiovascular risk scores, in predicting disease risk.

BMC Med Res Methodol 2018 Dec 29;18(1):179. Epub 2018 Dec 29.

Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece.

Background: The use of Cardiovascular Disease (CVD) risk estimation scores in primary prevention has long been established. However, their performance still remains a matter of concern. The aim of this study was to explore the potential of using ML methodologies on CVD prediction, especially compared to established risk tool, the HellenicSCORE. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
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http://dx.doi.org/10.1186/s12874-018-0644-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6311054PMC
December 2018
2 Reads
2.270 Impact Factor

The generation of consensus guidelines for carrying out process evaluations in rehabilitation research.

BMC Med Res Methodol 2018 Dec 29;18(1):180. Epub 2018 Dec 29.

Bangor Institute for Health & Medical Research, School of Healthcare Sciences, Bangor University, Ffriddoedd Road, Bangor, UK.

Background: Although in recent years there has been a strong increase in published research on theories (e.g. realist evaluation, normalization process theory) driving and guiding process evaluations of complex interventions, there is limited guidance to help rehabilitation researchers design and carry out process evaluations. Read More

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http://dx.doi.org/10.1186/s12874-018-0647-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6311071PMC
December 2018
1 Read

Factors associated with retention in a smoking cessation trial for persons with a mental illness: a descriptive study.

BMC Med Res Methodol 2018 Dec 27;18(1):177. Epub 2018 Dec 27.

Psychology administration office, University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia.

Background: Exploring factors associated with retention in randomised trials provides insight into potential threats to internal and external study validity, and may inform the development of interventions to increase retention in future trials. Given a paucity of existing research in the field, a study was conducted to explore factors associated with retention in a smoking intervention trial involving persons with a mental illness, considering demographic and smoking characteristics, treatment condition and engagement in prior follow-up assessments.

Method: A descriptive study was undertaken using data derived from a RCT of a smoking cessation intervention initiated in four adult psychiatric inpatient units in New South Wales (NSW), Australia. Read More

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http://dx.doi.org/10.1186/s12874-018-0640-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307187PMC
December 2018
1 Read

Mechanisms, contexts and points of contention: operationalizing realist-informed research for complex health interventions.

BMC Med Res Methodol 2018 Dec 27;18(1):178. Epub 2018 Dec 27.

University of Toronto, Institute of Health Policy, Management and Evaluation, Toronto, Canada.

Background: The concept of "mechanism" is central to realist approaches to research, yet research teams struggle to operationalize and apply the concept in empirical research. Our large, interdisciplinary research team has also experienced challenges in making the concept useful in our study of the implementation of models of integrated community-based primary health care (ICBPHC) in three international jurisdictions (Ontario and Quebec in Canada, and in New Zealand).

Methods: In this paper we summarize definitions of mechanism found in realist methodological literature, and report an empirical example of a realist analysis of the implementation ICBPHC. Read More

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http://dx.doi.org/10.1186/s12874-018-0641-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307288PMC
December 2018
2 Reads

Adjustment for unmeasured confounding through informative priors for the confounder-outcome relation.

BMC Med Res Methodol 2018 Dec 22;18(1):174. Epub 2018 Dec 22.

Department of Methodology and Statistics, Faculty of Social and Behavioral Sciences, Utrecht University, Utrecht, The Netherlands.

Background: Observational studies of medical interventions or risk factors are potentially biased by unmeasured confounding. In this paper we propose a Bayesian approach by defining an informative prior for the confounder-outcome relation, to reduce bias due to unmeasured confounding. This approach was motivated by the phenomenon that the presence of unmeasured confounding may be reflected in observed confounder-outcome relations being unexpected in terms of direction or magnitude. Read More

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http://dx.doi.org/10.1186/s12874-018-0634-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6303957PMC
December 2018
1 Read

Validity of the International Physical Activity Questionnaire (IPAQ) for assessing moderate-to-vigorous physical activity and sedentary behaviour of older adults in the United Kingdom.

BMC Med Res Methodol 2018 Dec 22;18(1):176. Epub 2018 Dec 22.

UKCRC Centre of Excellence for Public Health (NI)/Centre for Public Health, Queen's University Belfast, Institute for Clinical Sciences B, Royal Victoria Hospital, Grosvenor Road, Belfast, UK.

Background: In order to accurately measure and monitor levels of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) in older adults, cost efficient and valid instruments are required. To date, the International Physical Activity Questionnaire (IPAQ) has not been validated with older adults (aged 60 years plus) in the United Kingdom. The current study aimed to test the validity of the IPAQ in a group of older adults for both MVPA and SB. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
Publisher Site
http://dx.doi.org/10.1186/s12874-018-0642-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6303992PMC
December 2018
3 Reads

Evaluation of the quality and value of data sources for postmarket surveillance of the safety of cough and cold medications in children.

BMC Med Res Methodol 2018 Dec 22;18(1):175. Epub 2018 Dec 22.

Rocky Mountain Poison & Drug Center, Denver Health and Hospital Authority, 1391 Speer Blvd, 777 Bannock St. MC 0180, Denver, CO, 80204, USA.

Background: The purpose of this report is to evaluate the quality of data sources used to study cough and cold medication (CCM) safety in children via the Pediatric Cough and Cold Safety Surveillance System.

Methods: The System utilized the National Poison Data System (NPDS), FDA Adverse Event Reporting System (FAERS), English-language medical literature, manufacturer postmarket safety databases, and news/media reports to identify cases from January 2008 through September 2016. Each data source was evaluated by the proportion of detected cases determined to be eligible (met case criteria) and the proportion determined to be evaluable (able to determine causal relationship between adverse event and exposure). Read More

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http://dx.doi.org/10.1186/s12874-018-0626-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6303866PMC
December 2018
1 Read

Strategies and challenges associated with recruiting retirement village communities and residents into a group exercise intervention.

BMC Med Res Methodol 2018 Dec 20;18(1):173. Epub 2018 Dec 20.

Institute for Physical Activity and Nutrition, Deakin University, 221 Burwood Highway, Burwood, VIC, 3125, Australia.

Background: Randomized controlled trials (RCTs) provide the highest level of scientific evidence, but successful participant recruitment is critical to ensure the external and internal validity of results. This study describes the strategies associated with recruiting older adults at increased falls risk residing in retirement villages into an 18-month cluster RCT designed to evaluate the effects of a dual-task exercise program on falls and physical and cognitive function.

Methods: Recruitment of adults aged ≥65 at increased falls risk residing within retirement villages (size 60-350 residents) was initially designed to occur over 12 months using two distinct cohorts (C). Read More

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http://dx.doi.org/10.1186/s12874-018-0633-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6302307PMC
December 2018
1 Read

Analysis of self-report and biochemically verified tobacco abstinence outcomes with missing data: a sensitivity analysis using two-stage imputation.

BMC Med Res Methodol 2018 Dec 18;18(1):170. Epub 2018 Dec 18.

Division of General Internal Medicine, Department of Medicine, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN, 55414, USA.

Background: Missing data are common in tobacco studies. It is well known that from the observed data alone, it is impossible to distinguish between missing mechanisms such as missing at random (MAR) and missing not at random (MNAR). In this paper, we propose a sensitivity analysis method to accommodate different missing mechanisms in cessation outcomes determined by self-report and urine validation results. Read More

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http://dx.doi.org/10.1186/s12874-018-0635-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299502PMC
December 2018
1 Read

Study filters for non-randomized studies of interventions consistently lacked sensitivity upon external validation.

BMC Med Res Methodol 2018 Dec 18;18(1):171. Epub 2018 Dec 18.

Information Management Unit, Institute for Quality and Efficiency in Health Care (IQWiG), Im Mediapark 8, 50670, Cologne, Germany.

Background: Little evidence is available on searches for non-randomized studies (NRS) in bibliographic databases within the framework of systematic reviews. For instance, it is currently unclear whether, when searching for NRS, effective restriction of the search strategy to certain study types is possible. The following challenges need to be considered: 1) For non-randomized controlled trials (NRCTs): whether they can be identified by established filters for randomized controlled trials (RCTs). Read More

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http://dx.doi.org/10.1186/s12874-018-0625-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299552PMC
December 2018
1 Read

A nonparametric Bayesian continual reassessment method in single-agent dose-finding studies.

BMC Med Res Methodol 2018 Dec 18;18(1):172. Epub 2018 Dec 18.

Key Lab of Statistical Modeling and Data Analysis of Yunnan Province, Yunnan University, Kunming, 650091, People's Republic of China.

Background: The main purpose of dose-finding studies in Phase I trial is to estimate maximum tolerated dose (MTD), which is the maximum test dose that can be assigned with an acceptable level of toxicity. Existing methods developed for single-agent dose-finding assume that the dose-toxicity relationship follows a specific parametric potency curve. This assumption may lead to bias and unsafe dose escalations due to the misspecification of parametric curve. Read More

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http://dx.doi.org/10.1186/s12874-018-0604-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299663PMC
December 2018
2 Reads

Discrepancies in endpoints between clinical trial protocols and clinical trial registration in randomized trials in oncology.

BMC Med Res Methodol 2018 Dec 12;18(1):169. Epub 2018 Dec 12.

Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson, 1515 Holcombe Blvd, Unit 426, Houston, TX, 77030, USA.

Background: Clinical trials are an essential part of evidence-based medicine. Hence, to ensure transparency and accountability in these clinical trials, policies for registration have been framed with emphasis on mandatory submission of trial elements, specifically outcome measures. As these efforts evolve further, we sought to evaluate the current status of endpoint reporting in clinical trial registries. Read More

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https://bmcmedresmethodol.biomedcentral.com/articles/10.1186
Publisher Site
http://dx.doi.org/10.1186/s12874-018-0627-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292048PMC
December 2018
4 Reads

Participatory action research, mixed methods, and research teams: learning from philosophically juxtaposed methodologies for optimal research outcomes.

BMC Med Res Methodol 2018 Dec 12;18(1):167. Epub 2018 Dec 12.

School of Social Science, University of the Sunshine Coast, Room D1.32, Locked Bag 4, Maroochydore DC, QLD, 4558, Australia.

Background: Workplace health interventions incorporating qualitative and quantitative components (mixed methods) within a Participatory Action Research approach can increase understanding of contextual issues ensuring realistic interventions which influence health behaviour. Mixed methods research teams, however, face a variety of challenges at the methodological and expertise levels when designing actions and interventions. Addressing these challenges can improve the team's functionality and lead to higher quality health outcomes. Read More

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http://dx.doi.org/10.1186/s12874-018-0636-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6290508PMC
December 2018
1 Read

A comparison of multiple imputation methods for missing data in longitudinal studies.

BMC Med Res Methodol 2018 Dec 12;18(1):168. Epub 2018 Dec 12.

Clinical Epidemiology and Biostatistics Unit, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia.

Background: Multiple imputation (MI) is now widely used to handle missing data in longitudinal studies. Several MI techniques have been proposed to impute incomplete longitudinal covariates, including standard fully conditional specification (FCS-Standard) and joint multivariate normal imputation (JM-MVN), which treat repeated measurements as distinct variables, and various extensions based on generalized linear mixed models. Although these MI approaches have been implemented in various software packages, there has not been a comprehensive evaluation of the relative performance of these methods in the context of longitudinal data. Read More

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http://dx.doi.org/10.1186/s12874-018-0615-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292063PMC
December 2018
1 Read

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

BMC Med Res Methodol 2018 Dec 11;18(1):166. Epub 2018 Dec 11.

Department of Health Sciences, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA.

Background: Multidrug-resistant tuberculosis (MDR-TB) cohorts often lack long-term survival data, and are summarized instead by initial treatment outcomes. When using Cox proportional hazards models to analyze these cohorts, this leads to censoring subjects at the time of the initial treatment outcome, instead of them providing full survival data. This may violate the non-informative censoring assumption of the model and may produce biased effect estimates. Read More

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http://dx.doi.org/10.1186/s12874-018-0637-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6290510PMC
December 2018
3 Reads

Impact of linkage quality on inferences drawn from analyses using data with high rates of linkage errors in rural Tanzania.

BMC Med Res Methodol 2018 Dec 10;18(1):165. Epub 2018 Dec 10.

Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.

Background: Studies based on high-quality linked data in developed countries show that even minor linkage errors, which occur when records of two different individuals are erroneously linked or when records belonging to the same individual are not linked, can impact bias and precision of subsequent analyses. We evaluated the impact of linkage quality on inferences drawn from analyses using data with substantial linkage errors in rural Tanzania.

Methods: Semi-automatic point-of-contact interactive record linkage was used to establish gold standard links between community-based HIV surveillance data and medical records at clinics serving the surveillance population. Read More

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http://dx.doi.org/10.1186/s12874-018-0632-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288858PMC
December 2018
2 Reads
2.270 Impact Factor