Articles

Double-adjustment in propensity score matching analysis: choosing a threshold for considering residual imbalance

Double-adjustment can be used to remove confounding if imbalance exists after propensity score (PS) matching. However, it is not always possible to include all covariates in adjustment. We aimed to find the op...

Authors: Tri-Long Nguyen, Gary S. Collins, Jessica Spence, Jean-Pierre Daurès, P. J. Devereaux, Paul Landais and Yannick Le Manach

Measurement properties of the Danish version of the Awareness and Beliefs about Cancer (ABC) measure

The International Cancer Benchmarking Partnership aims to study international differences in cancer survival and the possible causes. Participating countries are Australia, Canada, Norway, Sweden, Denmark and ...

Authors: Line Hvidberg, Anette Fischer Pedersen, Christian Nielsen Wulff, Anders Helles Carlsen and Peter Vedsted

Assessing the complexity of interventions within systematic reviews: development, content and use of a new tool (iCAT_SR)

Health interventions fall along a spectrum from simple to more complex. There is wide interest in methods for reviewing ‘complex interventions’, but few transparent approaches for assessing intervention comple...

Authors: Simon Lewin, Maggie Hendry, Jackie Chandler, Andrew D. Oxman, Susan Michie, Sasha Shepperd, Barnaby C. Reeves, Peter Tugwell, Karin Hannes, Eva A. Rehfuess, Vivien Welch, Joanne E. Mckenzie, Belinda Burford, Jennifer Petkovic, Laurie M. Anderson, Janet Harris…

An experimental comparison of web-push vs. paper-only survey procedures for conducting an in-depth health survey of military spouses

Previous research has found that a “web-push” approach to data collection, which involves contacting people by mail to request an Internet survey response while withholding a paper response option until later ...

Authors: Hope Seib McMaster, Cynthia A. LeardMann, Steven Speigle and Don A. Dillman

The effectiveness of a monetary incentive offer on survey response rates and response completeness in a longitudinal study

Achieving adequate response rates is an ongoing challenge for longitudinal studies. The World Trade Center Health Registry is a longitudinal health study that periodically surveys a cohort of ~71,000 people ex...

Authors: Shengchao Yu, Howard E. Alper, Angela-Maithy Nguyen, Robert M. Brackbill, Lennon Turner, Deborah J. Walker, Carey B. Maslow and Kimberly C. Zweig

Sample size and power determination when limited preliminary information is available

We describe a novel strategy for power and sample size determination developed for studies utilizing investigational technologies with limited available preliminary data, specifically of imaging biomarkers. We...

Authors: Christine E. McLaren, Wen-Pin Chen, Thomas D. O’Sullivan, Daniel L. Gillen, Min-Ying Su, Jeon H. Chen and Bruce J. Tromberg

Using evaluability assessment to assess local community development health programmes: a Scottish case-study

Evaluation of the potential effectiveness of a programme’s objectives (health or otherwise) is important in demonstrating how programmes work. However, evaluations are expensive and can focus on unrealistic ou...

Authors: Melissa Belford, Tony Robertson and Ruth Jepson

Evaluation of the impact of disease prevention measures: a methodological note on defining incidence rates

In studies of recurrent events, it is common to consider a person who has suffered a disease episode and received curative treatment to be not at risk of suffering a new episode for a duration of time. It is a...

Authors: Yin-Bun Cheung, Ying Xu, Matthew Cairns and Paul Milligan

Sharp bounds on sufficient-cause interactions under the assumption of no redundancy

Sufficient-cause interaction is a type of interaction that has received much attention recently. The sufficient component cause model on which the sufficient-cause interaction is based is however a non-identif...

Authors: Wen-Chung Lee

The impact of the mode of survey administration on estimates of daily smoking for mobile phone only users

Over the past decade, there have been substantial changes in landline and mobile phone ownership, with a substantial increase in the proportion of mobile-only households. Estimates of daily smoking rates for t...

Authors: Joseph Hanna, Damien V. Cordery, David G. Steel, Walter Davis and Timothy C. Harrold

Evaluation of a modified version of the Posttraumatic Growth Inventory-Short Form

Posttraumatic growth is the positive change resulting from traumatic experiences and is typically assessed with retrospective measures like the Posttraumatic Growth Inventory (PTGI). The PTGI was designed to i...

Authors: Navjot Kaur, Ben Porter, Cynthia A. LeardMann, Laura E. Tobin, Hector Lemus and David D. Luxton

Does the association between adherence to statin medications and mortality depend on measurement approach? A retrospective cohort study

The aim of this study was to examine the relationship between mortality and statin adherence using two different approaches to adherence measurement (summary versus repeated-measures).

Authors: Mhd. Wasem Alsabbagh, Dean Eurich, Lisa M. Lix, Thomas W. Wilson and David F. Blackburn

Treatment-seeking behaviour in low- and middle-income countries estimated using a Bayesian model

Seeking treatment in formal healthcare for uncomplicated infections is vital to combating disease in low- and middle-income countries (LMICs). Healthcare treatment-seeking behaviour varies within and between c...

Authors: Victor A. Alegana, Jim Wright, Carla Pezzulo, Andrew J. Tatem and Peter M. Atkinson

Assessing the impact of natural policy experiments on socioeconomic inequalities in health: how to apply commonly used quantitative analytical methods?

The scientific evidence-base for policies to tackle health inequalities is limited. Natural policy experiments (NPE) have drawn increasing attention as a means to evaluating the effects of policies on health. ...

Authors: Yannan Hu, Frank J. van Lenthe, Rasmus Hoffmann, Karen van Hedel and Johan P. Mackenbach

Impact of correlation of predictors on discrimination of risk models in development and external populations

The area under the ROC curve (AUC) of risk models is known to be influenced by differences in case-mix and effect size of predictors. The impact of heterogeneity in correlation among predictors has however bee...

Authors: Suman Kundu, Madhu Mazumdar and Bart Ferket

Grey literature in systematic reviews: a cross-sectional study of the contribution of non-English reports, unpublished studies and dissertations to the results of meta-analyses in child-relevant reviews

Systematic reviews (SRs) are an important source of information about healthcare interventions. A key component of a well-conducted SR is a comprehensive literature search. There is limited evidence on the con...

Authors: Lisa Hartling, Robin Featherstone, Megan Nuspl, Kassi Shave, Donna M. Dryden and Ben Vandermeer

Kappa statistic to measure agreement beyond chance in free-response assessments

The usual kappa statistic requires that all observations be enumerated. However, in free-response assessments, only positive (or abnormal) findings are notified, but negative (or normal) findings are not. This...

Authors: Marc Carpentier, Christophe Combescure, Laura Merlini and Thomas V. Perneger

Protocol for the development of a salutogenic intrapartum core outcome set (SIPCOS)

Maternity intrapartum care research and clinical care more often focus on outcomes that minimise or prevent adverse health rather than on what constitutes positive health and wellbeing (salutogenesis). This wa...

Authors: Valerie Smith, Deirdre Daly, Ingela Lundgren, Tine Eri, Cecily Begley, Mechthild M. Gross, Soo Downe, Zarko Alfirevic and Declan Devane

Review and evaluation of performance measures for survival prediction models in external validation settings

When developing a prediction model for survival data it is essential to validate its performance in external validation settings using appropriate performance measures. Although a number of such measures have ...

Authors: M. Shafiqur Rahman, Gareth Ambler, Babak Choodari-Oskooei and Rumana Z. Omar

Clinical patient registry recruitment and retention: a survey of patients in two chronic disease registries

The collection of routine clinical data in the setting of research registries can serve an important role in understanding real world care. However, relatively little is known about the patient experience in r...

Authors: Daniel H. Solomon, Nancy A. Shadick, Michael E. Weinblatt, Michelle Frits, Christine Iannaccone, Agnes Zak and Joshua R. Korzenik

Practical application of opt-out recruitment methods in two health services research studies

Participant recruitment is an ongoing challenge in health research. Recruitment may be especially difficult for studies of access to health care because, even among those who are in care, people using services...

Authors: Christopher J. Miller, James F. Burgess Jr., Ellen P. Fischer, Deborah J. Hodges, Lindsay K. Belanger, Jessica M. Lipschitz, Siena R. Easley, Christopher J. Koenig, Regina L. Stanley and Jeffrey M. Pyne

Statistical evaluation of adding multiple risk factors improves Framingham stroke risk score

Framingham Stroke Risk Score (FSRS) is the most well-regarded risk appraisal tools for evaluating an individual’s absolute risk on stroke onset. However, several widely accepted risk factors for stroke were no...

Authors: Xiao-Hua Zhou, Xiaonan Wang, Ashlee Duncan, Guizhou Hu and Jiayin Zheng

Evidence synthesis to inform model-based cost-effectiveness evaluations of diagnostic tests: a methodological review of health technology assessments

Evaluations of diagnostic tests are challenging because of the indirect nature of their impact on patient outcomes. Model-based health economic evaluations of tests allow different types of evidence from vario...

Authors: Bethany Shinkins, Yaling Yang, Lucy Abel and Thomas R. Fanshawe

Estimating the standardized incidence ratio (SIR) with incomplete follow-up data

A standard parameter to compare the disease incidence of a cohort relative to the population is the standardized incidence ratio (SIR). For statistical inference is commonly assumed that the denominator, the e...

Authors: Heiko Becher and Volker Winkler

Comparison of surveillance-based metrics for the assessment and monitoring of disease detection: simulation study about type 2 diabetes

Screening and detection of cases are a common public health priority for treatable chronic conditions with long subclinical periods. However, the validity of commonly-used metrics from surveillance systems for...

Authors: Ralph Brinks, Annika Hoyer, Deborah B. Rolka, Oliver Kuss and Edward W. Gregg

Time-dependent ROC curve analysis in medical research: current methods and applications

ROC (receiver operating characteristic) curve analysis is well established for assessing how well a marker is capable of discriminating between individuals who experience disease onset and individuals who do n...

Authors: Adina Najwa Kamarudin, Trevor Cox and Ruwanthi Kolamunnage-Dona

The importance of censoring in competing risks analysis of the subdistribution hazard

The analysis of time-to-event data can be complicated by competing risks, which are events that alter the probability of, or completely preclude the occurrence of an event of interest. This is distinct from ce...

Authors: Mark W. Donoghoe and Val Gebski

Practical partnered research to improve weight loss among overweight/obese veterans: lessons from the trenches

Obesity and obesity-related conditions, such as type 2 diabetes, are a major issue for Veteran health. Veterans Health Administration (VA) researchers and health systems leaders have worked separately and toge...

Authors: Mona AuYoung, Laura J. Damschroder, Linda Kinsinger, Tannaz Moin and Caroline R. Richardson

Erratum to: What impact do assumptions about missing data have on conclusions? a practical sensitivity analysis for a cancer survival registry

Authors: M. Smuk, J. R. Carpenter and T. P. Morris

The effect of postal questionnaire burden on response rate and answer patterns following admission to intensive care: a randomised controlled trial

The effects of postal questionnaire burden on return rates and answers given are unclear following treatment on an intensive care unit (ICU). We aimed to establish the effects of different postal questionnaire...

Authors: Robert Hatch, Duncan Young, Vicki Barber, David A Harrison and Peter Watkinson

Evaluation of AMSTAR to assess the methodological quality of systematic reviews in overviews of reviews of healthcare interventions

Overviews of reviews (overviews) compile information from multiple systematic reviews (SRs) to provide a single synthesis of relevant evidence for decision-making. It is recommended that authors assess and rep...

Authors: Michelle Pollock, Ricardo M. Fernandes and Lisa Hartling

Erratum to: Evaluation of biases present in the cohort multiple randomised controlled trial design: a simulation study

Authors: Jane Candlish, Alexander Pate, Matthew Sperrin and Tjeerd van Staa

Methods for conceptualising ‘visual ability’ as a measurable construct in children with cerebral palsy

Vision influences functioning and disability of children with cerebral palsy, so there is a growing need for psychometrically robust tools to advance assessment of children’s vision abilities in clinical pract...

Authors: Belinda Deramore Denver, Margareta Adolfsson, Elspeth Froude, Peter Rosenbaum and Christine Imms

Incorporating nonlinearity into mediation analyses

Mediation is an important issue considered in the behavioral, medical, and social sciences. It addresses situations where the effect of a predictor variable X on an outcome variable Y is explained to some extent ...

Authors: George J. Knafl, Kathleen A. Knafl, Margaret Grey, Jane Dixon, Janet A. Deatrick and Agatha M. Gallo

Standardizing effect size from linear regression models with log-transformed variables for meta-analysis

Meta-analysis is very useful to summarize the effect of a treatment or a risk factor for a given disease. Often studies report results based on log-transformed variables in order to achieve the principal assum...

Authors: Miguel Rodríguez-Barranco, Aurelio Tobías, Daniel Redondo, Elena Molina-Portillo and María José Sánchez

Implementation of clinical research trials using web-based and mobile devices: challenges and solutions

With the increasing implementation of web-based, mobile health interventions in clinical trials, it is crucial for researchers to address the security and privacy concerns of patient information according to h...

Authors: Roy Eagleson, Luis Altamirano-Diaz, Alex McInnis, Eva Welisch, Stefanie De Jesus, Harry Prapavessis, Meghan Rombeek, Jamie A. Seabrook, Teresa Park and Kambiz Norozi

The feasibility of matching on a propensity score for acupuncture in a prospective cohort study of patients with chronic pain

Propensity scores are typically applied in retrospective cohort studies. We describe the feasibility of matching on a propensity score derived from a retrospective cohort and subsequently applied in a prospect...

Authors: Eric S. Johnson, John F. Dickerson, William M. Vollmer, Alee M. Rowley, Cheryl Ritenbaugh, Richard A. Deyo and Lynn DeBar

Assignment of adverse event indexing terms in randomized clinical trials involving spinal manipulative therapy: an audit of records in MEDLINE and EMBASE databases

Reporting of adverse events in randomized clinical trials (RCTs) is encouraged by the authors of The Consolidated Standards of Reporting Trials (CONSORT) statement. With robust methodological design and adequa...

Authors: Lindsay M. Gorrell, Roger M. Engel, Reidar P. Lystad and Benjamin T. Brown

Why sample selection matters in exploratory factor analysis: implications for the 12-item World Health Organization Disability Assessment Schedule 2.0

Sample selection can substantially affect the solutions generated using exploratory factor analysis. Validation studies of the 12-item World Health Organization (WHO) Disability Assessment Schedule 2.0 (WHODAS...

Authors: Cadeyrn J. Gaskin, Sylvie D. Lambert, Steven J. Bowe and Liliana Orellana

Trial Sequential Analysis in systematic reviews with meta-analysis

Most meta-analyses in systematic reviews, including Cochrane ones, do not have sufficient statistical power to detect or refute even large intervention effects. This is why a meta-analysis ought to be regarded...

Authors: Jørn Wetterslev, Janus Christian Jakobsen and Christian Gluud

AIMD - a validated, simplified framework of interventions to promote and integrate evidence into health practices, systems, and policies

Proliferation of terms describing the science of effectively promoting and supporting the use of research evidence in healthcare policy and practice has hampered understanding and development of the field. To ...

Authors: Peter Bragge, Jeremy M. Grimshaw, Cynthia Lokker and Heather Colquhoun

A systematic review of studies with a representative sample of refugees and asylum seekers living in the community for participation in mental health research

The aim was to review the literature to identify the most effective methods for creating a representative sample of refugee and asylum seeker groups living in the community to participate in health and mental ...

Authors: Joanne C. Enticott, Frances Shawyer, Shiva Vasi, Kimberly Buck, I-Hao Cheng, Grant Russell, Ritsuko Kakuma, Harry Minas and Graham Meadows

Leveraging the EHR4CR platform to support patient inclusion in academic studies: challenges and lessons learned

The development of Electronic Health Records (EHRs) in hospitals offers the ability to reuse data from patient care activities for clinical research. EHR4CR is a European public-private partnership aiming to d...

Authors: Yannick Girardeau, Justin Doods, Eric Zapletal, Gilles Chatellier, Christel Daniel, Anita Burgun, Martin Dugas and Bastien Rance

Research waste in diagnostic trials: a methods review evaluating the reporting of test-treatment interventions

The most rigorous method for evaluating the effectiveness of diagnostic tests is through randomised trials that compare test-treatment interventions: complex interventions comprising episodes of testing, decis...

Authors: Lavinia Ferrante di Ruffano, Jacqueline Dinnes, Sian Taylor-Phillips, Clare Davenport, Chris Hyde and Jonathan J. Deeks

Test-treatment RCTs are susceptible to bias: a review of the methodological quality of randomized trials that evaluate diagnostic tests

There is a growing recognition for the need to expand our evidence base for the clinical effectiveness of diagnostic tests. Many international bodies are calling for diagnostic randomized controlled trials to ...

Authors: Lavinia Ferrante di Ruffano, Jacqueline Dinnes, Alice J. Sitch, Chris Hyde and Jonathan J. Deeks

Performance of Firth-and logF-type penalized methods in risk prediction for small or sparse binary data

When developing risk models for binary data with small or sparse data sets, the standard maximum likelihood estimation (MLE) based logistic regression faces several problems including biased or infinite estima...

Authors: M. Shafiqur Rahman and Mahbuba Sultana

Erratum to: Exploring functional data analysis and wavelet principal component analysis on ecstasy (MDMA) wastewater data

Authors: Stefania Salvatore, Jørgen G. Bramness and Jo Røislien

A statistical method utilizing information of imported cases to estimate the transmissibility for an influenza pandemic

In a new influenza pandemic, travel data such as arrival times of cases seeded by the originating country can be regarded as a combination of the epidemic size and the mobility networks of infections connectin...

Authors: Ka Chun Chong, Benny Chung Ying Zee and Maggie Haitian Wang

Participant retention practices in longitudinal clinical research studies with high retention rates

There is a need for improving cohort retention in longitudinal studies. Our objective was to identify cohort retention strategies and implementation approaches used in studies with high retention rates.

Authors: Martha Abshire, Victor D. Dinglas, Maan Isabella A. Cajita, Michelle N. Eakin, Dale M. Needham and Cheryl Dennison Himmelfarb

Estimation of treatment preference effects in clinical trials when some participants are indifferent to treatment choice

In the two-stage randomised trial design, a randomly sampled subset of study participants are permitted to choose their own treatment, while the remaining participants are randomised to treatment in the usual ...

Authors: Stephen D. Walter, Robin M. Turner, Petra Macaskill, Kirsten J. McCaffery and Les Irwig