Study design

Creating groups with similar expected behavioural response in randomized controlled trials: a fuzzy cognitive map approach

Controlling bias is key to successful randomized controlled trials for behaviour change. Bias can be generated at multiple points during a study, for example, when participants are allocated to different group...

Authors: Philippe J Giabbanelli and Rik Crutzen

You are how you recruit: a cohort and randomized controlled trial of recruitment strategies

Recruitment is a challenge in developing population-representative pregnancy and birth cohorts.

Authors: Amy Maghera, Paul Kahlke, Amanda Lau, Yiye Zeng, Chris Hoskins, Tom Corbett, Donna Manca, Thierry Lacaze-Masmonteil, Denise Hemmings and Piush Mandhane

The influence of ethnic group composition on focus group discussions

Focus groups are commonly used to explore participants’ experiences in health and social care research. Although it is suggested that having demographically homogenous groups may help put participants at ease,...

Authors: Nan Greenwood, Theresa Ellmers and Jess Holley

The effect of an internet option and single-sided printing format to increase the response rate to a population-based study: a randomized controlled trial

Paper questionnaires are a common means to collect self-reported information in population-based epidemiological studies. Over the past decades, the response rates to epidemiological studies have been decreasi...

Authors: Elisa Flüß, Christine M Bond, Gareth T Jones and Gary J Macfarlane

Developing a weighting strategy to include mobile phone numbers into an ongoing population health survey using an overlapping dual-frame design with limited benchmark information

In 2012 mobile phone numbers were included into the ongoing New South Wales Population Health Survey (NSWPHS) using an overlapping dual-frame design. Previously in the NSWPHS the sample was selected using rand...

Authors: Margo L Barr, Raymond A Ferguson, Phil J Hughes and David G Steel

Developing and evaluating interventions that are applicable and relevant to inpatients and those who care for them; a multiphase, pragmatic action research approach

Randomised controlled trials may be of limited use to evaluate the multidisciplinary and multimodal interventions required to effectively treat complex patients in routine clinical practice; pragmatic action r...

Authors: Jack J Bell, Tony Rossi, Judith D Bauer and Sandra Capra

Utilising a collective case study system theory mixed methods approach: a rural health example

Insight into local health service provision in rural communities is limited in the literature. The dominant workforce focus in the rural health literature, while revealing issues of shortage of maldistribution...

Authors: Robyn Adams, Anne Jones, Sophie Lefmann and Lorraine Sheppard

Comparison of two alternative study designs in assessment of medicines utilisation in neonates

Estimates of prevalence are known to be affected by the design of cross-sectional studies. A pan-European study provided an opportunity to compare the effect of two cross-sectional study designs on estimates o...

Authors: Georgi Nellis, Irja Lutsar, Heili Varendi, Karolin Toompere, Mark A Turner, Jennifer Duncan and Tuuli Metsvaht

Three steps to writing adaptive study protocols in the early phase clinical development of new medicines

This article attempts to define terminology and to describe a process for writing adaptive, early phase study protocols which are transparent, self-intuitive and uniform. It provides a step by step guide, givi...

Authors: Ulrike Lorch, Martin O’Kane and Jorg Taubel

Measuring health-related quality of life in chronic obstructive pulmonary disease: properties of the EQ-5D-5L and PROMIS-43 short form

The Patient Reported Outcomes Measurement Information System 43-item short form (PROMIS-43) and the five-level EQ-5D (EQ-5D-5L) are recently developed measures of health-related quality of life (HRQL) that hav...

Authors: Fang-Ju Lin, A Simon Pickard, Jerry A Krishnan, Min J Joo, David H Au, Shannon S Carson, Suzanne Gillespie, Ashley G Henderson, Peter K Lindenauer, Mary Ann McBurnie, Richard A Mularski, Edward T Naureckas, William M Vollmer and Todd A Lee

Procedures for assessing psychological predictors of injuries in circus artists: a pilot prospective study

Research on psychological risk factors for injury has focused on stable traits. Our objective was to test the feasibility of a prospective longitudinal study designed to examine labile psychological states as ...

Authors: Ian Shrier, John S Raglin, Emily B Levitan, Murray A Mittleman, Russell J Steele and Janette Powell

The effectiveness of recruitment strategies on general practitioner’s survey response rates – a systematic review

Low survey response rates in general practice are common and lead to loss of power, selection bias, unexpected budgetary constraints and time delays in research projects.

Authors: Sabrina Winona Pit, Tham Vo and Sagun Pyakurel

The performance of sequence symmetry analysis as a tool for post-market surveillance of newly marketed medicines: a simulation study

Sequence symmetry analysis (SSA) is a potential tool for rapid detection of adverse drug events (ADRs) associated with newly marketed medicines utilizing computerized claims data. SSA is robust to patient spec...

Authors: Nicole L Pratt, Jenni Ilomäki, Chris Raymond and Elizabeth E Roughead

Validation of self-reported weights and heights in the avoiding diabetes after pregnancy trial (ADAPT)

Randomized controlled trials that test the effectiveness of mobile health-based weight loss programs are attractive to participants, funders, and researchers because of the low implementation cost, minimal par...

Authors: Kathryn A Paez, Susan J Griffey, Jennifer Thompson and Matthew W Gillman

Challenges to be overcome using population-based sampling methods to recruit veterans for a study of post-traumatic stress disorder and traumatic brain injury

Many investigators are interested in recruiting veterans from recent conflicts in Afghanistan and Iraq with Traumatic Brain Injury (TBI) and/or Post Traumatic Stress Disorder (PTSD). Researchers pursuing such ...

Authors: Peter J Bayley, Jennifer Y Kong, Drew A Helmer, Aaron Schneiderman, Lauren A Roselli, Stephanie M Rosse, Jordan A Jackson, Janet Baldwin, Linda Isaac, Michael Nolasco, Marc R Blackman, Matthew J Reinhard, John Wesson Ashford and Julie C Chapman

Enabling research in care homes: an evaluation of a national network of research ready care homes

In the UK care homes are one of the main providers of long term care for older people with dementia. Despite the recent increase in care home research, residents with dementia are often excluded from studies. ...

Authors: Sue L Davies, Claire Goodman, Jill Manthorpe, Adam Smith, Natasha Carrick and Steve Iliffe

Recruiting and motivating black subjects to complete a lengthy survey in a large cohort study: an exploration of different strategies

The effectiveness of multiple innovative recruitment strategies for enrolling Black/African American participants to the Adventist Health Study-2 (AHS-2) is described. The study’s focus is diet and breast, pro...

Authors: Patti Herring, Terry Butler, Sonja Hall, Hannelore Bennett, Susanne B Montgomery and Gary Fraser

A randomized controlled trial of the effectiveness of a pre-recruitment primer letter to increase participation in a study of colorectal screening and surveillance

Recruiting cancer patients is a barrier often encountered in research trials. However, very few randomized trials explore strategies to improve participation rates. The purpose of this study was to evaluate th...

Authors: Christine Paul, Ryan Courtney, Rob Sanson-Fisher, Mariko Carey, David Hill, Jody Simmons and Shiho Rose

Challenges and strategies for cohort retention and data collection in an indigenous population: Australian Aboriginal Birth Cohort

Longitudinal prospective birth cohort studies are pivotal to identifying fundamental causes and determinants of disease and health over the life course. There is limited information about the challenges, reten...

Authors: Megan Lawrance, Susan M Sayers and Gurmeet R Singh

Influences on recruitment to randomised controlled trials in mental health settings in England: a national cross-sectional survey of researchers working for the Mental Health Research Network

Recruitment to trials is complex and often protracted; selection bias may compromise generalisability. In the mental health field (as elsewhere), diverse factors have been described as hindering researcher acc...

Authors: Rohan Borschmann, Sue Patterson, Dilkushi Poovendran, Danielle Wilson and Tim Weaver

Using mixed methods to select optimal mode of administration for a patient-reported outcome instrument for people with pressure ulcers

When developing new measuring instruments or deciding upon one for research, consideration of the ‘best’ method of administration for the target population should be made. Current evidence is inconsistent in d...

Authors: Claudia Rutherford, Jane Nixon, Julia M Brown, Donna L Lamping and Stefan J Cano

Using vignettes in qualitative research to explore barriers and facilitating factors to the uptake of prevention of mother-to-child transmission services in rural Tanzania: a critical analysis

Vignettes are short stories about a hypothetical person, traditionally used within research (quantitative or qualitative) on sensitive topics in the developed world. Studies using vignettes in the developing w...

Authors: Annabelle Gourlay, Gerry Mshana, Isolde Birdthistle, Grace Bulugu, Basia Zaba and Mark Urassa

Survey mode and asking about future intentions did not impact self-reported colorectal cancer screening accuracy

Self-reported colorectal cancer (CRC) screening behavior is often subject to over-reporting bias. We examined how the inclusion of a future intention to screen item (viz. asking about future intentions to get scr...

Authors: Timothy J Beebe, Jeanette Y Ziegenfuss, Sarah M Jenkins, Kandace A Lackore and Timothy P Johnson

Reasons for participation and non-participation in a diabetes prevention trial among women with prior gestational diabetes mellitus (GDM)

Gestational diabetes mellitus (GDM) is a risk factor for the development of type 2 diabetes. Lifestyle intervention can prevent progression to type 2 diabetes in high risk populations. We designed a randomised...

Authors: Jennifer J Infanti, Angela O’Dea, Irene Gibson, Brian E McGuire, John Newell, Liam G Glynn, Ciaran O’Neill, Susan B Connolly and Fidelma P Dunne

Factors influencing recruitment to research: qualitative study of the experiences and perceptions of research teams

Recruiting the required number of participants is vital to the success of clinical research and yet many studies fail to achieve their expected recruitment rate. Increasing research participation is a key agen...

Authors: Lisa Newington and Alison Metcalfe

Effect of numbering of return envelopes on participation, explicit refusals, and bias: experiment and meta-analysis

Tracing mail survey responses is useful for the management of reminders but may cause concerns about anonymity among prospective participants. We examined the impact of numbering return envelopes on the partic...

Authors: Thomas V Perneger, Stéphane Cullati, Sandrine Rudaz, Thomas Agoritsas, Ralph E Schmidt, Christophe Combescure and Delphine S Courvoisier

Erratum to: Qualitative systematic reviews of treatment burden in stroke, heart failure and diabetes - Methodological challenges and solutions

Authors: Katie Gallacher, Bhautesh Jani, Deborah Morrison, Sara Macdonald, David Blane, Patricia Erwin, Carl R May, Victor M Montori, David T Eton, Fiona Smith, G David Batty and Frances S Mair

Concordance between administrative claims and registry data for identifying metastasis to the bone: an exploratory analysis in prostate cancer

To assess concordance between Medicare claims and Surveillance, Epidemiology, and End Results (SEER) reports of incident BM among prostate cancer (PCa) patients. The prevalence and consequences of bone metasta...

Authors: Eberechukwu Onukwugha, Candice Yong, Arif Hussain, Brian Seal and C Daniel Mullins

Facilitating accrual to cancer control and supportive care trials: the clinical research associate perspective

Accrual to Cancer Control and Supportive Care (CCL) studies can be challenging. Our objective was to identify facilitators and perceived barriers to successful Children’s Oncology Group (COG) CCL accrual from ...

Authors: David VanHoff, Tanya Hesser, Katherine Patterson Kelly, David Freyer, Susan Stork and Lillian Sung

Lessons learnt recruiting to a multi-site UK cohort study to explore recovery of health and well-being after colorectal cancer (CREW study)

The UK leads the world in recruitment of patients to cancer clinical trials, with a six-fold increase in recruitment during 2001–2010. However, there are large variations across cancer centres. This paper deta...

Authors: Deborah Fenlon, Kim Chivers Seymour, Ikumi Okamoto, Jane Winter, Alison Richardson, Julia Addington-Hall, Jessica L Corner, Peter W Smith, Christine M May, Matthew Breckons and Claire Foster

Exploratory randomized controlled trial evaluating the impact of a waiting list control design

Employing waiting list control designs in psychological and behavioral intervention research may artificially inflate intervention effect estimates. This exploratory randomized controlled trial tested this pro...

Authors: John A Cunningham, Kypros Kypri and Jim McCambridge

A multi-arm multi-stage clinical trial design for binary outcomes with application to tuberculosis

Randomised controlled trials are becoming increasingly costly and time-consuming. In 2011, Royston and colleagues proposed a particular class of multi-arm multi-stage (MAMS) designs intended to speed up the ev...

Authors: Daniel J Bratton, Patrick PJ Phillips and Mahesh KB Parmar

Is a randomised controlled trial of a maternity care intervention for pregnant adolescents possible? An Australian feasibility study

The way in which maternity care is provided affects perinatal outcomes for pregnant adolescents; including the likelihood of preterm birth. The study purpose was to assess the feasibility of recruiting pregnan...

Authors: Jyai Allen, Helen Stapleton, Sally Tracy and Sue Kildea

Shortening the Current Opioid Misuse Measure via computer-based testing: a retrospective proof-of-concept study

The Current Opioid Misuse Measure (COMM) is a self-report questionnaire designed to help identify aberrant drug-related behavior in respondents who have been prescribed opioids for chronic pain. The full-lengt...

Authors: Matthew D Finkelman, Ronald J Kulich, Driss Zoukhri, Niels Smits and Stephen F Butler

The index ‘Treatment Duration Control’ for enabling randomized controlled trials with variation in duration of treatment of chronic pain patients

Treatment duration varies with the type of therapy and a patient’s recovery speed. Including such a variation in randomized controlled trials (RCTs) enables comparison of the actual therapeutic potential of di...

Authors: Hilbert W van der Glas and Robert J van Grootel

Integrating and extending cohort studies: lessons from the eXtending Treatments, Education and Networks in Depression (xTEND) study

Epidemiologic studies often struggle to adequately represent populations and outcomes of interest. Differences in methodology, data analysis and research questions often mean that reviews and synthesis of the ...

Authors: Joanne Allen, Kerry J Inder, Terry J Lewin, John R Attia, Frances J Kay-Lambkin, Amanda L Baker, Trevor Hazell and Brian J Kelly

Quality of life in dementia: a study on proxy bias

Measurement of health-related quality of life (HRQoL) in dementia is difficult. At some point people with dementia become unable to meaningfully assess their own HRQoL. At such a point in time researchers need...

Authors: Alexander MM Arons, Paul FM Krabbe, Carla JM Schölzel-Dorenbos, Gert Jan van der Wilt and Marcel GM Olde Rikkert

An audit of sample sizes for pilot and feasibility trials being undertaken in the United Kingdom registered in the United Kingdom Clinical Research Network database

There is little published guidance as to the sample size required for a pilot or feasibility trial despite the fact that a sample size justification is a key element in the design of a trial. A sample size jus...

Authors: Sophie AM Billingham, Amy L Whitehead and Steven A Julious

A counterfactual approach to bias and effect modification in terms of response types

The counterfactual approach provides a clear and coherent framework to think about a variety of important concepts related to causation. Meanwhile, directed acyclic graphs have been used as causal diagrams in ...

Authors: Etsuji Suzuki, Toshiharu Mitsuhashi, Toshihide Tsuda and Eiji Yamamoto

Selecting a sample size for studies with repeated measures

Many researchers favor repeated measures designs because they allow the detection of within-person change over time and typically have higher statistical power than cross-sectional designs. However, the pletho...

Authors: Yi Guo, Henrietta L Logan, Deborah H Glueck and Keith E Muller

Cognitive mapping: using local knowledge for planning health research

Cognitive mapping is a participatory research methodology that documents, in visual form, a construct of the local environment in which people live and work. We adapted this method to provide detailed data abo...

Authors: Jonathan Stadler, Charles Dugmore, Emilie Venables, Catherine MacPhail and Sinead Delany-Moretlwe

Sample size re-assessment leading to a raised sample size does not inflate type I error rate under mild conditions

One major concern with adaptive designs, such as the sample size adjustable designs, has been the fear of inflating the type I error rate. In (Stat Med 23:1023-1038, 2004) it is however proven that when observ...

Authors: Per Broberg

The impact of deployment experience and prior healthcare utilization on enrollment in a large military cohort study

Longitudinal cohort studies are highly valued in epidemiologic research for their ability to establish exposure-disease associations through known temporal sequences. A major challenge in cohort studies is rec...

Authors: Jaime L Horton, Isabel G Jacobson, Alyson J Littman, John E Alcaraz, Besa Smith and Nancy F Crum-Cianflone

Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia

As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase II...

Authors: Christina Yap, Andrew Pettitt and Lucinda Billingham

Measuring teamwork and taskwork of community-based “teams” delivering life-saving health interventions in rural Zambia: a qualitative study

The use of teams is a well-known approach in a variety of settings, including health care, in both developed and developing countries. Team performance is comprised of teamwork and task work, and ascertaining ...

Authors: Kojo Yeboah-Antwi, Gail Snetro-Plewman, Karen Z Waltensperger, Davidson H Hamer, Chilobe Kambikambi, William MacLeod, Stephen Filumba, Bias Sichamba and David Marsh

Proton pump inhibitors and the risk of pneumonia: a comparison of cohort and self-controlled case series designs

To compare the results of a new-user cohort study design and the self-controlled case series (SCCS) design using the risk of hospitalisation for pneumonia in those dispensed proton pump inhibitors compared to ...

Authors: Emmae N Ramsay, Nicole L Pratt, Philip Ryan and Elizabeth E Roughead

Inference of synergy/antagonism between anticancer drugs from the pooled analysis of clinical trials

Drug interactions can have a significant impact on the response to combinatorial therapy for anticancer treatment. In some instances these interactions can be anticipated based on pre-clinical models. However,...

Authors: Wenfeng Kang, Robert S DiPaola and Alexei Vazquez

Rethinking sources of representative controls for the conduct of case–control studies in minority populations

Recruitment of controls remains a challenge in case–control studies and particularly in studies involving minority populations.

Authors: Elisa V Bandera, Urmila Chandran, Gary Zirpoli, Susan E McCann, Gregory Ciupak and Christine B Ambrosone

Phase IV non-inferiority trials and additional claims of benefit

Non-inferiority (NI) trials in drug research are used to demonstrate that a new treatment is not less effective than an active comparator. Since phase IV trials typically aim at informing a clinical decision, ...

Authors: Rosemarie DLC Bernabe, Grace Wangge, Mirjam J Knol, Olaf H Klungel, Johannes JM van Delden, Anthonius de Boer, Arno W Hoes, Jan AM Raaijmakers and Ghislaine JMW van Thiel

Novel study design to assess the utility of the copd assessment test in a primary care setting

The quality of a consultation provided by a physician can have a profound impact on the quality of care and patient engagement in treatment decisions. When the COPD Assessment Test (CAT) was developed, one of ...

Authors: Kevin Gruffydd-Jones, Helen Marsden, Steve Holmes, Peter Kardos, Roger Escamilla, Roberto Dal Negro, June Roberts, Gilbert Nadeau, David Leather and Paul Jones