PhD Studentship: Predicting recruitment and retention to publicly funded randomised controlled tria

In 2015/16, the United Kingdom’s National Institute for Health Research (NIHR) spent £247.9 million across a broad range of research programmes to ensure that patients and the public benefit from the most cost effective, up-to-date health interventions and treatments as quickly as possible (NIHR Annual Report). A substantial proportion of this research expenditure was on Randomised Controlled Trials (RCTs) to assess the clinical effectiveness and cost-effectiveness of new health technologies. RCTs are widely regarded as the most powerful research design for evaluating new health technologies and decision makers, such as NICE (The National Institute for health and Care Excellence, are increasingly looking to the results of RCTs to guide practice and policy.

A frequently reported problem with publicly funded RCTs is that the recruitment of participants is often slower or more difficult than expected, with many trials falling to reach their planned sample size within the originally envisaged trial timescale and trial funding envelope. The NIHR has funded studies that, at the design and application stage, have been overly optimistic about the number of eligible patients, consent rates, recruitment rates and retention/attrition rates. Consequently, these studies have failed to recruit on time and on target. The investigators have been forced to ask the NIHR programme for an extension in both time and extra money to successfully complete the study. A recent review of a cohort of 151 trials funded by the UK NIHR Health Technology Assessment programme (HTA) found the final recruitment target sample size was achieved in 56% (85/151) of the RCTs and more than 80% of the final target sample size was achieved for 79% of the RCTs (119/151) (Walters et al 2016).

The proposed research plan would be to undertake a review of the literature on what factors influence consent, recruitment and attrition in RCTs; a second review of the literature on what statistical models have been developed to predict recruitment; followed by an audit of articles in leading medical journals to assess the consent, recruitment and attrition rates for single and multi-centre RCTs using the CONSORT checklist. The audit will assess whether any factors influence the consent, recruitment and attrition rates for such trials such as: source of funding (industry or publicly funded); number of centres; population/disease; affiliation of authors; type of intervention (drug or non-drug). The project would try and develop statistical models to predict consent and recruitment, and attrition rates for future RCTs; and compare this with the rates observed in several on-going RCTs at the Sheffield Clinical Trials Research Unit (CTRU); with the view to developing guidance on realistic consent, recruitment and attrition rates to RCTs.

Funding Notes

The Faculty Scholarships for Medicine, Dentistry & Health cover fees and stipend at Home/EU level. Overseas students may apply but will need to fund the fee differential between Home and Overseas rate from another source.

Eligibility Requirements

Candidates should possess either one of the following:

A First class honours degree in mathematics or statistics, or

An Upper Second class honours degree in mathematics or statistics and a Masters qualification