Steven Robertson

Smoking cessation support delivered via mobile phone text messaging (txt2stop): a single-blind, randomised trial

Summary Background Smoking cessation programmes delivered via mobile phone text messaging show increases in self-reported quitting in the short term. We assessed the effect of an automated smoking cessation programme delivered via mobile phone text messaging on continuous abstinence, which was biochemically verified at 6 months. Methods In this single-blind, randomised trial, undertaken in the UK, smokers willing to make a quit attempt were randomly allocated, using an independent telephone randomisation system, to a mobile phone text messaging smoking cessation programme (txt2stop), comprising motivational messages and behavioural-change support, or to a control group that received text messages unrelated to quitting. The system automatically generated intervention or control group texts according to the allocation. Outcome assessors were masked to treatment allocation. The primary outcome was self-reported continuous smoking abstinence, biochemically verified at 6 months. All analyses were by intention to treat. This study is registered, number ISRCTN 80978588. Findings We assessed 11 914 participants for eligibility. 5800 participants were randomised, of whom 2915 smokers were allocated to the txt2stop intervention and 2885 were allocated to the control group; eight were excluded because they were randomised more than once. Primary outcome data were available for 5524 (95%) participants. Biochemically verified continuous abstinence at 6 months was significantly increased in the txt2stop group (10·7% txt2stop vs 4·9% control, relative risk [RR] 2·20, 95% CI 1·80–2·68; p<0·0001). Similar results were obtained when participants that were lost to follow-up were treated as smokers (268 [9%] of 2911 txt2stop vs 124 [4%] of 2881 control [RR 2·14, 95% CI 1·74–2·63; p<0·0001]), and when they were excluded (268 [10%] of 2735 txt2stop vs 124 [4%] of 2789 control [2·20, 1·79–2·71; p<0·0001]). No significant heterogeneity was shown in any of the prespecified subgroups. Interpretation The txt2stop smoking cessation programme significantly improved smoking cessation rates at 6 months and should be considered for inclusion in smoking cessation services. Funding UK Medical Research Council, Primary Care Research Networks.

10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trial.

Summary Background If carotid artery narrowing remains asymptomatic (ie, has caused no recent stroke or other neurological symptoms), successful carotid endarterectomy (CEA) reduces stroke incidence for some years. We assessed the long-term effects of successful CEA. Methods Between 1993 and 2003, 3120 asymptomatic patients from 126 centres in 30 countries were allocated equally, by blinded minimised randomisation, to immediate CEA (median delay 1 month, IQR 0·3–2·5) or to indefinite deferral of any carotid procedure, and were followed up until death or for a median among survivors of 9 years (IQR 6–11). The primary outcomes were perioperative mortality and morbidity (death or stroke within 30 days) and non-perioperative stroke. Kaplan-Meier percentages and logrank p values are from intention-to-treat analyses. This study is registered, number ISRCTN26156392. Findings 1560 patients were allocated immediate CEA versus 1560 allocated deferral of any carotid procedure. The proportions operated on while still asymptomatic were 89·7% versus 4·8% at 1 year (and 92·1% vs 16·5% at 5 years). Perioperative risk of stroke or death within 30 days was 3·0% (95% CI 2·4–3·9; 26 non-disabling strokes plus 34 disabling or fatal perioperative events in 1979 CEAs). Excluding perioperative events and non-stroke mortality, stroke risks (immediate vs deferred CEA) were 4·1% versus 10·0% at 5 years (gain 5·9%, 95% CI 4·0–7·8) and 10·8% versus 16·9% at 10 years (gain 6·1%, 2·7–9·4); ratio of stroke incidence rates 0·54, 95% CI 0·43–0·68, p<0·0001. 62 versus 104 had a disabling or fatal stroke, and 37 versus 84 others had a non-disabling stroke. Combining perioperative events and strokes, net risks were 6·9% versus 10·9% at 5 years (gain 4·1%, 2·0–6·2) and 13·4% versus 17·9% at 10 years (gain 4·6%, 1·2–7·9). Medication was similar in both groups; throughout the study, most were on antithrombotic and antihypertensive therapy. Net benefits were significant both for those on lipid-lowering therapy and for those not, and both for men and for women up to 75 years of age at entry (although not for older patients). Interpretation Successful CEA for asymptomatic patients younger than 75 years of age reduces 10-year stroke risks. Half this reduction is in disabling or fatal strokes. Net benefit in future patients will depend on their risks from unoperated carotid lesions (which will be reduced by medication), on future surgical risks (which might differ from those in trials), and on whether life expectancy exceeds 10 years. Funding UK Medical Research Council, BUPA Foundation, Stroke Association.

Three controlled trials of interventions to increase recruitment to a randomized controlled trial of mobile phone based smoking cessation support.

Background Recruitment is a major challenge for trials but there is little evidence regarding interventions to increase trial recruitment. We report three controlled trials of interventions to increase recruitment to the Txt2stop trial. Purpose To evaluate: Trial 1. The impact on registrations of a text message regarding an online registration facility; Trial 2. The impact on randomizations of sending £5 with a covering letter to those eligible to join the trial; Trial 3. The impact on randomizations of text messages containing quotes from existing participants. Methods Single blind controlled trials with allocation concealment. Interventions: Trial 1: A text message regarding our new online registration facility; Trial 2: A letter with £5 enclosed; Trial 3: A series of four text messages containing quotes from participants. The control group in each trial received standard Txt2stop procedures. Results Trial 1: 3.6% (17/470) of the intervention group and 1.1% (5/467) of the control group registered for the trial, risk difference 2.5% (95% CI 0.6—4.5). 0% (0/ 470) of the intervention group and 0.2% (1/467) of the control group registered successfully online, risk difference —0.2 (95% CI —0.6—0.2); Trial 2: 4.5% (11/246) of the intervention group and 0.4% (1/245) of the control group were randomized into the Txt2stop trial, risk difference 4.0% (95% CI 1.4—6.7); Trial 3: 3.5% (14/405) of the intervention group and 0% (0/406) of the control group were randomized into the Txt2stop trial, risk difference 3.5 (95% CI 1.7—5.2). Limitations There were no baseline data available for trial 1. Allocation of participant IDs in trials 2 and 3 were systematic. Conclusion Sending a text message about an online registration facility increased registrations to Txt2stop, but did not increase online registrations. Sending a £5 reimbursement for participants’ time and sending text messages containing quotes from existing participants increased randomizations into the Txt2stop trial. Clinical Trials 2010; 7: 265—273. http://ctj.sagepub.com

Two controlled trials to increase participant retention in a randomized controlled trial of mobile phone-based smoking cessation support in the United Kingdom

Background Loss to follow-up of trial participants represents a threat to research validity. To date, interventions designed to increase participants’ awareness of benefits to society of completing follow-up, and the impact of a telephone call from a senior female clinician and researcher requesting follow-up have not been evaluated robustly. Purpose Trial 1 aimed to evaluate the effect on trial follow-up of written information regarding the benefits of participation to society. Trial 2 aimed to evaluate the effect on trial follow-up of a telephone call from a senior female clinician and researcher. Methods Two single-blind randomized controlled trials were nested within a larger trial, Txt2stop. In Trial 1, participants were allocated using minimization to receive a refrigerator magnet and a text message emphasizing the benefits to society of completing follow-up, or to a control group receiving a simple reminder regarding follow-up. In Trial 2, participants were randomly allocated to receive a telephone call from a senior female clinician and researcher, or to a control group receiving standard Txt2stop follow-up procedures. Results Trial 1: 33.5% (327 of 976) of the intervention group and 33.8% (329 of 974) of the control group returned the questionnaire within 26 weeks of randomization, risk ratio (RR) 0.99; 95% confidence interval (CI) 0.88–1.12. In all, 83.3% (813 of 976) of the intervention group and 82.2% (801 of/974) of the control group sent back the questionnaire within 30 weeks of randomization, RR 1.01; 95% CI 0.97, 1.05. Trial 2: 31% (20 of 65) of the intervention group and 32% (20 of 62) of the control group completed trial follow-up, RR 0.93; 95%CI 0.44, 1.98. Conclusions In presence of other methods to increase follow-up neither experimental method (refrigerator magnet and text message emphasizing participations benefits to society nor a telephone call from studys principal investigator) increased participant follow-up in the Txt2stop trial.

Do messages of scarcity increase trial recruitment

INTRODUCTION Psychological theory suggests that participants may be more likely to volunteer to join a clinical trial if they perceive places in the trial are a scarce commodity. MATERIAL AND METHODS We conducted a single blind, randomized controlled trial to test recruitment strategies within the larger txt2stop smoking cessation trial. 1862 people who were eligible for the txt2stop trial but had not yet consented to join were randomized to receive either A) a reminder about the txt2stop trial plus a message that there were only 300 places left, or B) a reminder about the trial only. The outcome was the participants consent to join the txt2stop trial 3days after messages were sent. RESULTS Of 895 participants randomized to the intervention group, 90 (10.1%) had consented to join the txt2stop trial. Of the 967 participants randomized to the control group, 67 (6.9%) had consented to join the txt2stop trial (OR=1.50, 95% CI 1.07-2.12). DISCUSSION Scarcity messages were an effective way to increase recruitment into the txt2stop trial and could be relevant to other trials. CONCLUSIONS Communicating scarcity is an effective way to increase trial recruitment.

A randomised tRial of expedited transfer to a cardiac arrest centre for non-ST elevation ventricular fibrillation out-of-hospital cardiac arrest : the ARREST pilot randomised trial

BACKGROUND Wide variation exists in inter-hospital survival from out-of-hospital cardiac arrest (OHCA). Regionalisation of care into cardiac arrest centres (CAC) may improve this. We report a pilot randomised trial of expedited transfer to a CAC following OHCA without ST-elevation. The objective was to assess the feasibility of performing a large-scale randomised controlled trial. METHODS Adult witnessed ventricular fibrillation OHCA of presumed cardiac cause were randomised 1:1 to either: (1) treatment: comprising expedited transfer to a CAC for goal-directed therapy including access to immediate reperfusion, or (2) control: comprising current standard of care involving delivery to the geographically closest hospital. The feasibility of randomisation, protocol adherence and data collection of the primary (30-day all-cause mortality) and secondary (cerebral performance category (CPC)) and in-hospital major cardiovascular and cerebrovascular events (MACCE) clinical outcome measures were assessed. RESULTS Between November 2014 and April 2016, 118 cases were screened, of which 63 patients (53%) met eligibility criteria and 40 of the 63 patients (63%) were randomised. There were no protocol deviations in the treatment arm. Data collection of primary and secondary outcomes was achieved in 83%. There was no difference in baseline characteristics between the groups: 30-day mortality (Intervention 9/18, 50% vs. Control 6/15, 40%; P=0.73), CPC 1/2 (Intervention: 9/18, 50% vs. Control 7/14, 50%; P>0.99) or MACCE (Intervention: 9/18, 50% vs. Control 6/15, 40%; P=0.73). CONCLUSIONS These findings support the feasibility and acceptability of conducting a large-scale randomised controlled trial of expedited transfer to CAC following OHCA to address a remaining uncertainty in post-arrest care.

Using marketing theory to inform strategies for recruitment: a recruitment optimisation model and the txt2stop experience

BackgroundRecruitment is a major challenge for many trials; just over half reach their targets and almost a third resort to grant extensions. The economic and societal implications of this shortcoming are significant. Yet, we have a limited understanding of the processes that increase the probability that recruitment targets will be achieved. Accordingly, there is an urgent need to bring analytical rigour to the task of improving recruitment, thereby increasing the likelihood that trials reach their recruitment targets. This paper presents a conceptual framework that can be used to improve recruitment to clinical trials.MethodsUsing a case-study approach, we reviewed the range of initiatives that had been undertaken to improve recruitment in the txt2stop trial using qualitative (semi-structured interviews with the principal investigator) and quantitative (recruitment) data analysis. Later, the txt2stop recruitment practices were compared to a previous model of marketing a trial and to key constructs in social marketing theory.ResultsPost hoc, we developed a recruitment optimisation model to serve as a conceptual framework to improve recruitment to clinical trials. A core premise of the model is that improving recruitment needs to be an iterative, learning process. The model describes three essential activities: i) recruitment phase monitoring, ii) marketing research, and iii) the evaluation of current performance. We describe the initiatives undertaken by the txt2stop trial and the results achieved, as an example of the use of the model.ConclusionsFurther research should explore the impact of adopting the recruitment optimisation model when applied to other trials.