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Trial Arms (trial + arm)
Selected AbstractsGRAPHICAL SENSITIVITY ANALYSIS WITH DIFFERENT METHODS OF IMPUTATION FOR A TRIAL WITH PROBABLE NON-IGNORABLE MISSING DATAAUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS, Issue 4 2009M. Weatherall Summary Graphical sensitivity analyses have recently been recommended for clinical trials with non-ignorable missing outcome. We demonstrate an adaptation of this methodology for a continuous outcome of a trial of three cognitive-behavioural therapies for mild depression in primary care, in which one arm had unexpectedly high levels of missing data. Fixed-value and multiple imputations from a normal distribution (assuming either varying mean and fixed standard deviation, or fixed mean and varying standard deviation) were used to obtain contour plots of the contrast estimates with their,P -values superimposed, their confidence intervals, and the root mean square errors. Imputation was based either on the outcome value alone, or on change from baseline. The plots showed fixed-value imputation to be more sensitive than imputing from a normal distribution, but the normally distributed imputations were subject to sampling noise. The contours of the sensitivity plots were close to linear in appearance, with the slope approximately equal to the ratio of the proportions of subjects with missing data in each trial arm. [source] The relative efficacy of two levels of a primary care intervention for family members affected by the addiction problem of a close relative: a randomized trialADDICTION, Issue 1 2009Alex Copello ABSTRACT Objectives A randomized trial to compare two levels of an intervention (full versus brief) for use by primary health-care professionals with family members affected by the problematic drug or alcohol use of a close relative. Design A prospective cluster randomized comparative trial of the two interventions. Setting A total of 136 primary care practices in two study areas within the West Midlands and the South West regions of England. Participants A total of 143 family members affected by the alcohol or drug problem of a relative were recruited into the study by primary health-care professionals. All recruited family members were seen on at least one occasion by the professional delivering the intervention and 129 (90 %) were followed-up at 12 weeks. Main outcome measures Two validated and standardized self-completion questionnaires measuring physical and psychological symptoms of stress (Symptom Rating Test) and behavioural coping (Coping Questionnaire) experienced by the family members. It was predicted that the full intervention would show increased reduction in both symptoms and coping when compared to the brief intervention. Results The primary analysis adjusted for clustering, baseline symptoms and stratifying variables (location and professional group) showed that there were no significant differences between the two trial arms. The symptom score at follow-up was 0.23 [95% confidence interval (CI): ,3.65, +4.06] higher in the full intervention arm than in the brief intervention arm, and the coping score at follow-up was 0.12 (95% CI: ,5.12, +5.36) higher in the full intervention arm than in the brief intervention arm. Conclusions A well-constructed self-help manual delivered by a primary care professional may be as effective for family members as several face-to-face sessions with the professional. [source] Does stage-based smoking cessation advice in pregnancy result in long-term quitters?ADDICTION, Issue 1 200518-month postpartum follow-up of a randomized controlled trial ABSTRACT Aims To evaluate the effect on quitting smoking at 18 months postpartum of smoking cessation interventions based on the Transtheoretical Model (TTM) delivered in pregnancy compared to current standard care. It has been claimed that TTM-based interventions will continue to create quitters after the end of the intervention period. Design Cluster randomized trial. Setting Antenatal clinics in general practices in the West Midlands, UK. Participants A total of 918 pregnant smokers originally enrolled in the trial, of which 393 women were followed-up at 18 months postpartum. Interventions One hundred general practices were randomized into the three trial arms. Midwives in these practices delivered three interventions: A (standard care), B (TTM-based self-help manuals) and C (TTM-based self-help manuals plus sessions with an interactive computer program giving individualized smoking cessation advice). Measurements Self-reported continuous and point prevalence abstinence since pregnancy. Findings When combined together, there was a slight and not significant benefit for both TTM arms compared to the control, with an odds ratio (OR) 95% confidence interval (CI) of 1.20 (0.29,4.88) for continuous abstinence. For point prevalence abstinence, the OR (95%CI) was 1.15 (0.66,2.03). Seven of the 54 (13%) women who had quit at the end of pregnancy were still quit 18 months later, and there was no evidence that the TTM-based interventions were superior in preventing relapse. Conclusions The TTM-based interventions may have shown some evidence of a short-term benefit for quitting in pregnancy but no benefit relative to standard care when followed-up in the longer-term. [source] The cost-effectiveness of computer-assisted anticoagulant dosage: results from the European Action on Anticoagulation (EAA) multicentre studyJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2009S. JOWETT Summary. Background: Increased demand for oral anticoagulation has resulted in wider adoption of computer-assisted dosing in anticoagulant clinics. An economic evaluation has been performed to investigate the cost-effectiveness of computer-assisted dosing in comparison with manual dosing in patients on oral anticoagulant therapy. Methods: A trial-based cost-effectiveness analysis was conducted as part of the EAA randomized study of computer-assisted dosage vs. manual dosing. The 4.5-year multinational trial was conducted in 32 centres with 13 219 anticoagulation patients randomized to manual or computer-assisted dosage. The main outcome measures were total health care costs, clinical event rates and cost-saving per clinical event prevented by computer dosing compared with manual dosing. Results: Mean dosing costs per patient were lower (difference: ,47) for computer-assisted dosing, but with little difference in clinical event costs. Total overall costs were ,51 lower in the computer-assisted dosing arm. There were a larger number of clinical events in the manual dosing arm. The overall difference between trial arms was not significant (difference in clinical events, ,0.003; 95% CI, ,0.010,0.004) but there was a significant reduction in events with DVT/PE, suggesting computer-assisted dosage with the two study programs (dawn ac or parma 5) was at least as effective clinically as manual dosage. The cost-effectiveness analysis indicated that computer-assisted dosing is less costly than manual dosing. Conclusions: Results indicate that computer-assisted dosage with the two programs (dawn ac and parma 5) is cheaper than manual dosage and is at least as effective clinically, indicating that investment in this technology represents value for money. [source] | ||||||||||