The safety and efficacy of the tetanus vaccine intramuscularly versus subcutaneously in anticoagulated patients: a randomized clinical trial.

BACKGROUND: In patients treated with oral anticoagulants, subcutaneous injections of anti-tetanus vaccine are usually recommended to reduce the risk of bleeding, although the effectiveness of the vaccine has only been proven for intramuscular injection. The objective of this study was to compare the safety and efficacy of intramuscular and subcutaneous injections of tetanus-diphtheria vaccine in patients treated with oral anticoagulants. METHODS/DESIGN: We present a prospective, double blinded, clinical trial comparing two groups of patients with oral anticoagulants: one group was administered tetanus-diphtheria vaccine by intramuscular injection, while the other was administered the same vaccine by subcutaneous injection. Allocation to each group was randomized and the duration of the study was six years. STUDY POPULATION: all patients treated with oral anticoagulants, who had been administered with at least one dose of vaccine, at 15 Health Centres in Vigo (Spain), and who agreed to participate in the study. The sample size was 115 patients in each group. The main variables for the safety analysis were the measurement of the brachial diameter, the appearance of basic injuries at the vaccine administration site, the appearance of pain and systemic reactions. The variable used for the efficacy analysis was a significant increase in the titres of anti-tetanus toxoid antibodies.An Intention-to-treat analysis will be performed. Details will be classified according to the administration route, while within each group a 3-tiered stratification will be defined by the administered number of doses. As a measure of association, relative risk will be estimated; the reduction of relative risk will also measured. For safety and to control the confounder effect, a logistic regression analysis will be carried out. As a measure of impact the reduction of absolute risk in relation to the total number of patients to be treated and the Number Needed to Treat will be estimated.CONSORT 2010 guidelines were applied for reporting parallel group randomised trials. DISCUSSION: The most significant difficulties on the project are related to the large number of participating centres, required to obtain a viable study population sample size, and the coordination given the scattering of the centres and researchers. TRIAL REGISTRATION: ISRCTN69942081.

CT colonography without cathartic preparation: positive predictive value and patient experience in clinical practice.

OBJECTIVE: To determine the positive predictive value (PPV) for polyps ≥ 6 mm detected at CT colonography (CTC) performed without cathartic preparation, with low-dose iodine faecal tagging regimen and to evaluate patient experience. METHODS: 1920 average-risk patients underwent CTC without cathartic preparation. Faecal tagging was performed by diatrizoate meglumine and diatrizoate sodium at a total dose of 60 ml (22.2 g of iodine).The standard interpretation method was primary 3D with 2D problem solving. We calculated per-patient and per-polyp PPV in relation to size and morphology. All colonic segments were evaluated for image quality (faecal tagging, amount of liquid and solid residual faeces and luminal distension). Patients completed a questionnaire before and after CTC to assess preparation and examination experience. RESULTS: Per-polyp PPV for detected lesions of ≥ 6 mm, 6-9 mm, ≥ 10 mm and ≥ 30 mm were 94.3%, 93.1%, 94.7% and 98%, respectively. Per-polyp PPV, according to lesion morphology, was 94.6%, 97.3% and 85.1% for sessile, pedunculated and flat polyps, respectively. Per-patient PPV was 92.8%. Preparation without frank cathartics was reported to cause minimal discomfort by 78.9% of patients. CONCLUSION: CTC without cathartic preparation and low-dose iodine faecal tagging may yield high PPVs for lesions ≥ 6 mm and is well accepted by patients. KEY POINTS: • Computed tomographic colonography (CTC) without cathartic preparation is well accepted by patients • Cathartic-free faecal tagging CTC yields high positive predictive values • CTC without cathartic preparation could improve uptake of colorectal cancer screening.