Control groups clinical trials

Desnuelle C, Dib M, Garrel C, Eavier A (2001) ALS Riluzole-Tocopherol Study Group. A double blind, placebo controlled randomized clinical trial of alpha tocopherol in the treatment of amyotrophic lateral sclerosis. Amyotroph Lateral Scler Other Motor Neuron Disord 2(1) 9-18. 

Balsano F, Rizzon P, VioU F, et al. Antiplatelet treatment witii ticlopidine in unstable angina A controlled multicenter clinical trial. The Studio della Ticlopidina nelT Angina Instabile Group. Circulation 1990 82 17— 26. 

Control. A term which can be used in a number of ways in clinical trials but which is always related to the idea of controlling for various sources of bias. In a controlled (parallel) clinical trial, the control group is a group of patients otherwise presumed similar to the patients given the experimental treatment, but who are given an alternative treatment (for example, a placebo) in order to provide a standard of comparison for the experimental treatment. 

Mattys. H., de Mey, C., Carls, C., Rys, A., Geib, A., Wittig, T. 2000. Ef cacy and tolerability of myrtol standardised in acute bronchitis. A multi-centre, randomised, double-blind, placebo-controlled parallel group clinical trial vs. cefuroxime and ambroxol. Arzneim-Forsch. 50(8) 700-711. 

Atrophic vaginitis is a common occurrence, particularly among postmenopausal women however, few seek or receive any treatment. One therapeutic solution is topically applied products. Oestrogen-based treatments have been shown to be effective but, many patients reluctant to use such formulations due to health concerns, hence the need to assess the efficacy of acceptable alternatives. The current, multicentre, randomised, controlled, open-label, parallel-group clinical trial was set out to evaluate the efficacy and safety of HA vaginal gel to treat vaginal dryness compared with oestriol cream in postmenopausal women [34 ]. 

Chen J, Ceng L, Song X, Li H, Giordan N, Liao Q. Evaluation of the efficacy and safety of HA vaginal gel to ease vaginal dryness a multicenter, randomized, controlled, open-label, parallel-group, clinical trial. J Sex Med 2012 10(6) 1575-84. 

In a double-blind, placebo-controlled, randomised clinical trial, the efficacy and safety of folic acid and vitamin Bi2 supplementation in reducing the incidence of diarrhoea and acute lower respiratory infections was evaluated in 1000 North Indian children aged 6-30 months [10 -]. Children in the folic acid groups were observed to have more episodes of diarrhoea compared with those in the placebo group. The investigators concluded that the safety of folic acid supplementation in young children warrants further research. 

Several clinical trials have been conducted with streptokinase adrninistered either intravenously or by direct infusion into a catheterized coronary artery. The results from 33 randomized trials conducted between 1959 and 1984 have been examined (75), and show a significant decrease in mortaUty rate (15.4%) in enzyme-treated patients vs matched controls (19.2%). These results correlate well with an ItaUan study encompassing 11,806 patients (76), in which the overall reduction in mortaUty was 19% in the streptokinase-treated group, ie, 1.5 million units adrninistered intravenously, compared with placebo-treated controls. The trial also shows that a delay in the initiation of treatment over six hours after the onset of symptoms nullifies any benefit from this type of thrombolytic therapy. Conversely, patients treated within one hour from the onset of symptoms had a remarkable decrease in mortaUty (47%). The benefits of streptokinase therapy, especially in the latter group of patients, was stiU evident in a one-year foUow-up (77). In addition to reducing mortahty rate, there was an improvement in left ventricular function and a reduction in the size of infarction. Thus early treatment with streptokinase is essential. 

E10 Choice of Control Group and Related Issues In Clinical Trials... 

Only two randomized, controlled trials have been completed, and neither provides anything like compelling data (Table 2.6). Chouinard and Albright (1997) conducted a unique evaluation of a subset of patients from a previously conducted clinical trial. Subjects were categorized and profiled at baseline and end point according to clinical severity, and a group of psychiatric nurses were asked to rate various aspects of likely outcome and quality of life to each profile (mild, moderate or severe symptoms). Health state utilities were then calculated risperidone was found to provide more than double the number of quality-adjusted life years compared with haloperidol. Csernansky and Okamoto (1999) conducted a rather more conventional trial, but included no economic analyses. However, they did find that the use of risperidone substantially reduced relapse rates compared with haloperidol—an outcome likely to have a positive impact on cost-effectiveness. 

The PRO ACT-11 trial was designed to assess the clinical efficacy and safety of lA r-pro-UK. In this study, 180 patients were enrolled in a 2 1 randomization scheme to receive either 9 mg lA r-pro-UK plus 4 hours of low-dose IV heparin, or low-dose IV heparin alone. The primary clinical outcome, the proportion of patients with slight or no disability at 90 days (mRS of < 2), was achieved in 40% of the 121 patients in the r-pro-UK treatment group, compared to 25% of the 59 patients in the control group (absolute benefit 15%, relative benefit 58%, number need to treat = 7 p = 0.04). The recanalization rate (TlMl 2 and 3) was 66% for the r-pro-UK group and 18% for the control group (p < 0.001). Symptomatic ICH within 24 hours occurred in 10% of r-pro-UK patients and 2% of control patients (p = 0.06). All symptomatic ICHs occurred in patients with a baseline NIHSS... 

Yamaguchi T, Sano K, Takakura K, Saito I, Shinohara Y, Asano T, Yasuhara H. Ebselen in acute ischemic stroke a placebo-controlled, double-blind clinical trial. Ebselen study group. Stroke 1998 29 12-17. 

Bellomo R, Chapman M, FinferS, et al. Low-dose dopamine in patients with early renal dysfunction a placebo-controlled randomized trial. Australian and New Zealand Intensive Care Society (ANZICS) Clinical Trials Group. Lancet 2000 356 2139-2143. 

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