Crossover and noncrossover designs in four-point parallel line analgesic assays

Analgesia evaluation of 2 NSAID drugs as adjuvant in management of chronic temporomandibular disorders

The aim of this triple-blind full-randomized clinical trial was to quantify analgesia in masticatory muscles and temporomandibular joints after occlusal splint therapy associated with the adjuvant administration of nonsteroidal anti-inflammatory drugs (NSAID) isolated or associated with other therapeutic agents. Pain relief was also recorded. Eighteen volunteers who had been suffering from chronic pain in masticatory muscles due to temporomandibular disorders were selected after anamnesis and assessment using RDC/TMD translated to Portuguese. The 3 proposed treatments were NSAID (sodium diclofenac), panacea (sodium diclofenac + carisoprodol + acetaminophen + caffeine), and a placebo. The total treatment duration was 10 days, preceded and succeeded by patients' pain assessment. A washout interval of 11 days was established between each therapy. All participants received all treatments in different moments, in a full randomized crossover methodology. The assessment of drug therapies was performed using visual analogue scale for pain on palpation followed by 11-point numerical scale to quantify pain during treatment. Statistical analysis has shown that, after 10 days of treatment, all therapies were effective for pain relief. NSAID therapy promoted analgesia on the third day, while placebo only promoted analgesia in the eighth day. It has been concluded that sodium diclofenac used as splint adjuvant therapy, promotes significant analgesia in a shorter time.

The classic caries clinical trial: constraints and opportunities

The history of clinical trials would include events in 1747 on board the Salisbury, a British Navy vessel at sea with 12 seamen critically ill with scurvy. Involving these 12 sailors in a study, an officer on board by the name of Lind evaluated six potential treatments for scurvy, and rapidly reached the conclusion that daily consumption of citrus fruits returned the men fit for duty in approximately six days (Bull, 1959). The concept of experimental randomization was first developed by Sir R.A. Fisher (1925, 1926), and the method was introduced to medical research via a study of tuberculosis treatment by Amberson and co-workers (1931), who randomized 24 TB patients into two groups, one to receive the experimental therapy, the other serving as the control. Amberson et al. also incorporated the concept of blinding into their study. Sir Austin Bradford Hill codified and built on the principles of scientific experimentation developed by Fisher, and introduced the use of random numbers in the allocation of patients in the British Medical Research Council (1948) study of the effect of streptomycin in the treatment of tuberculosis (Daniels and Hill, 1952; Hill, 1952). The first applications of clinical trial methodology for testing interventions on dental, oral, and maxillofacial diseases and conditions are more difficult to determine. For dental caries prevention, however, Chilton and Fertig (1958) and Slack and Martin (1964) were certainly among the early caries clinical trial pioneers. As clinical trials have come into the mainstream of clinical research in medicine and dentistry, a great deal of developmental work has focused on their methodological enhancement. The most successful of these efforts have come from fruitful, ongoing collaborations among clinician investigators, biostatisticians, data management specialists, biomedical ethicists, and others with an academic interest in clinical trial design and utilization. During the past 25 years, the emergence of systematic reviews and the evidence-based medicine (EBM) movement have also contributed significantly to the increasing reliance on randomized clinical trial outcomes for the advancement of better clinical practice (Richards et al., 1997; Straus and Sackett, 1998; www.cochrane.org/cochrane/ccbroch.htm#BDL, 2002).

Clinical trials in wound care I: the advantages and limitations of different clinical trial designs

Clinical trials need to be robust if practitioners are to apply their recommendations into practice. This article describes the various research designs used in wound care and the pitfalls that may compromise the reliability and validity of the results.

Randomized clinical trials in medical rehabilitation research

The purpose of this article is to provide researchers and clinicians with a basic understanding of randomized clinical trials and to discuss their potential application to and limitations in the field of physical medicine and rehabilitation. A brief history of the development of randomized clinical trials, definitions of clinical trials, types of trials, and overview of methodological issues related to design are offered. Information is provided about the need to establish clear and concise study objectives and to explicitly define interventions and expected outcomes. Recommendations for developing clinical protocols and determining adequate sample size are presented, and various statistical considerations, including power, are discussed. Issues related to sampling strategies, and recruitment are reviewed. Importance of randomization and blinding is emphasized. Readers are also referred to other resources available on this topic. Finally, the authors describe shortfalls associated with the use of this design in rehabilitation research. These are further explored and discussed in terms of the actual benefits and limitations of randomized clinical trials in physical medicine and rehabilitation research. Recommendations are made regarding the use of this methodology to address relevant needs in clinical practice.