Effect of design-adaptive allocation on inference for a regression parameter: Two-group, single-covariate and double-covariate cases

Comparative effectiveness of traditional Chinese medicine and psychosocial care in the treatment of temporomandibular disorders-associated chronic facial pain

This dual-site study sought to identify the appropriate role for traditional Chinese medicine (TCM; acupuncture and herbs) in conjunction with a validated psychosocial self-care (SC) intervention for treating chronic temporomandibular disorders (TMD)-associated pain. Participants with Research Diagnostic Criteria for Temporomandibular Disorders-confirmed TMD (n = 168) entered a stepped-care protocol that began with a basic TMD class. At weeks 2 and 10, patients receiving SC whose worst facial pain was above predetermined levels were reallocated by minimization to SC or TCM with experienced practitioners. Characteristic facial pain (CFP: mean of worst pain, average pain when having pain, and current pain; each visual analog scale [VAS] 0-10) was the primary outcome. Social activity interference (VAS 0-10) was a secondary outcome. Patients were monitored for safety. TCM provided significantly greater short-term (8-week) relief than SC (CFP reduction difference, -.60 [standard deviation of the estimate .26], P = .020) and greater reduction in interference with social activities (-.81 [standard deviation of the estimate .33], P = .016). In 2 of 5 treatment trajectory groups, more than two thirds of participants demonstrated clinically meaningful responses (≥30% improvement) in pain interference over 16 weeks. This study provides evidence that TMD patients referred for TCM in a community-based model will receive safe treatment that is likely to provide some short-term pain relief and improved quality of life. Similar designs may also apply to evaluations of other kinds of chronic pain. (ClinicalTrials.gov number NCT00856167).

PERSPECTIVE

This short-term comparative effectiveness study of chronic facial pain suggests that TCM is safe and frequently efficacious alone or subsequent to standard psychosocial interventions. TCM is widely available throughout North America and may provide clinicians and patients with a reasonable addition or alternative to other forms of therapy.

The use of minimization in clinical trials

Since its introduction in 1974 the use of the term Minimization has been broadened to include other algorithms. All algorithms use patient characteristics to determine the assignment that produces the best overall balance between treatment groups. They differ in whether or not they use all of the data from each previously assigned subject to assign subsequent subjects so the methods are classified as complete or partial minimization. PubMed, Citation Index and Cochrane searches determined the frequency of articles using these types of minimization and a subset was selected for detailed review regarding the adequacy of the usage and reporting of minimization. In the past 10 years usage has increased three fold over the previous decade but is still less than 2% of clinical trials. None of the studies makes maximum use of minimization and they are not following good reporting practices. Concerns about the use of minimization have involved selection bias and statistical analysis. Several modifications to minimization are suggested to reduce the possibility of selection bias so that adding randomization will rarely be required. Separating primary and secondary analyses can avoid the statistical problems that minimization poses. The two types of analyses are distinguished by opposite limiting signs, providing reliable, simplified statistical results. This will improve data utilization and make clinical trials more reproducible. Minimization should be the method of choice in assigning subjects in all clinical trials.