Modifying Clinical Trial Designs to Test Treatments for Clinical Significance in Individual Patients
Author: Becker R.E.
Source: Clinical Drug Investigation, Volume 21, Number 10, 1 October 2001 , pp. 727-733(7)
Publisher: Adis International
Abstract:The aim of this article was to design clinical trials that test treatments for clinical significance in individual patients. In a repeated measures design a scalar summary statistic describes the clinical course of each individual. To provide satisfactory reliability for each patient's clinical course to be the unit of analysis, a study of measurement reliability prior to the trial forms the basis of the plan of assessment using outcome measures. The null hypothesis is rejected if statistically significant differences in patient courses arise among the treatment arms. Using criteria of clinical and statistical significance, the investigator evaluates each individual patient's outcome: first for response to the treatment; second to assign a probability for occurrence of the patient's outcome under treatment and placebo conditions. This method of analysis provides the practitioner with a model evidence based in a clinical trial to evaluate treatment effects in patient care. The method of analysis develops a probabilistic model that identifies individuals as responders or non-responders to a treatment condition. The modified clinical trial design refines and makes more specific the current clinical trial confirmation that a treatment is effective with a model that identifies patients as responding and non-responding to the treatments in the trial and provides a probability of occurrence for each patient outcome.These methods offer a practical modification of clinical trial design. With modification, clinical trials evidence individual patient responses to treatments in the trial. The clinical trial model for judging individual patient responses provides the physician with an evidence base for judging individual patient responses to treatment with improved reliability compared with current practices. The clinical care advantages from the design changes in clinical trials are readily apparent in Alzheimer's therapy where large error variances in measurements preclude accurate assessments of treatment response for most patients. The suggested modifications to clinical trial design and analysis apply in other disease categories because of improved reliability in clinical assessments and the clinical trial evidence base for evaluating individual patient responses to treatment.
Keywords: Clinical trial design
Document Type: Short communication
Publication date: 2001-10-01