MEASUREMENT METHODS OF DRUG CONSUMPTION AS A SECONDARY JUDGMENT CRITERION FOR CLINICAL-TRIALS IN CHRONIC RHEUMATIC DISEASES

Drug consumption is sometimes used as a secondary judgment criterion f or clinical trials. Many measurement methods are available to quantify drug consumption. Several methods were applied in a rheumatic disease trial involving 121 patients with chronic low back pain who lived aro und Saint-Nectaire, France, and who participated in the trial from Apr il to November 1993 to determine an easily used and practical measurem ent method to detect a significant drug consumption change over time. Analgesic and nonsteroidal antiinflammatory drugs (NSAIDs) were classi fied according to the anatomical therapeutic chemical classification, Consumption was quantified on a weekly basis in number of tablets (met hod 1), unit of defined daily dose (method 2), milligrams of active pr inciple (method 3), and NSAID equivalence score (method 4), These meth ods were applied in a randomized clinical trial of spa therapy on suff erers of chronic low back pain, An analysis of variance with repeated measures showed a significant difference in drug consumption between t reatment and central groups detected by all methods, except for the NS AID consumption measured with method 3. The comparison of each method by the relative efficiency index indicated that method 1 had a greater sensitivity for detecting changes of drug consumption, Tablet count a ppears to be a more sensitive and more practical method far detecting a drug consumption change in clinical trials.