Dosage and treatment response in randomized clinical trials of therapeutic ultrasound

Abstract

Objectives: Effective treatments usually have a known dose-response relationship. For physiotherapists, ultrasound is perhaps the single most widely and frequently used modality. Until now no dose–response relationship for this therapy has been identified. This study provides a first step in that direction by analysing the dosages used and treatment response, in randomized controlled trials investigating therapeutic ultrasound. Design: Dosage related variables from an existing set of randomized controlled trials published in the English-language literature between 1975 and 1999 on the use of ultrasound to treat pain and soft tissue lesions were analyzed. Results:too few details are still provided in most studies to identify a relationship between dosage and treatment responses. An apparently effective treatment window of pulsed ultrasound, 0·16–0·50 W/cm2 (SATA), proved illusory on closer scrutiny. Conclusions: without a known dose-response relationship users of therapeutic ultrasound can only guess at what dosage might be effective for a patient and how to modify it. Considerably more clinical research is necessary to justify the dosages used in treatment at present.