The Impact of Extracorporeal Shockwave Therapy on the Reported Pain Levels of Chronic Patients in a Clinical Setting

BackgroundA review of literature for in-office, low to medium energy (.04mj/mm2 to .4mj/mm2) Extracorporeal Shockwave Therapy (ESWT) shows a substantial body of evidence suggesting strong efficacy and safety for the use of this form of Acoustic Compression Therapy. Much of this evidence is focused on the treatment of a specific region of the body, such as lateral epicondylitis, plantar fasciitis, and shoulder tendinopathies. This evaluation is designed to address the clinical utility of low to medium energy ESWT in an outpatient health care office setting, including delivery to multiple regions of the body, and for patients considered good candidates based on the failure of at least six months of prior conservative care. MethodsOrdinary least squares (OLS) models with errors clustered at the patient level estimate the association between shockwave treatments and patient-reported pain levels. Additional models utilizing polynomial treatment indicators test for a non-linear relationship between treatment number and reported pain level. ResultsFor the sixty-one patients represented in this analysis, the mean reduction in pain was 2.3 points on a 10 point scale, representing a 47% reduction in average reported pain levels. Results suggest that each treatment is associated with a 0.33 point reduction in reported pain levels (on a 10 point scale), controlling for patient demographics and treatment intensity. Additional models utilizing polynomial treatment indicators suggest a non-linear relationship between treatment number and reported pain level, indicating that the initial benefit of treatment is a 0.67 point reduction in pain for the first treatment, and falling slightly with each subsequent treatment. A subset of patients responded to follow up requests to ascertain reported pain levels at least three months after the final treatment. All patients were contacted, out of which 24 responded, reporting average pain levels of 2.9 out of 10, a substantial improvement from initial reported pain levels following final treatment (4.0), representing a decrease of 28%. ConclusionThe results suggest the use of Acoustic Compression at these doses on properly selected cases can improve clinical outcomes for conservatively treated patients who may otherwise end up requiring more aggressive measures in the absence of ESWT. Evidence reviewed suggests that continued healing time leads to further improvement.