Haddad FS, Kerry RM, McEwen JA, Appleton L, Garbuz DS, Masri BA, Duncan CP.
Unanticipated variations between expected and delivered pneumatic compression
therapy after elective hip surgery: a possible source of variation in reported
patient outcomes.
J Arthroplasty 2001 Jan;16(1):37-46

Division of Reconstructive Orthopaedics, University of British Columbia,
Vancouver, BC, Canada.

The differences between the pneumatic compression thromboprophylaxis delivered
after elective total hip arthroplasties and that was expected were quantified
before (49 patients) and after a concerted nursing education program (30
patients) that was designed to ensure maximum compliance and to verify the
correct application of the devices. The expected therapy was not delivered to any
of the patients monitored. Therapy was delivered only an average of 77.8% of the
time during the expected treatment periods. During 99.9% of the expected therapy
times, values of key outcomes-related parameters of the therapy delivered to the
patients varied by >10% from expected values. These variations were not reduced
significantly by medical and nursing education. This variation may be a
significant confounding factor in comparatively evaluating thromboembolic disease
outcome reports.