Collagenase ointment application at 24-versus 48-hour intervals in the treatment of pressure ulcers -: A randomised multicentre study

Objective: The purpose of the present study was to demonstrate clinical equivalence between the application of collagenase ointment at 24- and 48-hour intervals in the healing of pressure ulcers. Design and Setting: This was a multicentre, randomised, nonblind, parallel group study conducted at eight hospitals in Spain. Patients: A total of 102 hospitalised or institutionalised patients of either gender aged 55 years or over having had stage III pressure ulcers for <1 year were included in the study. Methods: Reduction of ulcer area by direct and indirect measurements at 1-week intervals was the primary outcome measure. The equivalence margin was established in advance at +/-20% of ulcer area. Two one-sided t-test procedures and the confidence intervals of the differences were used to test equivalence. Results: Both therapeutic regimens significantly reduced the mean ulcer areas throughout the 8-week study. In the first month the two regimens proved to be equivalent. It would have been necessary to include more patients to demonstrate equivalence in the second month of treatment. Conclusions: Once the healing process is initiated the daily collagenase ointment application can be changed to alternate days.