Outcomes
REGRESSION, EVENTS, EVENT, RECRUITMENT
Twenty-five months after recruitment started, study data was submitted for the planned interim analysis. At the time, with 46% of the expected sample there were 69 validated primary outcome events (76% of the minimum expected, 34 in the experimental arm) in a total of 7959 hospitalization days. The report recommended to stop the trial for futility, based on the calculated conditional power to surpass the minimal efficacy threshold (0.0012) under the trends expected with collected data thus far.Our findings at the closing time corresponded to an overall PU incidence rate of 8.7 per 1000 person-days: it was 9.6 for the intervention group and 7.9 for the control group per 1000 person-days (relative risk RR 1.21, 95% CI [0.74 to 2.01]). The HR raw estimate using the regression model of proportional risk was 1.07, 95% CI, [0.67 to 1.71]; the age-adjusted HR was 1.05, [95% CI 0.66, 1.69], and the BMI-adjusted was 1.07, 95% CI [0.66, 1.71], (Fig. Time for the irst PU event analysis according to the study groups. Median (interquartile range) from time to event of 5.5 [3.0, 12.0] and 5.0 [3.0, 13.0] days for patients assigned to cream and dressing, respectively. Incidence rates of 7.9 and 9.6 events per 1,000 patient-days in patients assigned to cream and dressing, respectively (incidence rate ratio: 1.21, 95% CI [0.73, 2.01]).PUs were more frequently located in the sacrum (47.1% for intervention and 42.9 for control), in the right trochanter (11.8% for intervention and 8.6 for control), in the left trochanter (5.9% for intervention and 2.9% for control), and in the right heel (2.9% for Intervention and 11.4 for control group). The median time to event for PU in days was 5.5 IQR [3.0, 12.0] and 5.0 [3.0, 13.0] for patients assigned to control and the intervention, respectively.