Work package 7

Statistical Analysis

Leader: Prof. Philip Bath
University of Nottingham (UNOTT)

Main objectiveS

Design the Statistical Analysis Plan and perform the final statistical analyses of all outcomes of interest.

Develop a statistical analysis plan

Develop analysis software

Check the central database

Perform the final statistical analysis

The statistical work will be done at the Nottingham Stroke Trial Unit (NSTU).

Description of the tasks

Appropriate use of statistical methodology and analysis was essential for evaluating the benefits and harms of the PRECIOUS study interventions, and for providing reliable interpretation of the results.

The primary outcome of interest in PRECIOUS was the score on the so-called ‘modified Rankin Scale’, which is a scale for measuring the degree of disability or dependence in daily activities of patients who have had a stroke. Other outcomes of interest were the quality of life and the extent of cognitive functioning after stroke. The team at the Nottingham Stroke Trial Unit performed several statistical analyses to assess whether any of the three medical treatment in PRECIOUS improves functional outcome on the ‘modified Rankin Scale’, quality of life and cognitive functioning at three months in patients with acute stroke, compared to patients who did not receive any medical treatment in PRECIOUS.

In addition, in subgroup analyses, the team assessed whether one or more particular patient groups are more or less likely to benefit from each of the interventions, based on for example age, sex or stroke severity. In collaboration with UMC, the technical description of the statistical methodology and procedures for performing the statistical analysis was written down in the Statistical Analysis Plan, which was completed before the end of the study. A statistical software was developed by the Nottingham Stroke Trial Unit to analyse the data which was collected during the PRECIOUS trial.

After the information of the last patient in PRECIOUS has been collected at the end of the study, the final statistical analysis was performed according to the Statistical Analysis Plan. Also, the team at the Nottingham Stroke Trial Unit used the data of PRECIOUS to develop prediction models, which could be used in clinical practice to predict the occurrence of infections or poor outcome in elderly patients with acute stroke.

PRECIOUS: List of Work Packages

WP 1: Trial Management

WP 2: Outcome Adjudication

WP 3: Infections and Antimicrobial Resistance

WP 4: Monitoring

WP 5: Health Economics

WP 6: Safety Monitoring

WP 7: Statistical Analysis

WP 8: Dissemination, Exploitation and Communication

WP 9: Project Management