Table 2 An estimand framework for estimating the intervention effect in the analysis of the primary outcome in the PRO B study
Scientific research question | Is the average in fatigue score measured by the EORTC CAT Core after 6 months lower (superior) in the intervention group compared to the control group? |
|---|---|
Estimand attributes | |
Intervention | Intervention: patients receiving weekly PRO surveys with an alarm contact in case of worsening PRO scores Control: patients receiving quarterly PRO surveys without an alarm contact in case of worsening PRO scores |
Target population | - Female with MBC - Older than 18 years - Able to read and understand German - Receive drug treatment for MBC with a life expectancy at enrolment of more than 3 months - Having access to the Internet through a smartphone - Having the ECOG performance status of 0 to 2 |
Endpoint of interest | Fatigue score at 6 months post-randomisation |
Addressing intercurrent events | |
Discontinuation | |
- Overload due to the PRO survey | Assuming missing data at random, implicitly impute data using MICE with m = 30 imputations |
- Lack of interest or relevance | Assuming missing data at random, implicitly impute data using MICE with m = 30 imputations |
- Patients feel too ill to continue participating in the study | Assuming missing data is not at random, a worst-case scenario will be applied |
Loss to follow-up | Assuming missing data at random, implicitly impute data using MICE with m = 30 imputations |
Death | Assuming missing data is not at random, a worst-case scenario will be applied |
Estimator | Linear mixed model, adjusting for baseline fatigue score and potential confounding factorsa. The study centre is set as a random intercept |
Summary measure | Mean difference of fatigue score (IG–CG) and 95%CI (two-sided) |
Interpretation | The mean difference of the fatigue score and the upper 95%CI limit are less than 0, it means the intervention group is superior to the control group |