Comorbidities
comorbidity, respiratory comorbidities
REGRESSION, SECONDARY, PCT
A second sub-study embedded into the BATCH trial will examine the differential effect of the intervention in children with multiple long-term conditions. We will describe the frequency and percentage of the BATCH cohort with different types and numbers of comorbidities and present information on antibiotic use, clinical outcomes, and adherence to the PCT algorithm for each type and number of comorbidities.The primary outcome is duration of IV antibiotic treatment, and secondary outcomes are the composite safety outcome and adherence to the PCT algorithm, as defined in the host trial (BATCH). All participants will remain in the trial arm assigned by randomisation in the main trial, regardless of protocol deviations or non-adherence, and will be included in the analysis if outcome and comorbidity data are available. Missing data on patient comorbidities is likely to be minimal.For the primary analysis, we will fit a Cox proportional hazards model with duration of IV antibiotic treatment as dependent variable. Patients will be classified into three comorbidity subgroups (no comorbidity, single comorbidity, or multiple comorbidities). Secondary analyses will involve similar regression models, depending on the type of the outcome variable. The procedure for subgroup analyses is described in the “Subgroup analyses” section. Secondary analysis of the composite safety outcome in this sub-study will not be performed if the primary BATCH analysis finds that the intervention is inferior to standard care.As an additional exploratory analysis, we will plot post-intervention PCT trajectories, stratified by subgroup. We will also explore the influence of respiratory comorbidities by further sub-dividing the comorbidity subgroups.Trial documents