Recommendation | Potential benefits | Potential issues |
---|---|---|
More extensive inclusion and exclusion criteria that are more descriptive of the population to be enrolled | Less opportunity for patient variability and sites having to 'learn as they go' | Lower likelihood of extrapolating efficacy observed in the clinical trial to effectiveness in clinical practice |
Standardize the major facets of severe sepsis concomitant care | Reduced variability as caring for patients with severe sepsis may be a more complex 'procedure' than many commonly performed surgical procedures | May be questions related to the applicability of the study results to a more general severe sepsis population, in which concomitant care has not been standardized |
Given the heterogeneity of severe sepsis patients, different populations of patients may require unique sets of inclusion and exclusion criteria (for example, medical patients and surgical patients). | Optimizes inclusion and exclusion criteria without the extra time and resources that would be needed to run two separate studies | May be issues with interpretation of data and powering if the treatment effect differs significantly between the two populations, in which two separate studies may be preferable |
Use a clinical coordinating center to assist study sites in enrollment of eligible patients. | Helps to optimize protocol compliance | May be questions related to the applicability of the study results to a more general severe sepsis population |
Site selection should be based on having good clinical trial and critical care experience. | Helps to minimize variability and (potentially) protocol violations | May be questions related to the applicability of the study results to a more general severe sepsis population |
The use of severity scoring systems in clinical trials may require training and validation of the training to ensure proper collection of severity of illness information. | Helps to ensure the collection of accurate data | Additional time and resources required |
Given the potential influence of site experience on outcomes, randomization stratified by site should be considered a requirement for studies in complex disease states. | Helps to minimize effect of differences between sites and enrollment sequence effect | May limit ability to stratify by additional parameters |
Planned enrollment per site should be based on the block size used for randomization. Expected enrollment per site should be at least two full blocks of patients. | Helps to minimize enrollment sequence effect | May only be able to have larger sites in the study, raising questions related to generalizability of the results |
Futility stopping rules should incorporate the potential for learning curves to obscure a beneficial treatment effect in the early stages of a clinical trial. | Helps to avoid type II error | May be a delay in identifying futility signals if no enrollment sequence effect is present |
Statistical analysis plans should explore the potential for learning curves within the clinical trial dataset. | Prospectively defined analyses have greater weight and may help to explain study findings | Additional workload |
Clinical studies should have a prospectively defined monitoring plan. Source data verification and documentation of protocol violations should be performed on the first few patients enrolled at a site until the site demonstrates adequate understanding of the protocol. | Helps to minimize protocol violations | Additional time and resources required |