The following elements are recommended when describing the study design:
1. Major Design Characteristics
The major design characteristics should be identified, including level of blinding (e.g. double-blinded, partially blinded, open-label), type of controls (e.g. placebo, active, historical), duration of the study, method of allocation to treatment groups (e.g. randomization), and use of a run-in period to identify potential responders or eliminate placebo responders from subsequent phases of the study. Often, many of these factors can be summarized in a phrase such as “randomized, double-blind, placebo-controlled study.”
2. Treatment Arms
The dose, regimens, and any titration procedure should be identified for each trial arm.
3. Concomitant Therapy
Information about concomitant therapies should be included to the extent it helps to understand the use of the study drug or its effects.
4. Study Population
The description of the study population should identify those characteristics that are important for understanding how to interpret and apply the study results. The description thus should identify important inclusion and exclusion criteria, the demographic characteristics of the studied population, baseline values of any clinically relevant variables important for understanding the treatment effect, and other characteristics of the population that have important implications for the extent to which results can be generalized. For example, the description should discuss enrollment factors that exclude subjects prone to adverse effects, the age distribution of the study population, a baseline value that results in a study population that is more or less sick than usual, or a study population enriched by a study design that eliminates nonresponders.
5. Critical Endpoints
Endpoints critical to establishing effectiveness should be identified, and those that are not commonly understood should be defined.
