8. Study objectives
Section 8 of a clinical study report states what the study aims to find out, which is the question that the plan in Section 9 investigates and the efficacy and safety findings in Sections 11 and 12 answer. ICH E3 asks for a statement of the study’s overall purpose or purposes. Each objective is tied to the endpoints that address it, and objectives differ from one another by their role in the study and by their subject.
What Section 8 asks for
Section 8 states what the study aims to find out. Before reading about treatment schedules, measurements or results, the reader needs a clear question to hold in mind.
ICH E3 asks for a statement describing the overall purpose or purposes of the study, and that is the one requirement of Section 8. It has no numbered subsections and prescribes no particular table, no fixed number of objectives and no mandatory set of objective categories.
For a trial of a blood-pressure medicine, “Learn about this medicine” is too vague to guide the reader, while “Assess whether the medicine lowers blood pressure compared with placebo in adults with hypertension” is a more useful purpose. The same study can also ask about unwanted effects or other aspects of treatment.
How the objectives connect to the rest of the report
The objective gives the later parts of the report a common direction. Section 7 provides the background and rationale, Section 8 makes the study’s purposes explicit, Section 9 explains how the study investigates them, and Sections 11 and 12 present the findings that answer the efficacy and safety questions.
Objectives and endpoints
The objectives introduced in the synopsis connect the rationale in Section 7 to the measurable outcomes:
| Part of the study story | Everyday question | Fictional blood-pressure example |
|---|---|---|
| Rationale | Why is this study worth doing? | Existing treatment leaves some adults with inadequately controlled blood pressure, and further evidence about this medicine is needed. |
| Objective | What does this study aim to find out? | Assess whether the medicine lowers blood pressure compared with the comparison treatment. |
| Endpoint | What specific outcome provides evidence for that question? | Change from baseline in systolic blood pressure at Week 12. |
| Result | What does the study observe? | The report gives the measured change in each group and the comparison between them. |
An objective states what the study aims to find out, and an endpoint is the specific outcome that provides evidence for that question. Each objective needs at least one endpoint capable of addressing it, and one objective may have several.
Specifying how and when the endpoint is measured makes a broad question answerable. “Blood pressure” names the general concept, and a defined measurement at a defined time makes the measurement more precise.
An objective does not promise a favourable answer. “To assess whether the medicine lowers blood pressure” remains the objective whether the findings show a benefit, no clear difference, or an unexpected pattern.
Primary, secondary and exploratory objectives
Studies commonly distinguish primary, secondary and exploratory objectives, labels that describe the role of a question within the study.
| Label | Meaning | Fictional example |
|---|---|---|
| Primary objective | The central purpose the study is designed to address | Assess the effect of treatment on blood pressure. |
| Secondary objective | An additional planned question that broadens or supports the assessment | Assess the effect of treatment on interference with everyday activities. |
| Exploratory objective | A question intended to investigate possibilities and generate ideas for further research | Explore whether a blood measurement is associated with the response to treatment. |
The study’s protocol determines its objectives and how they are classified. The three labels are vocabulary for describing objectives, and Section 8 of E3 does not require every study to have all three categories.
“Secondary” does not mean unimportant to patients. The label names a question’s role in the study, and its relevance to patients is a separate consideration. For example, being able to work or carry out daily activities may matter greatly to someone with hypertension.
An exploratory objective is hypothesis-generating: it can suggest a possible explanation or relationship for further investigation. A hypothesis is a proposition that can be investigated, such as “the treatment lowers blood pressure more than the comparison treatment.” The objective states the task of investigating, and the hypothesis expresses a possible relationship. The report must preserve the distinction between evidence that explores a possibility and evidence designed to test a principal claim.
Subjects of objectives
Objectives also differ by subject. Common subjects include:
- Efficacy: for example, the reduction in blood pressure.
- Safety: for example, the frequency of medically important problems.
- Pharmacokinetics, or PK: how the body absorbs, distributes, processes and removes the medicine. A study might assess how the amount of medicine in the blood changes over time.
The subject and the priority are separate: a safety question can be a primary objective and an efficacy question can be secondary. These subjects help interpret a study’s purposes and are not a compulsory checklist for Section 8.
A clear objective
A useful objective identifies the treatment, the people studied and the effect or characteristic being assessed, and where relevant it also names the comparison and the period of interest. The detail should make the purpose understandable without turning Section 8 into the full methods section.
SMART objectives, which are specific, measurable, achievable, relevant and time-based, are recommended as a writing aid. For a reader, the five criteria are a way to check whether a statement points towards an answer the study can actually provide.