Tip of the Week Archive

Aims/Objectives in a protocol are sometimes confused with outcome measures. However, if an aim or objective is entered into ClinicalTrials.gov as an outcome measure, this can lead to the record being rejected during QC review. Therefore, it’s important to understand the differences between aims/objectives and outcome measures.

 

Aims/Objectives:	Outcome Measures
Serve as deliverables. They involve intent to do something with data derived from outcome measures.	Outcome measures are the data measurements gathered by the study, and used to evaluate the protocol aims/objectives
Are typically expressed with verbs.	Outcome measures are measurements expressed in quantifiable units (with nouns).
Example: To assess the efficacy of the STOMP intervention to improve opioid risk understanding and decision-making	Example: Number of opioid-related adverse events

 

Primary Aims/Objectives are the primary goals of the clinical trial, expressed as a statement of purpose (e.g., to assess…; to determine…; to compare…; to evaluate…). They:

• Drive statistical planning (e.g., sample size calculation / statistical power)
• Describe either a general purpose (e.g., efficacy, effectiveness, safety) or  a specific purpose (e.g., dose-response, superiority to placebo, effect of an intervention on disease incidence, disease severity, or health behavior)

 

Secondary Aims/Objectives are goals that will provide further information on use of the intervention

 

Primary Outcome Measures are the outcome measure(s) of greatest importance specified in the protocol, usually the one(s) used in the power calculation. Primary Outcome Measures:

• Are the most important data measurements gathered by the study, the ones that determine its design and the study size
• Generally correspond to the primary study objective and hypotheses
• Are used to assess the effect of the study intervention
• Provide the basis for concluding whether the study met its objective
• Precisely define the individual endpoints used to address the study’s primary objective:
• Includes the time point(s) at which data will be assessed

 

Secondary Outcome Measures are the outcome measure of lesser importance than primary outcome but part of a pre-specified analysis plan for evaluating the effects of the intervention or interventions. Secondary outcome measures:

• Are written similarily to Primary outcome measures, and are specific measurements which include the time frame of assessment
• Usually address goals of secondary objectives.
• May be related to efficacy and/or safety.
• May provide supportive information about the intervention’s effect on the primary endpoint or demonstrate additional effects on the disease or condition.
• Note: Unless a protocol specifically defines “Other/exploratory” outcome measures as such, the regulations will assume that those are secondary outcome measures

 

Primary, secondary, and (if applicable) exploratory/other outcomes for clinical trials should be clearly defined in the protocol and registered on ClinicalTrials.gov prior to the start of enrollment.