## What is a surrogate endpoint in a clinical trial?

A surrogate endpoint is a clinical trial endpoint used as a substitute for a direct measure of how a patient feels, functions, or survives. A surrogate endpoint does not measure the clinical benefit of primary interest in and of itself, but rather is expected to predict that clinical benefit.

**What is the endpoint of a study?**

In clinical trials, an event or outcome that can be measured objectively to determine whether the intervention being studied is beneficial.

**What is a surrogate measure?**

In clinical trials, a surrogate endpoint (or surrogate marker) is a measure of effect of a specific treatment that may correlate with a real clinical endpoint but does not necessarily have a guaranteed relationship.

### What is a surrogate marker in medicine?

A surrogate marker can be defined as a laboratory measurement or physical sign that is used in therapeutic trials as a substitute for a clinically meaningful endpoint that is a direct measure of how a patient feels, functions, or survives and is expected to predict the effect of the therapy.5 The primary …

**What is primary endpoint clinical trial?**

The primary endpoint of a clinical trial is the endpoint for which the trial is powered. Secondary endpoints are additional endpoints, preferably also pre-specified, for which the trial may not be powered.

**What is a clinical end point?**

Clinical endpoints are distinct measurements or analyses of disease characteristics observed in a study or a clinical trial that reflect the effect of a therapeutic intervention.

#### What is the difference between outcome and endpoint?

The term outcome usually refers to the measured variable (eg, peak volume of oxygen or PROMIS Fatigue score), whereas an endpoint refers to the analyzed parameter (eg, change from baseline at 6 weeks in mean PROMIS Fatigue score).

**Why are secondary endpoints studied?**

A Secondary endpoint has secondary objectives. For example, a drug designed to prevent allergy-related deaths might also have a measure of whether quality of life is improved. A Secondary endpoint is therefore always paired with a primary one.

**What is a digital endpoint?**

Digital endpoints are the newest type of endpoint. They are assessed using data captured by a sensor, typically outside of the clinic during activities of daily living. The sensor could be worn, like an accelerometer in a smartwatch used to capture motion data.

## What are digital biomarkers?

Digital biomarkers are defined as objective, quantifiable physiological and behavioral data that are collected and measured by means of digital devices such as portables, wearables, implantables or digestibles. The data collected is typically used to explain, influence and/or predict health-related outcomes.

**What is the difference between primary and secondary endpoints?**

A clearly defined, relevant primary endpoint is critical to successful clinical trial design. These secondary endpoints establish the premise for future direction of study and the need for additional clinical trials.

**What is a key secondary endpoint?**

In this case, such a secondary endpoint is like a primary end- point and is sometimes called a key secondary endpoint. Its result, after proper multiplicity adjustments, if statistically significant in favor of the treatment, can provide a persuasive evidence of a clinical benefit of the study treatment.

### What is statistical multiplicity?

In statistics, the multiple comparisons, multiplicity or multiple testing problem occurs when one considers a set of statistical inferences simultaneously or infers a subset of parameters selected based on the observed values.

**What are Type 1 errors in statistics?**

A type 1 error is also known as a false positive and occurs when a researcher incorrectly rejects a true null hypothesis. This means that your report that your findings are significant when in fact they have occurred by chance. For example, a p-value of 0.01 would mean there is a 1% chance of committing a Type I error.

**Do multiple outcome measures require P value adjustment?**

Readers should balance a study’s statistical significance with the magnitude of effect, the quality of the study and with findings from other studies. Researchers facing multiple outcome measures might want to either select a primary outcome measure or use a global assessment measure, rather than adjusting the p-value.

#### What’s wrong with Bonferroni adjustments?

The first problem is that Bonferroni adjustments are concerned with the wrong hypothesis. If one or more of the 20 P values is less than 0.00256, the universal null hypothesis is rejected. We can say that the two groups are not equal for all 20 variables, but we cannot say which, or even how many, variables differ.

**What is unadjusted p value?**

The ordinary, unadjusted P-value for a single hypothesis test can be defined in two equivalent ways: (1) The P-value is the probability, under the sampling distribution of the test statistic when the null hypothesis is true, of obtaining a result as extreme as or more extreme than the one observed in the sample; (2) …