IVD Performance Study Objectives: Defining Endpoints Regulators Accept
Clear objectives are the foundation of every IVD performance study. They decide which samples you test, how many you need and whether your results will support your claims. Here are the five objectives most IVD studies cover, with a worked rapid-test example.
Why study objectives make or break an IVD performance study
Every claim in your instructions for use, from sample types to sensitivity, needs evidence. Study objectives turn those claims into measurable endpoints with acceptance criteria set before any testing begins.
Vague objectives lead to studies that answer the wrong question, sample sizes that are too small and Notified Body findings. Well-defined objectives keep the study focused and the results defensible.
From intended claims to a study plan
The 5 core objectives of an IVD performance study
Most IVD studies cover these five areas. The exact set depends on your assay and claims.
| Objective | What it shows | Typical endpoints |
|---|---|---|
| 1. Clinical diagnostic performance | Agreement with a validated reference method or clinical diagnosis | PPA and NPA, or sensitivity and specificity, with 95% confidence intervals |
| 2. Analytical performance | How little analyte the test detects and what disturbs it | Limit of detection, cross-reactivity, endogenous and exogenous interference |
| 3. Repeatability and reproducibility | Consistent results across conditions | Agreement or CV% across operators, reagent lots, days and sites |
| 4. Matrix equivalency | Same results across claimed sample types | Agreement between whole blood, serum, plasma, venous and fingerstick |
| 5. Operational robustness | Reliable results in real use | Read-time window, invalid rate, hook effect, temperature and humidity flex |
PPA and NPA vs sensitivity and specificity
Which metric you report depends on how good your comparator is.
| Sensitivity and specificity | PPA and NPA | |
|---|---|---|
| Comparator | Clinical truth or an accepted reference standard | Another test that may itself be imperfect |
| What it measures | How often the test is right about the condition | How often the test agrees with the comparator |
| When used | Reference standard available | Comparator is an assay such as ELISA or RT-PCR |
| Reporting | Point estimate with 95% confidence interval | Point estimate with 95% confidence interval |
Example: objectives for a dengue NS1 antigen rapid test
An illustration of how the five objectives apply to a lateral flow rapid test.
Common gaps in IVD study objectives
How REGHELPS helps define and deliver your study objectives
IVD performance study objectives FAQs
What are the typical objectives of an IVD performance study?
Most studies combine clinical objectives, such as diagnostic sensitivity and specificity or positive and negative percent agreement against a reference method, with analytical objectives such as limit of detection, cross-reactivity, interference, precision, matrix equivalency and robustness. Each objective needs a defined endpoint and acceptance criterion.
What is the difference between PPA/NPA and sensitivity/specificity?
Sensitivity and specificity compare results with the true clinical status. When the comparator is another test rather than a perfect reference standard, results are reported as positive percent agreement (PPA) and negative percent agreement (NPA), because the comparator itself can be wrong.
What is the hook (prozone) effect and why test for it?
In some immunoassays, including many rapid tests, very high analyte levels can produce a falsely weak or negative result. Testing high concentrations shows whether the hook effect occurs within the clinically relevant range and whether the IFU needs a warning.
Why is matrix equivalency tested?
If a test claims to work with whole blood, serum and plasma, or with fingerstick and venous samples, the study must show results agree across those matrices. Otherwise only the matrices actually tested can be claimed.
How are acceptance criteria set?
From the state of the art, comparable devices on the market, published literature, clinical need and, for certain Class D IVDs, the EU common specifications in Implementing Regulation (EU) 2022/1107. Criteria must be set in the study plan before testing starts.
Need clear objectives for your IVD study?
Share your assay and claims using the form below and we'll propose objectives, endpoints and a sample size.
