A reference interval is the range of values for a laboratory test found in a defined healthy reference population, usually the central 95%. Values outside it are flagged as abnormal, but not necessarily clinically significant.
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Haemoglobin HGB · g/dL
3 strataIn short
Explained
When sites use their own local laboratories, each lab reports against its own reference intervals, which differ with method, population and units. A multi-site trial therefore has to store the range that applied to each result, not a single study-wide range, so out-of-range flags and shift tables are correct. Central laboratories simplify this but are not always practical.
Stratification matters too. Haemoglobin, creatinine and many other analytes have different ranges for men and women, and paediatric and elderly ranges differ from adult ones. Applying an adult male range to a female participant or a child produces false flags and missed abnormalities.
In Capture
Define reference ranges per laboratory, grouped by analyte, with strata for sex and age. Capture applies the most specific range for each participant, blocks overlapping strata and warns about gaps. Out-of-range values are flagged at entry and prompt a clinical significance decision; alert values are routed to the medical monitor, and a clinically significant result can raise an AE directly.
| Analyte | Result | Range | Significant? |
|---|---|---|---|
| ALT | 212 U/L | 7-56 | Yes |
| Creatinine | 0.9 mg/dL | 0.6-1.2 | - |
Alert value
Routed to the medical monitor and PI
One step
Raise adverse event from this result
Yes, the terms are used interchangeably. "Reference interval" is the preferred technical term.
Because of different methods, instruments, units and reference populations.
Not necessarily. About 5% of healthy people fall outside the interval by definition; the investigator judges clinical significance.
Limits beyond which a result needs urgent clinical attention, separate from the reference interval.
Ranges by lab, sex and age. Free sandbox.