1. You are here:
  2. Association for Laboratory Medicine
  3. Our resources
  4. Science Knowledge Hub
  5. Guidance test

Guidance test

PaCTS group guidance

Validating and adopting capillary blood testing (CBT) in the routine laboratory

A summary of LabMed's UK recommendations for laboratories planning or reviewing a capillary blood testing service, from the patient-centred testing and sampling (PaCTS) group.

Before you validate

Define your cohort

Identify the target patient group and complete a risk assessment covering the risks of self-collection.

Check the evidence

Review published comparability data for the analyte(s) of interest before designing new studies.

Consider interference

Review medications, sampling technique and topical creams that could affect results.

Prepare the basics

Write concise patient instructions and set sample acceptance and rejection criteria.

Validation requirements

  • Use 40 paired capillary and venous samples (minimum 20, with justification), covering the full measuring range and clinical decision points.
  • Apply Passing-Bablok or Deming regression alongside Bland-Altman difference plots to assess bias against agreed acceptance criteria.
  • Test analytical imprecision using IQC material at the low sample volumes typical of capillary collection.
  • Decide whether capillary results are interchangeable with existing reference intervals, or whether a capillary-specific interval is needed.
  • Run stability studies at the temperatures and time periods the samples will actually experience in transport.

Implementation and ongoing review

  • Review sample volume requirements so neither too little nor too much blood is collected.
  • Agree how samples are returned, by post or drop-off, and check stability across that journey.
  • Record the sample type on every report so capillary results are never mistaken for venous ones.
  • Dispose of lancets and collection devices in line with local sharps policy.
  • Repeat stability testing whenever a new analyte or transport condition is introduced.
  • Review patient results periodically if validation samples don't cover the full clinical range.
  • Audit rejection rates and sample volume requirements as part of routine service review.
  • Gather patient feedback on the sampling process and act on it.

Full guideline

LM

Woolley, Hepburn & Perkins

Annals of Clinical Biochemistry, 2026 · doi.org/10.1177/00045632261454300