3 mins read

How Accurate are Home Blood Tests?

August 30, 2023

General wellbeing

Single yellow kit with app and backdrop

Home blood tests are an affordable and convenient way of keeping track of your health. But are the results accurate? 

What do home blood tests check?

It’s easier than ever to check and monitor your health at home, without having to visit your GP. You can check a wide range of health areas and conditions, including your:

  • Heart (cardiovascular health)
  • Bone and muscle
  • Hormones (male and female)
  • Liver and kidneys
  • Mental health
  • Nutrition (vitamins and minerals)

They’re easy to do, too. The kits include everything you need to collect a small amount of blood and post it back for analysis. You can choose how you want to collect the blood sample, from either finger prick tests (the DIY option) or by phlebotomy, where a nurse will draw the blood from your veins, either at your home or at a clinic.

Are home blood tests accurate?

Here at Forth we ensure that all our tests deliver accurate results. All the finger prick blood tests we offer have been validated through an NHS study for their comparability to venous (where a needle is used to draw blood from your veins), and stability for use in a postal service. This means the NHS labs we use to analyse the samples are confident the tests produced statistically validated results and were safe and reliable to use – on par with a test you would get from your GP.

The labs we use to carry out the blood analysis are accredited by UKAS.All the biomarkers we analyse at our labs are ISO 15189 accredited – the gold standard – which specifies requirements for quality and competence in medical laboratories. In addition, all our kits are CE marked as medical devices under ISO 13485.

All results are viewed by our UK registered medical doctors, who provide comments on results. They’ll compare your results to the healthy range for your age and gender and provide feedback on how you can improve your overall health and wellbeing. 

Tests that provide an instant answer, known as spot tests, don’t provide quantitative results and may not be as accurate as blood tests analysed by a lab. So, although they may be cheaper, they may not be as accurate and could leave you with more questions than answers. You also don’t have a medical professional overseeing the results and providing feedback. 

It’s also important to note that no two labs will provide the same result, as they have their own processes, analysers and assays. These may only be marginally different though. 

Accuracy is vitally important to us. Thanks to the validation work which has been completed by our lab partners and the use of home test kits by the NHS, finger prick samples are now widely accepted as an accurate sample collection method.  This offers people not only great convenience but means they can have confidence in the accuracy of the result.”

Sarah Bolt, CEO, Forth

How is the Accuracy Measured?

To measure the difference between capillary and venous blood tests, the Westgard rule is used. Westgard Rules is the statistical standard used by laboratories to measure the accuracy of lab results. This is an international method of quality control that looks at the variability between results.  It can therefore be used to assess the difference between two blood sample collection methods.

We ran tests with our NHS labs on all the biomarkers we offer using this method, and the results showed that finger prick tests were as accurate as venous blood tests. There were a few exceptions to this, specifically the cell differentials within full blood count, which had shorter stability time and poor comparability to venous tests. Because of this, we do not offer a FBC finger prick blood test.

Benefits of home blood testing

As well as being accurate, there are a host of benefits to home blood testing. 

Speed: Orders placed before 1pm are dispatched the same day via Royal Mail 1st class post, so you should receive your kit quickly after ordering. We also offer a guaranteed next day delivery service. You can view your results via your results app within 2 working days of your sample reaching our labs. 

Control: Your results are yours to keep, download and share as you need. You’ll be able to view them in the app and share them with your doctor if needed. We offer a bespoke test service that allows you to create personalised blood tests to help you cut costs and only track the areas you really need to. 

Convenience: Arranging an appointment with your GP and getting a blood test can be a challenge, with long waiting times and getting time off work. Home blood tests work around you. They fit through your letterbox, so no need to wait in for it, and you can complete it at a time or day that suits you*.

*Some tests have an optimal time or day to collect your blood sample, such as our MyFORM test, which requires you collect the same on days 14 and 21 of your menstrual cycle.

This information has been medically written by Dr Thom Phillips

Thom works in NHS general practice and has a decade of experience working in both male and female elite sport. He has a background in exercise physiology and has published research into fatigue biomarkers.

Dr Thom Phillips

Dr Thom Phillips

Head of clinical services