Using point-of-care CRP testing

C-reactive protein (CRP) is a marker of inflammation, produced in the liver, that increases 4-6 hours after the onset of inflammation or acute tissue injury (peaking at 36-90 hours (1.5-4 days). In uncomplicated infections the CRP is usually below 10 mg/l after a week’s illness. CRP testing can help differentiate a serious from a self-limiting infection (NICE CG191 [24]).

There are many different point-of-care (POC) CRP tests available. In the STEP-UP IMPLEMENT study there are two types of POC CRP tests available as this may give you more flexibility in when and how you can use tests.



Afinion CRP


SureScreen CRP
CRP reading Quantitative;
Numeric result in the range: 5 to 200 mg/l
Result as a line for CRP levels over 10, 40 or 80 mg/l
Time for the result 3-4 minutes 5 minutes  (don't interpret the result after 8 min)
Other benefits

The analyser can be used with cartridges for other types of markers (e.g. HbA1c, lipids, ACR).

Cartridges can be stored at room temperature for up to 4 weeks.

It gives numeric results with excellent correlation to laboratory methods.

The test is portable and can be taken to your patients (e.g. on home visits).

It can be stored at room temperature until the expiry date.

It doesn't require calibrating or quality assurance tests.


Below are suggestions for how you may interpret POC CRP test results, based on the NICE guidelines [24].

Download a summary sheet for interpreting POC CRP test results (pdf). You can print and place it where it is easy to refer to when using the POC CRP tests.

interpreting crp results picturev2

Training Task

When your practice starts using POC CRP testing, it is important that all prescribers complete training in using the tests.

This will help you feel confident about using the tests and will give you some idea of the CRP levels for your patients.



You may have had an Abbott training session in using the Afinion analyser; however it is also important to try the test in your consultations with patients.

  1. Carry out a CRP test on 5 patients presenting with acute cough using the Afinion analyser
  2. Record the CRP results on the summary sheet with details about the suspected infection.
    Download the summary sheet for recording CRP test results.


Sure Screen

  1. Carry out a CRP test on 5 patients presenting with acute cough using the SureScreen CRP test.