Filter Function Tests

Filter function tests should be used prior to referral to:

• Support GPs to refer patients via the most appropriate route (i.e. non-specific symptoms or site-specific), leading to a higher referral quality;
• Reduce the risk of test duplication later in a patient’s pathway;
• Ensure all necessary pre-investigation testing (e.g. kidney function) has been completed, removing potential delays further along the pathway.

It is recommended the following filter function tests are carried out in primary care, where relevant for patients, to make a successful referral into an RDC:
Core tests for patients with non-specific symptoms:

• CXR;
• Urine;
• FIT;
• FBC;
• ESR and/or CRP;
• U&E with eGFR;
• LFTS (including globulins);
• TFTS;
• HBA1c;
• Bone;
• CA-125 (Women);
• PSA (Men)
• B12/Ferritin/Folate and Iron Studies (if anaemic);

Optional Additional Tests

Optional additional tests (where relevant to symptoms):

• Ultrasound;
• TTG AB (if anaemic);
• GGT;
• Prot EP;
• HIV;
• Hepatitis C
• Clotting (for lymphadenopathy referrals, this should be considered as a core test)
• Glucose;
• LDH.