Getting the best from your local path lab

Biomedical scientist Barry Hill explains the value of diagnostic testing to primary care and how nurses and prescribers can take greater advantage of this key service

It's a little known fact that pathology investigations are involved in 70% of all diagnoses and medical decisions affecting NHS patient treatment and care. This ranges from diagnosing tumours and leukaemia, to cervical screening or even determining a patient's blood group. Millions of pathology tests are carried out every year - over 14 tests for every man, woman and child in the country.

The NHS spends an estimated £2.5 billion each year on pathology services, equating to 4% of the total NHS overall budget. Pathology is therefore the science at the very heart of modern medicine, be it in the hospital Emergency Department or the GP surgery itself.

Last year, 2012, was officially designated as 'National Pathology Year' to showcase the central role that pathology plays in helping to keep patients healthy, and ensuring that they get the correct treatment.

It is important that primary care staff make extensive use of their local pathology services, particularly in areas such as screening for conditions such as anaemia, or in chronic disease management areas such as diabetes. Additionally, early testing via laboratory services as part of a referral process has the capacity to speed up the patient journey and thus improve quality of care and outcomes. The downside of this however is that primary care now requests a variety of investigations which were previously restricted to secondary care, and which require specialist knowledge. This is where your local laboratory staff can play a key role in advising you on test selection and the interpretation of results, helping you to make the best use of your local laboratory.

PATHOLOGY DISCIPLINES

Traditionally pathology was limited to only a narrow range of disciplines, however these have grown over recent years to encompass the following different specialties:

• Chemical pathology or Biochemistry The study of changes in chemical composition of body fluids in the diagnosis and monitoring of disease processes, for example measuring blood glucose levels in the treatment of diabetes
• Clinical embryology covers in vitro fertilisation (IVF) and other aspects of assisted reproduction
• Cytopathology The study of abnormal cells in body fluids, smears and tissue samples, for example cervical smears for the detection of changes in the cervix that could lead to cancer
• Forensic Pathology The determination of causes of death for medico-legal purposes such as to distinguish between accidental death, suicide and murder
• Genetics The study of the changes underlying genetic diseases, for example cystic fibrosis
• Haematology and Blood Transfusion Medicine Includes the diagnosis and treatment of diseases of the blood, for example the use of an FBC and differential film analysis to diagnose types of anaemia and leukaemia, plus the organisation of blood transfusion services and antibody screening in pregnancy
• Histopathology The study of diseased tissue such as breast lumps or specimens of bowel removed because of suspected cancer, including examination under the microscope
• Immunology, Histocompatibility and Immunogenetics The study of the body's immune system and its disorders, e.g. allergies, rheumatoid arthritis and tissue matching for organ transplants
• Microbiology The diagnosis of infection caused by bacteria, fungi, parasites and viruses including identification of the best treatment options for infection, the monitoring of antibiotic resistance, and how well a patient is responding to treatment
• Neuropathology The study of diseases of the nervous system including stroke and brain tumours
• Paediatric Pathology The study of disease in fetuses, babies and children, e.g. stillbirths and childhood cancers
• Toxicology The science of poisons, for example measuring blood levels of drugs after an overdose
• Veterinary pathology The study of diseases in animals, e.g. BSE and rabies by specialised veterinary surgeons

However, it is in the key pathology disciplines of microbiology, haematology and biochemistry that most contact between primary care and pathology occurs, as pathology laboratories have traditionally performed and continue to offer a wide range of analytical tests on patient samples.

ADVISORY ROLE

A vital role that pathology laboratories offer primary care is to provide advice and interpretation of pathology tests results, either by the addition of standard computer generated comments on laboratory reports, or by contacting the GP surgery directly in urgent situations, or where abnormal results have been noticed. Laboratories can also assist primary care in the interpretation of what is now becoming increasingly complex clinical data, particularly in the case of some of the more newly introduced or lesser used investigations or where important pre-analytical factors may have contributed. Not only can laboratory interventions such as this assist in better patient outcomes, but they can improve the efficiency of GP practices. Reducing the need for additional patient consultation and unnecessary phlebotomy associated with any additional testing, for example, can then reduce delays and impact on reducing overall healthcare costs to the system.

The introduction of point of care testing schemes (POCT) in primary care can also help to improve the management of chronic conditions, providing an on-the-spot facility for earlier detection of, and therefore intervention for, abnormalities. It is important, however, that primary care staff seek advice from local accredited laboratories to ensure that meaningful, reliable and accurate results are obtained. Laboratories can assist with staff training, the use of testing protocols and standard operating procedures, result documentation, equipment selection and maintenance, health and safety issues and most importantly, the use of internal and external quality assurance testing.

HARMONISATION

Pathologists endeavour to produce high quality results for all diagnostic investigations, and the results or reports leaving their laboratories are usually accompanied by appropriate reference ranges and values, which are in many cases age or sex related.

These values may often vary from laboratory to laboratory as different laboratories may be using alternative methodologies, equipment or even differing units of measurement to express their results, and this may account for much of the confusion surrounding interpretation of test results.

Some surgeries for example may seek pathology services from various providers in their areas, and may then receive results for similar investigations in different formats and units of measurements, often performed on identical analysers incorporating similar methodology and reagents. This not only causes confusion for users of pathology services, but also can affect patient safety. To help overcome this problem an initiative known as 'Pathology Harmony' was established in January 2007. The aim is to achieve reporting harmonisation in UK pathology laboratories. The organisation is supported by a grant from the DH and is comprised of representatives from the major UK pathology professional bodies including the Royal College of Pathologists, the Association for Clinical Biochemistry, the Institute of Biomedical Science and the British Society of Haematology. Several key areas were identified where there is potential for harmonisation, including units of measurement, reference intervals, and test names, together with standardising procedures for reporting abnormal results to primary care and protocols for simple pathology tests. Among the first results of the initiative have been recommendations on the standardisation of haematological reporting units for FBCs and serum sodium reference intervals.

IMPROVED PATIENT OUTCOMES

With pathology laboratories offering an ever-increasing range of services and diagnostic tests to primary care, a key role for laboratory staff is to advise on the most appropriate investigations for patients. As more near-patient testing and treatment is transferred to primary care, there needs to be close links with local pathology services to achieve reliable, safe and accurate results. These partnerships will result in a higher standard of patient care being provided, but good communication is vital: not only can this contribute to more efficient use of resources by reducing duplicate or unnecessary investigations, it can also improve patient care by improving diagnosis and treatment. Pathology laboratories can help primary care to make savings to the NHS budget, and by working in partnership, construct new care pathways. Closer links between primary care and local laboratories can benefit everyone concerned, especially patients, not only in 'National Pathology Year', but in the longer term.