Diagnostic Testing in Primary Care - Probably the Best Kept Secret in the NHS
In recent years there has been something of a quiet revolution in the medical diagnostics industry. On the one hand, clinical laboratories in hospitals have been improving their efficiency with the installation of large automated instruments. On the other, technological advances in solid-phase chemistry, electronics and miniaturisation of instrumentation have led to a new breed of diagnostic tests that can move diagnostics out of the traditional laboratory and closer to the patient. This type of near patient testing, or point of care testing as it has become known, is set to expand dramatically. In the United States it now accounts for around one fifth of all tests and European countries are quickly following suit - the creation of Primary Care Trusts is bound to be a key driver in the implementation of point of care testing in the UK.
Point of care testing has potential benefits for primary care, particularly in improved diagnostic accuracy to give earlier and more appropriate treatment. Take the treatment of vaginal infection as a case in point. The symptoms of vaginitis are non-specific and differential diagnosis is problematic. Broadly speaking, the causative agents are 60:40 bacteria:yeast - guess correctly and write out a prescription for clotrimazole, and 40% of patients won't be back next week taking up another appointment slot - but 60% of prescriptions will simply have been wasted. And vice versa for metranidazole. A new, 1 minute test using a vaginal swab can now accurately differentiate between a bacterial and yeast infection - the patient is on the right therapy within 5 minutes, and won't be back again next week. Sorted!
Far from always diagnosing disease, many point of care tests offer benefits of ruling out disease. For example, in suspected urinary tract infection, simple urine leucocyte esterase and nitrite dipstick tests can rule out UTI and cut inappropriate antibiotic prescribing. Similarly, a new rapid test for antibodies to H pylori can reduce the numbers of patients referred for expensive endoscopy.
Chronic disease management can certainly be enhanced in primary care using point of care tests. Community-based anticoagulant clinics have evident benefits to both doctor and patient alike. Taking a regular trip into the local DGH is time-consuming and stressful - just trying to park the car in a hospital carpark is bad enough! Far better to take a gentle stroll round to the Health Centre, generate an INR with a simple finger-prick sample and review therapy dosage.
Similarly, small bench top analysers to measure glycated haemoglobin and urinary albumin can be easily and accurately used in a primary care-based diabetes clinic, with doctors having the right tools at their finger-tips to help them with their decisions.
Even acute disease management can effectively utilise rapid tests to improve outcomes. G.P.'s in rural practices face particular difficulties in the management of patients with chest pain. Many now carry portable ECG instruments, but diagnosis of myocardial infarction can now be improved by using a small device about the size of a credit card - 6 to 8 drops of blood, and in 15 minutes it can confirm elevated levels of the three key cardiac enzymes indicative of heart attack.
Definite benefits of point of care testing in primary care? Certainly. But what about the downside? The first concern is quite legitimate. Who will actually do the testing? Experienced medical laboratory scientists control testing in the hospital laboratory. Of course, instruments and kits designed for use in primary care are designed for use with less skilled hands. But even so, testing away from the laboratory raises serious issues of training, quality control , instrument maintenance and interpretation of results. These potential obstacles will require careful and continued attention in order to maintain high standards of quality of testing results.
Secondly, and probably inevitable, is the concern of higher cost - almost without exception, a test designed for use in primary care will cost more than a test used in a modern laboratory. To overcome this objection, it is vital that the health service takes a more holistic approach to the whole issue of "cost".
Firstly, let's accept a higher direct cost per test. Then try and balance the deficit with savings down the line - costs of unnecessary or inappropriate therapy, sample transport to hospital laboratories - even patient transport to the hospital, the cost of needlessly taking up a bed. Factor in extra costs of out of hours service, or the costs of that extra, unnecessary repeat appointment.
The problem is that the NHS cannot cope with the concept of overall cost rationalisation. "Silo budgeting" means that each department in each NHS Trust or PCT is only concerned with meeting its individual budget target. A Laboratory Director in a NHS Trust will not be concerned about increased prescribing costs in a Primary Care Trust. The Chief Executive of an Ambulance Trust will not be too concerned about a patient taking up a bed unnecessarily. With such compartmentalised budgeting, potential savings with new technologies tend to cancel themselves out - so the only real outcome of point of care testing is the increased direct cost per test.
It is equally fair to say that little independent published evidence exists to support the proposition that moving diagnostics closer to the patient will have positive economic benefits. A recent study by Professor Richard Hobbs at the University of Birmingham concluded that most studies focused on technical performance rather than patient outcomes. But perhaps hidden in this study may lie the key driver in the increased move towards point of care testing at primary care level. Try substituting the words "customer satisfaction" for "patient outcomes".
Under "new" Labour, the National Health Service has undergone dramatic change - creating internal markets where there are healthcare providers and customers. With "new" diagnostics, Primary Care Trusts can better satisfy their customer's needs. Not only by increasing patient confidence in the way that their problem is being handled, but looking to apply on the spot testing to not only diagnosis and monitor disease - but to implement programmes designed to prevent onset of disease.
Nationally sponsored screening programmes have been slow to evolve. Primary Care Trusts are in an ideal position to implement their own "mini" programmes, making investments from their budgets to increasingly prevent patients falling ill. Colorectal cancer screening, cardiovascular risk assessment, prostate cancer screening, osteoporosis risk - local programmes swiftly and effectively organised with simple to use tests which will have real impact on the PCT's customer base - after all, a customer only becomes a patient when they fall ill!
The changes in the structure of the NHS announced earlier this year are probably the most important since the inception of the National Health Service in 1948. The primary care sector will increase in importance dramatically over the next decade as general practitioners take on greater responsibility for early diagnostic triage, disease management and preventative medicine.
The availability of a wider range of diagnostic testing products to meet the challenges demanded by an increasingly demanding customer base will go a long way to helping the long term strategic objectives of the NHS Plan.
Bill Cunningham
Chairman, Point of Care Forum
British In Vitro Diagnostics Association (BIVDA)