As part of my CPD I attended a meeting organised by Osteoporosis Dorset1 and Poole Primary Care Trust at which speakers outlined a toolkit being developed to assist community pharmacists in supporting osteoporosis patients. Dr Paul Thompson2 said the gold standard for osteoporosis diagnosis is an axial scan of the hip and spine using dual emission X-ray densitometry. While this is available almost exclusively in hospitals, he thought there could be scope for peripheral scanning (heel or forearm) in the community and that pharmacists would be well placed to provide this service.

I knew that the cost of a scanner was prohibitive, with no prospect of a return, so I asked the meeting’s sponsors, Merck Sharpe & Dohme (MSD), if there was any chance of sponsorship for a pharmacy project. The answer was a qualified “yes” so I proceeded to investigate the possibility of renting a peripheral scanner, to discover whether patients and GPs would benefit from scanning in the community.

There are two types of peripheral scanner and two sites for scanning. The first and most commonly used is an ultrasound3 scanner, which is used on the heel bone (calcaneum), but many experts say it gives an unacceptably high number of false positive diagnoses for osteoporosis. However such scanners are less expensive than the alternative DEXA scanners and are used in some hospitals. They are also used in the vans that appear in supermarket car parks, offering scanning for virtually every condition under the sun.

On the assumption that I would obtain funding, I opted for the second type, a dual emission X-ray absorptiometer[4] (DEXA scanner) and managed to source one through Churchill Medical. They were prepared to rent one for three months, which I managed to extend to four months. There are two types of DEXA-scanners used on different sites: one scans the calcaneum but the one I chose was a portable G4 scanner, which scans the forearm (radius and ulna). MSD offered an educational grant, which just about covered the rental and pharmacist time involved in scanning.

The idea was that the grant would be supplemented by medicines use reviews (MURs) on the patients scanned but this did not work out, as it was inappropriate to combine the two services. I was trained how to use the scanner but then discovered I needed to undergo training under the Ionising Radiation Medical Exposure Regulations (IRMER) and had to pay for a one-day course on the pharmacy premises, an expense I had not taken into account.

Waiting for the training unfortunately ate into the rental period, as I could not undertake any scans until I had been trained and the scanner professionally assessed for safety. Although the X-ray emission from a DEXA-scanner is very low (about the equivalent of a trans-Atlantic crossing in a jumbo jet), there is no lower limit to the IRMER requirements and so the training was obligatory.

I had to dig deep into hidden recesses to recall the appropriate physics and human biology in order to keep up with the trainer, but I was pleased to be able to work out that radiation kills white blood cells quicker than red cells as the former have nuclei.

I also discovered that I had to appoint an IRMER practitioner, who was qualified to authorise me to undertake scanning, and here Dr Thompson came to the rescue. I sometimes wondered how I got myself into all this, but persevered nonetheless.

Equally important was the need to get support and approval from all the potential stakeholders and to ensure that whatever project we undertook did not qualify as research or screening, which would have demanded approval by the Medical Ethics Committee. In contrast to commercial organisations, which will scan anybody prepared to pay for the service, I wanted to work strictly within NHS guidelines and so made the first approach to the local GPs. I needed their approval because diagnosing osteoporosis would increase their prescribing costs and incur costs of axial scanning if osteopenia was detected (more of that later).

The GPs were a little sceptical and insisted that I obtained the co-operation of the Radiology Department at the Royal Bournemouth and Christchurch Hospital (RBCH). It was with some trepidation that I made a cold telephone call and asked to speak to somebody with authority in the DEXA Unit. The RBCH has the only axial DEXA-scanner in Dorset and is therefore the referral point for GPs. I was put through to Samantha Barker, Senior Radiographer, who runs the department and turned out to be most interested in the project. She agreed to let me have a duplicate copy of the results of her scans on my patients. Protocol demanded that all referrals were made by GPs but a copy of my findings were sent with the GP referral form. With the hospital on board, the GPs agreed to support the project.

The intention had been to recruit patients in February 2006 and start scanning in March but because of the inevitable delays in getting training and the meetings with the hospital, the scanner arrived on 1 March and I could not use it for nearly two weeks. No groundwork had been possible in recruiting patients.

Osteoporosis Dorset kindly produced posters and flyers to distribute from the GP surgery and the pharmacy. We also used an opportunistic approach to patients in the right age group presenting prescriptions. One reason for choosing the G4 was that it is portable and I hoped I could take it to other sites, but this did not happen.

Because we had chosen a strictly ethical approach we had to stick to the guidelines for scanning issued by the National Institute for Health and Clinical Excellence (NICE). These state that the only parameters for routine scanning are for women aged 65–74 years with either a history of low impact fracture or family history of severe osteoporosis. These guidelines are surprisingly restrictive and severely limited the number of patients eligible for a scan. I will discuss the NICE guidelines later.

So after all the trials and tribulations I launched the service with our local MP, Annette Brooke. I then started scanning patients by appointment. Before each session I had to calibrate the scanner using a phantom, which is a piece of radio-opaque material of known density conforming roughly to the shape of a forearm. One advantage of the forearm scanner over the heel scanner is that patients do not have to remove their tights, only bare a forearm and remove watches or bracelets.

There are three questions to ask the patient first: 

1. Are you left or right handed? Always scan the non-dominant arm.
2. Have you broken the non-dominant arm in the last five years? If yes, scan the dominant arm.
3. Is there any possibility you might be pregnant? If yes, do not scan even though there would be no risk to a foetus.

This last question usually causes some mirth when asked of ladies over 65 and at my age I can get away with it without offence!

The patient then places the appropriate arm in the scanner and has to keep it still for about 3.5 minutes. The scanner is supplied with a laptop computer and controlled by the software. When the scan is complete the computer analyses the data and produces a printed report. The patient’s result is superimposed on a colour graph showing the anticipated decline in Bone Mineral Density (BMD) with age. This is a most useful tool to help explain to patients the state of their bones.

BMD is expressed as a T score that can be combined with the patient’s age, weight and height to produce a Z score. I had agreed with RBCH that I would work only on T scores even though the G4 software produces Z scores. The World Health Organization (WHO) has issued guidelines on the interpretation of T scores. The National Osteoporosis Society (NOS) has recently issued new guidelines, which are slightly different, but we agreed to stick to the WHO guidelines as these are still quoted in most papers.

The WHO guidelines are: 

1. T score between 0 and -1, normal (NOS 0 to -1.4);
2. T score between -1 and -2.5, osteopenic    (NOS -1.4 to -2.6);
3. T score below -2.5, osteoporotic    (NOS below -2.6).

1. Patients informed that their bones were healthy and given advice on diet and exercise;
2. Patients informed that they could be osteopenic with a full explanation of the term and referred via the GP to RBCH for an axial scan; lifestyle advice also given;
3. Patients informed that they were osteoporotic, given counselling and referred to the GP for medication.

References