Feedback to patients with low bone mineral density after bone densitometry

Abstract

Osteoporosis is defined as a skeletal disorder characterised by low bone mass and micro-architectural deterioration of bone tissue, with the overall focus on bone quality. It affects more than 75 million people worldwide, and cause people to become bedridden with life threatening secondary complications.

An estimated 10 million South Africans, out of a population of 43 million people, are at high risk of developing osteoporosis. In South Africa osteoporosis affects one in three women over 50 and one in five men. Within one year after a hip fracture, up to 20% of the people die, 15-20% needs to be institutionalised and 50% of the remainder will not be able to lead an independent life. The number of fractures is two to three times higher in women than in men due to the hormonal changes that occur after menopause.

The prevalence of osteoporosis increases markedly with age and, based on the bone mineral density at the femoral neck of the hip, approximately 30% of Caucasian women, by age of 75 years will be classified as having osteoporosis.

Dual-Energy X-ray Absorptiometry (DEXA) is the preferred method for measuring BMD. The results of the DEXA scan are scored in comparison with the BMD of young, healthy individuals, resulting in a measurement called a T-score. A T-score of –2.5 or lower is considered to be osteoporosis and T-scores between –0.1 and –2.5 are generally considered to show osteopenia.

The aim of the study was to examine communication between referring physicians and patients who had been referred for a DEXA scan.

A total of fifty patients were included in the study group. This was much smaller than was anticipated. The ideal would have been a much bigger sample group for a bigger representation of the population. Patients, who complied with the inclusion criteria and also gave their consent, were recruited between January 2004 and November 2004. Not all the patients referred for a DEXA scan had the required low BMD.

Bone scans were performed on the HOLOGIC 4500 QDR, a multiple detector, fan beam, Dual Energy X-ray Densitometer. The Hologic 4500 QDR Bone Densitometer estimates the Bone Mineral Content (BMC) in grams, and the BMD in grams per cm2. The QDR 4500 uses a low level of X-rays with two different energies to estimate BMC and BMD. The radiation exposure at a distance of two metres from the equipment is less than one mR/hour.

The age distribution of the study group ranged between 14 and 84 years (average age was 57,2 years). Out of the total of 50 patients, only one was male and the entire patient population was Caucasian. This may be due to the small sample size and inclusion/exclusion criteria. Concerning the references of the patient population, Universitas Academic Hospital (UAH) referred more than half of the patients (64%), while the other points of care referred only 36%.

In this study, it was found that BMD results do influence the management of osteopenia/osteoporosis in the majority of patients and the test has a positive impact on the management of patients with this condition. There was however 22% of patients that did not receive feedback concerning the results of the DEXA and the necessary treatment. These findings also highlighted the fact that communication between physician and patient is a very important component in using the information provided by this test to its full potential. The ideal is to identify a low BMD early enough to stop the damaging consequences thereof, but this is not always feasible due to the high costs involved in a DEXA scan. Access to treatment and care is also not readily available to a large section of the population and, in State Hospitals; the availability of drugs to treat osteoporosis is limited due to the high costs.