Major Challenge in the Treatment of Osteoporosis

Fractures (especially hip fractures) from osteoporosis (brittle bones) are on the rise worldwide. In fact, hip fractures are expected to increase by 200 to 300 percent in men and women around the world.

There is a drug treatment for osteoporosis. Bisphosphonates such as alendronate (Fosamax) or risedronate (Actonel) help slow down how fast the bone is resorbed (destroyed). Everyday new bone cells are formed and old bone cells are resorbed or destroyed. During childhood, new bone cells are formed faster than old ones are destroyed. In the aging adult, resorption exceeds formation.

Despite the number of older adults with osteoporosis and even a history of hip fracture, not very many people are taking these medications. And for those patients who do have a prescription, taking it on a regular basis is not consistent.

In this study from Belgium, the problem of adherence is presented as a major challenge in the treatment of osteoporosis. Adherence includes both treatment persistence (taking medications over a long period of time) and treatment compliance (taking the drug correctly).

Treatment persistence and compliance are important because the risk of a second hip fracture after the first is very high. Taking bisphosphonates reduces that risk. The mortality (death) rate after a hip fracture is also high (up to 50 per cent). And for those people who survive the fracture, half will never walk unassisted again and 25 per cent end up in a nursing home.

Postmenopausal women hospitalized with a hip fracture were included in this retrospective study. Retrospective means the medical records were reviewed after treatment was over. All women in the study received Alendronate (Fosamax) for one year. The main measures assessed were treatment persistence and treatment compliance.

There were three groups based on when they took the medications (daily, weekly, or switch). Weekly doses are packaged with enough pills for each month (referred to as weekly monthly) or for each quarter (weekly quarterly packaging). Switch is a label for patients in the daily group who went to a weekly dose and patients in the weekly group who changed from the monthly to quarterly packaging system.

The authors used a simple calculation of medication possession ratio to measure compliance with treatment. The daily dose delivered during the first year was divided by 365 (number of days in the year). The daily dose delivered was determined using initial drug purchases and refill dates. A ratio of 80 per cent or more was considered good compliance. Anyone with a ratio less than 80 per cent or who stopped taking the drug was labeled as noncompliant.

Three important facts were uncovered with this study. First, only six per cent of patients who had a hip fracture even received anti-osteoporosis treatment. The use of bisphosphonates accounted for two to three per cent of that total. Second, the death rate was decreased by two-thirds for those patients taking the bisphosphonates.

And third, the compliance rate was 80 per cent or more in less than half of the patients (48.7 per cent). Many women (60 per cent) took it inconsistently with gaps of more than five weeks at a time. It didn't seem to matter whether patients took the drugs daily or weekly. The medication possession ratio was the same for all three groups.

The authors report a situation of undertreatment and poor compliance with treatment for a medication known to be successful in preventing hip fractures. Although, in theory, prevention of hip fractures is possible with bisphosphonates, in practice, this isn't happening.

The authors suggest several possible reasons for the gap between evidence-based treatment guidelines and treatment. First, there may be the mistaken idea that once a fracture has occurred, it's too late for drug therapy. Second, with patients seeing more than one physician, it's not clear who should treat the osteoporosis. Sometimes the condition of osteoporosis isn't even identified (even after a hip fracture). Without a diagnosis, no treatment occurs.

Patients may be partly responsible for the lack of treatment. Medications may be prescribed but not purchased due to a lack of money. Or they may be purchased and then discontinued later due to side effects. Some patients stop taking their bisphosphonates because they don't understand why it's important to take these medications as prescribed over a lifetime. Since there aren't very many (if any) obvious symptoms of osteoporosis, it's easy to think, I don't really need this drug.

The new and improved dosing (one pill each month instead of daily pills) may help improve adherence and reduce the rate of hip fractures. National programs to cover the costs may help improve drug compliance. Such a program would be in the interest of everyone since the cost of treating hip fractures runs into the billions each year. And most of the medical costs linked to osteoporosis are caused by hip fractures.

Primary care physicians are more likely to see patients on a long-term basis. It makes sense that they will be the ones to diagnose osteoporosis and initiate treatment for their patients. Close monitoring of treatment compliance is advised given the low medication-taking behavior shown in this study.

Exactly how to achieve better patient compliance to an anti-osteoporosis therapy program is unclear. Future studies are needed to improve the number of older adults who receive bisphosphonate medications and who follow the drug therapy program for osteoporosis.



References: Véronique Rabenda, MSc, et al. Low Incidence of Anti-Osteoporosis Treatment After Hip Fracture. In The Journal of Bone & Joint Surgery. October 2008. Vol. 90-A. No. 10. Pp. 2142-2148.