WASHINGTON — Postmenopausal women with a prior fall or those 80 years or older have a significantly greater risk of a subsequent fall, according to data presented at an international symposium sponsored by the National Osteoporosis Foundation.
Specifically, investigators found that women with a prior fall had an odds ratio of 2.7 and those 80 years or older had a OR of 1.5 for a future fall, based on a analysis of potential risk factors among 66,134 women in the National Osteoporosis Risk Assessment (NORA) study, said Dr. Elizabeth Barrett-Connor, chief of epidemiology in the department of family and preventive medicine at the University of California at San Diego.
The NORA study enrolled over 200,000 community-dwelling, postmenopausal women between 1997 and 1999. Women had to be at least 50 years old without osteoporosis. They also could not have had a bone mineral density measurement in the previous year or be taking an osteoporosis drug. At baseline, BMD was measured at the heel, forearm, or finger. The women were followed up at 1, 3, and 6 years with surveys asking about fractures in the previous 12 months. At baseline, average age was 63 years. Most (91%) were white. The average T score was −0.78. In all, 38% reported at least one fall in the past year.
“History of a fall in the year before a query was a strong predictor for falls,” said Dr. Barrett-Connor.
Potential risk factors included age, body mass index, a self-rating of health as being poor/fair, functional limitations, smoking, alcohol use, early menopause, height loss, peripheral T score, history of fracture after age 45, maternal history of fracture and/or osteoporosis, first-degree relatives with a history of fracture, estrogen therapy, calcium supplementation, use of medications (oral corticosteroids, thyroid medication, osteoporosis-specific drugs), history of depression, osteoporosis self-knowledge, and self-report of a fall within the previous 12 months at the year 1 survey. They also included arthritis, coronary artery disease, hypertension, diabetes, kidney/liver disease, cancers, memory problems, stroke, hyperthyroidism, hypothyroidism, epilepsy, poor vision, and poor hearing.
History of depression and history of stroke increased fall risk by more than 40%. An additional nine factors were identified that significantly increased fall risk by 9%–23%. The number of baseline risk factors was linearly associated with a risk of falling.
The study has several limitations. First, participants were volunteers and may not be a representative sample. Second, falls were self-reported and limited to a 12-month recall. That likely means that falls were underreported. Longitudinal attrition resulted in a slightly younger and healthier analytic sample, which may mean falls were underestimated for the whole cohort. No data were collected on factors known to be tied to falls, such as prescription medications, environment, gait, balance, and strength. Lastly, the cause of falls was not known.
Dr. Barrett-Connor disclosed research support from several pharmaceutical companies. She consults for Merck & Co. Two collaborators are employees of Merck.
JULIE KELLER/ELSEVIER GLOBAL MEDICAL NEWS