Background Little is known about osteoporosis medication use among high-risk patients in nursing homes [NHs]. We studied the patterns and predictors of osteoporosis medication use in elderly patients who sustained a fracture and were admitted to an NH.
Methods We linked pharmaceutical claims data from 2 state-run drug assistance programs for elderly patients to Medicare data for the years 1995 through 2004. We defined the rates of osteoporosis medication use among patients admitted to an NH following a hip, wrist, or humeral fracture for the 12-month period after the fracture. Predictors of using an osteoporosis medication were assessed in a multivariate Cox proportional hazards model adjusting for age and sex.
Results Of the 4430 eligible postfracture patients, only 11.5% were prescribed an osteoporosis medication. There was a progressive increase in use from 1.6% in 1995 to 18.7% in 2001 but no increases in 2001 through 2004. Patient characteristics associated with osteoporosis medication use included a history of osteoporosis medication use in the prior 12 months [hazard ratio, 19.5; 95% confidence interval, 16.0-23.7] and female sex [hazard ratio, 1.57; 95% confidence interval, 1.13-2.21]. A history of falls or fracture was not a significant factor. Calcitonin was the most commonly used osteoporosis medication [56%].
Conclusions While the rate of osteoporosis medication use increased across the 10-year period, a low rate of osteoporosis medication use persists in the NH setting. More appropriate use of drug treatment of high-risk patients is needed in NHs.
Osteoporosis has been reported in 80% of all nursing home [NH] residents.1 Prospective cohort studies have reported rates of 3.7 to 5.0 hip fractures per 100 NH residents per year, a risk 2.5- to 10-times greater than in community-dwelling elderly subjects.2-4 Fractures significantly increase morbidity5 and health care utilization in NH residents.6 In one study of 1427 female NH residents, those who had a fracture were hospitalized 15 times more often in the month following the fracture compared with those who did not have a fracture, and this risk persisted 3 to 12 months after fracture.6
Fracture prevention in the NH environment may focus on fall prevention, bone protection, and bone mineral density [BMD] enhancement. The role of low BMD in fracture risk has been acknowledged in NH patients.7 Many widely available pharmaceutical agents improve BMD, with the essential treatment goal of fracture reduction and ultimately reduced mortality.8-11 Alendronate sodium in particular has been proven to be efficacious in both community-dwelling elderly subjects and residents of long-term care facilities.12 Despite the wide availability of effective pharmacotherapy for osteoporosis, the use of these agents is uncommon among all patients with osteoporosis.13 Prior studies of osteoporosis medication use in NHs among various populations have found rates as low as 20%.14,15 Patients with a recent history of a fragility fracture are at high risk of future fractures.16 They warrant particular attention to secondary prevention of fractures, but the rate of use among this high-risk population is unclear.
The relatively controlled environment of the NH presents a unique opportunity for fracture prevention. These strategies include fall prevention, hip protectors, and pharmacotherapy including adequate vitamin D replacement. Fall reduction may lead to fracture reduction; however, randomized control data are lacking. The direct impact of hip protectors on fracture risk remains uncertain.17,18 Prescribing data for NH residents is widely available and makes it possible to assess an important aspect of fracture prevention. We conducted a retrospective analysis on prospectively collected data to describe the patterns of osteoporosis medication use in elderly NH patients with a recent fracture and then determined patient-level predictors of medication use in this population.
Study population and data sources
The study cohort was identified from all individuals enrolled in the New Jersey Medicaid and Pharmaceutical Assistance for the Aged and Disabled [PAAD] programs, with data linked to their corresponding clinical encounter and diagnosis data from the Medicare program. The study spanned medication use between January 1, 1995, and December 31, 2004. The PAAD program is a state-specific program for reimbursement of drug expenses for elderly and disabled citizens. The majority of patients in this program are older than 65 years. The New Jersey Medicaid program has no deductible with no maximum benefit and charges no copayment for prescription drugs. The PAAD also has no deductible and no maximum benefit, but there is a nominal $2 copayment with each prescription. There were no prescribing or reimbursement restrictions for osteoporosis medications during this study period. Available information from the database included demographic information, dates of enrollment and hospitalization, NH utilization data, and all recorded diagnosis, procedures, physician visits, and filled prescriptions.
From these patients, we identified those who sustained a hip, wrist, or humerus fracture and were then admitted to an NH within 30 days after discharge from an acute care facility [Figure 1]. For those patients not admitted to an acute care facility for fracture treatment, we required NH admission to have occurred within 30 days from the date of the fracture. Patients may have been residents in the community or in an NH at the time of the index fracture. Fractures were defined using validated algorithms, which have high positive predictive value.19 Fractures were identified from International Classification of Diseases, Ninth Revision [ICD-9] diagnostic codes combined with procedure codes.
The New Jersey Medicaid and PAAD databases were then queried to identify osteoporosis medications prescribed in the 12-month period following NH admission. Nursing homes studied included all long-term care facilities, including skilled nursing facilities. Each individual was required to be a patient continuously for 30 days or more from the time of the index NH admission. Patients were excluded if they had not had any prescription filled for any condition during the first 30 days of NH admission. To reduce the possibility that patients were receiving their medication from another source, patients were also excluded if they did not have any prescriptions filled or did not have a Medicare claim in each of the two 6-month periods preceding the date of the index fracture. This ensured that each subject had a uniform period of eligibility during which medication coverage was in place and covariates could be assessed. To ensure continuing system use of the pharmaceutical benefit, subjects were also excluded if they did not have a minimum of 1 prescription filled per 30-day period within 12 months after their fracture. Patients were followed for 30-day periods until the first prescription was filled for an osteoporosis medication, death, or discharge from the NH or end of the 12-month study period. The institutional review board of the Brigham and Women's Hospital, Boston, Massachusetts, approved the study.
The osteoporosis medications studied were bisphosphonates [both oral and intravenous], raloxifene hydrochloride, calcitonin, teriparatide acetate, and estrogen-containing hormone therapy. Because indications for medications were not identified, they could have been used for other purposes rather than secondary fracture prevention. However, in the setting of a recent fracture in an elderly population, this seemed less likely. Calcium and vitamin D supplementation and hip protectors were not studied because the available data could not identify these therapies.
Age and sex were identified from program enrollment information. All covariates were assessed in the 12 months preceding the index fracture. International Classification of Diseases, Ninth Revision diagnostic information was used to calculate a modified Charlson comorbidity index score.20 Specific codes were reviewed in conjunction with all filled prescriptions during the previous 12 months to create particular variables; this included a history of dementia, falls, osteoporosis, osteoporosis medication, or prior BMD examination. Covariates assessed were either those in the literature relevant to the pathogenesis of osteoporosis or those likely to influence prescription and relevant in an NH population.
The overall rate of osteoporosis medication use was defined and then examined for each year of the study period. Use of individual categories of medication was also studied by year and collectively over the 10-year period. Initially, we studied the relationship of each variable to osteoporosis medication prescribing in an unadjusted Cox proportional hazard regression. We then entered these variables into a multivariate Cox proportional hazard model to determine the predictors of treatment. A similar analysis was conducted on patients with hip fractures to determine the influence of location of fracture in prescribing osteoporosis medications. Statistical analyses were performed with SAS version 9.1 software [SAS Institute Inc, Cary, North Carolina]. P