Patterns of Pharmacotherapy and Counseling for Osteoporosis Management in Visits to US Ambulatory Care Physicians by Women FREE

OSTEOPOROSIS IS the most common bone disease leading to increased fracture risk. Most fractures serve as the first clinical manifestation¹ and can lead to permanent disability with debilitating pain, dependency of daily living, or even death. Osteoporosis is responsible for more than 1.5 million fractures annually, with approximately 300 000 hip fractures, 700 000 vertebral fractures, 250 000 wrist fractures, and 300 000 fractures at other sites. It is not surprising that osteoporosis has been a major public health problem affecting millions of people and a tremendous medical and economic burden. According to recent guidelines on osteoporosis prevention, diagnosis, and therapy from the National Institutes of Health, optimization of bone health must occur throughout life with a balanced diet rich in calcium and vitamin D and regular physical activity.² Age-related osteoporosis often follows menopause in women,² and prevention of osteoporosis is especially important because of lack of effective methods for restoring high-quality bone to the osteoporotic skeleton.³

The most important risk factors for osteoporosis are female sex and increasing age.⁴ Estrogen deficiency is also considered a significant factor contributing to osteoporosis development. The prevalence of osteoporosis was significantly higher among women 65 years and older than younger women and higher among white women than nonwhite women.⁵ Of women who are 65 years or older, 33% experience at least 1 vertebral fracture during their lifetime.⁶ Other factors that may increase the risk of developing osteoporosis include genetics, nutrition, drugs, low weight and body mass index, and lifestyle.^2,4 The incidence of osteoporotic fracture varies; it is greatest in whites and Asians, with a higher incidence among urban vs rural dwellers.³

The universal recommendations for all patients include an adequate dietary intake of calcium and vitamin D, regular weight-bearing exercise while avoiding heavy or vigorous exercise, and avoidance of tobacco use to maximize and preserve bone mass.¹ Antiosteoporosis medications (AOMs) are also recommended as effective medical treatment including calcium and cholecalciferol (vitamin D) supplements, estrogen replacement therapy (ERT), raloxifene, calcitonin, and alendronate and cyclical etidronate among the bisphosphonates.^2,7

In the present study, we evaluated recent national patterns of AOM uses, analyzing data from the 1997 and 1998 National Ambulatory Medical Care Survey (NAMCS) among visits made by women 40 years and older. Women of this age were selected for our study because osteoporosis is more prevalent among postmenopausal women (with an age distribution of menopause ranging from age 40 to 58 years⁸), and we believed that emphasis on osteoporosis prevention should be reinforced in premenopausal, perimenopausal, and postmenopausal women. Our objectives were to estimate prevalence of overall AOM visits among these women; to estimate the association between AOM visits and visit characteristics such as age, race, insurance type, region, metropolitan status, and physician specialties; and to describe the rates of counseling on lifestyle modification in the ambulatory care setting, where primary care physicians play a major role in therapy decision making. This study is primarily descriptive. We hypothesize that certain visit characteristics, such as race, age, insurance type, and physician specialty, are associated with AOM visits.

We used combined NAMCS data from 1997 and 1998 among visits made by nonpregnant women 40 years and older. The NAMCS, which began in 1973, is an annual survey conducted by the National Center for Health Statistics (NCHS) and is a population-based estimate of service utilization.^9- 10 The NAMCS collected data on the utilization of ambulatory medical care services provided by office-based physicians from office visits,^9- 10 which facilitates tracking ambulatory care utilization by supplying information regarding national trends, medication use, or practice patterns among various types of providers in the United States. The unit of measure in the NAMCS is an office visit. Office-based physicians provide data on patients' office visits including up to 3 diagnoses, types of counseling, and up to 6 medications per visit. In addition, the NAMCS provides information on the physician specialty, type of practice, limited patient demographics, and types of payers or insurance.^9- 10 The NAMCS data are directly collected from participating physicians, thereby it provides information about physician's prescription behavior.

The NAMCS uses a multistage probability sampling design, involving probability samples of primary sampling units (PSUs), physician practices within the PSUs, and patient visits within the sampled practices. Statistics derived from NAMCS data are representative of all ambulatory office visits to physicians engaged in office-based patient care.^9- 10 The sample from 1997 and 1998 consisted of 24 715 and 23 339 completed patient visits, respectively.^9- 10 Each visit record is assigned an inflation factor called the "patient visit weight." By aggregating the visit weights provided by NCHS from the sample records, a national estimate of office visits can be obtained.^11- 12

A visit was considered an AOM visit if 1 or more AOMs were recorded as being prescribed, provided, or continued by the physician at that visit. Antiosteoporosis medications available during the 1997 and 1998 periods include ERT (estrogen or estrogen combinations with progesterone or androgen), oral contraceptive pills, bisphosphonates (alendronate, etidronate, and pamidronate), calcitonin, selective estrogen receptor modulator (tamoxifen), calcium supplements, and vitamin D. Raloxifene, a selective estrogen receptor modulator, was not available in 1997 and 1998.

Counseling recommendations from the National Osteoporosis Foundation consist of smoking cessation, proper calcium intake from diet, exercise, and fall preventions to maximize and preserve bone mass.¹ Physicians recorded counseling services by checking the appropriate boxes under "Counseling/Education" in the NAMCS.^11- 12 To describe patterns of counseling during office visits, we analyzed records of counseling services related to diet and nutrition, exercise, tobacco use and exposure, and injury prevention.

The analysis of medication therapy and counseling provision for osteoporosis prevention and treatment focuses on estimating the prevalence by office visit characteristics. The analysis file was created by combining information from NAMCS data files from 1997 to 1998. To obtain national visit estimates, the assigned patient visit weights were aggregated. To estimate the prevalence of AOM visits, we combined each year national estimates and reported the average of the 2-year estimates associated with AOM. Annual visit rates are reported by age group, racial category, insurance type, physician specialty, and location of the physician office by geographic region (Northeast, Midwest, South, and West) as well as metropolitan (urban) vs nonmetropolitan (nonurban) location.

The NCHS provided formulas to calculate relative SEs of the survey estimates. The overall coefficients to calculate relative SEs for 2 years were provided by the NCHS (David A. Woodwell, survey statistician, written communication, 2001) when combining 2 years of data. Using the calculated relative SE values, we computed 95% confidence intervals around the survey estimate. National estimates based on fewer than 30 office visits or with relative SEs higher than 30% are considered to be unreliable. Therefore, we combined calcium with vitamin D and selective estrogen receptor modulator with calcitonin to present stable estimates. All estimates mentioned in this article meet these minimal standards.

While all numbers representing national estimates are based on weighted estimates, statistical analyses are based on the unweighted sample (N = 15 978). Bivariate differences in the prevalence of each AOM therapy by visit characteristics were tested with the χ² test and unadjusted odds ratios were calculated. Adjusted odds ratios were calculated by using a logistic regression model that included covariates such as race, age, metropolitan status, geographic region, insurance type, and physician specialty for the visit. To characterize the provision of counseling during office visits, we calculated and compared prevalence of office visits associated with preventive counseling by both AOM status and visit characteristics. All analyses were performed with SAS statistical software, version 8.01 (SAS Institute Inc, Cary, NC).

Estimated annual physician office visits made by women 40 years and older were 260 million (33.2%) and 273 million (33.1%) in 1997 and 1998, respectively. The mean ± SD age of our study population was 61.7 ± 13.9 years, and most visits were made by women of white race and were at physician's offices located in metropolitan areas (Table 1). Of the 267 million annual visits, 25.9% of women were aged 40 to 49 years; 21.7%, 50 to 59 years; 19.3%, 60 to 69 years; and 33.1%, 70 years and older. The most common form of insurance was private insurance (45.0%) followed by Medicare (35.1%) (Table 1).

Of the visits made by the study population, 26.2 million visits (9.8% of total visits) were associated with AOM therapy (95% confidence interval, 23.5 million to 28.9 million) (Table 2). More than 50% of AOM visits were made by women in their 50s (30.6%) and 60s (22.3%), and 18.8% of AOM visits were made by women in their 40s, 21.1% by women in their 70s, and 7.1% by women older than 80 years. The most prevalent form of AOM therapy (79.4% of AOM visits) was ERT, followed by calcium or vitamin D supplements (15.3%). Bisphosphonates and other forms of AOM therapy (ie, selective estrogen receptor modulator and calcitonin) were each recorded in less than 10% of AOM visits. More than three quarters of AOM visits were made to physician specialty groups of internal medicine (27.1%), general and family practice (26.5%), and obstetrics and gynecology (24.3%).

Visits made by women in their 50s and 60s were about 2 to 3 times more likely to include a prescription for AOM therapy compared with physician visits by women aged 40 to 49 years. Compared with white women, visits made by nonwhite women are less likely to have a prescription for AOM therapy. Office visits to physicians whose offices were located in an urban, metropolitan area were more likely to result in a prescription for AOM therapy than those in nonurban area. Office visits to physicians specializing in obstetrics and gynecology were most likely to include AOM therapy compared with any other physician specialty. Visits made by patients with private insurance and Medicare were more likely to be associated with AOM therapy than patients with Medicaid or other forms of insurance (Table 3). The proportion of visits with private insurance was significantly higher among AOM visits (53.6%) compared with non-AOM visits (44.1%). Among non-AOM visits, there was a significantly higher proportion of visits made by patients with either self-pay or Medicaid status compared with AOM visits (6.4% vs 3.7% with self-pay status; 5.4% vs 2.3% with Medicaid status).

Of all physician office visits, 21.3% were reported to include some type of counseling on smoking, diet and nutrition, exercise, or injury prevention. Among visits made by women who were prescribed an AOM therapy, 30.2% were associated with the counseling. Women making AOM visits were about twice as likely to receive counseling on smoking, diet and nutrition, exercise, or injury prevention than women making non-AOM visits (Table 4). The most common form of counseling was diet and nutrition, followed by smoking cessation. Prevalence of counseling did not vary by patients' age, race, or insurance type. However, physicians who specialized in cardiovascular diseases were more likely to provide counseling than generalists or other specialists.

Osteoporotic fractures or kyphosis among elderly women used to be perceived as unavoidable consequences of aging. However, we now have a better understanding of its causes, diagnosis, and, more importantly, treatment options. Consensus on management of osteoporosis has been developed over the years, emphasizing the identification of women at risk with improved prevention, diagnosis, and treatment of osteoporosis.^1- 3,7,13

Our study findings showed that about 10% of all physician office visits made by women 40 years and older were associated with providing medications to prevent or treat osteoporosis. In other words, 9 of 10 office visits made by women 40 years and older did not have any records of receiving AOMs. About 28 million Americans have osteoporosis or osteopenia.¹⁴ The number of women with osteoporosis in the United States is estimated at 4 to 6 million, and osteopenia affects an additional 13 to 17 million women.¹⁵ It has also been reported that 93% of estrogen-deficient women with osteoporosis were unaware of having the condition.⁵ Considering the high prevalence and the conflictingly low awareness of osteoporotic conditions among women, our results indicate that the status of osteoporosis prevention and treatment using antiresorptive medications was less than optimal during 1997 and 1998.

Our study examined the patterns of medication use not only for osteoporosis treatment, but also for prevention at the national level, with a representative group sampling of visits to physicians in ambulatory care settings. Estrogen replacement therapy is an established approach for osteoporosis treatment and prevention.² Stafford et al¹⁶ reported low rates (8.0 % of all visits) of hormone replacement in the 1993 and 1994 NAMCS data among women 40 years and older. Our results showed similar findings on the prevalence of ERT as an AOM therapy (7.8% of all visits) in 1997 to 1998. Recently, the Women's Health Initiative (WHI) study reported that the use of combined estrogen plus progestin increased breast cancer risk as well as cardiovascular disease events.¹⁷ The most prevalent form of AOM therapy in our study was ERT. We would expect this pattern to shift to nonhormonal therapies such as bisphosphonates and selective estrogen receptor modulator for prevention of osteoporosis because of the WHI findings.

A retrospective medical record review at a large university-based center reported a 65.5% prevalence of bone-preserving treatment among women 50 years and older with osteoporosis or an osteoporosis-related diagnoses including past or current antiresorptive medications for treatment.¹⁸ Our results also demonstrated that 53.6% of physician office visits with records of osteoporosis or an osteoporosis-related diagnoses included the prescribing of AOM therapy (data not shown).

Calcium is the most important nutrient for attaining and maintaining peak bone mass, thereby treating as well as preventing osteoporosis.² Recommendations on calcium intake for older adults range from 1000 to 1500 mg/d. However, only 50% to 60% of older adults meets these recommendations.² From a randomized, placebo-controlled trial with calcium or vitamin D supplementation, baseline median dietary calcium intake was 546 mg/d in men and women older than 60 years.¹⁹ Similar findings from an Australian cross-sectional study reported that median dietary calcium intake was 580 mg/d among elderly men and women, and the intake was lower among older cohorts.²⁰ From our study results, less than 2% of total visits were associated with the use of calcium and/or vitamin D supplements. As suggested by Recker,²¹ calcium supplements may be destined to become an important source of calcium even though optimum calcium intake is best obtained from food sources, especially in this population. Therefore, we believe that some attention should be paid to facilitate the use of calcium supplements in older adults through individual care by their primary care providers.

Counseling on lifestyle modification during office visits was examined in our study. Antiosteoporosis medication visits were about twice more likely to be associated with counseling than non-AOM visits. Only 20% of the non-AOM visits by women had some type of relevant counseling on lifestyle modification. The rates of counseling across age groups were similar in non-AOM visits. However, a higher rate of counseling in women in their 50s was observed in AOM visits than in women of other age groups (data not shown). A report from the US Preventive Services Task Force, which is intended for primary care providers, provides recommendations for clinical practice on preventive interventions specifically including counseling to promote physical activity, a healthy diet, smoking cessation, and fall prevention.²² Using 1995 NAMCS data, the Centers for Disease Control and Prevention reported that physicians reported offering counseling about physical activity (18%) and diet (21%) during either a general medical or routine gynecological examination among visits by women 20 years and older.²³ Our results showed similar rates of counseling on exercise (12%) and diet (16%) among women 40 years and older. In terms of physician specialty, our results coincide with the previous study²³ such that cardiologists were more likely than other specialties to provide counseling. We believe that there should be an increased emphasis on preventive counseling efforts within the US health care system, possibly through training programs to all health care providers or working with professional organizations.

Using NAMCS data has some limitations. The sample of NAMCS represents practices on the basis of visits, not by individual patient. Therefore, we cannot control for clinical, social, and temporal factors potentially affecting patterns of osteoporosis medication use, including personal preferences, drug history, disease history of the patient, bone mineral density, or drug coverage status of the patient. It is also difficult to assess the quality of counseling as well as physician-patient interaction from a survey such as the NAMCS. There is the possibility of truncated drug use records among visits with high prescribing volume because the NAMCS drug data contain up to 6 medications. In our study population, 93.9% of visits indicated between 0 and 5 prescribed medications. Therefore, less than 10% of visits were associated with the possibility of bias due to truncated drug records. Although the NAMCS database includes all prescription and nonprescription medication, we also believe that our results might underestimate actual use, particularly owing to the use of over-the-counter medications and dietary supplements. In addition, patient drug use cannot be directly measured from this data because the prescription made by physician does not necessarily mean that the patient took the medication or even filled the prescription.

In summary, the status of AOM therapy in ambulatory care practice in the United States during 1997 and 1998 was less than optimal considering the risk of osteoporosis among older women and reflect findings by other prevalence studies of osteoporosis and its therapy.^5,14- 16,18 Our findings support the need for greater awareness about the disease and the importance of osteoporosis prevention efforts by health care providers.

Accepted for publication May 7, 2002.

This study was supported by a grant from the Women's Health Research Group, University of Maryland, Baltimore.

Presented at the Annual Meeting of the Academy for Health Services Research and Health Policy, Atlanta, Ga, June 10, 2001.

Corresponding author and reprints: Euni Lee, PharmD, PhD, School of Pharmacy, Howard University, 2300 Fourth St, NW, Washington, DC 20059 (e-mail: eunlee@howard.edu).