Publications

BACKGROUND: Sources of regional variation in spending for prescription drugs under Medicare Part D are poorly understood, and such variation may reflect differences in health status, use of effective treatments, or selection of branded drugs over lower-cost generics.

METHODS: We analyzed 2008 Medicare data for 4.7 million beneficiaries for prescription-drug use and expenditures overall and in three drug categories: angiotensin-converting-enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs), 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), and selective serotonin-reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). Differences in per capita expenditures across hospital-referral regions (HRRs) were decomposed into annual prescription volume and cost per prescription. The ratio of prescriptions filled as branded drugs to all prescriptions filled was calculated. We adjusted all measures for demographic, socioeconomic, and health-status differences.

RESULTS: Mean adjusted per capita pharmaceutical spending ranged from $2,413 in the lowest to $3,008 in the highest quintile of HRRs. Most (75.9%) of that difference was attributable to the cost per prescription ($53 vs. $63). Regional differences in cost per prescription explained 87.5% of expenditure variation for ACE inhibitors and ARBs and 56.3% for statins but only 36.1% for SSRIs and SNRIs. The ratio of branded-drug to total prescriptions, which correlated highly with cost per prescription, ranged across HRRs from 0.24 to 0.45 overall and from 0.24 to 0.55 for ACE inhibitors and ARBs, 0.29 to 0.60 for statins, and 0.15 to 0.51 for SSRIs and SNRIs.

CONCLUSIONS: Regional variation in Medicare Part D spending results largely from differences in the cost of drugs selected rather than prescription volume. A reduction in branded-drug use in some regions through modification of Part D plan benefits might lower costs without reducing quality of care. (Funded by the National Institute on Aging and others.).

BACKGROUND: Antipsychotic medications are commonly prescribed to nursing home residents despite their well-established adverse event profiles. Because little is known about their use in Veterans Affairs (VA) nursing homes [ie, Community Living Centers (CLCs)], we assessed the prevalence and risk factors for antipsychotic use in older residents of VA CLCs.

METHODS: This cross-sectional study included 3692 Veterans age 65 or older who were admitted between January 2004 and June 2005 to one of 133 VA CLCs and had a stay of ≥90 days. We used VA Pharmacy Benefits Management data to examine antipsychotic use and VA Medical SAS datasets and the Minimum Data Set to identify evidence-based indications for antipsychotic use (eg, schizophrenia, dementia with psychosis). We used multivariable logistic regression and generalized estimating equations to identify factors independently associated with antipsychotic receipt.

RESULTS: Overall, 948/3692(25.7%) residents received an antipsychotic, of which 59.3% had an evidence-based indication for use. Residents with aggressive behavior [odds ratio (OR)=2.74, 95% confidence interval (CI), 2.04-3.67] and polypharmacy (9+ drugs; OR=1.84, 95% CI, 1.41-2.40) were more likely to receive antipsychotics, as were users of antidepressants (OR=1.37, 95% CI, 1.14-1.66), anxiolytic/hypnotics (OR=2.30, 95% CI, 1.64-3.23), or drugs for dementia (OR=1.52, 95% CI, 1.21-1.92). Those residing in Alzheimer/dementia special care units were also more likely to receive an antipsychotic (OR=1.66, 95% CI, 1.26-2.21). Veterans with dementia but no documented psychosis were as likely as those with an evidence-based indication to receive an antipsychotic (OR=1.10, 95% CI, 0.82-1.47).

CONCLUSIONS: Antipsychotic use is common among VA nursing home residents aged 65 and older, including those without a documented evidence-based indication for use. Further quality improvement efforts are needed to reduce potentially inappropriate antipsychotic prescribing.

OBJECTIVES: To describe facility-level variation in two measures of potentially inappropriate prescribing prevalent in Veterans Affairs (VA) facilities-exposure to high-risk medications in elderly adults (HRME) and drug-disease interactions (Rx-DIS)-and to identify facility characteristics associated with high-quality prescribing.

DESIGN: Cross-sectional.

SETTING: VA Healthcare System.

PARTICIPANTS: Veterans aged 65 and older with at least one inpatient or outpatient visit in 2005-2006 (N = 2,023,477; HRME exposure) and a subsample with a history of falls or hip fractures, dementia, or chronic renal failure (n = 305,059; Rx-DIS exposure).

MEASUREMENTS: Incident use of any HRME (iHRME) and incident Rx-DIS (iRx-DIS) and facility-level rates and facility-level predictors of iHRME and iRx-DIS exposure, adjusting for differences in patient characteristics.

RESULTS: Overall, 94,692 (4.7%) veterans had iHRME exposure. At the facility level, iHRME exposure ranged from 1.6% at the lowest facility to 12.8% at the highest (median 4.7%). In the subsample, 9,803 (3.2%) veterans had iRx-DIS exposure, with a facility-level range from 1.3% to 5.8% (median 3.2%). In adjusted analyses, veterans seen in facilities with formal geriatric education had lower odds of iHRME (odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.77-0.96) and iRx-DIS (OR = 0.95, 95% CI = 0.88-1.01). Patients seen in facilities caring for fewer older veterans had greater odds of iHRME (OR = 1.54, 95% CI = 1.35-1.75) and iRx-DIS exposure (OR = 1.22, 95% CI = 1.11-1.33).

CONCLUSION: Substantial variation in the quality of prescribing for older adults exists across VA facilities, even after adjusting for patient characteristics. Higher-quality prescribing is found in facilities caring for a larger number of older veterans and facilities with formal geriatric education.

BACKGROUND: Although four-dollar programs ($4 per 30-day supply for selected generic drugs) have become important options for seniors to obtain affordable medications, little is known about access to these programs and the characteristics of those who use them.

OBJECTIVES: We quantify access to $4 programs based on driving distance; evaluate factors affecting the program use and potential cost-savings associated with switching to $4 programs in Medicare.

DESIGN: Observational study.

SETTING: US Medicare Part D data, 5% random sample, 2007

PARTICIPANTS: 347,653 elderly beneficiaries without Medicaid coverage or low-income subsidies.

MAIN MEASURES: We evaluated how use of $4 programs was affected by driving distance to the store and the beneficiary's demographic and socioeconomic status, insurance coverage, health status, comorbidities, and medication use. For those who did not use the $4 programs, we calculated potential savings from switching to $4 generics.

KEY RESULTS: Eighty percent of seniors in Medicare Part D filled prescriptions for generic drugs that were commonly available at $4 programs. Among them, only 16.3% filled drugs through $4 programs. Beneficiaries who lived in poor areas, had less insurance, more co-morbidities, and used more drugs and lived closer to $4 generic retail pharmacies, were more likely to use these programs. Blacks were less likely to use the program relative to Whites (15.0% vs. 16.4%; OR=0.75, 95% CI 0.71-0.80). While 53.2% of nonusers would save by switching to $4 program after incorporating travelling costs, 58% of those who could save would have net annual out-of-pocket savings of less than $20.

CONCLUSIONS: The take-up rate of $4 programs was low in 2007 among Medicare beneficiaries. As more stores offer $4 programs and increasing numbers of drugs become generic, more beneficiaries could potentially benefit, as could the Medicare program.

BACKGROUND: The risk of potentially inappropriate medication (PIM), both prescription and over-the-counter, use in dementia patients is high. Informal caregivers often facilitate patients' use of medications, but the effect of caregiver factors on PIM use has not been a focus of previous research.

OBJECTIVE: The aim of this study was to examine PIM use in dementia patients and caregivers and identify caregiver risk factors for PIM use in dementia patients.

METHODS: We conducted a secondary data analysis of the baseline wave of the Resources for Enhancing Alzheimer's Caregiver's Health study. The sample comprised 566 persons with dementia aged 65 and older and their coresiding family caregiver. PIM was defined using the 2003 Beers criteria and was examined in both dementia patients and their caregivers. Caregiver and patient risk factors included a range of sociodemographic and health variables.

RESULTS: In dementia patients, 33% were taking at least 1 PIM, and 39% of their caregivers were also taking a PIM. In fully adjusted models, the following caregiver factors were associated with an increased risk of dementia patient PIM use: caregiver's own PIM use, spouse caregivers, Hispanic caregivers, and greater number of years that the caregiver has lived in the United States. Increased caregiver age was associated with a decreased risk of PIM use in patients.

CONCLUSIONS: PIM use may be higher in dementia patients and their informal caregivers compared with the general older adult population. Further, patterns of medication use in 1 member of the dyad may influence PIM risk in the other dyad member. These results suggest that interventions to increase appropriate medication use in dementia patients and their caregivers should target both members of the dyad and target over-the-counter agents along with prescription medications.

OBJECTIVES: The objectives of this study were to describe changes in glyburide prescribing in cohorts that were and were not targeted by a risk reduction project, assess factors associated with glyburide discontinuation, and evaluate changes in glycated hemoglobin (ie, HbA(1c)) levels and rates of serious hypoglycemia.

METHODS: This historical cohort study included a targeted cohort of 4368 outpatient veterans aged ≥65 years with active prescriptions for glyburide between April 1, 2007 and June 30, 2007 and serum creatinine (SCr) ≥2 mg/dL and a nontargeted cohort of 1886 outpatients meeting these same criteria between July 1, 2007 and September 3, 2007. The intervention in the risk reduction project took place on September 4, 2007 and entailed giving regional pharmacy leaders information about the increased risk of hypoglycemia with glyburide and the list of targeted patients for follow up with providers. For each patient, the study period was the time between the date they first met the eligibility criteria and March 31, 2008. All data were obtained from Veterans Affairs (VA) administrative databases. The primary outcome was the discontinuation of glyburide. Secondary outcomes were the change in HbA(1c) after stopping glyburide and the rate of serious hypoglycemia after intervention.

RESULTS: Incidence rate ratios (IRRs) for glyburide discontinuation in targeted versus nontargeted cohorts were statistically significantly elevated in September (IRR 2.1; 95% CI 1.7-2.5), October (IRR 1.3; 95% CI 1.1-1.6), and November 2007 (IRR 1.4; 95% CI 1.1-1.7). The intervention, black race, SCr, Charlson comorbidity score, new glyburide use, and VA region were independently associated with discontinuation. Among patients in the targeted cohort who discontinued glyburide, mean (SD) HbA(1c) at baseline and after discontinuation were 7.17% (1.35%), and 7.22% (1.34%), respectively (P = 0.36). The hypoglycemia rates/1000 person-days were 0.093 before the intervention and 0.070 afterwards (P = 0.10).

CONCLUSION: A one-time intervention in a risk reduction project decreased glyburide use over a 3-month period in elderly outpatients with renal insufficiency without compromising glucose control.

OBJECTIVE: To compare the cost-effectiveness of four, six, and eight doses per month of vardenafil in the context of pharmacy benefit decision making.

METHODS: A Markov model was used to estimate the incremental cost-effectiveness of zero, four, six, or eight doses of vardenafil per month in hypothetical cohorts of 60-year-old male veterans with erectile dysfunction. Efficacy values for vardenafil were obtained from the literature, and vardenafil costs were obtained from Veterans Affairs pharmacy data. The analysis was conducted from a third-party payer perspective with a lifetime horizon, and the effect of parameter uncertainty was explored in one-way and probabilistic sensitivity analyses.

RESULTS: In the base case analysis, the cost per quality-adjusted life-year gained for four doses of vardenafil per month compared with no therapy was $576. Six doses per month compared with four cost $2585/quality-adjusted life-year gained, and eight doses per month compared with six cost $5169/quality-adjusted life-year gained. In one-way sensitivity analyses of six doses per month compared with four, variation of two parameters caused the incremental cost-effectiveness ratio to cross a willingness-to-pay threshold of $20,000: when the increased utility associated with giving two additional doses/month was less than 0.001 (baseline 0.01) and when the cost per dose increased to $15.00 (baseline $1.69).

CONCLUSION: Although four doses per month of vardenafil was the most cost-effective strategy, the use of six or eight doses per month also compares favorably with other accepted medical treatments. The results were stable across a range of inputs and help to support the current Veterans Affairs policy on the number of vardenafil doses provided per month for erectile dysfunction.

OBJECTIVES: To examine the change in use of high-risk medications for the elderly (HRME), as defined by the National Committee on Quality Assurance's Healthcare Effectiveness Data and Information Set (HEDIS) quality measure (HEDIS HRME), by older outpatient veterans over a 3-year period and to identify risk factors for HEDIS HRME exposure overall and for the most commonly used drug classes.

DESIGN: Longitudinal retrospective database analysis.

SETTING: Outpatient clinics within the Department of Veterans Affairs (VA).

PARTICIPANTS: Veterans aged 65 by October 1, 2003, and who received VA care at least once each year until September 30, 2006.

MEASUREMENTS: Rates of use of HEDIS HRME overall and according to specific drug classes each year from fiscal year 2004 (FY04) to FY06.

RESULTS: In a cohort of 1,567,467, high-risk medication exposure fell from 13.1% to 12.3% between FY04 and FY06 (P<.001). High-risk antihistamines (e.g., diphenhydramine), opioid analgesics (e.g., propoxyphene), skeletal muscle relaxants (e.g., cyclobenzaprine), psychotropics (e.g., long half-life benzodiazepines), endocrine (e.g., estrogen), and cardiac medications (e.g., short-acting nifedipine) had modest but statistically significant (P<.001) reductions (range -3.8% to -16.0%); nitrofurantoin demonstrated a statistically significant increase (+36.5%; P<.001). Overall HEDIS HRME exposure was more likely for men, Hispanics, those receiving more medications, those with psychiatric comorbidity, and those without prior geriatric care. Exposure was lower for individuals exempt from copayment. Similar associations were seen between ethnicity, polypharmacy, psychiatric comorbidity, access-to-care factors, and use of individual HEDIS HRME classes.

CONCLUSION: HEDIS HRME drug exposure decreased slightly in an integrated healthcare system. Risk factors for exposure were not consistent across drug groups. Future studies should examine whether interventions to further reduce HEDIS HRME use improve health outcomes.

OBJECTIVE: Understanding provider perceptions of and experiences with order entry and order checks (drug alerts) in an electronic prescribing system may help improve medication safety technology.

DESIGN: Cross-sectional, national survey of Veterans Administration physicians practicing in various specialties.

MEASUREMENT: Thirty-five question instrument was divided into 4 content domains. Response options included dichotomous, numeric, multiple choices, and Likert-like scales. Statistical methods included logistic regression.

RESULTS: The adjusted response rate was 1543 of 3588 (43%). Almost all providers (90%) felt that the VA electronic prescribing system, including its order checks, improved prescribing safety to some degree. Most respondents (72%) reported that they always or almost always document outside medications in a clinic note, although only 44% always or almost always entered outside medications in the non-VA medication data field. Most physicians (88%) who encountered serious allergic or adverse drug reactions reported either notifying a pharmacist or entering the information in the allergies/adverse reactions field. Generalists and physicians with higher numbers of prescriptions were more likely to enter relevant data into the electronic medical record (or notify a pharmacist, in the case of adverse reactions). In addition, 48% of providers described critical drug-drug interaction alerts as very useful; medical specialists found these less useful, whereas surgical specialists found these more useful when compared with generalists.

LIMITATIONS: Survey was conducted within a single healthcare system.

CONCLUSION: Computerized provider order entry and related order checks are perceived to improve prescribing safety; however, provider entry of some relevant information into the appropriate electronic fields may not be optimal.