Sherrie L. Aspinall

Prevalence of unplanned hospitalizations caused by adverse drug reactions in older veterans.

To describe the prevalence of unplanned hospitalizations caused by adverse drug reactions (ADRs) in older veterans and to examine the association between this outcome and polypharmacy after controlling for comorbidities and other patient characteristics.

Consensus Guidelines for Oral Dosing of Primarily Renally Cleared Medications in Older Adults

OBJECTIVES: To establish consensus oral dosing guidelines for primarily renally cleared medications prescribed for older adults.

Bleeding Risk Index in an anticoagulation clinic. Assessment by indication and implications for care.

BACKGROUND: The Outpatient Bleeding Risk Index (BRI) prospectively classified patients who were at high, intermediate, or low risk for warfarin-related major bleeding. However, there are only 2 published validation studies of the index and neither included veterans. OBJECTIVE: To determine the accuracy of the BRI in patients attending a Veterans Affairs (VA) anticoagulation clinic and to speifically evaluate the accuracy of the BRI in patients with atrial fibrillation. DESIGN: Retrospective cohort study. PATIENTS AND MEASUREMENTS: Using the BRI, all patients managed by the Anticoagulation Clinic between January 1, 2001 and December 31, 2002 were classified as high, intermediate, or low risk for major bleeding. Bleeds were identified via quality-assurance reports. Poisson regression was used to determine whether there was an association between the index and the development of bleeding. RESULTS: The rate of major bleeding was 10.6%, 2.5%, and 0.8% per patient-year of warfarin in the high-, intermediate-, and low-risk groups, respectively. Patients in the high-risk category had 14 times the rate of major bleeding of those in the low-risk group (incidence rate ratio (IRR) 14; 95% confidence interval (CI), 1.9 to 104.7). The rate of major bleeding was significantly different between the high- and intermediate-risk categories (P<.001). Among those with atrial fibrillation, patients in the high-risk category had 6 times the major bleeding rate of those in the intermediate- and low-risk groups combined (IRR=6; 95% CI, 2.4 to 15.3). CONCLUSIONS: The BRI discriminates between high- and intermediate-risk patients in a VA anticoagulation clinic, including those with atrial fibrillation.

Potential Interaction between Warfarin and Fluvastatin

OBJECTIVE: To report three cases of a suspected interaction between warfarin and fluvastatin. CASE SUMMARIES: Three patients receiving stable warfarin dosages with therapeutic international normalized ratios (INRs) exhibited increased INRs when fluvastatin was added to their maintenance regimens. While none of the patients experienced a bleeding episode, they did require a reduction in their weekly warfarin dosage to achieve an appropriate level of anticoagulation. DISCUSSION: Reports of an interaction between warfarin and lovastatin have been described previously; however, to our knowledge, this is the first published report of a possible interaction between warfarin and fluvastatin. These cases were chosen because other factors that could potentially increase the INR were ruled out as significant contributors. CONCLUSIONS: The exact mechanism for the potential interaction between warfarin and fluvastatin is unknown. Until more is known, it is advisable to monitor patients more frequently when fluvastatin is initiated, discontinued, or adjusted in patients taking warfarin.

Severe Dysglycemia with the Fluoroquinolones: A Class Effect?

BACKGROUND Although gatifloxacin is no longer available, other fluoroquinolones may significantly interfere with glucose homeostasis. The objective of the present study was to compare the risk of severe hypo- and hyperglycemia in a cohort of patients treated with gatifloxacin, levofloxacin, ciprofloxacin, or azithromycin. METHODS This was a retrospective inception cohort study of outpatients with a new prescription for gatifloxacin, levofloxacin, ciprofloxacin, or azithromycin from 1 October 2000 through 30 September 2005 in the Veterans Affairs health care system. For patients who received one of these antibiotics, we identified outcomes of hospitalization with a primary diagnosis of hypo- or hyperglycemia. Multivariable logistic regression was used to determine the odds of hypo- and hyperglycemia with the individual fluoroquinolones versus azithromycin. RESULTS The crude incidence rates for severe hypo- and hyperglycemia among those who received gatifloxacin, levofloxacin, ciprofloxacin, and azithromycin were 0.35 and 0.45, 0.19 and 0.18, 0.10 and 0.12, and 0.07 and 0.10 cases per 1000 patients, respectively. Among patients with diabetes, the odds ratios for hypoglycemia compared with azithromycin were 4.3 (95% confidence interval [CI], 2.7-6.6) for gatifloxacin, 2.1 (95% CI, 1.4-3.3) for levofloxacin, and 1.1 (95% CI, 0.6-2.0) for ciprofloxacin. The odds ratios for hyperglycemia were 4.5 (95% CI, 3.0-6.9) for gatifloxacin, 1.8 (95% CI, 1.2-2.7) for levofloxacin, and 1.0 (95% CI, 0.6-1.8) for ciprofloxacin. CONCLUSIONS The odds of severe hypo- and hyperglycemia were significantly greater with gatifloxacin and levofloxacin, but not ciprofloxacin, than with azithromycin. Thus, the risk of a clinically relevant dysglycemic event appears to vary among the fluoroquinolones.

Use of antipsychotics among older residents in VA nursing homes

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.

Potentially inappropriate prescribing of primarily renally cleared medications for older veterans affairs nursing home patients.

BACKGROUND Inappropriate prescribing of primarily renally cleared medications in older patients with kidney disease can lead to adverse outcomes. OBJECTIVES To estimate the prevalence of potentially inappropriate prescribing of 21 primarily renally cleared medications based on 2 separate estimates of renal function and to identify factors associated with this form of suboptimal prescribing in older VA nursing home (NH) patients. DESIGN Longitudinal study PARTICIPANTS Participants were 1304 patients, aged 65 years or older, admitted between January 1, 2004, and June 30, 2005, for 90 days or more to 1 of 133 VA NHs. MAIN MEASURES Potentially inappropriate prescribing of primarily renally cleared medications determined by estimating creatinine clearance using the Cockcroft Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations and applying explicit guidelines for contraindicated medications and dosing. KEY RESULTS The median estimated creatinine clearance via CG was 67 mL/min, whereas it was 80 mL/min/1.73m(2) with the MDRD. Overall, 11.89% patients via CG and only 5.98% via MDRD had evidence of potentially inappropriate prescribing of at least 1 renally cleared medication. The most commonly involved medications were ranitidine, glyburide, gabapentin, and nitrofurantoin. Factors associated with potentially inappropriate prescribing as per the CG were age older than 85 (adjusted odds ratio [AOR] 4.24, 95% confidence interval [CI] 2.42-7.43), obesity (AOR 0.26, 95% CI 0.14-0.50) and having multiple comorbidities (AOR 1.09 for each unit increase in the Charlson comorbidity index, 95% CI 1.01-1.19). CONCLUSIONS Potentially inappropriate prescribing of renally cleared medications is common in older VA NH patients. Intervention studies to improve the prescribing of primarily renally cleared medications in nursing homes are needed.

The evolving use of cost-effectiveness analysis in formulary management within the Department of Veterans Affairs.

The Veterans Health Administration (VHA) runs the largest integrated healthcare system in the nation. Formulary management within VHA primarily involves 3 national groups: the Medical Advisory Panel, the Veterans Integrated Service Network Formulary Leaders, and the Pharmacy Benefits Management Strategic Healthcare Group. Together, these groups manage the VHA national drug formulary with a goal of providing a comprehensive, safe, and cost-effective pharmacy benefit for veterans. Traditionally, VHA has relied on cost-minimization analyses in formulary decisions. More recently, VHA has emphasized the use of cost-effectiveness data, especially for newer, costly drugs. In addition to including this data in drug monographs, the VHA has begun requiring formal cost-effectiveness analysis from manufacturers of selected pharmaceuticals. VHA has also requested that clinically relevant information such as quality of life plus mortality benefit be made available from industry so that internal cost analyses can be performed. It is hoped that by setting the expectation that cost-effectiveness will be formally considered in all VHA formulary decisions, the pharmaceutical industry and others will be stimulated to collect and report data that enables these analyses. We believe that if other organizations also place an emphasis on economic evaluations, industry and the public will be more accepting of decisions that incorporate cost considerations.

Impact of a geriatric nursing home palliative care service on unnecessary medication prescribing

BACKGROUND There is a lack of studies concerning improvement of medication use in palliative care patients in nursing homes. OBJECTIVE This study was conducted to evaluate whether a geriatric palliative care team reduced unnecessary medication prescribing for elderly veterans residing in a nursing home. METHODS This was a retrospective, descriptive study of patients who died while residing in a geriatric palliative care unit between August 1, 2005, and July 31, 2007. Prescribed medications were evaluated using the Unnecessary Drug Use Measure, which contains 3 items from the Medication Appropriateness Index concerning lack of indication, lack of effectiveness, and therapeutic duplication. This measure was applied at 2 time points: on transfer/admission to the palliative care unit and at the last 30-day pharmacist medication review before death. Paired t tests and McNemar tests were used to compare medication use at these 2 points. RESULTS Eighty-nine patients were included in the study. The majority were male (97.8%) and white (78.7%), with a mean (SD) age of 79.7 (7.8) years. The median length of stay on the unit was 39.0 days, and the mean number of chronic medical conditions was 8.4 (4.3). At baseline, the mean number of scheduled medications was 9.7 (4.3). The number of unnecessary medications per patient decreased from a mean of 1.7 (1.5) at admission to 0.6 (0.8) at closeout (P = 0.003). The decrease was seen in all 3 categories of the Unnecessary Drug Use Measure. CONCLUSIONS The geriatric palliative care team was associated with a reduction in the number of unnecessary medications prescribed for older veterans in this nursing home. Future studies should evaluate the impact of decreasing unnecessary prescribing on clinical outcomes such as adverse drug reactions.

Antibiotic prescribing for presumed nonbacterial acute respiratory tract infections

OBJECTIVE The objective of the study was to identify patient and provider factors associated with prescribing antibiotics for outpatients with acute respiratory tract infections of likely nonbacterial etiology. METHODS We identified outpatients who were diagnosed in the emergency department with nonspecific upper respiratory tract infections (URIs) and acute bronchitis at the VA Pittsburgh Healthcare System from June 15, 2003, to June 14, 2004, and the Philadelphia VA Medical Center from November 30, 2003, to March 31, 2004. Stepwise logistic regression was used to identify factors independently associated with antibiotic prescribing. RESULTS Overall, 26% of the 667 eligible patients with URIs and/or acute bronchitis received antibiotics. Antibiotics were prescribed significantly more frequently for acute bronchitis at one site (97% vs 65%, P < .001). Using multivariable analysis, the following factors were independently associated with antibiotic prescribing (odds ratio, 95% confidence interval): presence of 1 or more comorbidities (2.1, 1.2-3.5), fever (2.5, 1.4-4.4), purulent sputum (2.5, 1.5-4.4), shortness of breath (2.8, 1.4-5.4), altered breath sounds (4.6, 2.4-8.6), diagnosis of acute bronchitis (15.9, 8.0-31.8), provider age > or = 30 years (2.6, 1.1-6.3), and noninternal medicine specialty (2.7, 1.2-6.0). CONCLUSIONS Antibiotic use was high and varied substantially for URIs and acute bronchitis. Specific signs and symptoms, a diagnosis of acute bronchitis, and provider age and specialty were associated with antibiotic prescribing. Interventions to decrease inappropriate prescribing should address the perceived utility of antibiotics in acute bronchitis and the accuracy of signs and symptoms in diagnosing a bacterial respiratory infection.