Christine M. Ruby

Use of inappropriate prescription drugs by older people

OBJECTIVES To determine the prevalence and predictors of inappropriate drug prescribing defined by expert national consensus panel drug utilization review criteria for community-dwelling older people. DESIGN Survey. SETTING Five adjacent urban and rural counties in the Piedmont area of North Carolina. PARTICIPANTS A stratified random sample of participants from the fourth (n = 3,234) and seventh (n = 2,508) waves of the Duke Established Populations for Epidemiological Studies of the Elderly. MEASUREMENTS The prescribing appropriateness for digoxin, calcium channel blockers, angiotensin-converting enzyme inhibitors, histamine(2) receptor antagonists, nonsteroidal antiinflammatory drugs (NSAIDs), benzodiazepines, antipsychotics, and antidepressants as determined by explicit criteria (through Health Care Financing Administration expert consensus panel drug utilization review criteria for dosage, duplication, drug-drug interactions and duration, and U.S. and Canadian expert consensus panel criteria for drug-disease interactions). Multivariable analyses, using weighted data adjusted for sampling design, were conducted to assess the association between inappropriate prescribing and demographic, health-status, and access-to-healthcare factors cross-sectionally and longitudinally. RESULTS We found that 21.0 of the fourth wave and 19.2 of the seventh wave participants who used one or more agents from the eight drug classes had one or more elements identified as inappropriate. The therapeutic classes with the most problems were benzodiazepines and NSAIDs. The most common problems were with drug-disease interactions and duration of use. Longitudinal multivariable analyses found that participants who were white (adjusted odds ratio (AOR) = 1.67, 95 confidence interval (CI) = 1.28-2.17), were married (AOR = 1.40, 95% CI = 1.01-1.93), had arthritis (AOR = 1.74, 95% CI = 1.27-2.38), had one or more physical function disabilities (AOR = 1.42, 95% CI = 1.02-1.96), and had inappropriate drugs prescribed at wave 4 (AOR = 6.87, 95% CI = 5.11-9.22) were more likely to have inappropriate prescribing at wave 7. CONCLUSION These results indicate that inappropriate prescribing is common among community-dwelling older people and persists over time. Longitudinal studies in older people are needed to examine the impact of inappropriate drug prescribing on health-related outcomes.

Adverse drug reaction risk factors in older outpatients.

BACKGROUND Adverse drug reactions (ADRs) are common in older (age >or=65 years) outpatients (prevalence, 5%-35%), but there is no consensus on factors that put these patients at high risk for ADRs. Identifying a uniform set of risk factors would be helpful to develop risk models for ADRs for older outpatients and to implement targeted interventions for those patients at high risk for ADRs. OBJECTIVE The aim of this study was to identify potential risk factors for ADRs in older outpatients through a survey of geriatric experts and to determine their prevalence. METHODS A comprehensive literature search was conducted to find published articles on ADRs in older patients. Forty-four potential risk factors were identified through the literature search and 6 additional factors were suggested by the expert panel. Through a modified 2-round survey, based on the Delphi consensus method, of an expert panel of 5 physicians and 5 pharmacists, the probability that each of these 50 potential factors could contribute independently to placing an older outpatient at high risk for an ADR was rated on a 5-point Likert scale. After the survey responses were received, means and 95% Cls were calculated. Consensus was defined as a lower 95% confidence limit >or=4.0. Potential risk factors that reached consensus were then applied to a sample of older outpatients to determine their prevalence. RESULTS After 2 rounds, the expert panel reached consensus on 21 factors, including 12 medication-related factors and 9 patient characteristics. The most prevalent medication-related risk factors were opioid analgesics; warfarin; non-acetylsalicylic acid, non-cyclooxygenase-2 nonsteroidal anti-inflammatory drugs; anticholinergics; and benzodiazepines. The most prevalent patient characteristics included polypharmacy, multiple chronic medical problems, prior ADR, and dementia. CONCLUSIONS An expert panel was able to reach a consensus on potential risk factors that increase the risk for ADRs in older outpatients. Many risk factors were common in a sample of older outpatients. Future research is needed to determine the predictive validity of these risk factors for ADRs in older outpatients.

Unnecessary Drug Use in Frail Older People at Hospital Discharge

Objectives: To determine the prevalence and predictors of unnecessary drug use at hospital discharge in frail elderly patients.

Inappropriate Medication Use Among Frail Elderly Inpatients

BACKGROUND: Inappropriate prescribing in frail elderly inpatients has not received as much investigation as in frail elderly nursing home patients. OBJECTIVE: To determine the prevalence and predictors of inappropriate prescribing for hospitalized frail elderly patients. METHODS: The study was conducted at 11 Veterans Affairs Medical Centers and involved a sample of 397 frail elderly inpatients. Inappropriate prescribing was measured by physician—pharmacist pairs consensus ratings for 10 criteria on the Medication Appropriateness Index (MAI). The MAI ratings generated a weighted score of 0–18 per medication (higher score = more inappropriate) and were summed across medications to achieve a patient score. RESULTS: Overall, 365 (91.9%) patients had ≥1 medications with ≥1 MAI criteria rated as inappropriate. The most common problems involved expensive drugs (70.0%), impractical directions (55.2%), and incorrect dosages (50.9%). The most common drug classes with appropriateness problems were gastric (50.6%), cardiovascular (47.6%), and central nervous system (23.9%). The mean ± SD MAI score per person was 8.9 ± 7.6. Stepwise ordinal logistic regression analyses revealed that both the number of prescription (adjusted OR 1.28; 95% CI 1.21 to 1.36) and nonprescription drugs (adjusted OR 1.17; 95% CI 1.06 to 1.29) were related to higher MAI scores. Analyses excluding the number of drugs revealed that the Charlson index (adjusted OR 1.62; 95% CI 1.12 to 2.35) and fair/poor self-rated health (adjusted OR 1.15; 95% CI 1.05 to 1.26) were related to higher MAI scores. CONCLUSIONS: Inappropriate drug prescribing is common for frail elderly veteran inpatients and is related to polypharmacy and specific health status characteristics.

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.

Number and Dosage of Central Nervous System Medications on Recurrent Falls in Community Elders: The Health, Aging and Body Composition Study

BACKGROUND Few studies have examined the risk of multiple or high doses of combined central nervous system (CNS) medication use for recurrent falls in the elderly. The study objective was to evaluate whether multiple- or high-dose CNS medication use in older adults was associated with a higher risk of recurrent (>or=2) falls. METHODS This longitudinal cohort study included 3,055 participants from the Health, Aging and Body Composition study who were well functioning at baseline. CNS medication use (benzodiazepine and opioid receptor agonists, antipsychotics, antidepressants) was determined annually (except Year 4) during in-person interviews. The number and summated standard daily doses (SDDs; low, medium, and high) of CNS medications were computed. Falls 1 year later were ascertained annually for 5 years. RESULTS For a period of 5 years, as many as 24.1% of CNS medication users took 2+ agents annually, whereas as no more than 18.9% of CNS medication users took high doses annually (3+ SDDs). Yearly, as many as 9.7% of participants reported recurrent falls. Multivariable Generalized Estimating Equation analyses showed that multiple CNS medication users compared with never users had an increased risk of sustaining 2+ falls (adjusted odds ratio [OR] 1.95; 95% confidence interval [CI] 1.35-2.81). Those taking high (3+) CNS SDDs also exhibited an increased risk of 2+ falls (adjusted OR 2.89; 95% CI 1.96-4.25). CONCLUSIONS Higher total daily doses of CNS medications were associated with recurrent falls. Further studies are needed to determine the impact of reducing the number of CNS medications and/or dosage on recurrent falls.

Clinically important drug-disease interactions and their prevalence in older adults

BACKGROUND Older adults may have decreased homeostatic reserve, have multiple chronic diseases, and take multiple medications. Therefore, they are at risk for adverse outcomes after receiving a drug that exacerbates a chronic disease. OBJECTIVES The aims of this study were to compile a list of clinically important drug-disease interactions in older adults, obtain the consensus of a multidisciplinary panel of geriatric health care professionals on these interactions, and determine the prevalence of these interactions in a sample of outpatients. METHODS This analysis included a 2-round modified Delphi survey and cross-sectional study. Possible drug-disease interactions in patients aged > or =65 years were identified through a search of the English-language literature indexed on MEDLINE and International Pharmaceutical Abstracts (1966-July 2004) using terms that included drug-disease interaction, medication errors, and inappropriate prescribing. Nine health care professionals with expertise in geriatrics (2 geriatricians, 7 geriatric clinical pharmacist specialists) were selected based on specialty training and continuing clinical work in geriatrics, academic appointments, and geographic location. The panel rated the importance of the potential drug-disease interactions using a 5-point Likert scale (from 1 = definitely not serious to 5 = definitely serious). Consensus on a drug-disease interaction was defined as a lower bound of the 95% CI > or =4.0. The prevalence of drug-disease interactions was determined by applying the consensus criteria to a convenience sample of frail older veterans at hospital discharge who were enrolled in a health services intervention trial. RESULTS The panel reached consensus on 28 individual drug-disease interactions involving 14 diseases or conditions. Overall, 205 (15.3%) of the 1340 veterans in the sample had > or =1 drug-disease interaction. The 2 most common drug-disease interactions were use of first-generation calcium channel blockers in patients with congestive heart failure and use of aspirin in patients with peptic ulcer disease (both, 3.7%). CONCLUSIONS A survey of multidisciplinary geriatric health care professionals resulted in a concise consensus list of clinically important drug-disease interactions in older adults. Further research is needed to examine the impact of these drug-disease interactions on health outcomes and their applicability as national measures for the prevention of drug-related problems.

Effect of central nervous system medication use on decline in cognition in community-dwelling older adults: Findings from the health, aging and body composition study

OBJECTIVES: To evaluate whether combined use of multiple central nervous system (CNS) medications over time is associated with cognitive change.

Epidemiology of over-the-counter drug use in community dwelling elderly: United States perspective.

Among US community dwelling individuals aged ≥65 years, about as many persons take nonprescription drugs as take prescription drugs. A review of US data from the last 2 decades indicates that the average number of over-the-counter (OTC) drugs taken daily is around 1.8, but varies with geographical area (highest in the Midwest) and race/ethnicity (lowest use among Hispanics, followed by African Americans, and highest use among Whites). Use has consistently been found to be higher in women than in men. While OTC use appears to be increasing over time, it also decreases with increase in age. The most common OTC classes used are analgesics, laxatives and nutritional supplements. Our ability to explain or to predict OTC use and change in use is poor, and further studies, particularly on use by elderly individuals of minority races, are needed.

Potential Drug—Disease Interactions in Frail, Hospitalized Elderly Veterans

BACKGROUND: Drugs can improve quality of life for many older people, but they may cause adverse health outcomes (eg, drug—disease interactions) if used inappropriately. OBJECTIVE: To determine the prevalence of potential drug—disease interactions as defined by explicit criteria and examine associations between sociodemographic and health status variables and potential drug—disease interactions. METHODS: The study design was cross-sectional. We evaluated 397 frail elderly inpatients from the Geriatric Evaluation and Management trial conducted at 11 Veterans Affairs Medical Centers. Drug—disease interactions were defined using explicit criteria from consensus expert panels of geriatricians from the US and Canada. RESULTS: Overall, 159 (40.1%) patients had one or more potential drug—disease interaction. The most common potential interactions were calcium-channel blockers and heart failure (12.3%) and β-blockers and diabetes (6.8%). Multivariable logistic regression analyses revealed that age ⩾75 years (adjusted OR 2.43; 95% CI 1.52 to 3.88), being married (adjusted OR 1.77; 95% CI 1.11 to 2.82), comorbidity index defined by Charlson method (adjusted OR 1.19; 95% CI 1.05 to 1.34), and use of multiple prescription drugs (5–8: adjusted OR 4.17; 95% CI 1.96 to 8.88, ⩾9: adjusted OR 9.22; 95% CI 4.26 to 19.95), were significantly (p < 0.05) associated with having one or more potential drug—disease interaction. CONCLUSIONS: Potential drug—disease interactions are common in hospitalized elderly patients and are related to specific sociodemographic and health status factors. Further research is needed to examine the relationship between health outcomes and drug—disease interactions.