Catherine I. Lindblad

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.

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.

Update on drug-related problems in the elderly

BACKGROUND Although pharmacotherapy for the elderly can treat diseases and improve well-being, its benefits can be compromised by drug-related problems. OBJECTIVE This article reviews recent publications concerning drug-related problems in the elderly, as well as articles describing the development of 3 sets of quality indicators for medication use in the elderly. METHODS Relevant articles were identified through a search of MEDLINE (2002-March 2003) for articles on drug-related problems, inappropriate prescribing, and adverse drug events in the elderly. RESULTS The review included 7 articles published in 2002 and 2003. A study in ambulatory elderly persons reported that approximately 5.0% of patients had > or =1 adverse drug event within the previous year. Another study found that approximately 20.0% of ambulatory elderly persons used > or =1 inappropriate drug, as defined by drug utilization review (DUR) criteria, with drug-disease interactions and duration of use being the most common drug-related problems. A third study involving elderly individuals in assisted living facilities found that 16.0% used > or =1 inappropriate drug, as defined by the Beers criteria. Another study examined whether inappropriate drug use, as defined by the Beers or DUR criteria, was associated with death or a decline in functional status; it found that only use of drugs defined as inappropriate by DUR criteria (particularly those drugs associated with drug-drug or drug-disease interactions) was associated with a decline in the ability to perform basic self-care. Three studies, 1 from the United States, 1 from the United Kingdom, and 1 from Canada, described consensus development of quality indicators for drug use in the elderly, including drugs to avoid, maximum daily dose, drug duplication, limits on duration of use, drug-drug and drug-disease interactions, need for drug monitoring, underuse of necessary drugs to treat or prevent common problems, and inappropriate drug-administration technique. CONCLUSIONS Drug-related problems are common in elderly patients. Data from recently published studies provide guidance to practitioners and directions for future research.

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.

Therapeutic Failure-Related Hospitalisations in the Frail Elderly

Background and objectiveAlthough therapeutic failure may be a common cause of drug-related morbidity in older adults, few studies have focused on this problem. The study objective was to determine the frequency and types of, and the factors associated with, therapeutic failure leading to hospitalisation in frail, elderly patients, using a new instrument named the Therapeutic Failure Questionnaire (TFQ).MethodsThe sample included 106 frail, hospitalised elderly patients enrolled in a 1-year-long health service intervention trial at 11 Veterans Affairs Medical Centres. The TFQ was developed by a team of clinicial geriatricians and tested for reliability by two clinical pharmacists and a geriatrician on a sample of 32 patients. To establish validity, a geriatrician retrospectively reviewed the computerised medication records and clinical charts for these patients and applied the TFQ to determine probable therapeutic failures at the time of hospital admission.ResultsInter- and intra-rater reliability for the TFQ were very good = 0.82 for both). Overall, 11% of patients had one or more probable therapeutic failures (TFQ scores between 4 and 7) leading to hospitalisation. Cardiopulmonary disease was a common ‘indicator’ of therapeutic failure and was often the result of non-adherence. The only factor associated with therapeutic failure occurrence was severe chronic kidney disease (crude odds ratio 5.87; 95% CI 1.20, 28.69; p = 0.01).ConclusionsThe TFQ was able to identify several cases of probable therapeutic failure leading to hospitalisation in frail, elderly patients. Non-adherence to effective therapies for chronic serious cardiopulmonary disease was a common cause of therapeutic failure and represents a target for interventions to reduce hospitalisation. Further research on the occurrence, risk factors for and types of therapeutic failure is needed in a larger cohort of older non-veterans.

Antidiabetic Drug Therapy of African-American and White Community-Dwelling Elderly Over a 10-Year Period

Objectives: To determine the prevalence and predictors of antidiabetic medication use over a 10‐year period in a general population of African‐American and white community‐dwelling elderly.