Frequency, severity and risk factors for adverse drug reactions in adult out-patients: a prospective study

Adverse drug reactions as cause of hospital admissions: results from the Italian Group of Pharmacoepidemiology in the Elderly (GIFA)

OBJECTIVES

To determine the prevalence of adverse drug reaction (ADR)-related hospital admissions in an older population, to describe the most common clinical manifestations and drugs most frequently responsible for ADR-related hospital admissions, and to identify independent factors predictive of these ADRs.

DESIGN

Multicenter pharmacoepidemiology survey conducted between 1988 and 1997.

SETTING

Eighty-one academic hospitals throughout Italy.

PARTICIPANTS

Twenty-eight thousand four hundred eleven patients consecutively admitted to participating centers during the survey periods.

MEASUREMENTS

For each suspected ADR at admission, a physician, who coded description, severity, and potentially responsible drugs, completed a questionnaire.

RESULTS

Mean age +/- standard deviation of the patients was 70 +/- 16. One thousand seven hundred four ADRs were identified upon hospital admission. In 964 cases (3.4% of all admissions), ADRs were considered to be the cause of these hospital admissions. Of these, 187 ADRs were coded as severe. Gastrointestinal complaints (19%) represented the most common events, followed by metabolic and hemorrhagic complications (9%). The drugs most frequently responsible for these ADRs were diuretics, calcium channel blockers, nonsteroidal antiinflammatory drugs, and digoxin. Female sex (odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.10-1.54), alcohol use (OR = 1.39, 95% CI = 1.20-1.60), and number of drugs (OR = 1.24, 95% CI = 1.20-1.27 for each drug increase) were independent predictors of ADR-related hospital admissions. For severe ADRs, age (OR = 1.50, 95% CI = 1.01-2.23 for age 65-79 and OR = 1.53, 95% CI = 1.00-2.33 for age > or =80, respectively), comorbidity (OR = 1.12, 95% CI = 1.05-1.20 for each point in the Charlson Comorbidity Index), and number of drugs (OR = 1.18, 95% CI = 1.11-1.25 for each drug increase) were the only predisposing factors.

CONCLUSIONS

The most important determinant of risk for ADR-related hospital admissions in older patients is number of drugs being taken. When considering only severe ADRs, risk is also related to age and frailty.

Information technology and medication safety: what is the benefit?

Medication errors occur frequently and have significant clinical and financial consequences. Several types of information technologies can be used to decrease rates of medication errors. Computerized physician order entry with decision support significantly reduces serious inpatient medication error rates in adults. Other available information technologies that may prove effective for inpatients include computerized medication administration records, robots, automated pharmacy systems, bar coding, "smart" intravenous devices, and computerized discharge prescriptions and instructions. In outpatients, computerization of prescribing and patient oriented approaches such as personalized web pages and delivery of web based information may be important. Public and private mandates for information technology interventions are growing, but further development, application, evaluation, and dissemination are required.

Principles of drug therapy in older patients: rational drug prescribing

Health care providers must be aware of the issues involved in using drugs therapies in older patients because older patients are very vulnerable to the adverse effects of drugs. Although more data are needed to guide clinical decision making in prescribing drugs to older patients, some simple considerations can make drug use safer and more effective (Table 10). Careful, compassionate attention to these factors can have a profound effect on improving the quality of life, medication use, and the overall cost of health care in this vulnerable population.

Principles of perioperative pain management in older adults

The consequences of poor planning for pain management during surgery of geriatric patients not only affect the immediate well-being of the patient but also have terrible socioeconomic implications. Delays in rehabilitation, increases in hospital lengths of stay, and increased comorbidity can be expected if interventions for pain management are either inadequate or excessive without appropriate monitoring. During surgery, seniors are likely to suffer from acute and chronic pain that must be addressed aggressively in the postoperative period to ensure a rapid functional recovery. New pain scales have been developed with seniors in mind, and greater testing of older scales in elderly populations have helped to identify measures of pain more suited to frail seniors. This article is designed to help clinicians to strategically implement optimal pain management principles and techniques and, thus, help to fulfill the obligation to relieve pain and suffering in patients in the perioperative period, which will ensure the greatest chance of recovery to optimal independence for patients.

Using computerized data to identify adverse drug events in outpatients

OBJECTIVE

To evaluate the use of a computer program to identify adverse drug events (ADEs) in the ambulatory setting and to evaluate the relative contribution of four computer search methods for identifying ADEs, including diagnosis codes, allergy rules, computer event monitoring rules, and text searching.

DESIGN

Retrospective analysis of one year of data from an electronic medical record, including records for 23,064 patients with a primary care physician, of whom 15,665 actually came for care.

MEASUREMENT

Presence of an ADE; sensitivity and specificity of computer searches for ADE.

RESULTS

The computer program identified 25,056 incidents, which were associated with an estimated 864 (95 percent confidence interval [CI], 750-978) ADES. Thus, the ADE rate was 5.5 (CI, 5.2-5.9) per 100 patients coming for care. Furthermore, in 79 (CI, 68-89) ADEs, the patient required hospitalization, resulting in an estimated rate of 3.4 (CI, 2.7-4.3) admissions per 1,000 patients. The sensitivity of the search methods for identifying ADEs was estimated to be 58 (CI, 18-98) percent, and the estimated specificity was 88 (CI, 87-88) percent. The positive predictive value was 7.5 (CI, 6.5-8.5) percent, and the negative predictive value was 99.2 (CI, 95.5-99.98) percent. Compared with age and gender-matched controls with no positive screen, patients with ADEs had twice as many outpatient visits and were taking nearly three times as many drugs. Antihypertensives, ACE-inhibitors, antibiotics, and diuretics were associated with 56 (CI, 47-65) percent of ADES. Among ADEs, 23 (CI, 16-32) percent were life-threatening or serious, and 38 (CI, 29-47) percent were judged preventable.

CONCLUSION

Computerized search programs can detect ADEs, and free-text searches were especially useful. Adverse drug events were frequent, and admissions were not rare, although most hospitals today do not identify them. Thus, such detection programs demonstrate "value-added" for the electronic record and may be useful for directing and assessing the impact of quality improvement efforts.

Drug-related morbidity and mortality: updating the cost-of-illness model

OBJECTIVE

To update the 1995 estimate of $76.6 billion for the annual cost of drug-related morbidity and mortality resulting from drug-related problems (DRPs) in the ambulatory setting in the United States to reflect current treatment patterns and costs.

DESIGN

For this study, we employed the decision-analytic model developed by Johnson and Bootman. We used the model's original design and probability data, but used updated cost estimates derived from the current medical and pharmaceutical literature. Sensitivity analyses were performed on cost data and on probability estimates.

SETTING

Ambulatory care environment in the United States in the year 2000.

PATIENTS AND OTHER PARTICIPANTS

A hypothetical cohort of ambulatory patients.

MAIN OUTCOME MEASURES

Average cost of health care resources needed to manage DRPs.

RESULTS

As estimated using the decision-tree model, the mean cost for a treatment failure was $977. For a new medical problem, the mean cost was $1,105, and the cost of a combined treatment failure and resulting new medical problem was $1,488. Overall, the cost of drug-related morbidity and mortality exceeded $177.4 billion in 2000. Hospital admissions accounted for nearly 70% ($121.5 billion) of total costs, followed by long-term-care admissions, which accounted for 18% ($32.8 billion).

CONCLUSION

Since 1995, the costs associated with DRPs have more than doubled. Given the economic and medical burdens associated with DRPs, strategies for preventing drug-related morbidity and mortality are urgently needed.

Pain management in older adults: prevention and treatment

The release of guidelines in 1998 by the American Geriatrics Society on "The Management of Chronic Pain in Older Persons" was a breakthrough in helping to manage pain in this population. Already advances have fostered a need to update recommendations. This article focuses on the treatment strategies available for seniors that are likely to help to fulfill the obligation to relieve pain and suffering in patients. A review was done of the literature using Medline and other search techniques. New pain scales have been developed with seniors in mind and greater testing of older scales in elderly populations have helped to identify measures of pain more suited to frail seniors. Advances in cyclooxygenase inhibition selectivity, alternative medicine, and progress in the identification of nonopioid pain receptors and the development of products to target them are just a few of changes that have altered the way clinicians think about treating pain. The use of hospice in end-of-life palliative care is a valuable resource for clinicians managing pain at that phase in care as well. Tools are available to prevent and treat pain successfully in seniors. Educating clinicians about available assessment tools, techniques and interventions may be the biggest challenge to comforting the older adult in pain.

Drug complications in outpatients

OBJECTIVE

Outpatient drug complications have not been well studied. We sought to assess the incidence and characteristics of outpatient drug complications, identify their clinical and nonclinical correlates, and evaluate their impact on patient satisfaction.

DESIGN

Retrospective chart reviews and patient surveys.

SETTING

Eleven Boston-area ambulatory clinics.

PATIENTS

We randomly selected 2,248 outpatients, 20 to 75 years old.

MEASUREMENTS AND MAIN RESULTS

Among 2,248 patients reporting prescription drug use, 394 (18%) reported a drug complication. In contrast, chart review revealed an adverse drug event in only 64 patients (3%). In univariate analyses, significant correlates of patient-reported drug complications were number of medical problems, number of medications, renal disease, failure to explain side effects before treatment, lower medication compliance, and primary language other than English or Spanish. In multivariate analysis, independent correlates were number of medical problems (odds ratio [OR] 1.17; 95% confidence interval [95% CI] 1.05 to 1.30), failure to explain side effects (OR 1.65; 95% CI, 1.16 to 2.35), and primary language other than English or Spanish (OR 1.40; 95% CI, 1.01 to 1.95). Patient satisfaction was lower among patients who reported drug complications (P <.0001). In addition, 48% of those reporting drug complications sought medical attention and 49% experienced worry or discomfort. On chart review, 3 (5%) of the patients with an adverse drug event required hospitalization and 8 (13%) had a documented previous reaction to the causative drug.

CONCLUSIONS

Drug complications in the ambulatory setting were common, although most were not documented in the medical record. These complications increased use of the medical system and correlated with dissatisfaction with care. Our results indicate a need for better communication about potential side effects of medications, especially for patients with multiple medical problems.

Incidence and costs of adverse drug reactions during hospitalisation: computerised monitoring versus stimulated spontaneous reporting

OBJECTIVE

To implement a computer-based adverse drug reaction monitoring system and compare its results with those of stimulated spontaneous reporting, and to assess the excess lengths of stay and costs of patients with verified adverse drug reactions.

DESIGN

A prospective cohort study was used to assess the efficacy of computer-based monitoring, and case-matching was used to assess excess length of stay and costs.

SETTING

This was a study of all patients admitted to a medical ward of a university hospital in Germany between June and December 1997.

PATIENTS AND PARTICIPANTS

379 patients were included, most of whom had infectious, gastrointestinal or liver diseases, or sleep apnoea syndrome. Patients admitted because of adverse drug reactions were excluded.

METHODS

All automatically generated laboratory signals and reports were evaluated by a team consisting of a clinical pharmacologist, a clinician and a pharmacist for their likelihood of being an adverse drug reaction. They were classified by severity and causality. For verified adverse drug reactions, control patients with similar primary diagnosis, age, gender and time of admission but without adverse drug reactions were matched to the cases in order to assess the excess length of hospitalisation caused by an adverse drug reaction.

RESULTS

Adverse drug reactions were detected in 12% of patients by the computer-based monitoring system and stimulated spontaneous reporting together (46 adverse reactions in 45 patients) during 1718 treatment days. Computer-based monitoring identified adverse drug reactions in 34 cases, and stimulated spontaneous reporting in 17 cases. Only 5 adverse drug reactions were detected by both methods. The relative sensitivity of computer-based monitoring was 74% (relative specificity 75%), and that of stimulated spontaneous reporting was 37% (relative specificity 98%). All 3 serious adverse drug reactions were detected by computer-based monitoring, but only 2 out of the 3 were detected by stimulated spontaneous reporting. The percentage of automatically generated laboratory signals associated with an adverse drug reaction (positive predictive value) was 13%. The mean excess length of stay was 3.5 days per adverse drug reaction. 48% of adverse reactions were predictable and detected solely by computer-based monitoring. Therefore, the potential for savings on this ward from the introduction of computer-based monitoring can be calculated as EUR56 200/year ($US59 600/year) [ 1999 values].

CONCLUSION

Computer monitoring is an effective method for improving the detection of adverse drug reactions in inpatients. The excess length of stay and costs caused by adverse drug reactions are substantial and might be considerably reduced by earlier detection.

Adverse drug events in elderly patients receiving home health services following hospital discharge

OBJECTIVE

To assess incidence, healthcare consequences, and identify risk factors for adverse drug events (ADEs) in elderly patients receiving home health services during the month following hospital discharge.

METHOD

This was a prospective cohort study of three home health agencies in Madison, Wisconsin, and its surrounding area. The sample consisted of 256 participants aged > or =65 years who were hospitalized for medical illness, received home nursing after discharge, and completed the one-month interview. The main outcome measure was self-reported ADEs (possible, probable, or definite) during the month following hospital discharge.

RESULTS

Incidence of ADEs was 20%. Fifty-two participants (20.3%) reported 64 ADEs: 23 possible, 37 probable, and four definite. The most common ADEs involved the gastrointestinal tract (31.3%) and the central nervous system (31.3%). Of 53 ADEs reported to providers, 59% of the drugs were discontinued or altered. One ADE resulted in hospitalization. In logistic regression, female gender (OR = 2.26; 95% CI 1.06 to 4.77) and the interaction between number of new medications and cognition were significantly associated with ADEs. The risk of an event increased with the number of new medications at discharge; however, risk was elevated primarily for participants with lower cognition.

CONCLUSIONS

ADEs were common during the month following hospital discharge, were more frequent in women, and often resulted in medication changes. Individuals at particular risk were those with lower cognition who were discharged with several new medications.

Epidemiology of adverse drug reactions in the elderly by drug class

As the growth of the elderly population continues, the burden on the health care system and society will also increase. Since chronic diseases such as hypertension, coronary artery disease, arthritis, stroke, cancer and diabetes mellitus are more prevalent with age, the number of people with multiple chronic diseases will also increase. These patients are likely to be treated for some or all of their conditions with drug therapies. When used appropriately, drugs may be the single most important intervention in the care of an older patient, but when used inappropriately they no longer provide therapeutic benefit, and they may even endanger the health of an older patient by causing an adverse drug reaction (ADR). Factors believed to be responsible for increased adverse reactions in elderly patients are polypharmacy (including prescription and over-the-counter medications), increased drug-drug interaction, pharmacokinetic changes, pharmacodynamic changes, the pathology of aging and compliance. The exact role that age plays in ADRs is not clear. This is in part because few older patients are included in the large randomised trials, and so much of the information used to ascertain the age-associated risks of drugs comes from observational studies. Although the interactions of aging, concurrent comorbidities and polypharmacy are known, older patients do appear to be at increased risk. Improvements in the management of drug therapies of older patients can lead to improvements in their overall health, functioning and safety, as well as providing potential benefits to society by ameliorating some of the burden of their health care.

Drug-related hospitalization at a tertiary teaching center in Lebanon: incidence, associations, and relation to self-medicating behavior

OBJECTIVE

In Lebanon there is very limited restriction on drug use. Accordingly, self-medication is highly prevalent. This study examined the influence of these factors on the development of drug-related illnesses that lead to hospitalization.

METHODS

Patients admitted to the medical and pediatric wards of a tertiary teaching center in Beirut, Lebanon, over a period of 6 months were interviewed and their charts were reviewed. Admissions attributable to adverse drug reactions or therapeutic failures were identified and characterized with respect to demographic factors, medical history, drug intake, and self-medicating behavior. The influence of these variables on the development of drug-related illnesses was examined by logistic regression.

RESULTS

Of 1745 adults and 457 children, there were 177 (10.2%) and 36 (7.9%) drug-related illnesses, respectively. Adverse drug reactions accounted for 7.0% and 5.7% and therapeutic failures for 3.2% and 2.2% of adult and pediatric admissions, respectively. Self-medication was commonly practiced (52.6% of adults and 41.6% of children). Logistic regression analysis revealed that female sex increased the risk of adverse drug reaction in adults, whereas self-medication decreased the risk. In children, the risk of adverse drug reaction was increased in lower socioeconomic groups, whereas the risk of therapeutic failure was increased by a positive history of atopy or drug reaction.

CONCLUSIONS

These results provide the first detailed analysis of the problem of drug-related illnesses in a developing country and identify a number of related or risk factors. Despite the lack of regulation of drug dispensing and the unchecked access to drugs in Lebanon, the incidence of drug-related illnesses is not different from that in Western nations. This finding may have relevance to policies of drug regulation in other countries.

The aging liver. Drug clearance and an oxygen diffusion barrier hypothesis

A change in drug clearance with age is considered an important factor in determining the high prevalence of adverse drug reactions associated with prescribing medications for the elderly. Despite this, no general principles have been available to guide drug administration in the elderly, although a substantial body of clearance and metabolism data has been generated in humans and experimental animals. A review of age-related change in drug clearances established that patterns of change are not simply explained in terms of hepatic blood flow, hepatic mass and protein binding changes. In particular, the maintained clearance of drugs subject to conjugation processes while oxygen-dependent metabolism declines, and all in vitro tests of enzyme function have been normal, requires new explanations. Reduction in hepatic oxygen diffusion as part of a general change in hepatocyte surface membrane permeability and conformation does provide one explanation for the paradoxical patterns of drug metabolism, and increased hepatocyte volume would also modify oxygen diffusion path lengths (the 'oxygen diffusion barrier' hypothesis). The reduction in clearances of high extraction drugs does correlate with observed reduction in hepatic perfusion. Dosage guidelines emerge from these considerations. The dosage of high clearance drugs should be reduced by approximately 40% in the elderly while the dosage of low clearance drugs should be reduced by approximately 30%, unless the compound is principally subject to conjugation mechanisms. If the hepatocyte diffusion barrier hypothesis is substantiated, this concept may lead to therapeutic (preventative and/or restorative) approaches to increased hepatocyte oxygenation in the elderly. This may lead to approaches for modification of the aging process in the liver.

Iatrogenic illness. An overview with particular reference to neurologic complications

Neurologic illness relating to health care delivery has been increasingly described since the 1960's, primarily in the general medical literature. Iatrogenic neurologic complications have either been defined generically in terms of consequences of particular therapeutic or diagnostic approaches, or have been delineated with reference to more specific and serious complications such as intracerebral hemorrhage. In these reports, little attempt has been made to situate iatrogenic neurologic complications, either historically or conceptually, within the larger framework of medically related harms. Moreover, in this literature, few suggestions have been provided with regard to strategies to reduce such complications. The objective of the present review is to place the problem of iatrogenic neurologic complications within a larger historical and conceptual framework, as well as to provide suggestions for limiting such injuries.

Adverse cutaneous reactions to psychotropic drugs

Psychotropic drugs are frequently used in both psychiatric and general medical practice. Familiarity with common side effects and their management may assist psychiatrists in the selection of agents to suit individual patient needs. The authors describe the morphologic features and pathologic basis of cutaneous reactions to drugs and discuss the common and reported cutaneous side effects of psychotropic drugs. Although most dermatologic reactions to drugs follow a benign course after drug discontinuation, more serious effects are known to occur with certain agents. An overview of the diagnosis and management of these adverse drug reactions is provided.

Adverse drug events in high risk older outpatients

OBJECTIVE

To describe the prevalence, types, and consequences of adverse drug events (ADEs) in older outpatients with polypharmacy.

DESIGN

A cohort study.

SETTING

General Medicine Clinic at the Durham Veterans Affairs Medical Center.

PATIENTS

A total of 167 high risk (taking > or = 5 scheduled medications) ambulatory older veterans who participated in a year long health service intervention trial.

MEASUREMENTS

Potential ADEs were identified by asking patients during closeout interviews whether, in the past year, they had experienced any side effects, unwanted reactions, or other problems from any medication. All reported medications and corresponding adverse experiences were assessed for plausibility by a research clinical pharmacist using two standard pharmacological textbooks and categorized by predictability, therapeutic class, and organ system.

RESULTS

Eighty self-reported ADEs involving 72 medications taken by 58 (35%) of 167 patients were textbook confirmed. Seventy-six of 80 (95%) ADEs were classified as Type A (predictable) reactions. Cardiovascular (33.3%) and central nervous system (27.8%) medication classes were most commonly implicated. Gastrointestinal (30%) and central nervous system (28.8%) ADE symptoms were common. Sixty-three percent of patients with ADEs required physician contacts, 10% emergency room visits, and 11% hospitalization. Twenty percent of medications implicated with ADEs required dosage adjustments, and 48% of ADE-related medications were discontinued. No significant differences (P > .05) were observed when ADE reporters (n = 58) and nonreporters (n = 109) were compared.

CONCLUSION

Predictable ADEs are common in high risk older outpatients, resulting in considerable medication modification and substantial healthcare utilization.

Drug-induced delirium. Incidence, management and prevention

Drugs may be the most frequent single cause of delirium, and very often they are a critical element in a multifactorial aetiology. While delirium may be precipitated by virtually any drug, certain classes of drugs are more commonly implicated. Effective management of drug-induced delirium involves recognition, cessation or dosage reduction of the causative drug(s), and initiation of reorientation strategies and supportive medical care. Specific "antidotes' are appropriate in only a few limited cases. Drug treatment aimed at sedation should be introduced for specific indications, such as aggression, risk of harm to self or others, hallucinations, patient distress, and where compliance with therapy or procedures is essential. Certain benzodiazepines (diazepam, lorazepam, midazolam) and/or haloperidol may be the most appropriate choices in these circumstances. Primary prevention requires the prescription of alternative lower risk medications and the minimisation of polypharmacy. Secondary prevention may be achieved through improved recognition of the condition.

Interactions between alcohol and other drugs

More than 75% of people age 65 and older use medications. Of the drugs most commonly used by older people, many have potential to interact adversely with alcohol. The absorption, distribution, metabolism, and effects of drugs or alcohol may be affected. The major adverse clinical outcomes of drug-alcohol interactions are altered blood levels of the medication or of alcohol, liver toxicity, gastrointestinal inflammation and bleeding, sedation and delirium, disulfiram-like reactions, and interference with the desired effect of medications. Since alcohol is commonly used by elderly people, educating patients about the potential for these interactions should be a routine part of health care visits.

Potential for adverse drug-alcohol interactions among retirement community residents

OBJECTIVES

Medications and alcohol are both used commonly by older people. Thus, the potential for adverse drug-alcohol interactions is very high in this population, but data on actual concurrent use of alcohol and medicines likely to interact with alcohol are lacking. The objectives of this study were to determine the frequency of alcohol and medication use and the potential for specific adverse drug-alcohol interactions in residents of retirement communities.

DESIGN

Cross-sectional study using a mailed survey.

SETTING

Three retirement communities in suburban Milwaukee, Wisconsin.

PARTICIPANTS

All 454 independently living residents of the communities were surveyed. Of these, 311 residents (68%) returned completed questionnaires. Mean age of respondents was 83 +/- 6 years, 100% were white, 77% were female.

MEASUREMENTS

The questionnaire included alcohol use questions adapted from the Khavari questionnaire and the CAGE questionnaire to screen for alcohol abuse. Respondents were asked to list all prescription and nonprescription medications.

RESULTS

Thirty-eight percent of the population reported using both alcohol and a high risk medication. Six percent had seven or more drinks per week and took a high risk medication. High risk drugs commonly used by drinkers were antihypertensives in 50%, aspirin in 27%, nonsteroidal anti-inflammatory drugs in 20%, medication for congestive heart failure in 18%, antacids or H2 blockers in 16%, sedatives in 11%, narcotics in 5%, and warfarin in 5%.

CONCLUSIONS

Concurrent use of alcohol and medications is common in residents of these retirement communities. Many of the drugs taken by regular drinkers have potential for adverse drug-alcohol interactions even at moderate levels of alcohol use. This represents a strong possibility of adverse outcomes and a need for increased awareness on the part of both the public and physicians of the potential for interactions between drugs and alcohol.

Screening an elderly population for verifiable adverse drug reactions. Methodological approach and initial data of the Berlin Aging Study (BASE)

Older adults are known to carry the largest risk for potential adverse drug reactions (ADR) due to the increased number of diseases and concurrent drug therapies. Prevalence rates of the most frequently used drugs in this population have already been evaluated, but the actual rates of specific drug-related risks (e.g., renal dysfunction) have not. Precise estimates of specific ADR risks rely on careful evaluation of the complete drug regimen for potential adverse effects, especially for elderly subjects. In addition, evaluations of manifest ADR have generally been based on reviews of individual medical records of self-reported symptoms. Systematic screening of a representative sample of elders for verifiable potential ADR has not been performed to date and is methodologically challenging. However, the present study attempts to assess both the prevalence of explicitly defined risks for known ADR and the corresponding co-occurrence of laboratory parameter alterations using a new approach. Initial findings are reported for a nearly-representative, age and sex stratified sample of 70 to 100+ year old subjects (n = 336) who participated in the Berlin Aging Study (BASE). Analyses focused on adverse drug effects on fluid and electrolyte balance and renal function. The results indicated an overall prevalence rate of 50% for selected ADR risks and a rate of 26% for the co-occurrence of corresponding laboratory alterations. By taking age into account, preliminary multivariate analyses did not support the hypothesis of increasing ADR susceptibility with advancing age.

Is the public being protected? Prevention of suboptimal medical practice through training programs and credentialing examinations

Governments have traditionally looked to the medical profession for leadership in health planning and have charged the profession with the responsibility of establishing and monitoring standards of medical practice. Training program accreditation and licensure/certification exams have been used as the primary methods of preventing unqualified individuals from entering medical practice. Despite the critical nature of the decision made at the time of licensure/certification, there is no information about the validity of these examinations for predicting subsequent practice and health outcome. In this article, the assumptions implicit in the current use of licensing/certifying examinations are identified, the relevant evidence is reviewed, and the implications of this evidence for current methods of measurement are discussed.

Medication use by the elderly

Medication use is correlated with the age-associated onset of chronic diseases for which drug therapy offers symptomatic relief, and assists in preventing the onset of disabling and life-threatening complications. However, high rates of medication use by older people raise a number of issues, ranging from concerns with rising expenditures for individuals and third-party insurers; increased risk of adverse drug reactions; toxic or interaction effects from concomitant use of multiple pharmaceutical agents, both physician and self-prescribed; and poor compliance with complex medication regimens by the more physically and mentally impaired. Although existing data do not support the theory of age as an independent predictor of drug-specific adverse reactions, older people have typically been excluded from clinical trials in the dynamic and changing field of pharmacotherapy. Furthermore, ingestion of a greater number of different agents clearly exposes individuals to higher risk of adverse reactions and interactions. Recent advances in information technology have facilitated multicenter clinical trials and post-marketing epidemiological surveillance studies of specific and concomitant medication use by individuals of all ages. The employment of such technology by insurers to determine appropriate prescribing or to control costs in the present limited state of knowledge is, however, premature. Furthermore, such techniques will not replace the need for careful clinical review of symptoms and total drug therapy by prescribing physicians, with modification of regimens and provision of appropriate information and instructions to older individuals and their caregivers.

Is age an independent risk factor of adverse drug reactions in hospitalized medical patients?

OBJECTIVE

To study the incidence and the risk factors of adverse drug reactions.

DESIGN

Multicenter survey.

SETTING

Hospitalized care: 22 internal medicine and 19 geriatric wards.

PATIENTS

All patients (n = 9,148) consecutively admitted during two observation periods of 2 months.

MAIN OUTCOME MEASURE

Incidence of adverse drug reactions.

RESULTS

The mean age was 67.1 +/- 0.17 years (median 72); the mean duration of hospital stay was 18.1 +/- 0.19 days (median 14). Each patient was administered 5.1 +/- 0.03 (median 5) drug prescriptions. The incidence of probable or definite adverse drug reactions was 5.8% (532/9,148). In univariate analysis, the incidence of adverse drug reactions increased from 3.3% at under age 50 to 6.5% at age 70-79 and decreased over age 80 (5.8%). In multivariate logistic regression, taking more than four drugs (OR = 2.94, CI = 2.38-3.62), staying in hospital more than 14 days (OR = 2.82, CI = 2.26-3.52), having more than 4 active medical problems (OR = 1.78, CI = 1.29-2.45), staying in a medical ward instead of geriatric ward (OR = 1.33, CI = 1.09-1.63), and drinking alcohol (OR = 1.28, CI = 1.03-1.58) were positively correlated with adverse drug reactions occurrence (P less than 0.05). Age, gender, and smoking cigarettes were not significant predictors of adverse drug reactions.

CONCLUSION

Age is not an independent risk factor of adverse drug reactions, and good geriatric care can reduce the incidence of adverse drug reactions.

Old age--is it a risk for adverse drug reactions?

Pharmacotherapy is often the single most important medical intervention in the care of the elderly. However, there are obvious concerns about the vulnerability of this group to adverse drug reactions (ADRs). A rapidly accumulating literature regarding changes in pharmacokinetics and pharmacodynamics with advancing age suggests a strong pharmacologic basis for such concerns. Yet, the results of epidemiologic studies exploring the relationship between age and ADRs are ambiguous. Interpretation of the results of these studies is limited by inconsistent definitions of outcomes of interest and failure to control for important age-related covariates including the clinical status of the patient and the number of medications that a patient is receiving. Some recent studies have investigated age-related aspects of specific adverse consequences of drug therapy. For example, age, in and of itself, does not appear to be a risk factor for bleeding complications of warfarin therapy. Older patients may actually be at less risk than younger patients to experience depression associated with beta-blocker therapy. Although examination of data from premarketing studies might be considered a promising strategy to explore the relationship between age and ADR risk, the small number of truly elderly subjects included in these studies greatly limits their usefulness. Postmarketing studies utilizing databases containing clinical data for large numbers of older patients may provide the optimal approach for investigating whether old age is an independent risk factor for ADRs.

'Healthy' prescribing for the elderly. How to minimize adverse drug effects and prevent 'dementia in a bottle'

Despite constituting only 11% to 12% of the US population, the elderly use 31% of all prescription and over-the-counter drugs and, unfortunately, are most vulnerable to the adverse effects of drug therapy. Because of age-related physiologic changes and the likelihood of intercurrent disease, elderly patients need individualized prescribing. This requires the practitioner to be familiar with a few drugs in each class that are tolerated by and effective in elderly patients and to adhere to the principles of healthy prescribing, which have application in any setting. In conclusion, the words of Paracelsus (1493-1541) are worth recalling: "All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy."