Fatal upper gastrointestinal hemorrhage or perforation among users and nonusers of nonsteroidal anti-inflammatory drugs in Saskatchewan, Canada 1983

Assessing agreement between population-level administrative pharmaceutical databases and patient-reported medication dispensation in cardiac rehabilitation patients

BACKGROUND

Pharmacoepidemiology has emerged as a crucial field in evaluating the use and effects of medications in large populations to ensure their safe and effective use. This study aimed to assess the agreement of cardiac medication use between a provincial medication database, the Pharmaceutical Information Network (PIN), and reconciled medication data from confirmation through patient interviews for patients referred to cardiac rehabilitation.

METHODS

The study included data from patients referred to the TotalCardiology Rehabilitation CR program, and medication data was available in both TotalCardiology Rehabilitation charts and PIN. The accuracy of medication data obtained from patient interviews was compared to that obtained from PIN with proportions and kappa statistics to evaluate the reliability of PIN data in assessing medication use.

RESULTS

Patient-reported usage was higher for statins (41.6 %) vs. 38.4 %), ACE/ARB, beta-blockers (75.7 %) vs. 73.7 %), DOAC (3.5 %) vs. 2.6 %), and ADP-receptor antagonists (71.0 %) vs. 68.1 %) than if PIN was used. Patient-reported usage data was lower for Ezetimibe (4.7 vs. 4.8 %), Aldosterone antagonists (5.4 %) vs. 5.5 %), digoxin (0.9 %) vs. 1.0 %), calcium channel blockers (19.2 vs. 19.9 %) and warfarin (7.2 %) vs. 8.1 %). The results indicated that the differences between the two sources were very small, with an average agreement of 95.3 % and a kappa of 0.70.

CONCLUSION

The study's results, which show a high level of agreement between PIN and patient self-reporting, affirm the reliability of PIN data as a source for obtaining an accurate assessment of medication use. This finding is crucial in the context of pharmacoepidemiology research, where the accuracy of data is paramount. Further research to explore the complementary use of both data sources will be valuable.

A Prospective Evaluation of Shared Decision-making Regarding Analgesics Selection for Older Emergency Department Patients With Acute Musculoskeletal Pain

OBJECTIVES

Musculoskeletal pain is a common reason for emergency department (ED) visit by older adults. Outpatient pain management following ED visits in this population is challenging as a result of contraindications to, and side effects from, available therapies. Shared decision-making (SDM) between patients and emergency physicians may improve patient experiences and health outcomes. Among older ED patients with acute musculoskeletal pain, we sought to characterize their desire for involvement in the selection of outpatient analgesics. We also sought to assess the impact of SDM on change in pain at 1 week, patient satisfaction, and side effects.

METHODS

This was a prospective study of adults aged 60 years and older presenting to the ED with acute musculoskeletal pain. Participants' desire to contribute to outpatient analgesic selection was assessed by phone within 24 hours of ED discharge using the Control Preferences Scale and categorized as active, collaborative, or passive. The extent to which SDM occurred in the ED was also assessed within 24 hours of discharge using the 9-item Shared Decision Making Questionnaire, and scores were subsequently grouped into tertiles of low, middle, and high SDM. The primary outcome was change in pain severity between the ED visit and 1 week. Secondary outcomes included satisfaction regarding the decision about how to treat pain at home, satisfaction with the pain medication itself, and side effects.

RESULTS

Desire of participants (N = 94) to contribute to the decision regarding selection of outpatient analgesics varied: 16% active (i.e., make the final decision themselves), 37% collaborative (i.e., share decision with provider), and 47% passive (i.e., let the doctor make the final decision). The percentage of patients who desired an active role in the decision was higher for patients who were college educated versus those who were not college educated (28% vs. 11%; difference 17%, 95% confidence interval [CI] = 0% to 35%), received care from a nurse practitioner versus a resident or an attending physician (32% vs. 9%; difference 23%, 95% CI = 4% to 42%), or received care from a female versus a male provider (24% vs. 5%; difference 19%, 95% = CI 5% to 32%). After potential confounders were adjusted for, the mean decrease in pain severity from the ED visit to 1-week follow-up was not significantly different across tertiles of SDM (p = 0.06). Higher SDM scores were associated with greater satisfaction with the discharge pain medications (p = 0.006). SDM was not associated with the class of analgesic received.

CONCLUSIONS

In this sample of older adults with acute musculoskeletal pain, the reported desire of patients to contribute to decisions regarding analgesics varied based on both patient and provider characteristics. SDM was not significantly related to pain reduction in the first week or type of pain medication received, but was associated with greater patient satisfaction.

A secure distributed logistic regression protocol for the detection of rare adverse drug events

Background

There is limited capacity to assess the comparative risks of medications after they enter the market. For rare adverse events, the pooling of data from multiple sources is necessary to have the power and sufficient population heterogeneity to detect differences in safety and effectiveness in genetic, ethnic and clinically defined subpopulations. However, combining datasets from different data custodians or jurisdictions to perform an analysis on the pooled data creates significant privacy concerns that would need to be addressed. Existing protocols for addressing these concerns can result in reduced analysis accuracy and can allow sensitive information to leak.

Objective

To develop a secure distributed multi-party computation protocol for logistic regression that provides strong privacy guarantees.

Methods

We developed a secure distributed logistic regression protocol using a single analysis center with multiple sites providing data. A theoretical security analysis demonstrates that the protocol is robust to plausible collusion attacks and does not allow the parties to gain new information from the data that are exchanged among them. The computational performance and accuracy of the protocol were evaluated on simulated datasets.

Results

The computational performance scales linearly as the dataset sizes increase. The addition of sites results in an exponential growth in computation time. However, for up to five sites, the time is still short and would not affect practical applications. The model parameters are the same as the results on pooled raw data analyzed in SAS, demonstrating high model accuracy.

Conclusion

The proposed protocol and prototype system would allow the development of logistic regression models in a secure manner without requiring the sharing of personal health information. This can alleviate one of the key barriers to the establishment of large-scale post-marketing surveillance programs. We extended the secure protocol to account for correlations among patients within sites through generalized estimating equations, and to accommodate other link functions by extending it to generalized linear models.

Systematic review of peptic ulcer disease incidence rates: do studies without validation provide reliable estimates?

PURPOSE

Incidence rate (IR) estimates for peptic ulcer disease (PUD) vary widely among studies. We conducted a systematic review to quantify and examine the discrepancies.

METHODS

Of 4780 articles identified from PubMed and EMBASE databases, 31 published in the last three decades that had reported IRs of PUD in the general population were included. Random effects meta-analysis and meta-regression were performed to calculate pooled estimates and to identify sources of heterogeneity.

RESULTS

The pooled IR estimate per 1000 person-years was 0.90 (95% confidence interval: 0.78-1.04) for uncomplicated PUD, 0.57 (0.49-0.65) for peptic ulcer bleeding, 0.10 (0.08-0.13) for gastrointestinal perforations, and 3.18 (2.05-4.92) for nonspecific PUD. Within specific outcomes definitions, IR estimates were significantly lower in studies with restriction to hospitalized cases, case validation, and case ascertainment directly from hospital or clinical sources versus computerized health care databases. Younger age, female sex, and later calendar time were also associated with lower PUD incidence.

CONCLUSIONS

We found that the IR of uncomplicated PUD was in the order of one case per 1000 person-years in the general population, and that the IR of peptic ulcer complications was around 0.7 cases per 1000 person-years. Comparisons of IR estimates among studies need to take into account disease definition and other study characteristics, particularly whether outcome validation was performed in computerized claims. The use of claims to identify PUD cases might overestimate the IR by around 45%.

Prescription Drug Use and Seniors

L'augmentation des dépenses de médicaments a placé les aîné(e)s sous les feux de la réforme de santé puisqu'ils en sont les plus grands consommateurs. On pourrait apporter des modifications substantielles à la consommation de médicaments presents, ce qui rehausserait les bienfaits des traitements et en minimiserait les effets négatifs, surtout chez les aîné(e)s. On documente ici un bon nombre de problèmes, notamment la surconsommation et la sous-consommation des médicaments, les erreurs d'ordonnances, la conformité au traitement et les médicaments inutilement coûteux. On a démontré l'efficacité de certaines éléments à l'égard de certains aspects du problème; qu'on cite simplement les politiques reliées au système de soins de santé, les interventions de certains médecins et de pharmaciens d'hôpitaux, les aides à la prise de dècisions et à la conformité aux traitements. Il faut mettre en place l'intégration des principales politiques et des interventions en une solution globale visant une meilleure utilisation des médicaments. Elle pourrait se composer des éléments suivants: (1) la révision des politiques de relations entre l'industrie pharmacologique et le secteur de la santé; (2) l'établissement de règlements d'expérimentation des médicaments chez les aînés avant leur approbation; (3) un institut du consommateur servant de ressource centrale objective aux demandes de renseignements des patients et de système d'appui aux décisions; (4) des systèmes intégrés d'information clinique à l'appui des systèmes de gestion des ordonnances et de la fourniture des médicaments et de la gestion des médicaments et des maladies à l'intention des pharmaciens et des médecins de premier recours; (5) une réforme de la formation médicale et de l'octroi des permis.

Hospitalizations for gastrointestinal and cardiovascular events in the CADEUS cohort of traditional or Coxib NSAID users

AIMS

To assess hospital admission rates for gastrointestinal (GI) or cardiovascular (CV) events in real-life use of nonsteroidal anti-inflammatory drugs (NSAIDs).

METHODS

CADEUS is a real-life population-based cohort study of 23 535 coxib (celecoxib or rofecoxib) and 22 919 traditional NSAID (tNSAID) users. Each hospitalization reported between index day (NSAID delivery) and questionnaire submission (median = 75 days) was explored using hospital discharge summaries. An expert committee validated blindly serious GI and CV events according to predefined criteria.

RESULTS

Coxib users were older and had more GI history than tNSAID users. There were 21 hospitalizations for GI events, 12 in the coxib cohort and nine in the tNSAID cohort (respectively one and three upper GI haemorrhages and no ulcer perforations). Rates of GI events were 0.39 per 1000 patients [95% confidence interval (CI) 0.18, 0.75] for tNSAID users and 0.51 per 1000 patients (95% CI 0.26, 0.89) for coxib users. There were 21 hospitalizations for CV events, 13 in the coxib cohort and eight in the tNSAID cohort. None was fatal. Rates of CV events were, respectively, 0.59 (95% CI 0.24, 1.22), 0.51 (95% CI 0.19, 1.11) and 0.35 (95% CI 0.15, 0.69) per 1000 patients for celecoxib, rofecoxib and tNSAIDs. GI or CV event rates were not different between products even for patients >60 years old.

CONCLUSIONS

Hospitalization rates for GI bleeding were 10-20 times lower than expected from published randomized clinical trials, probably because of differences in drug usage and concomitant gastroprotection. CV event rates conformed to those expected from general population data. These results emphasize the necessity of developing population healthcare databases to explore such low event rates.

Risks of combined alcohol/medication use in older adults

BACKGROUND

Many older adults (ie, those aged >65 years) drink alcohol and use medications that may be harmful when consumed together.

OBJECTIVE

This article reviews the literature on alcohol and medication interactions, with a focus on older adults.

METHODS

Relevant articles were identified through a search of MEDLINE and International Pharmaceutical Abstracts (1966-August 2006) for English-language articles. The following medical subject headings and key words were used: alcohol medication interactions, diseases worsened by alcohol use, and alcohol metabolism, absorption, and distribution. Additional articles were identified by a manual search of the reference lists of the identified articles, review articles, textbooks, and personal reference sources.

RESULTS

Many older adults drink alcohol and take medications that may interact negatively with alcohol. Some of these interactions are due to age-related changes in the absorption, distribution, and metabolism of alcohol an medications. Others are due to disulfiram-like reactions observed with some medications, exacerbation of therapeutic effects and adverse effects of medications when combined with alcohol, and alcohol's interference with the effectiveness of some medications.

CONCLUSIONS

Older adults who drink alcohol and who take medications are at risk for a variety of adverse consequences depending on the amount of alcohol and the type of medications consumed. It is important for clinicians to know how much alcohol their older patients are drinking to be able to effectively assess their risks and to counsel them about the safe use of alcohol and medications. Similarly, it is important for older adults to understand the potential risks of their combined alcohol and medication use to avoid the myriad of problems possible with unsafe use of these substances..

Antipsychotic use in the elderly: shifting trends and increasing costs

OBJECTIVE

The purpose of this study was to assess trends in utilization and costs of antipsychotic drugs among a population of older adults over time, with respect to the prevalence of users, shifts in prescribing patterns, and related financial implications.

DESIGN

Cross-sectional time series of quarterly and annual antipsychotic utilization and cost were obtained from administrative databases for calendar years 1993 through 2002.

SETTING AND PARTICIPANTS

A population-based study of more than 1.4 million residents of the province of Ontario aged 65 years or older.

MEASUREMENTS

Data sources used included the Ontario Drug Benefits (ODB) database and Statistics Canada census data.

RESULTS

The prevalence of antipsychotic users increased by 34.8% over the study period from 2.2% at the beginning of 1993 to 3.0% of the elderly at the end of 2002 (p < 0.01). This was associated with a 749% increase in total cost (from $3.7 million in 1993 to $31.4 million in 2002; p < 0.01). The atypical antipsychotics, which were not available in 1993, made up 82.5% of the antipsychotics dispensed and 95.2% of costs in 2002.

CONCLUSIONS

The modest increase in antipsychotic prevalence in the elderly over the last ten years has been associated with a substantial increase in cost, with a significant shift towards use of the atypical antipsychotics. As the atypical antipsychotics are increasingly used for patients with dementia, which is becoming more prevalent in the aging population, an understanding of the benefits of these medications must be balanced with a detailed understanding of the material and financial implications.

Pharmacoepidemiology and rheumatic disorders

This article reviews the application of pharmacoepidemiology in the evaluation of drugs that are used commonly for rheumatic disorders. Data sources and methodology considerations for these studies are highlighted. The topics that are covered included the safety evaluation of nonsteroidal ant-inflammatory drugs, adverse pregnancy outcomes of pharmaceutical agents, gastroduodenal safety of alendronate, long-term beneficial effects of methotrexate for rheumatoid arthritis, and drug use study.

Over-the-counter analgesics in older adults: a call for improved labelling and consumer education

The use of analgesics increases with age and on any given day 20-30% of older adults take an analgesic medication. Over-the-counter (OTC) analgesics are generally well tolerated and effective when taken for brief periods of time and at recommended dosages. However, their long-term use, use at inappropriately high doses, or use by persons with contraindications may result in adverse effects, including gastrointestinal haemorrhage, cardiovascular toxicity, renal toxicity and hepatotoxicity. Many OTC drugs are also available through a prescription, for a broader range of indications and for longer durations of use and wider dose ranges, under the assumption that healthcare providers will help patients make safe choices about analgesics. Safe and effective use of medications is one of the greatest challenges faced by healthcare providers in medicine. More than 60% of people cannot identify the active ingredient in their brand of pain reliever. Additionally, about 40% of Americans believe that OTC drugs are too weak to cause any real harm. As a result of a recent US FDA policy, the conversion of prescription to OTC medications will result in a 50% increase of OTC medications. To reduce the risks of potential adverse effects from OTC drug therapy in older adults, we propose that the use of analgesics will be enhanced through the use of patient and healthcare provider education, as well as improved labelling of OTC analgesics. Improved labelling of OTC analgesics may help consumers distinguish common analgesic ingredients in a wide variety of preparations and facilitate informed decisions concerning the use of OTC drugs.

Time dependent risk of gastrointestinal complications induced by non-steroidal anti-inflammatory drug use: a consensus statement using a meta-analytic approach

OBJECTIVES

To provide an updated document assessing the global, NSAID-specific, and time dependent risk of gastrointestinal (GI) complications through meta-analyses of high quality studies.

METHODS

An exhaustive systematic search was performed. Inclusion criteria were: RCT or controlled study, duration of 5 days at least, inactive control, assessment of minor or major NSAID adverse effects, publication range January 1985 to January 2003. The publications retrieved were assessed during a specifically dedicated WHO meeting including leading experts in all related fields. Statistics were performed conservatively. Meta-regression was performed by regressing NSAID adjusted estimates against study duration categories.

RESULTS

Among RCT data, indolic derivates provided a significantly higher risk of GI complications related to NSAID use than for non-users: RR = 2.25 (1.00; 5.08) than did other compounds: naproxen: RR = 1.83 (1.25; 2.68); diclofenac: RR = 1.73 (1.21; 2.46); piroxicam: RR = 1.66 (1.14; 2.44); tenoxicam: RR = 1.43 (0.40; 5.14); meloxicam: RR = 1.24 (0.98; 1.56), and ibuprofen: RR = 1.19 (0.93; 1.54). Indometacin users had a maximum relative risk for complication at 14 days. The other compounds presented a better profile, with a maximum risk at 50 days. Significant additional risk factors included age, dose, and underlying disease. The controlled cohort studies provided higher estimates: RR = 2.22 (1.7; 2.9). Publication bias testing was significant, towards a selective publication of deleterious effects of NSAIDs from small sized studies.

CONCLUSION

This meta-analysis characterised the "compound" and "time" aspects of the GI toxicity of non-selective NSAIDs. The risk/benefit ratio of such compounds should thus be carefully and individually evaluated at the start of long term treatment.

Épidémiologie des complications gastro-duodénales associées aux anti-inflammatoires non stéroïdiens

Nonsteroidal anti-inflammatory agents (NSAIDs) are among the most widely prescribed drugs worldwide. In France, about 25% of individuals aged 40 years or older are treated with NSAIDs at least one week in the year. Although the therapeutic benefits of these drugs are substantial, their use is limited by their gastroduodenal toxicity. Dyspepsia occurs in about 30% of patients receiving NSAIDs, an approximately two-fold enhancement of risk compared with control subjects. Asymptomatic endoscopic lesions are observed in 20 to 80% of patients, depending on population characteristics, individual NSAIDs and definitions of endoscopic lesions. The risk of symptomatic ulcer, complicated ulcer (haemorrhage, perforation, stenosis) and death related to ulcer complication is multiplied by 4 in patients treated with NSAIDs. Established risk factors for NSAID-induced gastroduodenal complications are age, ulcer history, heavy alcohol consumption, individual NSAIDs, dose, association with corticoid or aspirin or anticoagulants (ulcer haemorrhage) while the role of treatment duration and Helicobacter pylori infection are controversial.

Epidemiology of analgesic use: a gender perspective

BACKGROUND AND OBJECTIVE

Women consistently report significantly more frequent analgesic use in epidemiological studies. The aim of this study was to analyse the influence of medical and non-medical factors on the difference in use of analgesics between women and men from a population perspective.

METHODS

Cross-sectional survey. Postal questionnaires were sent to a random sample of the general population in the country of Uppland, Sweden (5404 answered the questionnaire, response rate: 68%).

RESULTS

34.8% of the women and 21.4% of the men had used analgesics during the two week recall period (Odds Ratio = 1.96). Social structure, social status, marital status, educational level, economic situation, lifestyle, attitudes toward drugs, medication knowledge and self-care orientation were of minor importance for the difference in use between women and men. Difference in prevalence of various types of pain and ache and the degree of pain experienced were the most influential factors affecting the difference in use. However, when all factors were analysed there remained a substantial difference in use between women and men (OR = 1.39, CI (95%) 1.20 to 1.60).

CONCLUSIONS

In the population, women use analgesics much more frequently than men. Consequently women may be at greater risk for adverse effects and dependency. Some of the gender difference is explained by the greater frequency of pain conditions among women, but a significant difference in use still remains to be explained.

Incidence of serious upper gastrointestinal bleeding/perforation in the general population: review of epidemiologic studies

The object of this study was to quantify the incidence of serious upper gastrointestinal complications among nonusers of nonsteroidal anti-inflammatory drugs (NSAIDs). Systematic review of epidemiologic studies published between 1980 and 2000 that provided data on the incidence of upper gastrointestinal bleeding, perforation, or other upper gastrointestinal tract event resulting in death, hospitalization, or visit to a specialist among nonusers of nonsteroidal anti-inflammatory drugs. The authors calculated summary incidence rates and analyzed heterogeneity among results according to outcome definition, population characteristics, and methodology of primary studies. Forty-one population-based studies were reviewed, and 12 were included in the final analysis. Differences in outcome definitions accounted for much of the variability in incidence rate estimates reported in original studies. The pooled incidence rate estimate among nonusers of prescription NSAIDs per 1,000 person-years was 0.1 (95% confidence interval: 0.04-0.23) for perforations alone, 0.8 (0.58-0.68) for bleeding lesions alone, 0.9 (0.66-1.27) for bleeding or perforated lesions, and 1.0 (0.83-1.15) for serious gastrointestinal ulcer (complicated or without bleeding). Rates increased with age, and were approximately twice as high in men than in women. Epidemiologic studies based on automated data may slightly under- or overestimate the true incidence rate among nonusers of NSAIDs. Overall, the incidence rate of serious upper gastrointestinal complications was in the order of 1 per 1,000 person-years among nonusers of prescription NSAIDs.

Contribution of nonsteroidal anti-inflammatory drugs to deaths associated with peptic ulcer disease: a prospective toxicological analysis of autopsy blood samples

CONTEXT

Of the side effects occurring in temporal association with the use of nonsteroidal anti-inflammatory drugs (NSAIDs), peptic ulcer disease is reported most often.

OBJECTIVES

To (1) provide information on the temporal association between fatal peptic ulcer presenting as sudden death and NSAID use prior to death, and (2) to examine the diagnostic efficiency of postmortem determination of NSAID levels using high-pressure liquid chromatography.

DESIGN

Prospective autopsy study of all cases of sudden death associated with peptic ulcer disease from a total of 1139 medicolegal autopsies performed during a 12-month period.

METHODS

Postmortem femoral blood samples were analyzed for NSAIDs using high-pressure liquid chromatography, and specimens of gastric and duodenal mucosa were examined for coexisting pathologic conditions.

RESULTS

Twelve fatalities that occurred out of hospital as a result of peptic ulcer disease and presented as sudden death were identified. Autopsy blood samples were positive for NSAIDs in 7 cases (ibuprofen in 4 cases, levels 0.8 to 1.4 microg/mL; diclofenac in 2 cases, levels 0.6 and 1.6 microg/mL; and ketoprofen in 1 case, level 0.3 microg/mL). The ages of the affected individuals (3 men, 4 women) ranged from 43 to 60 years. No other drugs, including corticosteroids, anticoagulants, salicylic acid, and salicylates, were present. Microscopic examination revealed no pathologic antemortem mucosal conditions in any of the cases.

CONCLUSIONS

For the postmortem elucidation of etiopathogenetic factors contributing to fatal peptic ulcer disease, high-pressure liquid chromatography to determine NSAID levels in autopsy blood samples is of considerable diagnostic benefit, especially when combined with histology. The number of cases of sudden death involving younger individuals dying as a result of peptic ulcer disease in temporal association with preceding use of NSAIDs seems to be underestimated from the clinical viewpoint due to the underrepresentation of out-of-hospital fatalities in the field of clinical pathology.

Gastrointestinal toxicity associated with nonsteroidal anti-inflammatory drugs. Epidemiologic and economic issues

The large body of literature on the gastrointestinal side effects of NSAIDs has shown consistently that populations can be identified that have a markedly elevated risk for these iatrogenic conditions. These groups include the elderly, persons with prior history of peptic ulcer disease and its complications, persons receiving anticoagulant and corticosteroid therapy, and persons who require long-term NSAID therapy, especially at high dose. It is possible that several comorbidities (e.g., rheumatoid arthritis) predispose patients to gastrointestinal complications caused by NSAIDs, but few studies have adjusted carefully for the possibility that concomitant medication use (e.g., oral anticoagulants, corticosteroids) or increased NSAID dose may account best for apparent association of comorbidities as a risk factor for serious gastrointestinal events. The role of H. pylori infection in affecting the risk of complicated ulcer disease among NSAID users remains to be fully elucidated. Low-dose aspirin for cardioprotective use is associated with an increased risk for PUBs; when used concomitantly with NSAIDs, this increases the risk of PUBs above that of the NSAID itself. Apart from the physical toll NSAID-related gastrotoxicity places on the patient, there are considerable economic consequences to patients, providers, and society. This cost presents a subject for research for those interested not only in improving the quality of patient care, but also in the prudent use of health care resources.

Risk of upper gastrointestinal bleeding associated with use of low-dose aspirin

OBJECTIVE

Aspirin products are known to cause irritation and injury to the gastric mucosa. We examined the risk of hospitalization for upper gastrointestinal bleeding with use of low-dose aspirin.

METHODS

This was a cohort study based on record linkage between a population-based prescription database and a hospital discharge registry in North Jutland County, Denmark, from January 1, 1991, to December 31, 1995. Incidence rates of upper gastrointestinal bleeding in 27,694 users of low-dose aspirin were compared with the incidence rates in the general population in the county.

RESULTS

A total of 207 exclusive users of low-dose aspirin experienced a first episode of upper gastrointestinal bleeding with admission to the hospital during the study period. The standardized incidence rate ratio was 2.6 (95% confidence interval, 2.2-2.9), 2.3 in women and 2.8 in men. The standardized incidence rate ratio for combined use of low-dose aspirin and other nonsteroidal anti-inflammatory drugs was 5.6 (95% confidence interval, 4.4-7.0). The risk was similar among users of noncoated low-dose aspirin (standardized incidence rate ratio, 2.6; 95% confidence interval, 1.8-3.5) and coated low-dose aspirin (standardized incidence rate ratio, 2.6; 95% confidence interval, 2.2-3.0).

CONCLUSIONS

Use of low-dose aspirin was associated with an increased risk of upper gastrointestinal bleeding, with still higher risks when combined with other nonsteroidal anti-inflammatory drugs. Enteric coating did not seem to reduce the risk. The findings from this observational study raise the possibility that prophylactic use of low-dose aspirin may convey an increased risk of gastrointestinal bleeding, which may offset some of its benefits.

Are there seasonal patterns to ruptured aortic aneurysms and dissections of the aorta?

OBJECTIVE

to test the hypothesis that there are seasonal increases in aortic aneurysm ruptures and dissections.

METHODS

a retrospective, population-based time series analysis of hospital admissions for dissection and rupture of the aortic aneurysm in the Province of Ontario from 1988-1997. Analyses were carried out on weekly and monthly aggregations of hospital admissions.

RESULTS

there is weak statistical evidence of seasonality in the weekly time series (BKS=0.0987, p=0.03) and no evidence of seasonality in the monthly time series. There is no evident seasonality in the time plots. The incidence of dissections increased significantly over the study period while the incidence of ruptures decreased.

CONCLUSIONS

this large population-based study, contrary to other published reports, fails to find convincing evidence of seasonality in rupture or dissection of aortic aneurysm though did demonstrate contrasting trends in incidence.

Pharmacologic considerations for opiate analgesic and nonsteroidal anti-inflammatory drugs

When administering opioid analgesic drugs or nonsteroidal anti-inflammatory drugs, veterinarians are often not familiar enough with the underlying pharmacology of the drugs, particularly with the potential for drug interactions and adverse effects. This article considers some of the pharmacologic features of these drugs and provides a basis for important interactions, contraindications, and adverse effects.

The completeness of medication histories in hospital medical records of patients admitted to general internal medicine wards

AIMS

Accurate recording of medication histories in hospital medical records (HMR) is important when patients are admitted to the hospital. Lack of registration of drugs can lead to unintended discontinuation of drugs and failure to detect drug related problems. We investigated the comprehensiveness of medication histories in HMR with regard to prescription drugs by comparing the registration of drugs in HMR with computerized pharmacy records obtained from the community pharmacy.

METHODS

Patients admitted to the general ward of two acute care hospitals were included in the study after obtaining informed consent. We conducted an interview on drugs used just prior to hospitalization and extracted the medication history from the HMR. Pharmacy records were collected from the community pharmacists over a 1 year period before the admission. Drugs in the pharmacy records were defined as possibly used (PU-drugs) when they were dispensed before the admission date and had a theoretical enddate of 7 days before the admission date or later. If any PU-drug was not recorded in the HMR, we asked the patient whether they were using that drug or not.

RESULTS

Data were obtained from 304 patients who had an average age of 71 (range 40-92) years. The total number of drugs according to the HMR was 1239, 43 of which were not used. When compared with the pharmacy records we found an extra 518 drugs that were not recorded in the HMR but were possibly in use. After verification with the patients, 410 of these were indeed in use bringing the total number of drugs in use to 1606. The type of drugs in use but not recorded in the HMR covered a broad spectrum and included many drugs considered to be important such as cardiovascular drugs (n = 67) and NSAIDs (n = 31). The percentages of patients with 0, 1, 2, 3, 4, 5-11 drugs not recorded in the HMR were 39, 28, 16, 8, 3.6 and 5.5, respectively. Of the 1606 drugs in use according to information from all sources, only 38 (2.4%) were not retrievable in the pharmacy records when the complete year prior to hospitalization was evaluated.

CONCLUSIONS

The medication history in the hospital medical record is often incomplete, as 25% of the prescription drugs in use is not recorded and 61% of all patients has one of more drugs not registered. Pharmacy records from the community pharmacist can be used to obtain more complete information on the medication history of patients admitted to the hospital.

Cost-effectiveness of strategies for primary prevention of nonsteroidal anti-inflammatory drug-induced peptic ulcer disease

OBJECTIVE

Nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk of peptic ulcer disease by 5- to 7-fold in the first 3 months of treatment. This study examined the relative cost-effectiveness of different strategies for the primary prevention of NSAID-induced ulcers in patients that are starting NSAID treatment.

MEASUREMENTS AND MAIN RESULTS

A decision analysis model was developed to compare the cost-effectiveness of 6 prophylactic strategies relative to no prophylaxis for patients 65 years of age starting a 3-month course of NSAIDs: (1) testing for Helicobacter pylori infection and treating those with positive tests; (2) empiric treatment of all patients for Helicobacter pylori; (3) conventional-dose histamine2 receptor antagonists; (4) high-dose histamine2 receptor antagonists; (5) misoprostol; and (6) omeprazole. Costs were estimated from 1997 Medicare reimbursement schedules and the Drug Topics Red Book. Empiric treatment of Helicobacter pylori with bismuth, metronidazole, and tetracycline was cost-saving in the baseline analysis. Selective treatment of Helicobacter pylori, misoprostol, omeprazole, and conventional-dose or high-dose histamine2 receptor antagonists cost $23,800, $46,100, $34,400, and $15,600 or $21,500 per year of life saved, respectively, relative to prophylaxis. The results were sensitive to the probability of an ulcer, the probability and mortality of ulcer complications, and the cost of, efficacy of, and compliance with prophylaxis. The cost-effectiveness estimates did not change substantially when costs associated with antibiotic resistance of Helicobacter pylori were incorporated.

CONCLUSIONS

Several strategies for primary prevention of NSAID-induced ulcers in patients starting NSAIDs were estimated to have acceptable cost-effectiveness relative to prophylaxis. Empirically treating all patients for Helicobacter pylori with bismuth, metronidazole, and tetracycline was projected to be cost-saving in older patients.

The effect of alcohol abuse on the risk of NSAID-related gastrointestinal events

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to increase the risk of gastrointestinal (GI) complications. Excessive alcohol consumption may further increase this risk and the FDA is requiring warnings on over-the-counter (OTC) NSAIDs. Our objective is to evaluate the risk of NSAID-related GI events for persons with a history of alcohol abuse.

METHODS

This case control study used data from Saskatchewan Health. Cases consisted of 1083 patients hospitalized for severe GI events, whereas the control group consisted of 14,754 persons without such hospitalizations.

RESULTS

Five percent of cases and 1.9% of controls had a history of treatment for alcohol abuse. The presence of either NSAID use or a history of alcohol abuse led to an odds ratio (OR) of 2.9* for severe GI events, whereas the presence of both risk factors simultaneously led to an OR of 10.2* (additive would be 5.8). Similarly, the presence of ibuprofen and naproxen use, which are OTC in the USA, without alcohol abuse led to an OR of 1.9*, whereas alcohol abuse by itself led to an OR of 2.4*. The presence of both OTC NSAIDs and alcohol abuse simultaneously, led to an OR of 6.5 (additive would be 4.3). Thus with both risk factors present, the resulting risk ratio is greater than the additive risk of the separate risk factors.

CONCLUSIONS

The Food and Drug Administration (FDA) warning concerns concurrent use of alcohol with NSAIDs, whereas the present study presents the effect of long term alcohol abuse. Further research is needed to separate these two issues to allow physicians to provide the best advice to their patients. *Statistically significant at p<0.05.

Quantitative estimation of rare adverse events which follow a biological progression: a new model applied to chronic NSAID use

Randomised controlled trials (RCTs) alone are unlikely to provide reliable estimates of the incidence of rare events because of their limited size. Cohort, case control, and other observational studies have large numbers but are vulnerable to various kinds of bias. Wanting to estimate the risk of death from bleeding or perforated gastroduodenal ulcers with chronic usage of non-steroidal anti-inflammatory drugs (NSAIDs) with greater precision, we developed a model to quantify the frequency of rare adverse events which follow a biological progression. The model combined data from both RCTs and observational studies. We searched systematically for any report of chronic (>/=2 months) use of NSAIDs which gave information on gastroduodenal ulcer, bleed or perforation, death due to these complications, or progression from one level of harm to the next. Fifteen RCTs (19364 patients exposed to NSAIDs for 2-60 months), three cohort studies (215076 patients redeeming a NSAID prescription over a 3-12 month period), six case-control studies (2957 cases) and 20 case series (7406), and case reports (4447) were analysed. In RCTs the incidence of bleeding or perforation in 6822 patients exposed to NSAIDs was 0.69%; two deaths occurred. Of 11040 patients with bleeding or perforation with or without NSAID exposure across all reports, 6-16% (average 12%) died; the risk was lowest in RCTs and highest in case reports. Death from bleeding or perforation in all controls not exposed to NSAIDs occurred in 18 out of 849489 (0.002%). From these numbers we calculated the number-needed-to-treat for one patient to die due to gastroduodenal complications with chronic (>/=2 months) NSAIDs as 1/((0.69x¿6-16%, average 12%¿)-0.002%))=909-2500 (average 1220). On average 1 in 1200 patients taking NSAIDs for at least 2 months will die from gastroduodenal complications who would not have died had they not taken NSAIDs. This extrapolates to about 2000 deaths each year in the UK.

Recent nonsteroidal anti-inflammatory drug use increases the risk of early recurrence of bleeding in patients presenting with bleeding ulcer

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) use is a well-known risk factor for ulcer formation and ulcer complications. The purpose of this study was to determine whether recent NSAID use increases the risk of early recurrence of bleeding in patients who present with bleeding ulcer.

METHODS

Clinical and endoscopic data were collected prospectively. Dose, frequency, and duration of recent NSAID use were quantified. Recent NSAID use was defined as consumption of over-the-counter or prescription NSAIDs or aspirin for at least 5 days of the 2-week period preceding the index episode of bleeding. Endoscopy was performed within 24 hours of admission to confirm the source of bleeding and endoscopic intervention was applied for stigmata of bleeding. Early recurrence of bleeding was defined as melena, hematochezia or blood per nasogastric tube with a 2 gm or greater decrease in hemoglobin during a period of 48 hours, occurring less than 2 weeks from index episode of bleeding.

RESULTS

One hundred twenty patients (52 NSAID users and 68 nonusers) were enrolled in the study; mean age was 56 years. NSAID users were older than nonusers (p = 0.003); nonusers were more likely to have a history of ulcer disease (p < 0.0005) and higher prevalence of Helicobacter pylori infection (p = 0.05). Recent NSAID use was associated with a significantly higher frequency of early recurrence of bleeding and in-hospital recurrent bleeding compared with nonusers: 19% vs. 6%, p = 0.02, and 17% vs. 6%, p = 0.04, respectively. In multivariate logistic regression analysis, the significant association between recent NSAID use and early recurrence of bleeding persisted (p = 0.0048) while controlling for age and other covariates.

CONCLUSIONS

Recent NSAID use predisposes bleeding ulcer patients to early and in-hospital recurrent bleeding, probably via its effects on platelet function, mucosal prostaglandins, and ulcer healing.

Differences between males and females in risk of NSAID-related severe gastrointestinal events

PURPOSE

NSAID use has long been established as a risk factor for severe gastrointestinal (GI) events. It is also known that age and gender affect the risk of such events independently of nonsteroidal antiinflammatory drug (NSAID) use. The objective of the present study is to distinguish between gender as an independent risk factor for severe GI events, and the differences between males and females in risk of NSAID-related severe GI events.

METHODS

The study design was a nested case-control study. During the study period, 1029 cases were hospitalized with GI bleeds and/or perforations and 14 481 controls without such GI events were selected. Exposure consisted of the number of NSAID prescriptions dispensed by a pharmacy, prior to the data of hospitalization for cases and a corresponding date for controls.

RESULTS

Males have a risk of serious GI events 1.4 times greater than females, independent of NSAID use. However, females have the greater increase in risk of NSAID-related GI events, e.g. at four prescriptions women have an odds ratio (OR) of 7.4 (p<0.05), while men have a corresponding OR of 3.2 (p<0.05). The increasing risk of severe GI events with number of NSAID prescriptions was considerably greater for females than for males, indicating effect-modification. In a stratified analysis by age and gender, it was clear that gender was the greater influence. Various metabolic and epidemiological potential explanations are discussed.

CONCLUSIONS

Age and gender are separate risk factors for GI complications as related to NSAID use. Although implied in other studies, the effect of gender on the risk of NSAID-related GI events is clearly stated in this study.

Peptic ulcer bleeding: interaction between non-steroidal anti-inflammatory drugs, Helicobacter pylori infection, and the ABO blood group system

BACKGROUND

Helicobacter pylori infection is found in almost all patients with an uncomplicated ulcer. Non-steroidal anti-inflammatory drug (NSAID) use is the main risk factor for bleeding peptic ulcer. In the older literature ABO blood groups were mentioned as a risk factor. There is continuing uncertainty about the interaction between these risk factors and the development of peptic ulcer bleeding. We therefore determined the separate and combined effect of NSAIDs, H. pylori infection, and the ABO blood group system in patients with a bleeding peptic ulcer.

METHODS

The prevalence of NSAID use, H. pylori infection, and blood group O was determined in 227 patients who were admitted with a bleeding gastric or duodenal ulcer between 1990 and 1997. These results were compared with the expected frequency of these risk factors in the Dutch population.

RESULTS

NSAID use was reported in 48.2% of the patients with a bleeding peptic ulcer. The H. pylori prevalence was 62.0%, whereas blood group O was present in 49.3% of the patients. NSAID use was the strongest risk factor for hemorrhage caused by a peptic ulcer (relative risk, 8.4), whereas the relative risk associated with H. pylori infection and blood group O was 1.5 and 1.2, respectively. With univariate analysis NSAID use and H. pylori infection seemed to be separate risk factors and did not really potentiate each other's effect. Moreover, blood group O did not potentiate the strong effect of NSAIDs.

CONCLUSION

H. pylori infection may add only a little to the important risk of NSAID use in the development of bleeding peptic ulcers.

Prevalence of antidepressant use among older people: population-based observations

OBJECTIVE

To assess the prevalence of antidepressant use with respect to age, gender, and time during a 5-year period from 1993 to 1997.

DESIGN

A retrospective, population-based study in which data regarding a cross-sectional series of annual antidepressant use were obtained from administrative claims and census databases for more than 1.4 million older persons during calendar years 1993 through 1997.

PARTICIPANTS

All residents of Ontario aged 65 or older.

MAIN OUTCOME MEASURES

Changes in the prevalence of antidepressant users as a function of age group, gender, and time.

RESULTS

A general, positive, linear trend in the prevalence of antidepressant users with increasing age group was consistently detected regardless of gender and year assessed (P < .001 for both genders and all years). The age-adjusted relative risk of women being dispensed an antidepressant relative to men was significantly higher during each year but seemed to decrease slightly over time: 1.74 (95% CI, 1.72-1.76) in 1993 and 1.65 (95% CI, 1.63-1.67) in 1997. The multiple linear regression model revealed significant relationships between the prevalence of antidepressant users and increasing age group, female gender, and increasing year of assessment (P < .001 for each variable). The prevalence was observed to range from a low of 5.6% in 65 to 69-year-old men in 1993 to a high of 17.2% among 85 to 89-year-old women in 1997.

CONCLUSIONS

Our findings reveal that the prevalence of antidepressant users is dynamic and is significantly and independently associated with age, gender, and time of assessment.

Review article: nonsteroidal anti-inflammatory drug-associated gastrointestinal complications--guidelines for prevention and treatment

Chronic ingestion of NSAIDs increases the risk for gastrointestinal complications, which range from dyspepsia to gastrointestinal bleeding, obstruction, and perforation. Among patients using NSAIDs, 0.1 to 2.0% per year suffer serious gastrointestinal complications. Patients who require analgesic therapy should be carefully assessed for the lowest possible dosage and shortest duration of NSAID use and for the potential of treatment with a non-NSAID pain reliever. These patients should also be assessed for factors that increase their risk of gastrointestinal complications, including increased age, concomitant anticoagulant or corticosteroid use, and past history of NSAID-associated gastrointestinal complications. The exact association between Helicobacter pylori infection and NSAID-related ulcer disease is unclear, and the routine testing and treatment of all NSAID using patients for H. pylori infection is not recommended at this time. NSAID-using patients who suffer from dyspepsia should have NSAIDs discontinued, the dosage changed, or be changed to a different class of NSAID. If NSAIDs cannot be discontinued, then an antisecretory agent should be initiated. Misoprostol prevents NSAID-associated gastrointestinal complications. Proton pump inhibitors are the most effective at healing NSAID-associated ulcers among patients who cannot discontinue NSAID therapy.

Detailed examination of fenfluramine-phentermine users with valve abnormalities identified in Fargo, North Dakota

Although several studies have reported on valve abnormalities among users of fenfluramine or dexfenfluramine, detailed information on these subjects has not been provided, limiting the ability to understand who may be at risk for valve abnormalities and to generate hypotheses about the etiology and pathogenesis of these abnormalities. This study was a detailed medical record review of 18 previously reported users of fenfluramine and phentermine, all with valve abnormalities on echocardiogram and 2 with surgical pathology. Both clinical characteristics and medication use were recorded by trained abstracters using a standardized data collection form. Two subjects (11%) had other possible etiologies of valve disease: a history of rheumatic fever and prescribed ergotamine. Three subjects (17%) had a history of migraine headaches and 4 (22%) had murmurs noted before using fenfluramine. Use of medications that may affect serotonin receptors was common: ergotamine (1 subject, 5%), selective serotonin reuptake inhibitors (6, 33%), sumatriptan (2, 11%), and mirtazapine (1, 5%). Prior medication and nonmedication allergies were recorded in 6 (33%) and 3 (17%) subjects, respectively. All subjects had symptoms possibly due to fenfluramine or phentermine side effects. This study raises the hypotheses that valvular heart disease among fenfluramine users may be less common than previously estimated, that serotonin excess may play a role in valve pathology, and that a patient's response to anorexigens and other medications may serve as a marker for increased risk. Further study is needed to test these hypotheses.

Assessment and control for confounding by indication in observational studies

In the evaluation of pharmacologic therapies, the controlled clinical trial is the preferred design. When clinical trial results are not available, the alternative designs are observational epidemiologic studies. A traditional concern about the validity of findings from epidemiologic studies is the possibility of bias from uncontrolled confounding. In studies of pharmacologic therapies, confounding by indication may arise when a drug treatment serves as a marker for a clinical characteristic or medical condition that triggers the use of the treatment and that, at the same time, increases the risk of the outcome under study. Confounding by indication is not conceptually different from confounding by other factors, and the approaches to detect and control for confounding--matching, stratification, restriction, and multivariate adjustment--are the same. Even after adjustment for known risk factors, residual confounding may occur because of measurement error or unmeasured or unknown risk factors. Although residual confounding is difficult to exclude in observational studies, there are limits to what this "unknown" confounding can explain. The degree of confounding depends on the prevalence of the putative confounding factor, the level of its association with the disease, and the level of its association with the exposure. For example, a confounding factor with a prevalence of 20% would have to increase the relative odds of both outcome and exposure by factors of 4 to 5 before the relative risk of 1.57 would be reduced to 1.00. Observational studies have provided important scientific evidence about the risks associated with several risk factors, including drug therapies, and they are often the only option for assessing safety. Understanding the methods to detect and control for confounding makes it possible to assess the plausibility of claims that confounding is an alternative explanation for the findings of particular studies.

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.

Antihypertensive drugs and the risk of gastrointestinal bleeding

PURPOSE

Calcium channel blockers have been reported to increase the risk of gastrointestinal bleeding. We tested this hypothesis, and also assessed whether beta blockers decrease this risk.

SUBJECTS AND METHODS

A nested case-control design within a population-based cohort of all 34,074 new users of beta blockers, angiotensin-converting enzyme (ACE) inhibitors, or calcium channel blockers in Saskatchewan, from 1990 to 1993 and followed up to March 1995, was used. We identified all 311 subjects hospitalized because of gastrointestinal bleeding during this period, each of whom was matched to 10 randomly selected controls.

RESULTS

The rate of hospitalization for gastrointestinal bleeding was 3.0 per 1,000 per year. The adjusted rate ratio of gastrointestinal bleeding for current use of calcium channel blockers was 1.1 (95% confidence interval [CI] 0.8 to 1.4) and 0.66 (95% CI 0.44 to 0.98) for beta blockers compared with no current use of anti-hypertensive drugs. The adjusted rate ratio for ACE inhibitor use was 1.0 (95% CI 0.7 to 1.3) while that for diuretic use was 1.4 (95% CI 1.0 to 2.0).

CONCLUSIONS

The use of calcium channel blockers does not appear to increase the risk of gastrointestinal bleeding in the first five years of treatment, while beta blockers may prevent this adverse event. The unexpected elevated risk associated with the use of diuretics needs to be investigated further.

Agreement between the pharmacy medication history and patient interview for cardiovascular drugs: the Rotterdam elderly study

AIMS

To study whether there is agreement between cardiovascular drugs presented at patient interview and pharmacy records in an elderly population.

SETTING

The Rotterdam Elderly Study, a prospective population based cohort study of people older than 55 years of age.

METHODS

We compared cardiovascular drug use as presented during patient interview with the computerized pharmacy medication history. Concordance of cardiovascular drug use in patient interview and pharmacy data was measured by merging the two data sets and assessed in two episodes: in a period of 6 months before patient interview and within the legend duration of each cardiovascular drug.

RESULTS

We found 2706 concordant pairs in a total of 3365 prescriptions (80.4%) in the merged data. There were 195 prescriptions presented at patient interview which had not been filled at the pharmacy, and 464 which had been filled but were not presented by the patient. The percentage of concordant pairs slightly increased to 80.6% (2275 of a total of 2824) for prescriptions of which the legend duration included the date of patient interview. The highest agreement was noted with beta-adrenoceptor blocking agents with Kappa statistics of 0.97 for atenolol and metoprolol. The lowest Kappa statistic was found for organo-heparinoid, mainly as ointments against haemorrhoids (0.26).

CONCLUSION

The agreement between patient interview and pharmacy records is good for prescription only drugs, and pharmacy records are a useful resource for pharmacoepidemiological studies on cardiovascular agents.

Clinical aspects of upper gastrointestinal bleeding associated with the use of nonsteroidal antiinflammatory drugs

OBJECTIVE

The aim of this study was to compare the clinical features of major upper gastrointestinal bleeding among patients exposed to nonsteroidal antiinflammatory drugs (NSAID) and those not taking these drugs.

METHODS

Using data from a multicenter international case-control study designed to evaluate the role of drugs in the etiology of major upper gastrointestinal bleeding (UGIB), patients with a confirmed first episode of major UGIB were divided into two groups: those exposed to NSAIDs during the week before the onset of bleeding, and those not exposed. The groups were compared according to age and sex, clinical appearance and site of the bleeding, preceding symptoms, and requirement for transfusion and acute surgery.

RESULTS

The median age was significantly higher and the proportion of women was slightly higher among the NSAID users. There was no significant difference between users and nonusers according to the clinical presentation, the site of the bleeding, or the frequency of preceding symptoms. Forty percent in each group had no symptoms before the onset of bleeding. Slightly more NSAID users received blood transfusions, although the same median amount of blood per transfusion was given in both groups. There was no difference in the frequency of surgical intervention.

CONCLUSIONS

There are no important differences in the clinical presentation of major UGIB according to whether or not an individual is an NSAID user. An important finding is the frequent absence of preceding symptoms in patients with major UGIB, regardless of NSAID use.

Epidemiology of nonsteroidal anti-inflammatory drug-associated gastrointestinal injury

Nonaspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used drugs in many countries. Use of the majority of NSAIDs increases with age, primarily for symptoms associated with osteoarthritis and other chronic musculoskeletal conditions. Population-based studies have shown that, on any given day, 10-20% of elderly people (> or = 65 years old) have a current or recent NSAID prescription. Over a 6-month period in Alberta, Canada, 27% of elderly people were prescribed NSAIDs. Furthermore, in Tennessee (USA), 40% of elderly people received at least one NSAID prescription annually, and 6% had NSAID prescriptions for > 75% of the year. NSAIDs cause a wide variety of side-effects. The most clinically important side-effects are upper gastrointestinal tract dyspepsia, peptic ulceration, hemorrhage, and perforation, leading to death in some patients. Gastrointestinal side-effects are common; the most common NSAID-associated side-effect is epigastric pain/indigestion. Gastrointestinal side-effects are also a frequent reason both for withdrawal of NSAIDs and for co-treatment with another drug. Indeed, in two population-based studies of people aged > or = 65 years, the use of agents to prevent peptic ulcers or relieve dyspepsia was nearly twice as common in regular NSAID users (20-26%) than in non-NSAID users (11%). In Alberta, Canada, it has been estimated that NSAID use accounts for 28% of all prescriptions for anti-ulcer drugs in people aged at least 65 years. Many studies have now shown that NSAIDs increase the risk of peptic ulcer complications by 3-5-fold, and in several different populations it has been estimated that 15-35% of all peptic ulcer complications are due to NSAIDs. In the United States alone, there are an estimated 41,000 hospitalizations and 3,300 deaths each year among the elderly that are associated with NSAIDs. Factors that increase the risk of serious peptic ulcer disease include older age, history of peptic ulcer disease, gastrointestinal hemorrhage, dyspepsia, and/or previous NSAID intolerance, as well as several measures of poor health.

Concurrent use of antiulcerative agents

Many physicians prescribe more than one antiulcerative agent (AUA) simultaneously to the same patient, although there is little evidence to support this practice. The purposes of this study were to (a) determine patient factors associated with the concurrent use of these agents and (b) estimate the excess costs generated by the prescription of multiple rather than a single agent. We conducted a case-control study of concurrent AUA users among New Jersey Medicaid enrollees age 65 years and older. To evaluate the excess cost generated by the ongoing prescription of an additional AUA, we measured the additional drug expenditures associated with each regimen of concurrent use. Nearly 1 in 15 AUA users (6.6%) met our conservative definition of concurrent AUA use. In a multiple logistic regression model, previous gastrointestinal procedure, use of a nonsteroidal anti-inflammatory drugs, nursing home residency, and recent hospitalization for more than 20 days were all predictors of concurrent use of more than one AUA. No association was found with age, sex, or number of pharmacies used. The upper bound estimate of the cost generated by the concurrent prescription of a second AUA was $210 (range: $2-$942) over the 180-day study period, with a lower bound of $151 (range: $1-$449). Annually, such excess cost would range from $301 to $420 per patient. This would account for between $457 million and $637 million per year for the nation's elderly if these patterns are generalizable. Despite the lack of evidence of therapeutic benefit from multiple concurrent AUA use in most patients, this practice is fairly common. Besides introducing the risk of additional costs and side effects in the absence of additional efficacy, the costs of such duplicative prescribing are substantial.

Reliability of the recording of schizophrenia and depressive disorder in the Saskatchewan health care datafiles

Administrative data have long been used in psychiatric epidemiology and outcomes evaluation. This article examines the reliability of the recording of schizophrenia and depressive disorder in three Saskatchewan administrative health care utilization datafiles. Due to their comprehensive nature, these datafiles have been used in a wide range of epidemiologic studies. Close agreement was found between hospital computer data and patients' charts for personal and demographic factors (> or = 94.7%). Diagnostic concordance between computerized hospital data and medical charts was very good for schizophrenia (94%) but poor for depressive disorder (58%). Appropriate physician services were identified for 60% and 72% of hospital discharges for schizophrenia and depressive disorder, respectively, and exact diagnostic agreement between hospital and physician datafiles was 62% for schizophrenia and 66% for depressive disorder. Appropriate provincial mental health branch services were found for 83% and 38% of hospital discharges for schizophrenia and depressive disorder, respectively; exact diagnostic concordance between these datafiles was 75% for schizophrenia and 0% for depressive disorder. A significant number of patients with major or neurotic depression appeared to be wrongly coded as having depressive disorder in the hospital file. The differences in diagnostic agreement may also be partly a function of how the two conditions are differentially treated in the health system. These findings suggest that more specific and severe psychiatric diagnoses are likely to be recorded accurately and consistently in the Saskatchewan datafiles. However, disorders with multiple manifestations or those for which there are several possible codes should be examined with caution and ways sought to validate them. Attention should also be paid to which service sectors are involved in the treatment of specific disorders.

Validation of pharmacy records in drug exposure assessment

The validity of drug exposure measurement based on pharmacy records was investigated taking into account completeness of data, drug compliance, and different methods of drug exposure measurement in pharmacy records. Data on prescription drug use were collected from home inventories and community pharmacies in a survey on drug use and compliance in 115 elderly people. To compare drug exposure in pharmacy records with exposure in the home inventory, three different methods for exposure measurement in pharmacy records were used. Two employed a fixed time window of 30 and 90 days, respectively, and the third method was based on the calculated duration of use of a prescription ("legend time"). Drug exposure in the home inventory was taken as the gold standard and sensitivity, specificity, and positive predictive values of the different methods were calculated for the most frequently used drugs and drug categories. The specificity and positive predictive value of all three methods was generally high (0.93-1.00 and 0.67-1.00, respectively). The 90-day fixed method and the legend time method generally showed high sensitivity (range: 0.67-1.00 and 0.63-0.83, respectively) for drugs that were used on a chronic basis, while the 30-day fixed method had poor sensitivity (range: 0.29-0.69). Drugs that were used according to the home inventory but not according to the pharmacy records methods could be almost completely retrieved in the pharmacy records of a one-year period showing that these records were virtually complete with regard to prescription drugs. We conclude that computerized pharmacy records can be a reliable source of the true drug exposure as estimated in a home inventory, when adequate attention is paid to the definition of the exposure time-window and when these records are comprehensive with regard to prescription drugs.

Principles of analgesic drug therapy

The drugs most often used for pain relief in animals are the nonsteroidal antiinflammatory drugs (NSAIDS) and the opioid analgesics. The NSAIDS are effective, inexpensive, and long-acting drugs, but their degree of analgesia is limited by the adverse effects at high doses. The most common adverse effect from NSAIDS is gastritis and gastrointestinal hemorrhage and ulceration. This is most common from high doses, or from using NSAIDS not appropriate for dogs such as ibuprofen or indomethacin. The NSAIDS used in dogs include aspirin, phenylbutazone, naproxen, piroxicam, ketoprofen, and carprofen. Carprofen is a new drug with a low incidence of side effects and its popularity is increasing at a fast rate. For more acute pain, especially acute pain from surgery or trauma, opioids are frequently administered. Opioids have the advantage of higher efficacy when the dose is increased. The incidence of adverse effects is low, but side effects of sedation are common. An important disadvantage of opioids is their short duration and low oral absorption, which necessitates a frequent injection or i.v. infusion for most patients. Recent studies have established other applications for administration of opioids such as a transdermal fentanyl patch. These applications offer new possibilities for convenient administration.

Toxicity of nonsteroidal anti-inflammatory drugs in the elderly: is advanced age a risk factor?

We reviewed the pharmacokinetic, physiologic and epidemiologic data concerning nonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy and renal insufficiency in the elderly through a structured critical reading of the literature. References were collected through a search of MEDLINE and consultation with experts in the field. While there is an abundance of pharmacokinetic data comparing relevant parameters in young and old subjects, methods are not uniform and findings are inconsistent. Prostaglandin physiology appears to be altered in older versus younger subjects. Most surprisingly, there is a scarcity of epidemiologic data examining the contribution of age as a risk factor for NSAID-induced ulcers and/or renal insufficiency. The data that do exist do not clearly support age as an independent risk factor; and we believe that comorbidities, comedications and past history are more important predictors of NSAID-induced toxicity than age and more relevant in regard to therapeutic decision-making for this patient population.

Reliability of the recording of hysterectomy in the Saskatchewan health care system

OBJECTIVE

To determine the validity of data pertaining to hysterectomy in the Saskatchewan health care utilisation datafiles.

DESIGN

Retrospective analysis of routinely collected data covering hospital discharge records and practitioner claims for reimbursement of services, together with a review of clinical charts.

SETTING

Province of Saskatchewan, Canada.

SAMPLE

All 1905 cases of hysterectomy in one calendar year for analysis of datafiles and a random sample of 227 clinical charts for review.

METHOD

Information in the hospitalisation datafile was validated through an external comparison with data extracted from a review of clinical charts, as well as an internal comparison with independent data from the practitioner claims file. Corresponding context data on drug use and performance of related procedures were also analysed.

RESULTS

Concordance between hospital data and clinical charts was greater than 95% for those items of an administrative nature as well as type of hysterectomy and was around 85% for the diagnoses. When hospitalisation and practitioner claims data were compared, the concordance was 98% for type of hysterectomy but only 56% for diagnoses.

CONCLUSIONS

The agreement between hospital data and clinical charts was excellent. The concordance between hospitalisation and practitioner claims data was almost exact for type of hysterectomy, while discrepancies in diagnoses between these files were mostly explainable on the basis of accepted clinical practice. Saskatchewan health care utilisation datafiles provide a source of valid data for research and evaluation studies.

Excess costs from gastrointestinal disease associated with nonsteroidal anti-inflammatory drugs

OBJECTIVE

To quantify medical care costs for the diagnosis and treatment of gastrointestinal disorders attributable to use of nonsteroidal anti-inflammatory drugs (NSAIDs) other than aspirin in elderly persons.

DESIGN AND SETTING

Retrospective cohort study of 75,350 Tennessee Medicaid enrollees at least 65 years of age.

MEASUREMENTS

The cohort was classified by baseline NSAID use as nonusers (no use preceding 1988), occasional users (< 75% of days) or regular users (> or = 75% of days). For the follow-up year (1989), we calculated annual rates of utilization of and Medicare/Medicaid payments for: medical care for NSAID-associated gastrointestinal disorders; hospitalizations/emergency department visits for peptic ulcers, gastritis/duodenitis, and gastrointestinal bleeding; outpatient upper and lower gastrointestinal tract radiologic and endoscopic examinations; and histamine2 (H2)-receptor antagonist, sucralfate, and antacid prescriptions. Rates were adjusted for demographic characteristics and baseline health care utilization.

RESULTS

Among nonusers of NSAIDs, the adjusted mean annual payment for all types of medical care for study gastrointestinal disorders was $134. This increased to $180 among occasional users, an excess of $46 (p < .001); and to $244 among regular users, an excess of $111 (p < .001, comparison with both nonusers and occasional users). Cohort members with any baseline year NSAID use had an adjusted mean annual payment of $191, $57 (p < .001) higher than that for nonusers. In both users and nonusers of NSAIDs, medications and inpatient care accounted for the largest component of costs. Among regular NSAID users, excess payments increased with baseline NSAID dose: $56, $120, and $157 for less than 1, 1 to 2, and more than 2 standard units per day, respectively (p < .01, linear trend).

CONCLUSIONS

Nonsteroidal anti-inflammatory drug (NSAID) use in elderly patients was associated with substantial excess costs and utilization of medical care for gastrointestinal disorders.

The risks and costs of upper gastrointestinal disease attributable to NSAIDs

NSAIDs, including both aspirin and nonaspirin NSAIDs, are among the most frequently used drugs, and their use may result in serious adverse gastrointestinal outcomes and significant medical costs. The increased risks for adverse upper GI hemorrhage and peptic ulcer disease associated with NSAID use have been demonstrated in observational studies and clinical trials; an overview of these results is presented in this article. The magnitude of these risks should play an important role in clinical decision making and should influence decisions regarding the use of this class of drugs.

Validity of the recording of ischaemic heart disease and chronic obstructive pulmonary disease in the Saskatchewan health care datafiles

The internal validity of the recording of information about ischaemic heart disease (IHD) and chronic obstructive pulmonary disease (COPD) in the administrative health care datafiles of the Canadian province of Saskatchewan is investigated. Comparisons between hospital data and medical charts for acute myocardial infarction and chronic airways obstruction patients showed excellent diagnostic agreement: 97 per cent and 94 per cent, respectively. Appropriate physician service claims were identified for 89 per cent of hospitalizations for IHD and COPD and exact concordance between diagnoses in the two datafiles varied between 15 per cent for acute/sub-acute IHD and 80 per cent for asthma; including any physician diagnosis within the same broad category (IHD or COPD) increased concordance to 79-94 per cent for IHD and 64-88 per cent for COPD. Contextual information related to the hospitalizations was clinically and epidemiologically realistic.

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.