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Biomedical subjects

B Bégaud

Publications and source records attributed to B Bégaud.

At least 19 recordsLinked to original sources

The CADEUS study: methods and logistics.

PURPOSE: At the request of the French Health authorities, a study called CADEUS (COX-2 inhibitors and NSAIDs: description of users) aimed to describe the users of cyclo-oxygenase (COX)-2 inhibitors and traditional non-selective non-steroidal anti-inflammatory drugs (tNSAIDs). We report here the methodology, logistics and study design performances. METHODS: CADEUS is a cohort study designed to include 40,000 patients randomly sampled monthly in the French National Healthcare Insurance database, who received at least one dispensation of celecoxib, rofecoxib or tNSAIDs (1:1:2), from September 2003 to August 2004. Patients and prescribers were asked to fill a questionnaire on indication, medical history, risk factors and hospitalizations since drug acquisition. There was no reminder. For each respondent, healthcare resources used for the 6 months before and after inclusion were extracted from the database. Response rate, response delay, responders and non-responders characteristics were assessed. RESULTS: Of the 222,879 patients and their prescribers contacted, 20.8% patients and 32.6% prescribers responded. Median response delay was 16 days for patients and 17 days for physicians. Factors associated with patient response were age, cohort, type of prescriber and period of inclusion. CONCLUSION: This is the first study of this design in France, combining data from a claims database and direct patient and prescriber questionnaires.

Adult↗

Patterns of risperidone prescription: a utilization study in south-west France.

OBJECTIVE: To describe the patterns of prescriptions associated with risperidone in naturalistic clinical practice. METHOD: We analysed 500 prescription forms randomly selected from the social security insurance database in Aquitaine (south-west France). RESULTS: The prevalence of co-prescription was 42.5% for antidepressants, 46.4% for benzodiazepines, 26.6% for other neuroleptics, 21.8% for mood stabilizers and 19% for anticholinergic drugs. The high prevalence of co-prescribed antidepressants (59.3% Selective Serotonin Reuptake Inhibitors) may be explained by the frequent comorbidity of mood disorders in schizophrenia, and by the fact that risperidone was prescribed in naturalistic conditions in disorders other than schizophrenia. CONCLUSION: The high level of concomitant drug prescription in patients treated with risperidone illustrates the gap between clinical trials and utilization in naturalistic settings. The association antidepressant-risperidone has been insufficiently studied for efficacy or safety, and has to be explored further from both a pharmacological and clinical point of view.

Adolescent↗

Rapid high-performance liquid chromatographic measurement of amisulpride in human plasma: application to manage acute intoxication.

Amisulpride, a substituted benzamide derivative, is a second-generation (atypical) antipsychotic and is effective as maintenance therapy in patients with schizophrenia. For toxicological purpose, a rapid RP-HPLC assay was developed for the determination of amisulpride in human plasma. A linear response was observed over the concentration range 100-1000 ng/ml. A good accuracy (< or =5%) was achieved for all quality controls, with intra- and inter-day variation coefficients equal or inferior to 4.9%. The lower limit of quantification was 20 ng/ml, without interferences of endogenous components. This rapid method (run time <5 min) was used to monitor eight intoxications involving amisulpride.

Amisulpride↗

Accuracy of self-report and toxicological assays to detect substance misuse disorders in parasuicide patients.

OBJECTIVE: To assess the accuracy of self-reported substance use and toxicological assays in subjects admitted for Intentional Drug Overdose (IDO), using as a reference diagnosis of substance use disorder. METHOD: Self-reported substance use was collected and toxicological assays were carried out in urine samples in 507 patients with IDO. A standardized psychiatric evaluation was performed in 100 randomly selected subjects. RESULTS: In routine practice, the emergency department staff did not investigate substance use in nearly one of two patients. Patients' statements and toxicological assays were more specific than sensitive, with lower scores for toxicological assays. Patients' statements made it possible to detect nearly 80% of subjects with substance use disorder. CONCLUSION: Identification of substance use disorder in subjects with IDO has strong clinical consequences regarding treatment and prevention of suicidal behaviour. Thus, emergency department staff should be made aware of the value of more systematically exploring self-reported substance use.

Adolescent↗

Determination of the acetylator phenotype in Moroccan tuberculosis patients using isoniazid as metabolic probe.

A large interindividual variability in drug acetylation is associated with genetic polymorphism of the polymorphic Type 2 N-acetyltransferase (NAT2), and an important interethnic difference has been frequently observed. However, few data on this polymorphism in the Moroccan population are available. In the present study the acetylator phenotype in 89 Moroccan patients with tuberculosis has been determined using isoniazid (INH) as metabolic probe. The subjects (69 women and 20 men between 18 and 77) were each given a 5 mg/kg oral dose of INH. Plasma concentration of INH and its metabolite, acetylisoniazid (ac.INH), were measured by high-performance liquid chromatography at 3 hours post dose. The plasma level ratio of acetylisoniazid to isoniazid (Rm), and the plasma level of acetylisoniazid as a percentage (%ac.INH) were used to express the activity of the polymorphic NAT2. The distribution of these 2 parameters in the studied population was clearly bimodal resulting in 2 distinct groups: slow acetylators (Rm < or = 0.84, %ac.INH < or = 45.64%), and fast acetylators (Rm > or = 1.29, %ac.INH > or = 56.26%) who accounted respectively for 61.8% and 38.2% of the population. The 2 approaches used showed a complete concordance.

Acetylation↗

Benzodiazepines and hip fractures in elderly people: case-control study.

OBJECTIVE: To determine whether benzodiazepines are associated with an increased risk of hip fracture. DESIGN: Case-control study. PARTICIPANTS: All incident cases of hip fracture not related to traffic accidents or cancer in patients over 65 years of age. 245 cases were matched to 817 controls. SETTING: Emergency department of a university hospital. MAIN OUTCOME MEASURES: Exposure to benzodiazepines and other potential risk or protective factors or lifestyle items. RESULTS: The use of benzodiazepines as determined from questionnaires, medical records, or plasma samples at admission to hospital was not associated with an increased risk of hip fracture (odds ratio 0.9, 95% confidence interval 0.5 to 1.5). Hip fracture was, however, associated with the use of two or more benzodiazepines, as determined from questionnaires or medical records but not from plasma samples. Of the individual drugs, only lorazepam was significantly associated with an increased risk of hip fracture (1.8, 1.1 to 3.1). CONCLUSION: Except for lorazepam, the presence of benzodiazepines in plasma was not associated with an increased risk of hip fracture. The method used to ascertain exposure could influence the results of case-control studies.

Accidental Falls↗

Benzodiazepine use in an elderly community-dwelling population. Characteristics of users and factors associated with subsequent use.

OBJECTIVES: The objective of this study was to describe determinants of current and subsequent benzodiazepine use in an elderly population, the Paquid cohort. METHODS: The study was conducted on a cohort of 2,792 community-dwelling subjects 65 years of age or more living in the Gironde department, southwestern France. Benzodiazepine use and its correlates were studied with data collected at inclusion in the cohort. Longitudinal analysis over a 5-year period of follow-up was done to identify baseline predictors of subsequent use. RESULTS: At baseline, prevalence rate of benzodiazepine use was 31.9%. It was associated with female gender [odds ratio (OR) = 2.0; 95% confidence interval (CI): 1.66, 2.46], previous psychiatric disease (OR = 2.87; 95% CI: 2.31, 3.56), concomitant antidepressant use (OR = 2.45; 95% CI: 1.59, 3.78), depressive symptomatology (OR = 1.70; 95% CI: 1.28, 2.26), multiple drug use (OR = 1.82; 95% CI: 1.50, 2.21), multiple chronic diseases (OR = 1.37; 95% CI: 1.12, 1.67) and poor self-perceived health (OR = 1.63; 95% CI: 1.33, 2.0). For the 1926 benzodiazepine non-users at inclusion and followed during 5 years, incidence rate of subsequent use was 5.37 per 100 person-years (95% CI: 4.76, 5.98). In multivariate Cox proportional hazards regression analysis, previous psychiatric diseases, poor self-perceived life satisfaction and polymorbidity were significantly associated with subsequent benzodiazepine use. CONCLUSIONS: Elderly people are heavy users of benzodiazepines. Independently from mental health status, those in poor health were most at risk of benzodiazepine use.

Aged↗

Incidence of serious adverse drug reactions in general practice: a prospective study.

BACKGROUND: Many studies have been conducted to estimate the incidence and economic impact of adverse drug reactions. Most of these studies used historical data or were based on single hospital units. Little is known, however, about the frequency of serious adverse drug reactions in general practice. OBJECTIVE: To estimate the incidence of serious adverse drug reactions in the community. METHODS: A prospective study during 5 consecutive working days between March 1 and April 30, 1998, was conducted among a random representative sample of 254 general practitioners in Aquitaine, France. The main outcome measure was the number of serious adverse drug reactions (ie, resulting in death, life-threatening condition, hospitalization, incapacity, or sequel) observed by each general practitioner during the study period and validated by an expert panel. RESULTS: Thirteen validated serious adverse drug reactions, 2 of which were fatal (1 subarachnoidal hemorrhage with oral anticoagulant and 1 aplastic anemia with antineoplastics), were observed, resulting in an incidence density of 10.2 (95% confidence interval [CI], 5.4 to 17.5) per 1000 days of practice. Eleven case subjects (84.6%) were hospitalized. This represents an average of 2.6 cases per general practitioner per year, and 123,000 adverse drug reaction cases (95% CI, 65,400 to 210,000) for the 60,000 general practitioners in France. Antineoplastics and anticoagulants were the drugs most frequently involved, and blood dyscrasia and bleeding were the most frequent adverse drug reactions. CONCLUSION: This study, which is one of the few available that has prospectively measured the incidence of serious adverse drug reactions in general practice settings, confirms that serious adverse drug reactions are a major public health concern.

Adolescent↗

Comparison of patient questionnaires, medical records, and plasma assays in assessing exposure to benzodiazepines in elderly subjects.

OBJECTIVE: Exposure in pharmacoepidemiologic studies can rely on various sources such as medical records, patient questionnaires, or plasma samples, which do not always concur. This study endeavored to compare sources of information on current exposure to benzodiazepines in elderly subjects. METHODS: In a study in a hospital admissions department, 1136 elderly subjects included in a case-control study each completed a structured questionnaire. In addition, an inspection of the medical records of each subject was performed, as well as screening of a plasma sample (high-pressure liquid chromatography--diode array detector) for current exposure to benzodiazepines. RESULTS: Benzodiazepines were found in the plasma of 33% of 1013 patients, in the records of 31% of patients, and in the questionnaires of 36% of 797 respondents. With use of the plasma results as a standard, questionnaires had 11% false positives and 28% false negatives; medical records had 14% false positives and 23% false negatives. The kappa for concordance between questionnaires and records was 0.63. Most of the errors were related to the unexpected presence in plasma of clorazepate, commonly used as a hypnotic agent. CONCLUSIONS: Patient recall and medical records are not reliable measures of current exposure to benzodiazepines in elderly persons, although this unreliability may be more marked with certain drugs used as hypnotic agents.

Aged↗

[Incidence and prevalence of adverse drug reactions].

FUNDAMENTAL DATA: Estimation of incidence and prevalence rates of adverse drug reactions are necessary to assess the consequences and impact of these effects in a population. HOSPITAL STUDIES: During the last 20 years, several studies conducted in one or more departments of a single hospital have found incidence of hospitalizations induced by adverse drug reactions between 2 and 8%. Three meta-analyses confirm these reports with incidence varying from 4.4 to 5.8% in different countries and from 5.2 to 8.2% and from 2.37 to 3.6% in the United States and Australia respectively. Two recent studies conducted by the French pharmacovigilance regional centers on a representative sample of medical departments in public hospitals found a prevalence of adverse drug reactions between 4.2 and 22.1% (according to the type of department and hospital) and a hospitalization incidence due to adverse drug reaction between 2.37 and 4.01%. COMMUNITY STUDIES: In community medicine, few data are available. In general medicine, the incidence would be 1.99 adverse effects per general practitioner per day. The number of serious adverse drug reactions has been estimated at 0.01 per general practitioner per day. These numbers show the magnitude of adverse drug reactions in terms of morbidity and mortality.

Adverse Drug Reaction Reporting Systems↗

Adverse drug reactions in a department of systemic diseases-oriented internal medicine: prevalence, incidence, direct costs and avoidability.

OBJECTIVE: Adverse drug reactions (ADRs) are a major cause of hospital admission and in-hospital morbidity. Departments of internal medicine are at the forefront of this problem. To increase the knowledge base, we did a study of the frequency, hazard function, avoidability, and cost of ADRs as a cause for admission in internal medicine, or when occurring after admission. METHODS: This prospective cohort study was based on all admissions to an internal medicine unit over a 4-month period. Patients were intensively followed in order to assess any ADR occurring during the hospital stay. Causality, direct costs, and preventability were assessed. RESULTS: Of 444 admissions (2569 patient-days), 156 ADRs occurred in 116 patients (26.1% of all admissions); 95 (21.4%) of these had ADRs at admission, which were the reason for admission in 32 (7.2%). Twenty-one patients (4.7%) presented with 26 ADRs during hospitalization. The in-hospital ADR incidence rate was 10.1 per 1000 patient-days. The cost of ADRs leading to hospitalization was estimated at Euro 11,357 per hospital bed per year. Eighty percent of ADRs could be considered preventable. CONCLUSION: ADRs in hospitalized patients are common and often preventable. Since most ADRs occurred before admission, prevention strategies should preferentially target primary health care providers.

Drug Monitoring↗

Sample size calculations for risk equivalence testing in pharmacoepidemiology.

Equivalence testing has been widely discussed and is commonly used in pharmacokinetics (bioequivalence) and clinical trials (therapeutic equivalence). It can also be applied to pharmacoepidemiology, where the aim may be to test with a known risk (one-group design) or with another drug (two-group design). Whether the approach is two-sided or one-sided, predefined equivalence limits are required. The definition of the equivalence region can be based on either risk difference or risk ratio. Risk equivalence testing is complicated by the binary nature of the outcome, its low frequency, and by the absence of commonly defined equivalence limits for differences or ratios. In this context, we consider usable formulae for sample sizes. In most cases, at least when the risk studied is large enough (above 1/1,000), it appears that these formulae result in sample sizes that may be acceptable for practical purposes. For example, demonstrating equivalence with a known risk of 0.01, a 20% maximal risk difference, and a one-sided test (alpha = 0.05 and beta = 0.2) requires: under the one-group design (known risk), 15,309 patients; and under the two-group design, 30,617 patients per group. This approach is the appropriate way to conclude equivalence, rather than the commonly used approach of difference testing and concluding equivalence when the null hypothesis of equality is not rejected.

Clinical Trials as Topic↗