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Biomedical subjects

B Bégaud

Publications and source records attributed to B Bégaud.

At least 19 recordsLinked to original sources
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2000

[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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

Patterns of neuroleptic drug prescription: a national cross-sectional survey of a random sample of French psychiatrists.

AIMS: To describe the psychiatric indications of neuroleptics (especially the relative share of schizophrenic and other psychotic disorders) and the usage patterns of these drugs (dose, duration, coprescriptions). METHODS: A one-day national cross-sectional survey in a random sample of 723 French psychiatrists was carried out in 1996. Each psychiatrist was asked to complete a standardized questionnaire for the first three patients seen the day of the survey to whom at least one neuroleptic was prescribed (initiated or renewed). RESULTS: One thousand seven hundred and fifty-four questionnaires were returned. Three quarters of the patients (74%) were psychotic (664 with schizophrenia, and 636 other psychosis), 19. 3% were depressive and 6.7% had other psychiatric disorders. Phenothiazines were the most often prescribed (40.8%), followed by butyrophenones (22.5%), benzamides (15.8%), other neuroleptics (14. 8%) and thioxanthenes (6.1%). Among schizophrenic subjects, an average number of 1.54 (95% CI: 1.50-1.60) neuroleptics were prescribed per patient, compared with 1.4 (95% CI: 1.32-1.41) and 1. 2 (95% CI: 1.14-1.23) in other psychotic and depressive subjects, respectively. Regardless of the indication, non-neuroleptic psychotropic drugs were coprescribed in 75.4%, mainly benzodiazepines (75.7%). Adjuvant drugs used in prevention or treatment of side-effects were coprescribed in 46.7%, mostly anticholinergic antiparkinsonians (86.1%). CONCLUSIONS: Neuroleptics are mainly prescribed for psychotic disorders and especially schizophrenia. However, current recommendations are not always followed.

Adult↗
PubMed2000

The link between sunshine and phototoxicity of sparfloxacin.

AIMS: To test the association between reporting rates for sparfloxacin-induced phototoxicity and sunlight u.v. exposure, and the effects of regulatory action. METHODS: The reporting rates for phototoxicity with sparfloxacin to the French Pharmacovigilance System or to the Drug Manufacturer were compared with concurrent national mean u.v. exposure obtained from Météo-France, before and after the regulatory restrictions and warnings. RESULTS: There were 371 severe phototoxic reaction reports during the first 9 months of marketing (reporting rate of 0.4 per thousand treated patients), approximately four to 25 times that reported for other fluoroquinolones. The reporting rate correlated highly (r = 0.873, P < 0.001) with the mean monthly u.v. exposure from sunlight (from Météo-France). Regulatory action including warnings for physicians, and restricted indications dramatically decreased the number of reports, but not the reporting rate. CONCLUSIONS: This is the first demonstration of a strong association between sunlight exposure in a population and drug-induced phototoxicity. Regulatory action had no effect on the reporting rate (individual exposed patient risk), though it solved the public health issue.

Adolescent↗
PubMed1999

Is reporting rate a good predictor of risks associated with drugs?

AIMS: Uncertainty as to relative under-reporting plagues the comparisons of spontaneous reporting rates as a tool for decision-making in pharmacovigilance. However, it is generally accepted that under-reporting should be reasonably similar for similar drugs sharing the same indication, country and period of marketing. To test this, we compared the adverse drug reaction reporting rates to the French regional pharmacovigilance centres for six pairs of identical drug marketed at the same time by different companies under different brand names (co-marketing). METHODS: All reaction reports were related to sales, to compute reporting rate; within each pair, the reporting rate ratio and its confidence interval were calculated. RESULTS: The rate ratios were all between 0.76 and 1.33. Two of them were significantly different from 1 (1.28; 95% C.I. [1.01; 1.60] and 1.33; 95% C.I. [1.06; 1.74]). CONCLUSIONS: These small differences in reporting rates would not warrant regulatory action and support the usual assumption of similar reporting for similar drugs.

Adverse Drug Reaction Reporting Systems↗
PubMed1998

European network for the case-population surveillance of rare diseases (Euronet). A prospective feasibility study.

OBJECTIVE: Euronet, a case-population surveillance scheme, aims to estimate the risk of certain rare conditions which are commonly iatrogenic, by comparing drug use amongst non-selective cases with overall drug use in the general population. METHODS: The method is based on three provisos: (1) all incident cases (irrespective of suspected aetiology) should be ascertained and studied; (2) a full drug history should be obtained from cases by direct interview; and (3) drug-use data for the products of interest should be available for this population from which cases are chosen. The feasibility of this problem-oriented approach for the identification of new signals of adverse drug reactions and for risk estimation will be tested in relation to agranulocytosis, Stevens-Johnson syndrome and toxic epidermal necrolysis in four defined areas in Europe, totalling 19 x 10(6) inhabitants, with these latest two outcomes being studied in only three regions. The design, methods and main limitations of this case-population surveillance approach are described.

Adverse Drug Reaction Reporting Systems↗
PubMed1998

Under-reporting of adverse drug reactions. Estimate based on a spontaneous reporting scheme and a sentinel system.

OBJECTIVE: Spontaneous reporting is the most common method used in pharmacovigilance and the best one to generate signals on new or rare adverse drug reactions (ADRs). Under-reporting is a major drawback of this system. The objective of this study was to quantify the extent of under-reporting in general practice and to assess the factors which influence it. METHODS: Details of ADRs collected through a short intensive survey were compared with primary care spontaneous reports received by the Castilla y Leon Regional Pharmacovigilance Centre during a 12-month reference period. The survey was undertaken by a random sample of 146 general practitioners (GPs), providing care to 149,487 people. The pharmacovigilance centre received reports concerning the whole regional population (2.5 million) covered by primary health care. The under-reporting coefficient (U) was estimated as the ratio between the number of effects observed by physicians in the survey and those spontaneously reported to the pharmacovigilance centre. RESULTS: The overall under-reporting rate was 1144 [95% confidence interval (CI): 928-1409]. Under-reporting was greater for psychiatric (2119; 945-4752) and gastrointestinal (1946; 1424-2659) disorders. Severe effects were more reported (U = 605; 151-2431) than moderate (863; 473-1575) and mild (1209; 973-1503) ones. The under-reporting rate was lower for drugs recently marketed (706; 406-1230) and slightly lower for unlabelled effects (1031; 641-1657). CONCLUSION: The under-reporting rate of ADRs is considerable, though not homogeneous for the different cases. This should be taken into account when comparing adverse effects (AEs) for different drugs. Under-reporting seems to be positively selective, as it involves mainly the less severe and better-known effects, preserving the value of spontaneous reporting for signal detection.

Adolescent↗