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F Haramburu

Publications and source records attributed to F Haramburu.

At least 37 records · Page 2Linked to original sources
PubMed1996

Comparing the toxicity of two drugs in the framework of spontaneous reporting: a confidence interval approach.

Spontaneous reporting remains the most frequently used technique in post-marketing surveillance. Decision-making usually depends on comparisons between the number of adverse drug reactions (ADRs) reported for two drugs on the basis of an equivalent number of prescriptions. The validity of such comparisons is expected to be jeopardized by probable underreporting ADR cases. This problem is accentuated when it cannot be assumed that the magnitude of underreporting is the same for the both drugs. Differences in reporting ratios can overemphasize, cancel, or reverse the conclusions of a statistical comparison based on the number of reports. We propose a single method for (1) calculating confidence intervals for relative risks estimated in the context of spontaneous reporting and (2) deriving the range of reporting ratios for which the conclusion of the statistical comparison remains statistically valid.

Adverse Drug Reaction Reporting Systems↗
PubMed1994

Adverse drug reactions: physicians' opinions versus a causality assessment method.

Since spontaneous reporting of adverse drug reactions depends on the physician's opinion of the relationship between the drug and the adverse event, we compared physicians' opinions with the scores obtained by the causality assessment method used in France. During a 2 month period, all physicians who reported adverse drug reactions (ADRs) to our pharmacovigilance centre expressed their opinions on the causal link by means of visual analogue scales. ADR reports were then assessed with the French causality assessment method by a clinical pharmacologist who was blind to physicians' opinions. The assessment by both physicians and the standardized method was performed for 75 ADR cases involving 120 drugs. Physicians used a wide range of assessments, with a preponderance of extreme scores, resulting in a U-shaped distribution, while the standardized method gave generally low scores. Scores given by physicians were very high (causality considered very likely or likely) in 60% of cases and very low (causality considered unlikely or dubious/possible) in 32% of cases. Scores obtained using the causality assessment method were low (causality dubious/possible) in 89% of cases and causality considered likely in only 11 cases, essentially in cases with positive rechallenge. Complete agreement occurred in only 6% of cases. Adding complete agreement and minor discrepancies raised the percentage to 49%.

Adverse Drug Reaction Reporting Systems↗
PubMed1994

False-positives in spontaneous reporting: should we worry about them?

Spontaneous reporting remains the most used and, undoubtedly, the most cost-effective approach for the identification of adverse drug reactions (ADRs). Most of the limitations of this method are well recognised but the possibility of receiving false-positive reports of coincidental drug-event associations has received little attention. In this paper we propose a method based on the Poisson distribution for computing the maximum number of reports of an ADR that could be expected to be reported coincidentally. Three parameters are required: (i) the background risk of the event in the reference population, (ii) the total number of patients treated with the drug considered and, (iii) the proportion of cases that have been reported to the pharmacovigilance system. For most empirical situations occurring in the post-marketing surveillance setting, the expected number remains low and only a maximum of one to three cases could be accepted as possibly coincidental. For rare adverse events such as agranulocytosis or toxic epidermal necrolysis, coincidental associations are so unlikely that a number of reports greater than three constitutes a strong warning and requires further investigation. These findings suggest that for rare events, reports of coincidental drug-event associations are too unlikely to be considered as an important limitation of spontaneous reporting.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1994

[Organization and results of drug vigilance in France].

Pharmacovigilance represents all methods of detection, assessment, information and prevention of adverse drug reactions (ADRs). It mainly involves the post-marketing phase because of the low probability of detecting all possible adverse effects of a drug during pre-marketing development. The most widely used method for pharmacovigilance is spontaneous reporting which is an excellent signal generator but precludes satisfactory calculation of incidence rates. The French Pharmacovigilance System has been set up in 1973; reporting of ADRs has been made mandatory in 1984 for prescribers. This system consists in a network of 30 regional centres under supervision of a coordinating committee at the French Drug Agency. The number of ADR cases received, assessed and recorded by the regional centres is around 10,000 per year; a similar number of cases are reported to the Drug Agency by the pharmaceutical industry. Moreover, Regional Centres work as Drug Information Centres answering more than 23,000 inquiries per year.

Adverse Drug Reaction Reporting Systems↗
PubMed1992

Power and weakness of spontaneous reporting: a probabilistic approach.

It has been clearly demonstrated that spontaneous reporting remains one of the best ways for picking up new adverse drug reactions (ADRs) once a drug is on the market. The probability of revealing a new ADR by spontaneous reporting was studied as a function of reporting rate, strength of drug-event association (relative risk), background incidence of the event and number of patients treated. The model included determination of (i) the probability of reporting at least one drug-event association case and (ii) the overall probability of concluding that the drug-event association is not coincidental. Both probabilities were generally low. The results suggest that the identification of a new risk by spontaneous reporting implies a strong association between the drug treatment and the occurrence of the event.

Adverse Drug Reaction Reporting Systems↗
PubMed1991

Spontaneous reporting: how many cases are required to trigger a warning?

A statistical method is proposed to aid decisions on the recognition of new adverse drug reactions on the basis of spontaneous reports. The maximal number of associations between drug exposure and event is calculated from an independence test between drug and event, taking into account the expected incidence of that particular event in the general population. An example is given which illustrates the method.

Chemical and Drug Induced Liver Injury↗
PubMed1990

Comparison of 500 spontaneous and 500 published reports of adverse drug reactions.

The information and case quality of 500 spontaneous and 500 published adverse drug reaction (ADR) reports were compared, including a study of the most common criteria used in different causality assessment methods. The criteria were more often of positive value in the published reports. Nevertheless, spontaneous reports play an important role in the detection of new ADRs.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1986

Computerized comparison of six adverse drug reaction assessment procedures.

Several standardized assessment procedures are currently used in the evaluation of adverse drug reactions (ADRs). Disagreement in rating ADRs can result from between-raters variability and between-methods differences in weighting the evidence. We eliminated between-raters variability by computer simulation of 1134 ADRs (including all the possible combinations of criteria currently used) and by automatic rating using different algorithms adapted from six published methods. Percentage agreement (Po) and weighted kappa test (kappa w) between pairs of methods are always better than with randomized scores, but the strength of agreement is only moderate (0.26 less than Po less than 0.59; 0.14 less than kappa w less than 0.51). The weightings of criteria are evaluated in terms of sensitivity, specificity, and predictive values. Criteria are neither sensitive (0.41 less than Se less than 0.70) nor specific (0.18 less than Sp less than 0.63) and have poor predictive values. Disagreements on weightings are considerable for three major criteria: timing of event, dechallenge, and alternative etiologic candidates. We discuss some ways of improving reliability of ADR diagnosis.

Computers↗
PubMedDate not supplied

Abuse of prescription medicines in southwestern France.

BACKGROUND: Few quantitative data are available concerning abuse of medicine in the general population, although dependence on prescription medicines involves a significant proportion of the population. Falsified prescription forms can be used as an indicator of abuse. METHODS: Community pharmacists in a representative network were asked to report any falsified prescription form presented over a 1-year period. Sales data were used to express results as abuse rate and abuse rate ratio. RESULTS: Two-thirds of the 130 pharmacies in the network reported at least 1 falsified prescription. The reported incidence of falsified prescriptions was 2.3 per 10 000 inhabitants. A total of 392 falsified prescription forms was collected. The abuse rate ratios were 171 (95% CI 140 to 210) for dextroamphetamine-phenobarbital in combination, 168 (95% CI 131 to 216) for fenozolone, 67 (95% CI 53 to 84) for buprenorphine, and 40.5 (95% CI 33 to 50) for clobenzorex. CONCLUSIONS: These results show the efficiency of a method for detecting falsified prescriptions forms using community pharmacists. The abuse of medicines already known for their addictive potential can be estimated and alerts can also be detected.

Crime↗
PubMedDate not supplied

[Iatrogenic medication: estimation of its prevalence in French public hospitals. Regional Centers of Pharmacovigilance].

The French network of Regional Centres of Pharmacovigilance has made an estimation of the occurrence of adverse drug reactions in a representative sample of patients in French public hospitals (departments of medicine, of surgery and of geriatrics). The study looked at one specific day in the spring of 1997. Each observed case of adverse drug reaction was validated. The total sample comprised 2132 patients of whom 969 were in a university hospital and 1163 in a general hospital. The hospitals and units concerned are representative of the country as a whole. One adverse drug reaction at least was present for 221 patients on the day of the investigation. This means a prevalence rate of 10.3 per cent (95 per cent CI: 8.7 to 11.9 per cent). In 33 per cent of cases (95 per cent CI: 26 to 42 per cent), the observed effects were rated as serious. From an incidence rate of 1.8 per cent (95 per cent CI: 1.0 to 25 per cent) on one specified day it can be estimated that in France an adverse drug reaction will occur in about 1,300,000 patients per year during a stay in hospital.

Adverse Drug Reaction Reporting Systems↗
PubMedDate not supplied

[Substitution treatment for opiate dependence: survey of community pharmacies in Aquitaine].

The prescription of maintenance treatment for opioid dependence has increased dramatically in France since the approval of high-dose buprenorphine in general practice. Community pharmacists are particularly involved since daily dispensing is recommended. A postal survey was conducted within a representative network of community pharmacies in Aquitaine, south-western France. The objective was to assess quantitative and qualitative data on these treatments in the region through pharmacists' opinions and experiences. Out of 61 responders, 62 per cent had already dispensed maintenance treatment. During the survey, 88 patients were under treatment at these pharmacies. Nearly 80 per cent of the pharmacists agreed with the dispensing of these treatments and more than 60 per cent had a positive opinion of them. Community pharmacists feel concerned by the treatment for opioid dependence.

Buprenorphine↗
PubMedDate not supplied

[Cost of hospitalizations for adverse drug effects].

The French network of Regional Pharmacovigilance Centres evaluated in 1997 the prevalence of adverse effects of drugs (AED). In 1998, and again with the support of the French Drug Agency, in collaboration with the company CEMKA for economic evaluations, the incidence of AED-related hospitalizations in the medical department of French public hospitals was studied. The evaluation was performed over 14 consecutive days in 62 hospital departments, which were selected randomly. The total number of 3137 patients were hospitalized for a mean duration of 9 days and they were using a mean number of six different drugs. Taking into account the number of about 4 million patients admitted per year in the hospitals represented, it was estimated that the total number of AED-related hospitalizations amounts to about 130,000 annually (CI95%: 100,916-156,620). Using established cost calculations for hospitalized days (AP-HP, results of 1996) the mean cost for an AED-related hospitalization was estimated to be about FF16,000.

Adult↗