Resumen es: Antecedentes: Las descripciones practicas de los procedimientos utilizados para le re... more Resumen es: Antecedentes: Las descripciones practicas de los procedimientos utilizados para le revision dela medicacion por farmaceuticos son escasas. Objetivo: Desc...
Three hundred and thirteen consecutive admissions to a department of respiratory medicine were ev... more Three hundred and thirteen consecutive admissions to a department of respiratory medicine were evaluated in a prospective high-intensity monitoring scheme concerning adverse drug reactions or dose-related therapeutic failures as the contributing or sole cause of hospital admission. Eleven patients [3.5%, 95% confidence interval (CI) 2.0-6.2] were admitted because of adverse drug reactions. Only 3 of these patients manifested respiratory symptoms, while the remainder had various intercurrent nonpulmonary problems and were well known in the outpatient clinic, e.g. asthma or cancer patients. It is concluded that adverse drug reactions requiring admission rarely present as respiratory symptoms. Fourteen patient (4.5%, CI 2.7-7.4) were admitted because of dose-related therapeutic failures in all cases, except 2 with respiratory symptoms. Half of these were due to noncompliance. Analysis of theophylline samples taken on admission from 46 patients showed 25 (54%) to have concentrations below the therapeutic range of 55-110 microM, but contributed little to the identification of noncompliant patients. Eighty-three percent of the drug events were found to have been unavoidable. Nine patients admitted with acute asthma did not receive corticosteroids prior to admission (2.9%), all of which had therapy prescribed in general practice. The present study showed a comparatively low and hardly affectable prevalence of admissions caused by adverse drug reactions and dose-related therapeutic failure. However, therapeutic failure due to inappropriate choice of asthma medication, which was not included in this estimate, may be an important avoidable cause of admissions.
PurposeIn pharmacoepidemiological studies, the precision of effect estimates usually depends on t... more PurposeIn pharmacoepidemiological studies, the precision of effect estimates usually depends on the lowest number in the underlying two by two table. We denote this the “bottleneck count” (BNC). We describe how to translate the BNC into an achievable precision and provide empirical examples.MethodsFirst, we derive a theoretical prediction of the precision in a study where only the BNC determines precision. As an illustration, we calculated the expected precision of a null‐effect study on retinoids and peptic ulcer bleeding, expressed as the upper/lower confidence limit ratio (ULCLR). Finally, we reviewed 126 effect estimates from the literature, analyzing the relationship between the predicted and achieved precision.ResultsThe log–log transformed ULCLR was shown to be a simple linear function of log(BNC). The expected annual number of retinoid‐users experiencing a peptic ulcer bleeding was 9.8, yielding an estimated ULCLR for a 1‐year study of 3.84. The literature review showed an i...
For self-controlled studies of medication-related effects, time-varying confounding by indication... more For self-controlled studies of medication-related effects, time-varying confounding by indication can occur if the indication varies over time. We describe how active comparators might mitigate such bias, using an empirical example. Approaches to using active comparators are described for case-crossover design, case-time-control design, self-controlled case-series, and sequence symmetry analyses. In the empirical example, we used Danish data from 1996–2018 to study the association between penicillin and venous thromboembolism (VTE), using roxithromycin, a macrolide antibiotic, as comparator. Upper respiratory infection is a transient risk factor for VTE, thus representing time-dependent confounding by indication. Odds ratios for case-crossover analysis were 3.35 (95% confidence interval: 3.23, 3.49) for penicillin and 3.56 (95% confidence interval: 3.30, 3.83) for roxithromycin. We used a Wald-based method or an interaction term to estimate the odds ratio for penicillin with roxithr...
European journal of emergency medicine : official journal of the European Society for Emergency Medicine, Jan 25, 2016
Admission with severe sepsis is associated with an increased short-term mortality, but it is unes... more Admission with severe sepsis is associated with an increased short-term mortality, but it is unestablished whether sepsis severity has an impact on intermediate-term and long-term mortality following admission to an acute medical admission unit. This was a population-based study of all adults admitted to an acute medical admission unit, Odense University Hospital, Denmark, from September 2010 to August 2011, identified by symptoms and clinical findings. We categorized the mortality periods into intermediate-term (31-180 days) and long-term (181-365, 366-730, and 731-1096 days). Mortality hazard ratios (HRs), comparing patients admitted with sepsis with those of a well-defined background population, were estimated using multivariable Cox regression. HRs were presented with 95% confidence intervals. In total, 621 (36.3%) presented with sepsis, 1071 (62.5%) presented with severe sepsis, and 21 (1.2%) presented with septic shock. Thirty-day all-cause mortality for patients with sepsis, ...
S FROM THIS PROGRAM ALSO PRESENTED IN THIS CONFERENCE Arana A, et al. Do individual antimuscarini... more S FROM THIS PROGRAM ALSO PRESENTED IN THIS CONFERENCE Arana A, et al. Do individual antimuscarinic drugs to treat overactive bladder have different cardiovascular risks? A UK CPRD cohort study. Abstract #920. Poster Session C: Safety & Effectiveness GU & Hormones, Sunday, 28 August 2016, 8:00 AM-1:45 PM. Fortuny J, et al. Evaluation of free-text comments to validate common cancer diagnoses in the UK CPRD. Abstract #91. Poster Session A: Spotlight Session-Databases, Friday, 26 August 2016, 8:00 AM-6:00 PM. Hallas J, et al. Incidence of cardiovascular events in new users of overactive bladder medications in Denmark. Abstract #848. Oral presentation in session CV Adverse Events: Affairs of the Heart, Sunday, 28 August 2016, 3:15 PM-4:45 PM. Linder M, et al. Cancer risk in users of antimuscarinic drugs for overactive bladder: a cohort study in the Swedish national registers. Abstract #919. Poster Session C: Safety & Effectiveness GU & Hormones, Sunday, 28 August 2016, 8:00 AM-1:45 PM. L...
In register-based pharmacoepidemiological studies, each day of follow-up is usually categorized e... more In register-based pharmacoepidemiological studies, each day of follow-up is usually categorized either as exposed or unexposed. However, there is an underlying continuous probability of exposure, and by insisting on a dichotomy, researchers unwillingly force a nondifferential misclassification into their analyses. We have recently developed a model whereby probability of exposure can be modeled, and we tested this on an empirical case of nonsteroidal anti-inflammatory drug (NSAID)-induced upper gastrointestinal bleeding (UGIB). We used a case-controls data set, consisting of 3568 cases of severe UGIB and 35 552 matched controls. Exposure to NSAID was based on 3 different conventional dichotomous measures. In addition, we tested 3 probabilistic exposure measures, a simple univariate backward-recurrence model, a "full" multivariable model, and a "reduced" multivariable model. Odds ratios (ORs) and 95% confidence intervals for the association between NSAID use and U...
Sequence symmetry analysis (SSA) is a method for detecting adverse drug events by utilizing compu... more Sequence symmetry analysis (SSA) is a method for detecting adverse drug events by utilizing computerized claims data. The method has been increasingly used to investigate safety concerns of medications and as a pharmacovigilance tool to identify unsuspected side effects. Validation studies have indicated that SSA has moderate sensitivity and high specificity and has robust performance. In this review we present the conceptual framework of SSA and discuss advantages and potential pitfalls of the method in practice. SSA is based on analyzing the sequences of medications; if one medication (drug B) is more often initiated after another medication (drug A) than before, it may be an indication of an adverse effect of drug A. The main advantage of the method is that it requires a minimal dataset and is computationally efficient. By design, SSA controls time-constant confounders. However, the validity of SSA may be affected by time-varying confounders, as well as by time trends in the occu...
Resumen es: Antecedentes: Las descripciones practicas de los procedimientos utilizados para le re... more Resumen es: Antecedentes: Las descripciones practicas de los procedimientos utilizados para le revision dela medicacion por farmaceuticos son escasas. Objetivo: Desc...
Three hundred and thirteen consecutive admissions to a department of respiratory medicine were ev... more Three hundred and thirteen consecutive admissions to a department of respiratory medicine were evaluated in a prospective high-intensity monitoring scheme concerning adverse drug reactions or dose-related therapeutic failures as the contributing or sole cause of hospital admission. Eleven patients [3.5%, 95% confidence interval (CI) 2.0-6.2] were admitted because of adverse drug reactions. Only 3 of these patients manifested respiratory symptoms, while the remainder had various intercurrent nonpulmonary problems and were well known in the outpatient clinic, e.g. asthma or cancer patients. It is concluded that adverse drug reactions requiring admission rarely present as respiratory symptoms. Fourteen patient (4.5%, CI 2.7-7.4) were admitted because of dose-related therapeutic failures in all cases, except 2 with respiratory symptoms. Half of these were due to noncompliance. Analysis of theophylline samples taken on admission from 46 patients showed 25 (54%) to have concentrations below the therapeutic range of 55-110 microM, but contributed little to the identification of noncompliant patients. Eighty-three percent of the drug events were found to have been unavoidable. Nine patients admitted with acute asthma did not receive corticosteroids prior to admission (2.9%), all of which had therapy prescribed in general practice. The present study showed a comparatively low and hardly affectable prevalence of admissions caused by adverse drug reactions and dose-related therapeutic failure. However, therapeutic failure due to inappropriate choice of asthma medication, which was not included in this estimate, may be an important avoidable cause of admissions.
PurposeIn pharmacoepidemiological studies, the precision of effect estimates usually depends on t... more PurposeIn pharmacoepidemiological studies, the precision of effect estimates usually depends on the lowest number in the underlying two by two table. We denote this the “bottleneck count” (BNC). We describe how to translate the BNC into an achievable precision and provide empirical examples.MethodsFirst, we derive a theoretical prediction of the precision in a study where only the BNC determines precision. As an illustration, we calculated the expected precision of a null‐effect study on retinoids and peptic ulcer bleeding, expressed as the upper/lower confidence limit ratio (ULCLR). Finally, we reviewed 126 effect estimates from the literature, analyzing the relationship between the predicted and achieved precision.ResultsThe log–log transformed ULCLR was shown to be a simple linear function of log(BNC). The expected annual number of retinoid‐users experiencing a peptic ulcer bleeding was 9.8, yielding an estimated ULCLR for a 1‐year study of 3.84. The literature review showed an i...
For self-controlled studies of medication-related effects, time-varying confounding by indication... more For self-controlled studies of medication-related effects, time-varying confounding by indication can occur if the indication varies over time. We describe how active comparators might mitigate such bias, using an empirical example. Approaches to using active comparators are described for case-crossover design, case-time-control design, self-controlled case-series, and sequence symmetry analyses. In the empirical example, we used Danish data from 1996–2018 to study the association between penicillin and venous thromboembolism (VTE), using roxithromycin, a macrolide antibiotic, as comparator. Upper respiratory infection is a transient risk factor for VTE, thus representing time-dependent confounding by indication. Odds ratios for case-crossover analysis were 3.35 (95% confidence interval: 3.23, 3.49) for penicillin and 3.56 (95% confidence interval: 3.30, 3.83) for roxithromycin. We used a Wald-based method or an interaction term to estimate the odds ratio for penicillin with roxithr...
European journal of emergency medicine : official journal of the European Society for Emergency Medicine, Jan 25, 2016
Admission with severe sepsis is associated with an increased short-term mortality, but it is unes... more Admission with severe sepsis is associated with an increased short-term mortality, but it is unestablished whether sepsis severity has an impact on intermediate-term and long-term mortality following admission to an acute medical admission unit. This was a population-based study of all adults admitted to an acute medical admission unit, Odense University Hospital, Denmark, from September 2010 to August 2011, identified by symptoms and clinical findings. We categorized the mortality periods into intermediate-term (31-180 days) and long-term (181-365, 366-730, and 731-1096 days). Mortality hazard ratios (HRs), comparing patients admitted with sepsis with those of a well-defined background population, were estimated using multivariable Cox regression. HRs were presented with 95% confidence intervals. In total, 621 (36.3%) presented with sepsis, 1071 (62.5%) presented with severe sepsis, and 21 (1.2%) presented with septic shock. Thirty-day all-cause mortality for patients with sepsis, ...
S FROM THIS PROGRAM ALSO PRESENTED IN THIS CONFERENCE Arana A, et al. Do individual antimuscarini... more S FROM THIS PROGRAM ALSO PRESENTED IN THIS CONFERENCE Arana A, et al. Do individual antimuscarinic drugs to treat overactive bladder have different cardiovascular risks? A UK CPRD cohort study. Abstract #920. Poster Session C: Safety & Effectiveness GU & Hormones, Sunday, 28 August 2016, 8:00 AM-1:45 PM. Fortuny J, et al. Evaluation of free-text comments to validate common cancer diagnoses in the UK CPRD. Abstract #91. Poster Session A: Spotlight Session-Databases, Friday, 26 August 2016, 8:00 AM-6:00 PM. Hallas J, et al. Incidence of cardiovascular events in new users of overactive bladder medications in Denmark. Abstract #848. Oral presentation in session CV Adverse Events: Affairs of the Heart, Sunday, 28 August 2016, 3:15 PM-4:45 PM. Linder M, et al. Cancer risk in users of antimuscarinic drugs for overactive bladder: a cohort study in the Swedish national registers. Abstract #919. Poster Session C: Safety & Effectiveness GU & Hormones, Sunday, 28 August 2016, 8:00 AM-1:45 PM. L...
In register-based pharmacoepidemiological studies, each day of follow-up is usually categorized e... more In register-based pharmacoepidemiological studies, each day of follow-up is usually categorized either as exposed or unexposed. However, there is an underlying continuous probability of exposure, and by insisting on a dichotomy, researchers unwillingly force a nondifferential misclassification into their analyses. We have recently developed a model whereby probability of exposure can be modeled, and we tested this on an empirical case of nonsteroidal anti-inflammatory drug (NSAID)-induced upper gastrointestinal bleeding (UGIB). We used a case-controls data set, consisting of 3568 cases of severe UGIB and 35 552 matched controls. Exposure to NSAID was based on 3 different conventional dichotomous measures. In addition, we tested 3 probabilistic exposure measures, a simple univariate backward-recurrence model, a "full" multivariable model, and a "reduced" multivariable model. Odds ratios (ORs) and 95% confidence intervals for the association between NSAID use and U...
Sequence symmetry analysis (SSA) is a method for detecting adverse drug events by utilizing compu... more Sequence symmetry analysis (SSA) is a method for detecting adverse drug events by utilizing computerized claims data. The method has been increasingly used to investigate safety concerns of medications and as a pharmacovigilance tool to identify unsuspected side effects. Validation studies have indicated that SSA has moderate sensitivity and high specificity and has robust performance. In this review we present the conceptual framework of SSA and discuss advantages and potential pitfalls of the method in practice. SSA is based on analyzing the sequences of medications; if one medication (drug B) is more often initiated after another medication (drug A) than before, it may be an indication of an adverse effect of drug A. The main advantage of the method is that it requires a minimal dataset and is computationally efficient. By design, SSA controls time-constant confounders. However, the validity of SSA may be affected by time-varying confounders, as well as by time trends in the occu...
Uploads
Papers by Jesper Hallas