Characteristics of drugs safety signals that predict safety related product information update

Purpose: Investigation of drug safety signals is one of the major tasks in pharmacovigilance. Among many potential signals identified, only a few reflect adverse drug reactions requiring regulatory actions, such as product information (PI) update. Limited information is available regarding the signal characteristics that might predict PI update following signal evaluation. The objective of this study was to identify signal characteristics associated with PI updates following signal evaluation by the European Medicines Agency Pharmacovigilance Risk Assessment Committee during 2012 to 2016. Methods: A comparative study was performed based on data from 172 safety signals. Characteristics of signals were extracted from the European Pharmacovigilance Issues Tracking Tool database. Multivariable logistic regression analysis was used to assess the relationship between signal characteristics and the decision to update the PI. Results: Multivariable logistic regression analysis showed that the presence of evidence in multiple types of data sources (adjusted odds ratio [OR] 7.8 95% CI [1.5, 40.1]); mechanistic plausibility of the drug-event association (adjusted OR 3.9 95% CI [1.9, 8.0]); seriousness of the event (adjusted OR 4.2 95% CI [1.3, 13.9]); and age of drugs ≤5 years (adjusted OR 3.9 95% CI [1.2, 12.7]) were associated with the decision to change the PI (P < 0.05). Conclusions: This study identified 4 characteristics of drug safety signals that have shown to be associated with PI changes as outcome of signal evaluation. These characteristics may be used as criteria for selection and prioritization of potential signals that are more likely to necessitate product information updates

The Application and Implications of Novel Deterministic Sensitivity Analysis Methods

Deterministic sensitivity analyses (DSA) remain important to interpret the effect of uncertainties in individual parameters on results of cost-effectiveness analyses. Classic DSA methodologies may lead to wrong conclusions due to a lack of or misleading information regarding marginal effects, non-linearity, likelihood and correlations. In addition, tornado diagrams are misleading in some situations. Recent advances in DSA methods have the potential to provide decision makers with more reliable information regarding the effects of uncertainties in individual parameters. This practical application discusses advances to classic DSA methods and their implications. Three methods are discussed: stepwise DSA, distributional DSA and probabilistic DSA. For each method, the technical specifications, options for presenting results, and its implications for decision making are discussed. Options for visualizing DSA results in incremental cost-effectiveness ratios and in incremental net benefits are presented. The use of stepwise DSA increases interpretability of marginal effects and non-linearities in the model, which is especially relevant when arbitrary ranges are implemented. Using the probability distribution of each parameter in distributional DSA provides insight on the likelihood of model outcomes while probabilistic DSA also includes the effects of correlations between parameters. Probabilistic DSA, preferably expressed in incremental net benefit, is the most appropriate method for providing insight on the effect of uncertainty in individual parameters on the estimate of cost effectiveness. However, the opportunities provided by probabilistic DSA may not always be needed for decision making. Other DSA methods, in particular distributional DSA, can sometimes be sufficient depending on model features. Decision makers must determine to which extent they will accept and implement these new and improved DSA methodologies and adjust guidelines accordingly

Noacs replace VKA as preferred oral anticoagulant among new patients

Background: In 2012, around 400,000 patients in the Netherlands were treated with vitamin K antagonists (VKA) for thromboembolic diseases. Since 2011, non-VKA oral anticoagulants (NOACs) have been available. NOACs do not require frequent INR monitoring and cause less bleeding, which benefits patients, but also imposes a risk of reduced therapy adherence. Objectives: The objective of this study is to describe uptake of and patient compliance with NOACs in The Netherlands between July 2011 and October 2016. Methods: We analysed prescription data for 247.927 NOAC and/or VKA patients across 560 pharmacies. All patients who received at least one prescription of either VKA or NOACs between 1 July 2011 and 30 September 2016 were included in the study. Our database contained (not exhaustive) the following information about the prescriptions: dispensed medication and quantity, dispensing date, prescribed dosage and prescriber type, patient age and gender. We used these data to describe patient profiles, uptake of NOACs among new naïve patients and switch of patients between VKA and NOACs. We developed an algorithm to classify patients as new naïve starters, switcher or repeat patients. We calculated therapy compliance as the percentage of days covered (PDC). To obtain reliable results, in our PDC calculations we included only patients with a time period of at least 12 months between their first and last prescription. Results: During the studied period the share of NOACs in oral anticoagulants has grown to 57% of prescriptions to new patients. More than 70% of new NOAC users were new naïve patients and around 26% switched from VKA. The overall share of NOACs among starters is largest in the group of patients of 50-80 years. Calculated percentages of days covered (PDC) for NOAC patients show that 87% of all users were compliant. Conclusions: NOACs have overtaken VKA as the major treatment prescribed to patients starting on oral anticoagulants, and the number of starters on VKA is at present decreasing. We expect that almost all oral anticoagulants prescribed to new patients will be NOACs. NOAC users are in general compliant with therapy. This may provide additional confidence to physicians in prescribing NOACs instead of VKAs

Variability in market uptake of psychotropic medications in Europe reflects cultural diversity.

Background: In the last 20–30 years, many international studies have found substantial differences in the use of (older) psychotropic medication between European countries. The majority mentioned an important role for attitudes and beliefs towards psychotropic medication. So far, no studies have looked into the effects of cultural diversity on the use of new medications entering the market. As national cultures relate deeply to held values regarding, for example, what is seen as effective versus ineffective or safe versus dangerous, (cultural) diversity in decision making around the role of new medications in clinical practice may already be expected from the first day after market authorization. Methods: This study examined the relation between cultural diversity, described in Hofstede’s model of cultural dimensions (Power Distance, Individualism, Masculinity, Uncertainty Avoidance, Indulgence and Long-Term Orientation) and utilization of three new psychotropic medications, namely aripiprazole, duloxetine and pregabalin in Europe. Country level sales data of the case study medications were correlated to country-specific scores of Hofstede’s cultural dimensions. IMS Health’s MIDAS database has been used for sales data (converted to Defined Daily Doses/1000 inhabitants/day) for the case study medications from the market authorization date in 2004 until December 2009 for 23 EU member states. Results: Consumption of the case study medications was seen in all countries. In general, pregabalin was used more often than aripiprazole and duloxetine. In 2 years after market authorization, approximately 80% of all countries have reported use of all three molecules. Correlations between Hofstede dimensions individualism, long-term orientation and indulgence and total use of the case study medications tended to become stronger over time, but they were only statistically significant for indulgence at two years after market authorization (rho = 0.51, p = 0.014) and three years after market authorization (rho = 0.54, p = 0.008). A more detailed analysis showed (slight) variation by molecule. Conclusions: This study is a first step in including cultural dimensions when explaining cross-national variation in the use of new medications. The results indicate that indulgence, however marginally, is a cultural aspect that relates to the utilization of new psychotropic medications, suggesting that within the cultural context, less regulation of social norms is a main factor in explaining cross-national variation in uptake of these medications. (aut. ref.