Correction to: Impact of risk minimisation measures on the use of strontium ranelate in Europe: a multi-national cohort study in 5 EU countries by the EU-ADR Alliance.

The original version of this article, published on 26 November 2019 contained a mistake.

Impact of risk minimisation measures on the use of strontium ranelate in Europe: a multi-national cohort study in 5 EU countries by the EU-ADR Alliance.

INTRODUCTION: In May 2013 and March 2014, the European Medicines Agency (EMA) issued two decisions restricting the use of strontium ranelate (SR). These risk minimisation measures (RMM) introduced new contraindications and limited the indications of SR therapy. The EMA required an assessment of the impact of RMMs on the use of SR in Europe. Methods design: multi-national, multi-database cohort Setting: electronic medical record databases based on hospital (Denmark) and primary care provenance (Italy, Spain, the Netherlands, UK). PARTICIPANTS: the database source populations were included for population-based analyses, and SR users for patient-level analyses. INTERVENTION: New RMMs included contraindications (ischaemic heart disease, peripheral arterial disease, cerebrovascular disease, uncontrolled hypertension) and restricted SR indication to severe osteoporosis with initiation by experienced physician and not as first line anti-osteoporosis therapy. METHODS: Prevalence and incidence rates of SR use in the population; prevalence of contraindications and restricted indications in SR users, plus 1-year therapy persistence. Drug use measures were calculated in three periods for comparison: reference (2004 to May 2013), transition (June 2013 to March 2014) and assessment (from April 2014 to end 2016). RESULTS: The study population included 143 million person-years(PY) of follow-up and 76,141 incident episodes of SR treatment. Average monthly prevalence rates of SR use dropped by 86.4% from 62.6/10,000 PY (95 CI 62.4-62.9) in the reference to 8.5 (8.5-8.6) in the assessment period. Similarly, the incidence rate of SR use fell by 97.3% from 7.4/10,000 PY (7.4-7.4) to 0.2 (0.2-0.2) between the reference and assessment period. The prevalence of any contraindication decreased, whilst the prevalence of restricted indications increased in these periods. One-year persistence decreased in the assessment compared with reference period. CONCLUSIONS: Our study demonstrates a substantial impact of the regulatory action to restrict use of SR in Europe: SR utilisation overall decreased strongly. The proportion of patients fulfilling the restricted indications, without contraindications, increased after the proposed RMMs.

Use of antihistamines and risk of ventricular tachyarrhythmia: a nested case-control study in five European countries from the ARITMO project.

PURPOSE: After regulatory restrictions for terfenadine and astemizole in '90s, only scarce evidence on proarrhythmic potential of antihistamines has been published. We evaluate the risk of ventricular tachyarrhythmia (VA) related to the use of individual antihistamines. METHODS: A matched case-control study nested in a cohort of new users of antihistamines was conducted within the EU-funded ARITMO project. Data on 1997-2010 were retrieved from seven healthcare databases: AARHUS (Denmark), GEPARD (Germany), HSD and ERD (Italy), PHARMO and IPCI (Netherlands) and THIN (UK). Cases of VA were selected and up to 100 controls were matched to each case. The odds ratio (OR) of current use for individual antihistamines (AHs) was estimated using conditional logistic regression. RESULTS: For agents largely used to prevent allergic symptoms, such as cetirizine, levocetirizine, loratadine, desloratadine and fexofenadine, we found no VA risk. A statistically significant, increased risk of VA was found only for current use of cyclizine in the pooled analysis (ORadj, 5.3; 3.6-7.6) and in THIN (ORadj, 5.3; 95% CI, 3.7-7.6), for dimetindene in GEPARD (ORadj, 3.9; 1.1-14.7) and for ebastine in GEPARD (ORadj, 3.3; 1.1-10.8) and PHARMO (ORadj, 4.6; 1.3-16.2). CONCLUSIONS: The risk of VA associated with a few specific antihistamines could be ascribable to heterogeneity in pattern of use or in receptor binding profile.

Real life data on incidence and risk factors of severe asthma exacerbations in children in primary care.

Real-life data on the incidence rates (IR) and risk factors of severe asthma exacerbations in children are sparse. We aimed to assess IR and risk factors of severe asthma exacerbations in children in real life. We conducted a population-based cohort study using a Dutch GP database containing complete medical records of >1 million patients. All records of children with physician-diagnosed asthma aged 5-18 years between 2000 and 2012 were examined for exacerbations, defined as either hospitalization, emergency department visit or need of systemic steroids for asthma. IR was expressed as number of exacerbations per person year (PY). We identified 14,303 asthmatic children with 35,118 PY of follow-up and 732 exacerbations. The overall IR was 2.1/100PY (95% CI 1.9-2.2), 4.1/100PY (3.8-4.4) for children on asthma treatment. Re-exacerbation occurred in 2% (1.3-4.3) of patients within 1 month, in 25% (20.6-28.8) within 1 year. Predictors for (frequent) exacerbations were age, medication use and prior exacerbations (all p < 0.001). The overall IR of severe asthma exacerbations was 4/100PY in children on asthma treatment, highest in spring and fall. 25% of the patients with an exacerbation will experience a next exacerbation within 1 year. More severe asthma is a predictor of subsequent and future exacerbations.

Application of a Systems Pharmacology-Based Placebo Population Model to Analyze Long-Term Data of Postmenopausal Osteoporosis.

Osteoporosis is a progressive bone disease characterized by decreased bone mass resulting in increased fracture risk. The objective of this investigation was to test whether a recently developed disease systems analysis model for osteoporosis could describe disease progression in a placebo-treated population from the Early Postmenopausal Intervention Cohort (EPIC) study. First, we qualified the model using a subset from the placebo arm of the EPIC study of 222 women who had similar demographic characteristics as the 149 women from the placebo arm of the original population. Second, we applied the model to all 470 women. Bone mineral density (BMD) dynamics were changed to an indirect response model to describe lumbar spine and total hip BMD in this second population. This updated disease systems analysis placebo model describes the dynamics of all biomarkers in the corresponding datasets to a very good approximation; a good description of an individual placebo response will be valuable for evaluating treatments for osteoporosis.

The incidence of Barrett's oesophagus and oesophageal adenocarcinoma in the United Kingdom and The Netherlands is levelling off.

BACKGROUND: Barrett's oesophagus (BO) is a risk factor for oesophageal adenocarcinoma (OAC). Several studies report increasing incidences of BO with substantial variation. AIM: To determine age- and sex-stratified incidence rates (IR) of BO and OAC. METHODS: Cohort study using two primary care databases in the United Kingdom (UK) and the Netherlands (NL) (2000-2012). BO and OAC cases were identified using disease-specific READ codes (UK) and free-text search with manual validation (NL). Age- and sex-specific incidence rates (IRs) were calculated for both BO and OAC. RESULTS: From the study population of 6,885,420 subjects in the UK, we identified 12,312 incident BO and 40 (0.3%) subsequent incident OAC cases. There were 1383 incident BO, and subsequent 5 (0.4%) incident OAC cases among the 1,487,191 subjects in the NL. The IR of BO increased linearly with age: 15.6/100,000 PYs (UK) and 23.7/100,000 PYs (NL) for patients aged 40-44 years, increasing to 85.6/100,000 PYs (UK) and 87.0/100,000 PYs (NL) for 70-74 years. In both the UK and the NL, IR of BO was 2-4 times higher in males than females across all age groups. With respect to calendar time, the IR of BO increased by 35% (UK) and 41% (NL) from 2000 to 2003, after which IRs remained stable until 2012. CONCLUSIONS: The incidence rates of BO in the UK and the NL increased until 2003, but levelled off thereafter. Around 0.3% of patients with BO developed OAC at least 1 year after BO diagnosis. These findings may help tailor endoscopic surveillance strategies among patients with BO.

Establishing in vitro to clinical correlations in the evaluation of cardiovascular safety pharmacology.

Preclinical studies are vital in establishing the efficacy and safety of a new chemical entity (NCE) in humans. To deliver meaningful information, experiments have to be well defined and provide outcome that is relevant and translatable to humans. This review briefly surveys the various preclinical experiments that are frequently conducted to assess drug effects on cardiac conductivity in early drug development. We examine the different approaches used to establish correlations between non-clinical and clinical settings and discuss their value in the evaluation of cardiovascular risk.

Cyclo-oxygenase-2 inhibitors or nonselective NSAIDs plus gastroprotective agents: what to prescribe in daily clinical practice?

BACKGROUND: Two strategies for prevention of upper gastrointestinal (UGI) events for nonselective nonsteroidal anti-inflammatory drug (nsNSAID) users are replacement of the nsNSAID by a cyclo-oxygenase-2-selective inhibitor (coxib) or co-prescription of a gastroprotective agent (GPA). AIM: To identify whether and in whom either of these strategies should be preferred in daily practice. METHODS: A nested case-control study was conducted using three European primary care databases. We selected a cohort including all naive nsNSAID+GPA (≥80% GPA adherence) and coxib users (without GPA use) aged ≥50 years. Cases with an UGI event (i.e. symptomatic UGI ulcer or bleeding) were matched to cohort members without an UGI event on age, sex and number of individual UGI risk factors (i.e. UGI event history, age ≥65 years, concomitant use of anticoagulants, antiplatelets, or glucocorticoids) and calendar time. Conditional logistic regression analysis was used to calculate odds ratios (ORs) with 95% CI, while adjusting for potential confounders. RESULTS: Within the NSAID cohort (n = 617,220), 398 UGI cases were identified. The risk of UGI events was equivalent for coxib and nsNSAID+GPA (≥80% adherence) users (OR: 1.02; 95%CI: 0.77-1.37). In concurrent glucocorticoid users, the risk of UGI events was significantly elevated for nsNSAID+GPA (≥80% adherence) compared with coxib users (OR: 9.01; 95%CI: 1.61-50.50). CONCLUSIONS: The risk of UGI events was similar in nsNSAID+GPA (≥80% adherence) and coxibs users. In patients concurrently using glucocorticoids, a significant increase in the risk of UGI events for nsNSAID+GPA users was observed and coxibs should be preferred.

Assessing the risk of osteonecrosis of the jaw due to bisphosphonate therapy in the secondary prevention of osteoporotic fractures.

SUMMARY: There is evidence that the use oral bisphosphonates can lead to osteronecrosis of the jaws (ONJ). Although the occurrence of ONJ appears rare among oral bisphosphonates (BPs) users, it is important to know that it exists and can be opportunely minimized. INTRODUCTION: The purpose of this study is to evaluate the association between BPs prescribed for the secondary prevention of osteoporotic fractures and the occurrence of ONJ. METHODS: An Italian record linkage claims database with a target population of around 18 million individuals (6 million over 55 years of age) constituted the data source. We conducted a nested case-control study within a cohort of individuals aged 55+ years old, who were discharged from hospitals with a primary diagnosis of incident osteoporotic fracture. The date related to the discharge diagnosis of ONJ was the index date. Conditional logistic regression for matched data was fitted to estimate the odds ratio (OR) along with 95 % confidence intervals (95 % CI) for the likely association between use of BPs and the risk of ONJ. RESULTS: Any one of the 61 ascertained cases of ONJ (incidence rate, 36.6 per 100,000 person-years) was matched to 20 controls for a total of 1120 controls. When the exposure to BPs was modeled according to recency (i.e., exposure time window prior to the index date) of use, the adjusted OR (95 % CI) for current users was 2.8 (1.3-5.9) against never users. The cumulative use of BPs has shown to increase the incidence of ONJ among patients with primary osteoporotic fractures, although not statistically significant risk has been observed. CONCLUSIONS: Although the risk of BP-related ONJ appears low in non-oncological indications, it is important to be aware that it exists and to know how it may be predicted and possibly minimized.

Prescription of nonselective NSAIDs, coxibs and gastroprotective agents in the era of rofecoxib withdrawal - a 617,400-patient study.

BACKGROUND: Gastroprotective strategies are recommended for nonsteroidal anti-inflammatory drug (NSAID) users at risk of upper gastrointestinal (UGI) complications. AIM: To compare the use of gastroprotective strategies in NSAID users in three countries, and the subsequent impact of rofecoxib withdrawal. METHODS: We conducted a population-based cohort study in three general practice (GP) databases: (i) United Kingdom's (UK) GP Research Database (1998-2008); (ii) Italy's (IT) Health Search/CSD Longitudinal Patient Database (2000-2007); and (iii) the Dutch (NL) Integrated Primary Care Information database (1996-2006). Study cohorts comprised incident NSAID users ≥50 years. Preventive strategies included: (i) co-prescription of gastroprotective agents; or (ii) cyclooxygenase-2-selective inhibitor use. Under-use was defined as no gastroprotection in patients with ≥1 UGI risk factor (history of UGI event, age ≥65 years, concomitant use of anticoagulants, antiplatelets or glucocorticoids). Interrupted time-series analysis was performed to assess the impact of rofecoxib withdrawal on preventive strategies. RESULTS: The study populations consisted of 384 649 UK, 177 747 IT and 55 004 NL NSAID users. In UK, under-use of preventive strategies fell from 91% to 71% [linear trend (lt) P = 0.001], in NL from 92% to 58% (lt P < 0.001) and in IT from 90% to 76% (lt P = 0.38) in high-risk NSAID users. In 2000 and 2006, under-use was significantly lower in NL compared with UK and IT (P < 0.001) in high-risk users. After rofecoxib's withdrawal, under-use increased significantly in UK and NL. CONCLUSIONS: The prescription of gastropreventive strategies followed a similar pattern across countries. Despite a temporary negative effect of rofecoxib withdrawal on under-use, improvement of gastroprotection with nonsteroidal anti-inflammatory drugs was observed.

Incidence of multiple sclerosis in the general population in the Netherlands, 1996-2008.

BACKGROUND: We estimated the multiple sclerosis (MS) incidence in the Netherlands for better active monitoring of potential vaccine safety signals. METHODS: A retrospective cohort study (1996-2008) was conducted using a population-based general practice research database containing electronic medical records. Additional information was collected to validate incident probable cases. RESULTS: In the source population (648,656 persons), 146 incident probable MS cases were identified. Overall incidence rate was 6.3/100,000 person years (py; 95% CI, 5.2-7.2). In the subgroup in which MS could be fully validated, the incidence increased from 4/100,000 py (95% CI, 3-5) in 1996-2004 to 9/100,000 py in 2007/8 (95% CI, 6-16). This increase was highest among women, but not statistically significantly different by gender. The median lag time between first recorded symptoms and MS diagnosis decreased from 32 months (<1998) to 2 months (>2005). CONCLUSIONS: MS is rare in the Netherlands. In recent years, there was a slight increase in the incidence especially among women during the fertile age. This increase coincided with a decrease in lag time between symptoms and diagnosis, both for men and women. This trend should be taken into account in the interpretation of MS cases occurring in a population where new vaccinations will be introduced shortly.

Tiotropium Handihaler and the risk of cardio- or cerebrovascular events and mortality in patients with COPD.

BACKGROUND: Tiotropium has been associated with an increased risk of mortality and/or cardiovascular events. Recent data from RCTs suggests tiotropium Handihaler to be safe, but its safety has not yet been fully investigated under real-life circumstances. METHODS: We conducted 2 nested case-control studies in a COPD cohort from the Dutch IPCI database. In the first case-control study, cases had a cardiovascular or cerebrovascular endpoint (CCVE): stroke and transient ischemic attack (TIA), myocardial infarction, heart failure and/or ventricular arrhythmia. In the second, cases were all patients who died. Cases were matched to controls on age, sex and index date. Conditional logistic regression analysis was used to calculate adjusted odds ratios (OR(adj)) with 95% confidence intervals (CI) for tiotropium vs. long-acting beta-agonists (LABA). RESULTS: Within a cohort of 6788 COPD patients, 784 CCVE's and 1032 deaths were reported. Compared to current LABA use, use of tiotropium Handihaler was neither associated with an increased risk of a CCVE (OR(adj) 0.89, 95% 0.55-1.44) nor with an increased risk of death (OR(adj) 0.79, 95% CI 0.49-1.28). CONCLUSIONS: In real life, use of tiotropium Handihaler in COPD patients is not associated with an increased risk of a CCVE or mortality compared to LABA.

Cardiovascular and gastrointestinal safety of NSAIDs: a systematic review of meta-analyses of randomized clinical trials.

As part of the Safety of Non-Steroidal Anti-Inflammatory Drugs (SOS) Project, we reviewed the incidence of cardiovascular (CV) and gastrointestinal (GI) events associated with the use of this category of drugs. We collected data from published meta-analyses (MAs) of clinical trials of nonsteroidal anti-inflammatory drugs (NSAIDs). The Medline, Cochrane, ISI, and SCOPUS databases were systematically searched for MAs of NSAID clinical trials that could potentially contain data on adverse incidents such as myocardial infarction (MI), cerebrovascular events (CeVs), stroke, thromboembolic events (ThEs), heart failure (HF), gastrointestinal bleeding (GIB), and perforation, ulcer, and bleeding (PUB). From 1,733 identified references, 29 MAs were selected for the review. This allowed 109 estimations of incidence rates of CV adverse events and 26 estimations of incidence rates for GI adverse events. No data were found on hemorrhagic stroke or LGIB. Coxibs were studied in more MAs than traditional NSAIDs were (21 MAs for coxibs vs. 7 for traditional NSAIDs; one meta-analysis studied both). Many NSAIDs were not considered in any of the MAs. Our systematic review of MAs included information on the incidence of CV and GI events and identified important knowledge gaps regarding, in particular, the CV safety of traditional NSAIDs.

Incidence, treatment, and case-fatality of non-traumatic subarachnoid haemorrhage in the Netherlands.

BACKGROUND: Non-traumatic subarachnoid haemorrhage (SAH) is a devastating disorder and in the majority of cases it is caused by rupture of an intracranial aneurysm. No actual data are available on the incidence of non-traumatic SAH and aneursymal SAH (aSAH) in the Netherlands and little is known about treatment patterns of aSAH. Our purpose was therefore to assess the incidence, treatment patterns, and case-fatality of non-traumatic (a)SAH within the Dutch general population. METHODS: Two population based data sources were used for this retrospective cohort study. One was the nationwide hospital discharge registry (National Medical Registration, LMR). Cases were patients hospitalized for SAH (ICD-9-code 430) in 2001-2005. The second source was the Integrated Primary Care Information (IPCI) database, a medical record database allowing for case validation. Cases were patients with validated non-traumatic (a)SAH in 1996-2006. Incidence, treatment, and case-fatality were assessed. RESULTS: The incidence rate (IR) of non-traumatic SAH was 7.12 per 100,000 PY (95%CI: 6.94-7.31) and increased with age. The IR of aSAH was 3.78 (95%CI: 2.98-4.72). Women had a twofold increased risk of non-traumatic SAH; this difference appeared after the fourth decade. Non-traumatic SAH fatality was 30% (95%CI: 29-31%). Of aSAH patients 64% (95%CI: 53-74%) were treated with a clipping procedure, and 26% (95%CI: 17-37%) with coiling. CONCLUSION: Non-traumatic SAH is a rare disease with substantial case-fatality; rates in the Netherlands are similar to other countries. Case-fatality is also similar as well as age and sex patterns in incidence.

Risk of recurrent myocardial infarction with the concomitant use of clopidogrel and proton pump inhibitors.

BACKGROUND: The association between myocardial infarction (MI) and co-administration of proton pump inhibitors (PPIs) and clopidogrel remains controversial. AIM: To quantify the association between concomitant use of PPIs and clopidogrel and occurrence of recurrent MI. METHODS: We conducted a case-control study within a cohort of acute MI patients in PHARMO Record Linkage System (1999-2008). The cases were patients readmitted for MI. PPI exposure was categorized as current (3-1 days before MI), past (30-3 days before MI), or no use (>30 days before MI). We used conditional logistic regression analyses. RESULTS: Among 23 655 patients hospitalized following MI, we identified 1247 patients readmitted for MI. Among clopidogrel users, current PPI use was associated with an increased risk of recurrent MI (OR: 1.62, 95% CI: 1.15-2.27) when compared with no PPI use, but not when compared with past PPI use (OR: 0.95, 95% CI: 0.38-2.41). Among clopidogrel non-users, current PPI use was associated with an increased risk of recurrent MI (OR: 1.38, 95% CI: 1.18-1.61) when compared with no PPI use. CONCLUSIONS: The apparent association between recurrent MI and use of PPIs with clopidogrel depends on the design, and is affected by confounding by indication. The association is not present when (un)measured confounding is addressed by design.

Platelet aggregation inhibitors, vitamin K antagonists and risk of subarachnoid hemorrhage.

BACKGROUND: Use of platelet aggregation inhibitors and vitamin K antagonists has been associated with an increased risk of intracranial hemorrhage (ICH). Whether the use of these antithrombotic drugs is associated with an increased risk of subarachnoid hemorrhage (SAH) remains unclear, especially as confounding by indication might play a role. OBJECTIVE: The aim of the present study was to investigate whether use of platelet aggregation inhibitors or vitamin K antagonists increase the risk of SAH. METHODS: We applied population-based case-control, case-crossover and case-time-control designs to estimate the risk of SAH while addressing issues both of confounding by indication and time varying exposure within the PHARMO Record Linkage System database. This system includes drug dispensing records from community pharmacies and hospital discharge records of more than 3 million community-dwelling inhabitants in the Netherlands. Patients were considered a case if they were hospitalized for a first SAH (ICD-9-CM code 430) in the period between 1st January 1998 and 31st December 2006. Controls were selected from the source population, matched on age, gender and date of hospitalization. Conditional logistic regression was used to estimate multivariable adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of SAH during use of platelet aggregation inhibitors or vitamin K antagonists. In the case-crossover and case-time-control designs we selected 11 control periods preceding the index date in successive steps of 1 month in the past. RESULTS: In all, 1004 cases of SAH were identified. In the case-control analysis the adjusted OR for the risk of SAH in current use of platelet aggregation inhibitors was 1.32 (95% CI: 1.02-1.70) and in current use of vitamin K antagonists 1.29 (95% CI: 0.89-1.87) compared with no use. In the case-crossover analysis the ORs for the risk of SAH in current use of platelet aggregation inhibitors and vitamin K antagonists were 1.04 (95% CI: 0.56-1.94) and 2.46 (95% CI: 1.04-5.82), respectively. In the case-time-control analysis the OR for platelet aggregation inhibitors was 0.50 (95% CI: 0.26-0.98) and for vitamin K antagonists 1.98 (95% CI: 0.82-4.76). CONCLUSION: The use of platelet aggregation inhibitors was not associated with an increased SAH risk; the modest increase observed in the case-control analysis could be as a result of confounding. The use of vitamin K antagonists seemed to be associated with an increased risk of SAH. The increase was most pronounced in the case-crossover analysis and therefore cannot be explained by unmeasured confounding.

Time-trends in gastroprotection with nonsteroidal anti-inflammatory drugs (NSAIDs).

BACKGROUND: Preventive strategies are advocated in patients at risk of upper-gastrointestinal complications associated with nonsteroidal anti-inflammatory drugs (NSAIDs). AIM: To examine time-trends in preventive strategies. METHODS: In a study population comprising 50 126 NSAID users > or =50 years from the Integrated Primary Care Information database, we considered two preventive strategies: co-prescription of gastroprotective agents and prescription of a cyclooxygenase-2-selective inhibitor. In patients with > or =1 risk factor (history of upper-gastrointestinal bleeding/ulceration, age >65 years, use of anticoagulants, aspirin, or corticosteroids), correct prescription was defined as the presence of a preventive strategy and under-prescription as the absence of one. In patients with no risk factors, correct prescription was defined as the lack of a preventive strategy, and over-prescription as the presence of one. RESULTS: Correct prescription rose from 6.9% in 1996 to 39.4% in 2006 (P < 0.01) in high-risk NSAID users. Under-prescription fell from 93.1% to 59.9% (P < 0.01). In the complete cohort, over-prescription rose from 2.9% to 12.3% (P < 0.01). CONCLUSIONS: Under-prescription of preventive strategies has steadily decreased between 1996 and 2006; however, 60% of NSAID users at increased risk of NSAID complications still do not receive adequate protection.

Prediction of 60 day case-fatality after aneurysmal subarachnoid haemorrhage: results from the International Subarachnoid Aneurysm Trial (ISAT).

Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating event with substantial case-fatality. Our purpose was to examine which clinical and neuro-imaging characteristics, available on admission, predict 60 day case-fatality in aSAH and to evaluate performance of our prediction model. We performed a secondary analysis of patients enrolled in the International Subarachnoid Aneurysm Trial (ISAT), a randomised multicentre trial to compare coiling with clipping in aSAH patients. Multivariable logistic regression analysis was used to develop a prognostic model to estimate the risk of dying within 60 days from aSAH based on clinical and neuro-imaging characteristics. The model was internally validated with bootstrapping techniques. The study population comprised of 2,128 patients who had been randomised to either endovascular coiling or neurosurgical clipping. In this population 153 patients (7.2%) died within 60 days. World Federation of Neurosurgical Societies (WFNS) grade was the most important predictor of case-fatality, followed by age, lumen size of the aneurysm and Fisher grade. The model discriminated reasonably between those who died within 60 days and those who survived (c statistic = 0.73), with minor optimism according to bootstrap re-sampling (optimism corrected c statistic = 0.70). Several strong predictors are available to predict 60 day case-fatality in aSAH patients who survived the early stage up till a treatment decision; after external validation these predictors could eventually be used in clinical decision making.

Evaluation of serological trials submitted for annual re-licensure of influenza vaccines to regulatory authorities between 1992 and 2002.

BACKGROUND: As part of the regulatory requirements, serological evaluation of trivalent inactivated influenza vaccines must be performed before annual re-licensure in the European Union. These studies are typically set up as uncontrolled, open label trials including 2 groups of at least 50 healthy adults and healthy elderly. METHODS: The serological data submitted to the Dutch Medicines Evaluation Board (MEB) for annual re-licensure purposes between 1992 and 2002, were analysed with respect to their ability to assess the immunogenic properties of the vaccines. The trials in this meta-analysis were selected by strictly applying the inclusion and exclusion criteria described in the Committee of Human Medicinal Products (CHMP) Note for Guidance on harmonisation of requirements for influenza vaccines. To select the final dataset additional exclusion criteria were defined: age outside the inclusion criterion of the trial, incomplete demographics, co-morbid conditions, antibody determination by SRH assay, incomplete dataset and sample size smaller than 50 subjects. RESULTS: Out of 51 trials retrieved from the archives, 48 age-defined trials including 2510 adults and 2008 elderly fulfilled all the in- and exclusion criteria. A large proportion of vaccinees already met the threshold for seroprotection at baseline. Post-vaccination, the serological response was shown to be age dependent. Previous influenza vaccinations significantly affected pre-vaccination but not post-vaccination titres. CONCLUSIONS: The annual update trials performed for regulatory purposes have serious methodological limitations, which affect their ability to identify influenza vaccines with low immunogenicity. To establish clinical (protective) efficacy different trials and different assessment criteria are needed.