Development, assessment and educational impact of a blended e-learning training program on pharmacovigilance implemented in four African countries.

Introduction: Efforts to improve medication access in low-and middle-income countries, particularly in Sub-Saharan Africa, have made progress, especially in the fight against infectious diseases such as tuberculosis. However, challenges exist in establishing effective pharmacovigilance systems. The PhArmacoVIgilance Africa (PAVIA) project was committed to enhancing pharmacovigilance in Tanzania, Eswatini, Nigeria, and Ethiopia, with an emphasis on anti-tuberculosis drugs, utilizing various methods, including training. This study evaluates the PAVIA training program's effectiveness and its adaptation during the COVID-19 pandemic. Methods: A blended e-learning program, incorporating two courses and a platform for educational materials, was developed. This program, designed to train healthcare professionals in pharmacovigilance, was incorporated into a Training of Trainers model. To evaluate the program effectiveness, we used multiple measures such as assessing knowledge gain through pre-and post-test scores, assessing learners' satisfaction and attitudes via questionnaires, and analyzing Individual Case Safety Reports (ICSRs) in VigiBase to determine the impact on spontaneous reporting systems in the PAVIA countries. Results: 121 learners enrolled in the pilot trainings, including 36 from Tanzania, 34 from Eswatini, 25 from Nigeria, and 26 from Ethiopia. Notably, post-test scores were significantly higher than pre-test scores in all four countries. Following the pilot trainings, multiple step-down training sessions were held in Tanzania, Eswatini, and Nigeria, with a total of 827 learners registering and 421 successfully completing the program. Learners' scores on the post-tests were significantly higher than on the pre-tests for both courses in all three countries. Learners' feedback on the training was overwhelmingly positive. Additionally, a qualitative analysis of ICSRs revealed a substantial increase in reports after the training in Tanzania, Eswatini, and Nigeria. Discussion: An innovative e-learning program trained healthcare professionals in pharmacovigilance and anti-tuberculosis drug safety over 3 years in four PAVIA countries. The program effectively improved participants' knowledge, received positive feedback, and likely had an impact on reporting rates in Tanzania, Eswatini, and Nigeria, although a direct causal link could not be definitively established due to data limitations and other factors, such as the heightened reporting rates associated with COVID-19 vaccines, that could have contributed to the notable increase in ICSRs.

Drug-Related Hypersensitivity Reactions Leading to Emergency Department: Original Data and Systematic Review.

The aim of the present study is to describe pharmacological characteristics of drug-related allergies and anaphylaxis leading to the emergency department (ED). An 8-year post hoc analysis on the MEREAFaPS Study database was performed (2012−2019). Subjects who experienced drug-related hypersensitivity leading to an ED visit were selected. Logistic regression analyses were used to estimate the reporting odds ratios (RORs) of drug-related allergies and anaphylaxis adjusting for sex, age classes, and ethnicity. In addition, a systematic review of observational studies evaluating drug-related hypersensitivity reactions leading to ED visits in outpatients was performed. Out of 94,073 ED visits, 14.4% cases were drug-related allergies and 0.6% were anaphylaxis. Females accounted for 56%. Multivariate logistic regression showed a higher risk of drug-related allergy among males and all age classes < 65 years, while a higher risk of anaphylaxis was observed for females (ROR 1.20 [1.01−1.42]) and adults (ROR 2.63 [2.21−3.14]). The systematic review included 37 studies. ED visits related to allergy and anaphylaxis ranged from 0.004% to 88%, and drug-related allergies and anaphylaxis ranged from 0.007% to 88%. Both in our analysis and in primary studies, antibacterials, analgesics, and radiocontrast agents were identified as the most common triggers of hypersensitivity.

Risk of Hospitalization for Adverse Drug Events in Women and Men: A Post Hoc Analysis of an Active Pharmacovigilance Study in Italian Emergency Departments.

This post hoc analysis of an Italian active pharmacovigilance study describes pharmacological differences of ADEs leading to emergency department (ED) visits and hospitalization in women and men. During the study period (January 2007-December 2018), 61,855 reports of ADEs leading to ED visits were collected. Overall, 30.6% of ADEs resulted in hospitalization (30% in women and 31% in men). Multivariate logistic regression showed that, among women, drug classes significantly associated with an increased risk of hospitalization were heparins (ROR 1.41, CI 1.13-176), antidepressants (ROR 1.12, CI 1.03-1.23) and antidiabetics (ROR 1.13, CI 1.02-1.24). Among men, only vitamin K antagonists (ROR 1.28, CI 1.09-1.50), opioids (ROR 1.30, CI 1.06-1.60) and digitalis glycosides (ROR 1.32, CI 1.09-1.59) were associated with a higher risk of hospitalization. Overall, older age, multiple suspected drugs and the presence of comorbidities were significantly associated with a higher risk of hospitalization. A significantly reduced risk of hospitalization was observed in both women and men experiencing an adverse event following immunization (ROR 0.36, CI 0.27-0.48 and 0.83, 0.42-0.74, respectively) compared to drugs. Results obtained from this real-world analysis highlight important aspects of drug safety between sexes.

Analysis of fatal adverse drug events recorded in several Italian emergency departments (the MEREAFaPS study).

Fatal Adverse Events (FADEs) are a major public health problem, and some FADEs could be preventable. The aim of the present study is to describe the frequency, the drugs involved and the preventability in the FADEs collected through the MEREAFaPS Study between 2012 and 2018. All cases including the outcome "death" have been examined. We excluded cases with vaccine-related ADEs, overdose or suicide, and ADEs occurred during the hospitalisation. Two trained assessors evaluated all cases fulfilling the inclusion criteria. ADEs' preventability was evaluated applying the Schumock and Thornton algorithm. During the study period, we observed 429 cases of death, 92 of which were excluded. The remaining 337 cases involved 187 women and 150 men, with a mean age of 79 and of 77 years, respectively. For each report, the suspected drugs and concomitant ones were 1.26 and 4.20, respectively. Anticoagulants and antiplatelet agents account for more than 40% of FADE cases and the most frequent reactions are haemorrhages (37.5%). The 25% of the FADEs were preventable. This study confirms that FADEs are still a relevant clinical occurrence, and are often caused by widely used old drugs associated with adverse events. The death of one in four patients was preventable. Further efforts should be done to improve the appropriateness of the therapy, especially in older patients who are treated with anticoagulants.

Italian Emergency Department Visits and Hospitalizations for Outpatients' Adverse Drug Events: 12-Year Active Pharmacovigilance Surveillance (The MEREAFaPS Study).

BACKGROUND: Adverse drug event (ADEs) are a significant cause of emergency department (ED) visits and consequent hospitalization. Preventing ADEs and their related ED visits in outpatients remains a public health safety challenge. In this context, the aims of the present study were to describe the frequency, seriousness and preventability of outpatients' ADE-related ED visits and hospitalizations in the Italian general population, and to identify the presence of potential predictors of ADE-related hospitalization. METHODS: We performed a nationwide, multicentre, observational, retrospective study based on reports of suspected ADEs collected between January 1, 2007 and December 31, 2018 in 94 EDs involved in the MEREAFaPS project. Patients' demographic characteristics, their clinical status, suspected and concomitant drugs, ADE description, and its degree of seriousness, were collected. Causality and preventability were assessed using validated algorithms, and logistic regression analyses were used to estimate the reporting odds ratios (RORs) with 95% confidence intervals (CIs) of ADE-related hospitalization, considering the following covariates: age, sex, ethnicity, number of implicated medications, parenteral administration, presence of interaction, therapeutic error, and/or complementary and alternative medicines (CAM). RESULTS: Within 12 years, 61,855 reports of suspected ADE were collected, of which 18,918 (30.6%) resulted in hospitalization (ADE defined as serious). Patients were mostly female (56.6%) and Caucasians (87.7%), with a mean age of 57.5 ± 25.0 years. 58% of patients were treated with more than two drugs, and 47% of ADEs leading to hospitalization were preventable. Anticoagulants, antibiotics, and nonsteroidal anti-inflammatory drugs (NSAIDs) were the most frequently implicated agents for ED visits and/or hospitalization, which included clinically significant ADEs, such as haemorrhage for anticoagulants, moderate to severe allergic reactions for antibiotics, and dermatologic reactions and gastrointestinal disturbances for NSAIDs. Older age (1.54 [1.48-1.60]), higher number of concomitantly taken drugs (2.22 [2.14-2.31]), the presence of drug-drug interactions (1.52 [1.28-1.81]), and therapeutic error (1.54 [1.34-1.78]), were significantly associated with an increased risk of hospitalization. CONCLUSION: Our long-term active pharmacovigilance study in ED provided a valid estimation of ADE-related hospitalization in a representative sample of the Italian general population and can suggest further focus on medication safety in outpatients, in order to early recognise and prevent ADEs.

Risk of hospitalisation associated with benzodiazepines and z-drugs in Italy: a nationwide multicentre study in emergency departments.

Benzodiazepines (BZD) and z-drugs (ZD) are a widely prescribed group of medicines. They are often used inappropriately, and this is associated with adverse events (AEs), which may cause emergency department (ED) visits. The present study aimed to describe the characteristics of BZD and ZD related AEs leading to emergency department (ED) visit and hospitalisation in Italy, considering their plasma half-life. Ninety-two Italian EDs were monitored between 2007 and 2018. Rates of ED visit and hospitalisation were calculated. Multivariate logistic regression was used to estimate the reporting odds ratios (RORs) of hospitalisation. Univariate linear regression was performed to evaluate the ROR of hospitalisation according the plasma half-life of the suspected agents. A total of 3203 AE reports were collected. Overall, multivariate logistic regression showed that the risk of hospitalisation was higher for prazepam (3.26 [1.31-8.11]), flurazepam (1.62 [1.15-2.27]), and lorazepam (1.36 [1.15-1.61]). In the elderly, this risk was higher for prazepam (3.98 [1.03-15.3]), and lorazepam (1.58 [1.19-2.11]). Parenteral and rectal formulations were associated with a lower risk of hospitalisation compared to oral formulations. Our findings underlined the dangers in the use of BZD and ZD in Italy, particularly in women and older adults. ED clinicians must always take into account that the higher risk in terms of hospitalisation related to the use of BZD and ZD can be observed in patients treated with oral formulations, in those exposed to more than one sedative-hypnotics, and in patients exposed to compounds with intermediate or long plasma half-life.

Risk of Hospitalization Associated with Cardiovascular Medications in the Elderly Italian Population: A Nationwide Multicenter Study in Emergency Departments.

Background: There is a significant gap in knowledge addressing cardiovascular (CV) medications safety in elderly. In this context, our purposes were to define clinical and pharmacological characteristics of outpatients' adverse drug events (ADEs) related to CV medications leading to emergency department (ED) visits in the elderly Italian patients according to different age groups, and to evaluate the risk of hospitalization associated to ADEs in this population. Methods: A multicentre, retrospective study was performed on reports of suspected ADEs collected between 2007-2018 in 94 EDs involved in the MEREAFaPS Study. Elderly patients who experienced one or more CV medications-related ADEs leading to ED visit were selected. Patients' characteristics, suspected (ATC classes B and C) and concomitant drugs, and ADE description were collected. Elderly patients were stratified into three age groups (65-74, 75-84, and ≥85 years) and compared to adults (18-64 years). Logistic regression analyses were used to estimate the reporting odds ratios (RORs) with 95% confidence intervals (CIs) of ADE-related hospitalization adjusting for sex, presence of two or more suspected drugs, concomitant drugs, and one or more comorbidities. Results: Among elderly, 16,926 reports of suspected ADE related to CV medications were collected, and 6,694 (39.5%) resulted in hospitalization. Patients were mostly female, Caucasians, and middle-old (75-84). 78.9% of patients were treated with only one suspected drug, and 71.9% and 47.1% reported concomitant medications and comorbidities, respectively. Compared to adults, risk of hospitalization was significantly higher for middle-old and oldest-old patients exposed to vitamin K antagonists (1.29 [1.09-1.52] and 1.56 [1.30-187]), direct thrombin inhibitors (3.41 [1.44-8.08] and 4.12 [1.67-10.17]), antiplatelets (1.51 [1.26-1.81] and 2.09 [1.71-2.57]), and beta-blockers (1.89 [1.38-2.59 and 2.31 [1.60-3.35]). Overall, a higher risk of hospitalization was observed for renin-angiotensin system inhibitors (1.32 [1.04-1.68], 1.65 [1.32-2.06], and 2.20 [1.70-2.85]), presence of two or more concomitant drugs, and concomitant conditions. Conclusion: Our real-world findings underline relevant safety aspects of CV medications in the elderly Italian population. ED clinicians must always consider the higher risk of hospitalization related to the use of CV drugs in elderly, particularly in oldest-old ones, for antiarrhythmics, beta-blocking agents, renin-angiotensin system inhibitors, antiplatelets, and anticoagulants.

Comparative Safety of Originator and Biosimilar Epoetin Alfa Drugs: An Observational Prospective Multicenter Study.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) are biological molecules approved for the treatment of anemia associated with chronic renal failure. Biosimilars were licensed for use in Europe in 2007. AIM: This study aimed to compare the safety profile of biosimilars with respect to the reference product in a nephrology setting. METHODS: A prospective study was conducted in four Italian regions between 1 October 2013 and 30 June 2015. The study population included patients aged ≥ 18 years undergoing hemodialysis and treated with epoetins as per the clinical practice of the participating centers. The two comparison cohorts included patients treated with either an originator or a biosimilar epoetin alfa. Each patient was followed up until occurrence of any safety outcome of interest (grouped into three major categories), switch to a different ESA product, transplant or peritoneal dialysis, death, or end of the study period, whichever came first. RESULTS: Overall, 867 subjects were included in the study (originator: N = 423; biosimilar: N = 444). Biosimilar users were older than originator users (median age of 76 vs 64 years, respectively), more frequently affected by arrhythmia (29.3 vs 22.5%), and less frequently candidates for transplantation (3.8 vs 18.2%). Cox-regression analysis showed no increase in risk of safety outcomes in biosimilar users, even after adjusting for confounding factors: 1.0 (95% confidence interval [CI] 0.7-1.3) for any outcomes; 1.1 (95% CI 0.7-1.8) for problems related to dialysis device; 0.9 (95% CI 0.6-1.5) for cardio- and cerebro-vascular conditions; 0.9 (95% CI 0.6-1.5) for infections. CONCLUSION: This study confirms the comparable safety profiles of originator and biosimilar epoetin alfa drugs when used in patients receiving dialysis.

Comparative Effectiveness of Two Tiotropium Formulations: A Retrospective Cohort Study.

The effectiveness of the tiotropium Respimat® formulation in routine clinical practice is still an open issue due to concern about the generalizability of the Tiotropium Safety and Performance in Respimat® (TIOSPIR) trial findings. Our aim was to compare the incidence of acute respiratory events between new users of tiotropium Respimat® and HandiHaler®. The study population comprised patients aged ≥45 years resident in two Italian regions who received a first tiotropium prescription (HandiHaler® or Respimat®) between 1 July 2011 and 30 November 2013. The cohort was identified within the database of drug prescriptions reimbursed by the Italian National Health Service. Clinical outcomes were obtained from hospital records. The primary outcome was the first hospitalization for respiratory events, including chronic obstructive pulmonary disease (COPD) exacerbation, respiratory failure, hypoxemia/hyperventilation and pneumonia, during the exposure period. The hazard ratios were estimated for the propensity score matched groups with Cox regression. After matching, 31,334 patients with incident tiotropium prescriptions were included. Similar incidence rates of the primary outcome between the Respimat® and HandiHaler® users were identified (adjusted hazard ratio 0.95, 95% CI 0.84-1.07). No differences emerged in the subgroup analyses conducted according to the baseline characteristics of the tiotropium users. This study confirms the findings observed in the TIOSPIR trial in a more heterogeneous population that included patient subgroups with severe respiratory disease and unstable COPD.

Cardiovascular safety of tiotropium Respimat vs HandiHaler in the routine clinical practice: A population-based cohort study.

The cardiovascular safety of tiotropium Respimat formulation in the routine clinical practice is still an open issue. Our aim was to compare the risk of acute myocardial infarction and heart rhythm disorders in incident users of either tiotropium Respimat or HandiHaler. The study population comprises patients aged ≥45 years, resident in two Italian regions with a first prescription of tiotropium (HandiHaler or Respimat) between 01/07/2011-30/11/2013. The cohort was identified through the database of prescriptions reimbursed by the Italian National Health Service. Comorbidities and clinical outcomes were obtained from hospital records. The primary outcome was the first hospitalization for acute myocardial infarction and/or for heart rhythm disorders during the exposure period. Hazard ratios were estimated in the propensity score-matched groups through Cox regression. After matching, 31,334 patients with incident prescription of tiotropium were included. The two groups were balanced with regard to baseline characteristics. Similar incidence rates of the primary outcome between Respimat and HandiHaler users were identified (adjusted hazard ratio 1.02, 95% CI 0.82-1.28). No risk difference between Respimat and HandiHaler emerged when considering clinical events separately. This large cohort study showed a comparable acute cardiovascular safety profile of the two tiotropium formulations.

Safety profile of the direct oral anticoagulants: an analysis of the WHO database of adverse drug reactions.

AIM: Direct oral anticoagulants (DOACs) have shown noninferiority to warfarin for stroke prevention in nonvalvular atrial fibrillation (AF) and a more promising safety profile. Unanswered safety aspects remain to be addressed and available evidence on the risk associated with these drugs are conflicting. In order to contribute to the debate on their safety profile, we conducted a comparative analysis of the reports of suspected adverse drug reactions (ADRs) associated with DOACs in VigiBase. METHODS: Study based on reports of suspected ADRs held in VigiBase as at December 2014, in which a DOAC or warfarin were administered in patients with nonvalvular AF and listed as suspected/interacting drugs. Medical Dictionary for Regulatory Activities was used to classify ADRs. Reporting odds ratio (ROR) with 95% confidence interval were calculated. Results with P ≤ 0.05 were statistically significant. RESULTS: We retrieved 32 972 reports. We identified 204 ADRs with a ROR >1 (P ≤ 0.05) and we focused on 105 reactions. Positive ROR emerged for DOACs and gastrointestinal haemorrhage compared with warfarin [(1.6 (1.47-1.75)], but no disproportionality with cerebral haemorrhage was found [0.31 (0.28-0.34)]. We identified other potential signals that have not been associated with DOACs previously. CONCLUSIONS: As well as premarketing authorization clinical trial studies, we found a reduced risk of intracranial haemorrhage, but an increased risk of gastrointestinal haemorrhage in patients treated with DOACs compared to warfarin. We provide new data and we highlight several differences between the three novel oral anticoagulants, in the rate and type of ADRs occurred.

Acute renal failure in patients treated with dronedarone or amiodarone: a large population-based cohort study in Italy.

PURPOSE: Causes of ARF are numerous including drugs. In 2012, spontaneous reporting showed a possible association between dronedarone and ARF. To further investigate such association, a retrospective cohort study on health-service claim databases was performed taking amiodarone as comparison. METHODS: All patients receiving new prescription of amiodarone or dronedarone between September 2010 and December 2012 were selected. Cox regression models to estimate the hazard ratios (HRs), with 95 % confidence intervals (CIs), for dronedarone versus amiodarone were performed. HRs were calculated: (i) for the entire cohort; (ii) for matched cohorts using propensity score; (iii) and high-dimensional propensity score. RESULTS: New users without previous episodes of ARF were 56,739 and 1761 on dronedarone and 54,978 on amiodarone. After 1:1 matching for propensity score, new users with dronedarone and amiodarone were 1467 and 1467, respectively. The cumulative incidence rate of ARF was 1.6 % (95 % CI 0.7-3.6 %) among dronedarone group and 2.3 % (1.0-5.1 %) among amiodarone group (p from log rank test = 0.4884). The unadjusted HR of ARF was 0.34 (0.18-0.64) in dronedarone new users compared to amiodarone; in propensity score matched cohort, it was 0.75 (0.26-2.16), and in high-dimensional propensity score, it was 0.83 (0.25-2.73). CONCLUSIONS: This large community-based study did not confirm the signal of an increased nephrotoxicity from dronedarone compared to amiodarone. Nevertheless, given the increasing number of reports collected from pharmacovigilance databases worldwide on this association, it is advisable for clinicians and patients to be aware of the possible kidney damage due to dronedarone in order to improve clinical outcomes with early intervention.

Antipsychotic drug exposure and risk of pulmonary embolism: a population-based, nested case-control study.

BACKGROUND: Only three observational studies investigated whether exposure to antipsychotics is associated with an increased risk of pulmonary embolism, with conflicting results. This study was therefore carried out to establish the risk of pulmonary embolism associated with antipsychotic drugs, and to ascertain the risk associated with first- and second-generation antipsychotic drugs, and with exposure to individual drugs. METHODS: We identified 84,253 adult individuals who began antipsychotic treatment in a large Italian health care system. Cases were all cohort members who were hospitalized for non-fatal or fatal pulmonary embolism during follow-up. Up to 20 controls for each case were extracted from the study cohort using incidence density sampling and matched by age at cohort entry and gender. Each individual was classified as current, recent or past antipsychotic user. The occurrence non-fatal or fatal pulmonary embolism was the outcome of interest. RESULTS: Compared to past use, current antipsychotic use more than double the risk of pulmonary embolism (odds ratio 2.31, 95% confidence interval 1.16 to 4.59), while recent use did not increase the risk. Both conventional and atypical antipsychotic exposure was associated with an increase in risk, and the concomitant use of both classes increased the risk of four times (odds ratio 4.21, 95% confidence interval 1.53 to 11.59). CONCLUSIONS: Adding the results of this case-control study to a recent meta-analysis of three observational studies substantially changed the overall estimate, which now indicates that antipsychotic exposure significantly increases the risk of pulmonary embolism.

Seriousness, preventability, and burden impact of reported adverse drug reactions in Lombardy emergency departments: a retrospective 2-year characterization.

OBJECTIVE: The purpose of this study was to determine the prevalence of adverse drug reactions (ADRs) reported in emergency departments (EDs) and carry out a thorough characterization of these to assess preventability, seriousness that required hospitalization, subsequent 30-day mortality, and economic burden. METHODS: This was a retrospective cohort study of data from an active pharmacovigilance project at 32 EDs in the Lombardy region collected between January 1, 2010 and December 31, 2011. Demographic, clinical, and pharmacological data on patients admitted to EDs were collected by trained and qualified monitors, and deterministic record linkage was performed to estimate hospitalizations. Pharmacoeconomic analyses were based on Diagnosis-Related Group reimbursement. RESULTS: 8,862 ADRs collected with an overall prevalence rate of 3.5 per 1,000 visits. Of all ADRs, 42% were probably/definitely preventable and 46.4% were serious, 15% required hospitalization, and 1.5% resulted in death. The System Organ Classes most frequently associated with ADRs were: skin and subcutaneous tissue, gastrointestinal, respiratory thoracic and mediastinal, and nervous system disorders. The most common Anatomical Therapeutic Chemical classes involved in admissions were J (anti-infectives and immunomodulating agents), B (blood and blood-forming organs), and N (nervous system). Older age, yellow and red triage, higher number of concomitantly taken drugs, and previous attendance in ED for the same ADR were significantly associated with an increased risk of hospitalization. The total cost associated with ADR management was €5,184,270, with a mean cost per patient of €585. Fifty-eight percent of the economic burden was defined as probably/definitely preventable. CONCLUSION: ADRs are a serious health/economic issue in EDs. This assessment provides a thorough estimation of their seriousness, preventability, and burden impact in a large population from a representative European region.

Evaluation of safety of A/H1N1 pandemic vaccination during pregnancy: cohort study.

OBJECTIVE: To assess the risk of maternal, fetal, and neonatal outcomes associated with the administration of an MF59 adjuvanted A/H1N1 vaccine during pregnancy. DESIGN: Historical cohort study. SETTING: Singleton pregnancies of the resident population of the Lombardy region of Italy. PARTICIPANTS: All deliveries between 1 October 2009 and 30 September 2010. Data on exposure to A/H1N1 pandemic vaccine, pregnancy, and birth outcomes were retrieved from regional databases. Vaccinated and non-vaccinated women were compared in a propensity score matched analysis to estimate risks of adverse outcomes. MAIN OUTCOME MEASURES: Main maternal outcomes included type of delivery, admission to intensive care unit, eclampsia, and gestational diabetes; fetal and neonatal outcomes included perinatal deaths, small for gestational age births, and congenital malformations. RESULTS: Among the 86,171 eligible pregnancies, 6246 women were vaccinated (3615 (57.9%) in the third trimester and 2557 (40.9%) in the second trimester). No difference was observed in terms of spontaneous deliveries (adjusted odds ratio 1.02, 95% confidence interval 0.96 to 1.08) or admissions to intensive care units (0.95, 0.47 to 1.88), whereas a limited increase in the prevalence of gestational diabetes (1.26, 1.04 to 1.53) and eclampsia (1.19, 1.04 to 1.39) was seen in vaccinated women. Rates of fetal and neonatal outcomes were similar in vaccinated and non-vaccinated women. A slight increase in congenital malformations, although not statistically significant, was present in the exposed cohort (1.14, 0.99 to 1.31). CONCLUSIONS: Our findings add relevant information about the safety of the MF59 adjuvanted A/H1N1 vaccine in pregnancy. Residual confounding may partly explain the increased risk of some maternal outcomes. Meta-analysis of published studies should be conducted to further clarify the risk of infrequent outcomes, such as specific congenital malformations.