Antithrombotic Use Patterns in COVID-19 Patients from Spain: A Real-World Data Study.

Antithrombotics have been widely used to treat and prevent COVID-19-related thrombosis; however, studies on their use at population levels are limited. We aimed to describe antithrombotic use patterns during the pandemic in Spanish primary care and hospital-admitted patients with COVID-19. Methods: A real-world data study was performed. Data were obtained from BIFAP's electronic health records. We investigated the antithrombotic prescriptions made within ±14 days after diagnosis between March 2020 and February 2022, divided their use into prior and new/naive groups, and reported their post-discharge use. Results: We included 882,540 individuals (53.4% women), of whom 78,499 were hospitalized. The median age was 44.7 (IQR 39-59). Antithrombotics were prescribed in 37,183 (4.6%) primary care subjects and 42,041 (53.6%) hospital-admitted patients, of whom 7505 (20.2%) and 20,300 (48.3%), respectively, were naive users. Prior users were older and had more comorbidities than new users. Enoxaparin was the most prescribed antithrombotic in hospitals, with higher prescription rates in new than prior users (2348.2, IQR 2390-3123.1 vs. 1378, IQR 1162-1751.6 prescriptions per 10,000 cases, p = 0.002). In primary care, acetylsalicylic acid was the most used antithrombotic, with higher use rates in prior than in naïve users. Post-discharge use occurred in 6686 (15.9%) subjects (median use = 10 days, IQR 9-30). Conclusions: Our study identified a consensus on prescribing antithrombotics in COVID-19 patients, but with low use rates in hospitals.

Lack of association between COVID-19 vaccines and miscarriage onset using a case-crossover design.

Pregnant women might have an increased risk of SARS-COV-2 infection. Although evidence towards the efficacy and safety of COVID-19 is growing still there is room for improvement on the knowledge towards pregnancy adverse events, such as miscarriage. We explored the association of COVID-19 vaccine with the risk of miscarriages using the Real-World. We identified a cohort of vaccinated pregnancies using the BIFAP database which contains systematically recorded data on care patients in Spain (N = 4054). We then restricted it to those women who had a miscarriage using a validated algorithm (N = 607). Among them, we performed a case-crossover design to evaluate the effect of intermittent exposures on the risk of miscarriage. Adjusted Odds Ratio with their confidence intervals were calculated using two analytical approaches: conditional logistic regression and Generalized Linear Mixed-Effects Models. A total of 225 (37.1%) were aged 35-39 years. The most common comorbidities were asthma, migraine, gastritis, and hypothyroidism. A total of 14.7% received only one dose of COVID-19 and 85.3% two doses, respectively. A total of 36.8% of women with one dose and 27.6% with two doses received the vaccine 7 days prior to the miscarriage. Corresponding adjusted estimates for the risk of miscarriage using the conditional logistic regression where as follows: 1.65 (95% CI 0.85-3.23) when using as the sum of 3 control moments among women with one dose, 1.02 (95% CI 0.72-1.46) among women with two doses and 1.03 (95% CI 0.72, 1.46) using the whole study population. Very similar results were obtained when conducting the Generalized Linear Mixed-Effects Models. There was no overall increased risk of miscarriage onset associated with COVID-19 vaccine although contradictory results were found according to the number of doses. Further studies are required with larger sample sizes to assess this association.

COVID-19 Distribution in Pregnancy, Drug Use Patterns and COVID-19 Medication during the Pandemic in Spain: Data from Real-World Electronic Health Records.

Although pregnant women were considered a risk population for COVID-19, little is known of their drug use during the pandemic. We aimed to investigate COVID-19 distribution, drug use patterns and COVID-19 medication. We conducted a retrospective cohort of validated pregnancies aged 15-49 years, from January 2020 to December 2022, using the BIFAP database. An identified cohort of pregnant women with COVID-19 was matched by age, gestational age, length of pregnancy and outcome to a cohort free of COVID-19 (8413 vs. 24,975). We performed a descriptive analysis on COVID-19 cases, estimated the drug use patterns and assessed COVID-19-specific drugs within the week prior/after diagnosis, stratified by pandemic wave and gestational week. The results showed that 72% of pregnant women with COVID-19 received at least one prescription vs. 66.6% of those free of COVID-19, with analgesics, antibiotics and thyroid hormones being the most prescribed drugs in both groups. In the COVID-19 group, they were antithrombotics (40 prescriptions per 100 women), analgesic/NSAIDs (19.64/6.29) and antibiotics (6.95). COVID-19 cases gradually increased, peaking at the fifth and second waves. Prescription rates were similar when compared to pre-pandemic studies. The use of drugs compatible with COVID-19 treatments was in line with recommendations.

A Clinical Prediction Rule for Thrombosis in Critically Ill COVID-19 Patients: Step 1 Results of the Thromcco Study.

The incidence of thrombosis in COVID-19 patients is exceptionally high among intensive care unit (ICU)-admitted individuals. We aimed to develop a clinical prediction rule for thrombosis in hospitalized COVID-19 patients. Data were taken from the Thromcco study (TS) database, which contains information on consecutive adults (aged ≥ 18) admitted to eight Spanish ICUs between March 2020 and October 2021. Diverse logistic regression model analysis, including demographic data, pre-existing conditions, and blood tests collected during the first 24 h of hospitalization, was performed to build a model that predicted thrombosis. Once obtained, the numeric and categorical variables considered were converted to factor variables giving them a score. Out of 2055 patients included in the TS database, 299 subjects with a median age of 62.4 years (IQR 51.5-70) (79% men) were considered in the final model (SE = 83%, SP = 62%, accuracy = 77%). Seven variables with assigned scores were delineated as age 25-40 and ≥70 = 12, age 41-70 = 13, male = 1, D-dimer ≥ 500 ng/mL = 13, leukocytes ≥ 10 × 103/µL = 1, interleukin-6 ≥ 10 pg/mL = 1, and C-reactive protein (CRP) ≥ 50 mg/L = 1. Score values ≥28 had a sensitivity of 88% and specificity of 29% for thrombosis. This score could be helpful in recognizing patients at higher risk for thrombosis, but further research is needed.

The Risk of SARS-CoV-2 Infection in Pregnant Women: An Observational Cohort Study Using the BIFAP Database.

BACKGROUND: It has been suggested that women experiencing during pregnancy several physiological and immunological changes that might increase the risk of any infection including the SARS-CoV-2. OBJECTIVE: We aimed to quantify the risk of SARS-CoV-2 infection during pregnancy compared with women with no pregnancies. METHODS: We used data from the BIFAP database and a published algorithm to identify all pregnancies during 2020. Pregnancies were matched (1:4) by age region, and length of pregnancy with a cohort of women of childbearing age. All women with SARS-CoV-2 infection before entering the study were discarded. We estimated incidence rates of SARS-CoV-2 with 95% confidence intervals (CIs) expressed by 1000 person-months as well as Kaplan-Meier figures overall and also stratified according to pregnancy period: during pregnancy, at puerperium (from end of pregnancy up to 42 days) and after pregnancy. (from 43 days after pregnancy up to end pf study period (i.e., June 2021). We conducted a Cox regression to assess risk factors for SARS-COV infection. The incidence rate of SARS-CoV-2 infection expressed by 1000 person-months were. RESULTS: There was a total of 103,185 pregnancies and 412,740 matched women at childbearing, with a mean age of 32.3 years. The corresponding incidence rates of SARS-CoV-2 infection according to cohorts were: 2.44 cases per 1000 person-months (confidence interval (CI) 95%: 2.40-2.50) and 4.29 (95% CI: 4.15-4.43) for comparison cohort. The incidence rate ratio (IRR) of SARS-CoV-2 was 1.76 (95% CI: 1.69-1.83). When analyzing according to pregnancy period, the IRRs were 1.30 (95% CI: 11.20-1.41) during the puerperium and 1.19 (95% CI: 41.15-1.23) after pregnancy. In addition to pregnancy itself, other important risk factors were obesity (1.33 (95% CI: 1.23-1.44)) and diabetes (1.23 (95% CI: 11.00-1.50). CONCLUSION: Pregnant women are at increased risk of SARS-CoV-2 infection compared with women of childbearing age not pregnant. Nevertheless, there is a trend towards reverting during puerperium and after pregnancy.

[Non-inferiority studies efficacy and safety: review of methodological and statistical aspects in clinical trials and non-interventional studies with medicinal products.] / Estudios de no inferioridad de eficacia y seguridad: revisión e interpretación de aspectos metodológicos y estadísticos en ensayos clínicos y estudios observacionales con medicamentos.

Non-inferiority studies are increasingly more common for introducing new medicines in the market. Despite being situations where the use of this study design is justified, there is not a common analytical approach on how to conduct them. Pursuing a rigorous methodology, both in the study conduction and in its disseminations, is critical to ensure robust results to enable regulatory agencies and clinicians to reach valid conclusions and decisions which ultimately will benefit clinical practice. Most of the published reviews focus on the efficacy outcomes of non-inferiority clinical trials. We are unaware of other reviews that goes beyond and includes specific aspects for non-interventional designs and for studies focused on safety. Moreover, this review provides a simple and practical perspective with a minimum mathematical content on this complex type of studies.

Los estudios de no inferioridad son cada vez más frecuentes para introducir nuevos medicamentos en el mercado. Aunque existen situaciones en las que su uso está justificado, no existe un enfoque analítico único y conservador. Para arrojar resultados fiables y de calidad, deben seguir una estricta metodología, tanto en la ejecución como en la difusión de los resultados, la cual permita, tanto a las agencias reguladoras como a los clínicos, establecer conclusiones válidas y decisiones que repercutan en beneficio de la práctica clínica. La mayor parte de las revisiones publicadas se centran en los ensayos clínicos de no inferioridad de eficacia. En esta revisión se contemplan, además, los diseños observacionales y los aspectos específicos de los estudios de seguridad. Todo ello desde un punto de vista práctico y sencillo, con un contenido matemático mínimo.

Estudios de no inferioridadde eficacia y seguridad: revisión e interpretación de aspectosmetodológicos y estadísticosen ensayos clínicos y estudiosobservacionales con medicamentos / Non-inferiority studies efficacy and safety: review of methodological and statistical aspects in clinical trials and non-interventional studies with medicinal products

Los estudios de no inferioridad son cada vez más frecuentes para introducir nuevos medicamentos en el mercado. Aunque existensituaciones en las que su uso está justificado, no existe un enfoque analítico único y conservador. Para arrojar resultados fiables y decalidad, deben seguir una estricta metodología, tanto en la ejecución como en la difusión de los resultados, la cual permita, tanto alas agencias reguladoras como a los clínicos, establecer conclusiones válidas y decisiones que repercutan en beneficio de la prácticaclínica. La mayor parte de las revisiones publicadas se centran en los ensayos clínicos de no inferioridad de eficacia. En esta revisiónse contemplan, además, los diseños observacionales y los aspectos específicos de los estudios de seguridad. Todo ello desde unpunto de vista práctico y sencillo, con un contenido matemático mínimo.(AU)

Non-inferiority studies are increasingly more common for introducing new medicines in the market. Despite being situations wherethe use of this study design is justified, there is not a common analytical approach on how to conduct them. Pursuing a rigorousmethodology, both in the study conduction and in its disseminations, is critical to ensure robust results to enable regulatory agenciesand clinicians to reach valid conclusions and decisions which ultimately will benefit clinical practice. Most of the published reviewsfocus on the efficacy outcomes of non-inferiority clinical trials. We are unaware of other reviews that goes beyond and includes spe-cific aspects for non-interventional designs and for studies focused on safety. Moreover, this review provides a simple and practicalperspective with a minimum mathematical content on this complex type of studies.(AU)

Thromboembolic Events in a Socio-Economically Disadvantaged Population with COVID-19 Admitted to a Medicalized Hotel in Madrid.

Background: The social determinants of health (SDOH) of patients with COVID-19-related thrombosis have been scarcely explored. Our objective was to investigate the cases of thrombosis in a group of socially disadvantaged populations with COVID-19. Methods: We investigated the thrombotic events that occurred in a cohort of migrant and Spanish patients with COVID-19 that were admitted to a medicalized hotel in Madrid. Demographic data, past medical history, and socio-economic backgrounds, such as monthly household income, level of education, and living conditions, were explored to determine the factors related to thrombosis. Results: A cohort of 383 subjects (mean age 55.4 ± 14.6 years old, 69% male), of which 58% were migrants, was studied. Fourteen (3.6%) cases of thrombosis were reported. Thrombosis was more frequent in Spanish than in migrant individuals (OR 5.3, 95%CI 1.4-19.5, p = 0.005). Neither a low monthly household income nor a low education level showed a statistical association with thrombosis (p ≥ 0.05). History of venous thromboembolism (OR 8.1, 95%CI 2.2-28.6) and being a current smoker (OR 4.7, 95%CI 1.3-16.0) were factors associated with thrombosis. Conclusions: The SDOH studied were not associated with thrombosis; however, further investigation must be performed to investigate the socio-economic conditions of subjects with COVID-19 with adverse outcomes such as thrombotic events.

Effect of regulatory interventions on agomelatine use in Spain: A multiple intervention time-series analysis in a nationwide electronic healthcare record database.

BACKGROUND: Liver injury is an important identified risk for agomelatine and several measures were put in place to prevent and minimize such risk. The study aims to assess the impact of four interventions on the incidence of agomelatine use, particularly among patients aged ≥75 in Spain between 2011 and 2018. METHODS: Quasi-experimental interrupted time-series analysis to examine data from a nationwide electronic healthcare record database (BIFAP). Quarterly cumulative incidence of agomelatine use per 100 000 patients was calculated and the impact of four regulatory interventions was quantified. RESULTS: The incidence of agomelatine use decreased by 85% and 87% from first quarter 2011 to last quarter 2018 in patients below and above 75 years old, respectively. Regulatory actions taken were not associated with an immediate and significant falling level of use or slope. The incidence was less than expected 6 months after the first and third intervention for patients below and above 75 years old, and more than expected after the second and fourth intervention for both populations, though these analyses were underpowered to observe significant results. The downward trend became less pronounced, reaching a residual level of use, which remained stable in the last segment of the study period. CONCLUSION: New users of agomelatine decreased throughout the study period, starting before interventions took place. The effect of specific interventions might be masked by the progressive decrease tendency, constant over the study period. The effects of external factors that might overlap, unintended consequences, and issues concerning statistical modeling in situations where rates are already falling, should be considered when interpreting the results.

Flecainide and risk of skin neoplasms: Results of a large nested case-control study in Spain and Denmark.

Background: A previous study in Denmark suggested an increased melanoma risk associated with the use of flecainide. Objective: To study the association between flecainide use and the risk of melanoma and non-melanoma skin cancer in Spain and Denmark. Methods: We conducted a multi-database case-control study in (database/study period) Spain (SIDIAP/2005-2017 and BIFAP/2007-2017) and Denmark (Danish registries/2001-2018). We included incident cases of melanoma or non-melanoma skin cancer (NMSC) aged ≥18 with ≥2 years of previous data (≥10 years for Denmark) before the skin cancer and matched them to controls (10:1 by age and sex). We excluded persons with immunosuppression or previous cancer. We defined ever-use as any prescription fill and high-use as a cumulative dose of at least 200 g (reference: never-use). We categorized a cumulative dose for a dose-response assessment. We used conditional logistic regression to compute ORs (95% CI) adjusted for photosensitizing, anti-neoplastic, disease-specific drugs and comorbidities. Results: The total numbers of melanoma/NMSC cases included were 7,809/64,230 in SIDIAP, 4,661/31,063 in BIFAP, and 27,978/152,821 in Denmark. In Denmark, high-use of flecainide was associated with increased adjusted ORs of skin cancer compared with never-use [melanoma: OR 1.97 (1.38-2.81); NMSC: OR 1.34 (1.15-1.56)]. In Spain, an association between high-use of flecainide and NMSC was also observed [BIFAP: OR 1.42 (1.04-1.93); SIDIAP: OR 1.19 (0.95-1.48)]. There was a non-significant dose-response pattern for melanoma in Denmark and no apparent dose-response pattern for NMSC in any of the three databases. We found similar results for ever-use of flecainide. Conclusion: Flecainide use was associated with an increased risk of melanoma (Denmark only) and NMSC (Denmark and Spain) but without substantial evidence of dose-response patterns. Further studies are needed to assess for possible unmeasured confounders.

Drug utilization study on immediate release Fentanyl in Spain. Prevalence, incidence, and indication.

PURPOSE: We aimed to characterize the trends of immediate release fentanyl (IRF) use in Spain between 2012 and 2017 and indication for its use. IRF drugs are rapid-acting opioids approved to treat breakthrough cancer pain (BTCP) in patients already receiving maintenance opioid therapy for chronic cancer pain. A substantial increase in consumption of IRF has been observed with emerging cases of abuse and dependence, most of them in noncancer patients. METHODS: An ecological descriptive consumption study with aggregated data from drug dispensed by community pharmacies and reimbursed by the National Health System in which Defined Daily Doses per 10 000 inhabitants (DID) were calculated and a retrospective cohort study using data from the Spanish Database for Pharmacoepidemiological Research in Primary Care in which participants entered the cohort study after 1 year with the Primary Care Practitioners were performed. Annual prevalence and incidence rate of IRF use were estimated by sex and calendar year. Potential indication was also assessed. RESULTS: IRF use in Spain increased from 2.1 DID in 2012 to 3.8 DID in 2017. The incidence rate and prevalence increased in 53% and 74%, respectively. Patients without previous cancer or BCTP diagnosis represented 27% of incident users, predominantly women. Half of patients with noncancer-related diagnosis had a musculoskeletal disorder linked to the first IRF prescription. CONCLUSIONS: National consumption and new IRF users in Spain increased over the study period and one quarter of patients did not have a BTCP or cancer diagnosis registered in their clinical record.

ADVANCE system testing: Estimating the incidence of adverse events following pertussis vaccination in healthcare databases with incomplete exposure data.

The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid vaccine benefit-risk monitoring using existing European healthcare databases. Incidence rate (IR) estimates of vaccination-associated adverse events that are needed to model vaccination risks can be calculated from existing healthcare databases when vaccination (exposure) data are available. We assessed different methods to derive IRs in risk periods following vaccination when exposure data are missing in one database, using estimated IRs and IRRs from other databases for febrile seizures, fever and persistent crying. IRs were estimated for children aged 0-5 years in outcome-specific risk and non-risk periods following the first dose of acellular pertussis (aP) vaccination in four primary care databases and one hospital database. We compared derived and observed IRs in each database using three methods: 1) multiplication of non-risk period IR for database i by IR ratio (IRR) obtained from meta-analysis of IRRs estimated using the self-controlled case-series method, from databases other than i; 2) same method as 1, but multiplying with background IR; and 3) meta-analyses of observed IRs from databases other than i. IRs for febrile seizures were lower in primary care databases than the hospital database. The derived IR for febrile seizures using data from primary care databases was lower than that observed in the hospital database, and using data from the hospital database gave a higher derived IR than that observed in the primary care database. For fever and persistent crying the opposite was observed. We demonstrated that missing IRs for a post-vaccination period can be derived but that the type of database and the method of event data capture can have an impact on potential bias. We recommend IRs are derived using data from similar database types (hospital or primary care) with caution as even this can give heterogeneous results.

ADVANCE database characterisation and fit for purpose assessment for multi-country studies on the coverage, benefits and risks of pertussis vaccinations.

INTRODUCTION: The public-private ADVANCE consortium (Accelerated development of vaccine benefit-risk collaboration in Europe) aimed to assess if electronic healthcare databases can provide fit-for purpose data for collaborative, distributed studies and monitoring of vaccine coverage, benefits and risks of vaccines. OBJECTIVE: To evaluate if European healthcare databases can be used to estimate vaccine coverage, benefit and/or risk using pertussis-containing vaccines as an example. METHODS: Characterisation was conducted using open-source Java-based (Jerboa) software and R scripts. We obtained: (i) The general characteristics of the database and data source (meta-data) and (ii) a detailed description of the database population (size, representatively of age/sex of national population, rounding of birth dates, delay between birth and database entry), vaccinations (number of vaccine doses, recording of doses, pattern of doses by age and coverage) and events of interest (diagnosis codes, incidence rates). A total of nine databases (primary care, regional/national record linkage) provided data on events (pertussis, pneumonia, death, fever, convulsions, injection site reactions, hypotonic hypo-responsive episode, persistent crying) and vaccines (acellular pertussis and whole cell pertussis) related to the pertussis proof of concept studies. RESULTS: The databases contained data for a total population of 44 million individuals. Seven databases had recorded doses of vaccines. The pertussis coverage estimates were similar to those reported by the World Health Organisation (WHO). Incidence rates of events were comparable in magnitude and age-distribution between databases with the same characteristics. Several conditions (persistent crying and somnolence) were not captured by the databases for which outcomes were restricted to hospital discharge diagnoses. CONCLUSION: The database characterisation programs and workflows allowed for an efficient, transparent and standardised description and verification of electronic healthcare databases which may participate in pertussis vaccine coverage, benefit and risk studies. This approach is ready to be used for other vaccines/events to create readiness for participation in other vaccine related studies.

ADVANCE system testing: Can safety studies be conducted using electronic healthcare data? An example using pertussis vaccination.

INTRODUCTION: The Accelerated Development of Vaccine benefit-risk Collaboration in Europe (ADVANCE) public-private collaboration, aimed to develop and test a system for rapid benefit-risk monitoring of vaccines using healthcare databases in Europe. The objective of this proof-of-concept (POC) study was to test the feasibility of the ADVANCE system to generate incidence rates (IRs) per 1000 person-years and incidence rate ratios (IRRs) for risks associated with whole cell- (wP) and acellular- (aP) pertussis vaccines, occurring in event-specific risk windows in children prior to their pre-school-entry booster. METHODS: The study population comprised almost 5.1 million children aged 1 month to <6 years vaccinated with wP or aP vaccines during the study period from 1 January 1990 to 31 December 2015. Data from two Danish hospital (H) databases (AUH and SSI) and five primary care (PC) databases from, UK (THIN and RCGP RSC), Spain (SIDIAP and BIFAP) and Italy (Pedianet) were analysed. Database-specific IRRs between risk vs. non-risk periods were estimated in a self-controlled case series study and pooled using random-effects meta-analyses. RESULTS: The overall IRs were: fever, 58.2 (95% CI: 58.1; 58.3), 96.9 (96.7; 97.1) for PC DBs and 8.56 (8.5; 8.6) for H DBs; convulsions, 7.6 (95% CI: 7.6; 7.7), 3.55 (3.5; 3.6) for PC and 12.87 (12.8; 13) for H; persistent crying, 3.9 (95% CI: 3.8; 3.9) for PC, injection-site reactions, 2.2 (95% CI 2.1; 2.2) for PC, hypotonic hypo-responsive episode (HHE), 0.4 (95% CI: 0.4; 0.4), 0.6 (0.6; 0.6) for PC and 0.2 (0.2; 0.3) for H; and somnolence: 0.3 (95% CI: 0.3; 0.3) for PC. The pooled IRRs for persistent crying, fever, and ISR, adjusted for age and healthy vaccinee period were higher after wP vs. aP vaccination, and lower for convulsions, for all doses. The IRR for HHE was slightly lower for wP than aP, while wP was associated with somnolence only for dose 1 and dose 3 compared with aP. CONCLUSIONS: The estimated IRs and IRRs were comparable with published data, therefore demonstrating that the ADVANCE system was able to combine several European healthcare databases to assess vaccine safety data for wP and aP vaccination.

ADVANCE system testing: Benefit-risk analysis of a marketed vaccine using multi-criteria decision analysis and individual-level state transition modelling.

BACKGROUND: The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines using electronic health record (eHR) databases in Europe. Proof-of-concept studies were designed to assess the proposed processes and system for generating the required evidence to perform B/R assessment and near-real time monitoring of vaccines. We aimed to test B/R methodologies for vaccines, using the comparison of the B/R profiles of whole-cell (wP) and acellular pertussis (aP) vaccine formulations in children as an example. METHODS: We used multi-criteria decision analysis (MCDA) to structure the B/R assessment combined with individual-level state transition modelling to build the B/R effects table. In the state transition model, we simulated the number of events in two hypothetical cohorts of 1 million children followed from first pertussis dose till pre-school-entry booster (or six years of age, whichever occurred first), with one cohort receiving wP, and the other aP. The benefits were reductions in pertussis incidence and complications. The risks were increased incidences of febrile convulsions, fever, hypotonic-hyporesponsive episodes, injection-site reactions and persistent crying. Most model parameters were informed by estimates (coverage, background incidences, relative risks) from eHR databases from Denmark (SSI), Spain (BIFAP and SIDIAP), Italy (Pedianet) and the UK (RCGP-RSC and THIN). Preferences were elicited from clinical and epidemiological experts. RESULTS: Using state transition modelling to build the B/R effects table facilitated the comparison of different vaccine effects (e.g. immediate vaccine risks vs long-term vaccine benefits). Estimates from eHR databases could be used to inform the simulation model. The model results could be easily combined with preference weights to obtain B/R scores. CONCLUSION: Existing B/R methodology, modelling and estimates from eHR databases can be successfully used for B/R assessment of vaccines.

Advance system testing: Vaccine benefit studies using multi-country electronic health data - The example of pertussis vaccination.

The Accelerated Development of VAccine benefit-risk Collaboration in Europe (ADVANCE), a public-private consortium, implemented and tested a distributed network system for the generation of evidence on the benefits-risks of marketed vaccines in Europe. We tested the system by estimating the incidence rate (IR) of pertussis and pertussis-related complications in children vaccinated with acellular (aP) and whole-cell (wP) pertussis vaccine. Data from seven electronic databases from four countries (Denmark: AUH and SSI, Spain: SIDIAP and BIFAP, UK: THIN and RCGP RSC and Italy: Pedianet) were included in a retrospective cohort analysis. Exposure was defined as any pertussis vaccination (aP or wP). The follow-up time started 14 days after the first dose. Children who had received any pertussis vaccine from January 1990 to December 2015 were included (those who switched type, or had unknown type were excluded). The outcomes of interest were confirmed or suspected pertussis and pertussis-related pneumonia and generalised convulsions within one month of pertussis diagnosis and death within three months of pertussis diagnosis. The cohort comprised 2,886,367 children ≤5 years of age. Data on wP and aP vaccination were available in three and seven databases, respectively. The IRs (per 100,000 person-years) for pertussis varied largely and ranged between 0.15 (95% CI: 0.12; 0.19) and 1.15 (95% CI: 1.07; 1.23), and the trends over time was consistent with those observed from national surveillance databases for confirmed pertussis. The pertussis IRs decreased as the number of wP and aP vaccine doses increased. Pertussis-related complications were rare (89 pneumonia, 7 generalised convulsions and no deaths) and their relative risk (vs. non-pertussis) could not be reliably estimated. The study demonstrated the feasibility of the ADVANCE system to estimate the change in pertussis IRs following pertussis vaccination. Larger sample sizes would provide additional power to compare the risk for complications between children with and without pertussis. The feasibility of vaccine-type specific effectiveness studies may be considered in the future.

Quantifying outcome misclassification in multi-database studies: The case study of pertussis in the ADVANCE project.

BACKGROUND: The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines using European healthcare databases. Event misclassification can result in biased estimates. Using different algorithms for identifying cases of Bordetella pertussis (BorPer) infection as a test case, we aimed to describe a strategy to quantify event misclassification, when manual chart review is not feasible. METHODS: Four participating databases retrieved data from primary care (PC) setting: BIFAP: (Spain), THIN and RCGP RSC (UK) and PEDIANET (Italy); SIDIAP (Spain) retrieved data from both PC and hospital settings. BorPer algorithms were defined by healthcare setting, data domain (diagnoses, drugs, or laboratory tests) and concept sets (specific or unspecified pertussis). Algorithm- and database-specific BorPer incidence rates (IRs) were estimated in children aged 0-14 years enrolled in 2012 and 2014 and followed up until the end of each calendar year and compared with IRs of confirmed pertussis from the ECDC surveillance system (TESSy). Novel formulas were used to approximate validity indices, based on a small set of assumptions. They were applied to approximately estimate positive predictive value (PPV) and sensitivity in SIDIAP. RESULTS: The number of cases and the estimated BorPer IRs per 100,000 person-years in PC, using data representing 3,173,268 person-years, were 0 (IR = 0.0), 21 (IR = 4.3), 21 (IR = 5.1), 79 (IR = 5.7), and 2 (IR = 2.3) in BIFAP, SIDIAP, THIN, RCGP RSC and PEDIANET respectively. The IRs for combined specific/unspecified pertussis were higher than TESSy, suggesting that some false positives had been included. In SIDIAP the estimated IR was 45.0 when discharge diagnoses were included. The sensitivity and PPV of combined PC specific and unspecific diagnoses for BorPer cases in SIDIAP were approximately 85% and 72%, respectively. CONCLUSION: Retrieving BorPer cases using only specific concepts has low sensitivity in PC databases, while including cases retrieved by unspecified concepts introduces false positives, which were approximately estimated to be 28% in one database. The share of cases that cannot be retrieved from a PC database because they are only seen in hospital was approximately estimated to be 15% in one database. This study demonstrated that quantifying the impact of different event-finding algorithms across databases and benchmarking with disease surveillance data can provide approximate estimates of algorithm validity.

ADVANCE system testing: Can coverage of pertussis vaccination be estimated in European countries using electronic healthcare databases: An example.

INTRODUCTION: The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines, using existing healthcare databases in Europe. The objective of this paper was to assess the feasibility of using electronic healthcare databases to estimate dose-specific acellular pertussis (aP) and whole cell pertussis (wP) vaccine coverage. METHODS: Seven electronic healthcare databases in four European countries (Denmark (n = 2), UK (n = 2), Spain (n = 2) and Italy (n = 1)) participated in this study. Children were included from birth and followed up to age six years. Vaccination exposure was obtained from the databases and classified by type (aP or wP), and dose 1, 2 or 3. Coverage was estimated using period prevalence. For the 2006 birth cohort, two estimation methods for pertussis vaccine coverage, period prevalence and cumulative incidence were compared for each database. RESULTS: The majority of the 2,575,576 children included had been vaccinated at the country-specific recommended ages. Overall, the estimated dose 3 coverage was 88-97% in Denmark (birth cohorts from 2003 to 2014), 96-100% in the UK (2003-2014), 95-98% in Spain (2004-2014) and 94% in Italy (2006-2007). The estimated dose 3 coverage per birth cohort in Denmark and the UK differed by 1-6% compared with national estimates, with our estimates mostly higher. The estimated dose 3 coverage in Spain differed by 0-2% with no consistent over- or underestimation. In Italy, the estimates were 3% lower compared with the national estimates. Except for Italy, for which the two coverage estimation methods generated the same results, the estimated cumulative incidence coverages were consistently 1-10% lower than period prevalence estimates. CONCLUSION: This study showed that it was possible to provide consistent estimates of pertussis immunisation coverage from the electronic healthcare databases included, and that the estimates were comparable with the national estimates.

The Longitudinal Incidence of Human Papillomavirus Vaccination in Spanish Primary Care in the First 10 Years After Approval.

BACKGROUND: In Spain, girls are vaccinated against human papillomavirus (HPV) in the primary care setting, according to a national vaccination programme. Vaccination is voluntary and is covered by the public health system. OBJECTIVES: The aim of the study was to estimate the incidence and patterns of HPV vaccination amongst girls in primary care in Spain. METHODS: A cohort study was performed using the information recorded in the Spanish Primary Care Database for Pharmacoepidemiological Research (BIFAP) from 7.9 million patients from seven Spanish regions, between 2001 and 2016 (56.6% of the regional population). Data available in BIFAP include patient age, sex, life-style factors, clinical events, specialist referrals, prescriptions, and vaccinations as recorded by the primary care physician (PCP) or administering nurse. The study cohort comprised all girls aged 9-18 years registered in BIFAP between 1st January of 2007 and 31st December of 2016 who had at least 1 year of clinical record information with their PCP (inclusion criteria). The date the inclusion criteria were met was designated as the start date to the study cohort contribution. In order to estimate the incidence of HPV vaccination (initiation of vaccination schedule), girls with an HPV vaccination recorded before the start date or without vaccination date were excluded. Girls forming the study cohort were followed from start date until there was a recorded HPV vaccination, they reached 19 years of age or died, end of available information, or 31st December 2016. The person-time of all patients forming the study cohort was reckoned in the incidence estimations. The follow-up was replicated yearly from 2007 to 2016. The cumulative incidence (CuIn) of vaccination by birth cohort, year and region, was estimated using life tables (proportion of vaccination by intervals in which the denominator is the initial population corrected for losses). RESULTS: Of 388,690 girls forming the study population, 154,211 initiated the vaccination during 2007-2016. Ages ranged from 12 to 14 years at first dose in 84.5% of vaccinated girls, 42.79% received a quadrivalent vaccine, 21.86% a bivalent vaccine, and 35.35% an unknown type. Of the vaccinated population, 48.0% were completely vaccinated with a three-dose schedule and 28.9% with a two-dose schedule, 20.2% received one dose and 3.0% two doses in a three-dose schedule, at a maximum of 10 years of follow-up. The CuIn was highest among girls aged either 13 or 14 years over all regions (reaching 92.8% and 89.7%, respectively), and aged 12 in some regions/years (up to 89.8%). Girls aged 15 years were also vaccinated (although showing lower yearly incidence, i.e. < 69.1%) in two regions. The coverage was broadened to younger girls (11 years) during the last years of the study period in some regions. CONCLUSIONS: According to BIFAP primary care data, a high incidence of vaccination among girls aged 13-14 years was observed. Vaccination among younger and older girls were less common, although they reached high incidence in some regions and/or years. Most vaccination patterns adjusted to a complete vaccination regimen, as recommended posology.

RETRACTED ARTICLE: The Longitudinal Incidence of Human Papillomavirus Vaccination in Spanish Primary Care in the First 6 Years After Approval.

BACKGROUND: In Spain, girls and women are vaccinated against human papillomavirus (HPV) in the primary care setting, according to a national vaccination program. Vaccination is voluntary and the cost is covered by the public health system. OBJECTIVES: The aim of the study was to estimate the incidence and patterns of HPV vaccination amongst girls in Spain. METHODS: A cohort study was performed using the information recorded in the Spanish Primary Care Database for Pharmacoepidemiological Research (BIFAP) from 7.4 million patients from eight Spanish regions, between 2001 and 2013 (56% of the regional population). Data available in BIFAP include patient age, sex, lifestyle factors, clinical events, specialist referrals, prescriptions, and vaccinations as recorded by the primary care physician (PCP) or administering nurse. The study cohort comprised all girls aged 11-18 years registered in BIFAP between 1 January 2007 and 31 December 2013 who had at least 1 year of clinical record information with their PCP (inclusion criteria). The date the inclusion criteria were met was designated as the start date of the study cohort contribution. In order to estimate the incidence of HPV vaccination, girls forming the study cohort were followed from start date until there was a recorded HPV vaccination, they reached 19 years of age or died, the end of available information, or 31 December 2013. The person-time of all patients forming the study cohort was taken into account in the incidence estimations. The cumulative incidence (CuIn) of vaccination by birth cohort, year and region was estimated using life-tables (proportion of vaccination by intervals in which the denominator is the initial population corrected for losses). RESULTS: Out of 273,098 girls forming the study population, 81,461 were vaccinated during 2007-2013. Age ranged from 12 to 14 years at first dose in 86.0% of vaccinated girls; 54.1% received a quadrivalent vaccine, 21.9% a bivalent vaccine, and 24.0% an unknown type. Out of the vaccinated population, 87.9% received three doses, 8.2% two and 3.9% one dose, at a maximum of 7 years of follow-up. By calendar year and region, the CuIn reached 70.0-95.8% for birth cohorts between 1993 and 1999, 28.6-99.0% for births cohorts between 1990 and 1992, and exceptionally, 70.6-99.8% for births cohorts between 2000 and 2002 in three regions. CONCLUSIONS: According to BIFAP primary care data, a high incidence of vaccination among girls aged 13-15 years was observed. Vaccination among younger and older girls was less common although they reached high incidence in those regions that included girls aged 11-18 years in mass programs. Most vaccination patterns adjusted to a three-dose regimen, as recommended.