RESUMEN
OBJECTIVE: This study was undertaken to examine the comparative safety of antiseizure medication (ASM) monotherapy in pregnancy with respect to risk of major congenital malformations (MCMs), overall and by MCM subtype. METHODS: We conducted a population-based cohort study using national health register data from Denmark, Finland, Iceland, Norway, and Sweden (1996-2020). We compared pregnancies with first trimester exposure to lamotrigine monotherapy to ASM-unexposed, carbamazepine, valproate, oxcarbazepine, levetiracetam, and topiramate to lamotrigine monotherapy, and stratified monotherapy groups by dose. The outcome was nongenetic MCM and specific subtypes. We estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) with log-binomial regression and propensity score weights. RESULTS: There was a higher crude risk of any MCM in pregnancies exposed to lamotrigine monotherapy (n = 8,339) compared to ASM-unexposed pregnancies (n = 4,866,362), but not after confounder adjustment (aRR = 0.97, 95% CI = 0.87-1.08). Compared to lamotrigine, there was an increased risk of malformations associated with valproate (n = 2,031, aRR = 2.05, 95% CI = 1.70-2.46) and topiramate (n = 509, aRR = 1.81, 95% CI = 1.26-2.60), which increased in a dose-dependent manner. We found no differences in malformation risk for carbamazepine (n = 2,674, aRR = 0.91, 95% CI = 0.72-1.15), oxcarbazepine (n = 1,313, aRR = 1.09, 95% CI = 0.83-1.44), or levetiracetam (n = 1,040, aRR = 0.78, 95% CI = 0.53-1.13). Valproate was associated with several malformation subtypes, including nervous system, cardiac, oral clefts, clubfoot, and hypospadias, whereas lamotrigine and carbamazepine were not. INTERPRETATION: Topiramate is associated with an increased risk of MCM similar to that associated with valproate, but lower doses may mitigate the risks for both drugs. Conversely, we found no increased risks for lamotrigine, carbamazepine, oxcarbazepine, or levetiracetam, which is reassuring. ANN NEUROL 2023;93:551-562.
Asunto(s)
Anomalías Inducidas por Medicamentos , Epilepsia , Embarazo , Masculino , Femenino , Humanos , Ácido Valproico/efectos adversos , Lamotrigina/uso terapéutico , Topiramato/uso terapéutico , Epilepsia/tratamiento farmacológico , Oxcarbazepina/uso terapéutico , Levetiracetam/uso terapéutico , Estudios de Cohortes , Anticonvulsivantes/uso terapéutico , Carbamazepina , Benzodiazepinas/uso terapéuticoRESUMEN
OBJECTIVE: Research points to disparities in disease burden and access to medical care in epilepsy. We studied the association between socioeconomic status (SES) and antiseizure medication (ASM) use in pregnancies with maternal epilepsy. METHODS: We conducted a cross-sectional study consisting of 21 130 pregnancies with maternal epilepsy identified from Nordic registers during 2006-2017. SES indicators included cohabitation status, migrant background, educational attainment, and household income. Main outcomes were the proportion and patterns of ASM use from 90 days before pregnancy to birth. We applied multiple imputation to handle SES variables with 2%-4% missingness. We estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) using modified Poisson regression with the highest SES category as reference. RESULTS: Mothers with the highest education and the highest income quintile used ASMs least frequently (56% and 53%, respectively). We observed increased risks of ASM discontinuation prior to or during the first trimester for low SES. The risk estimates varied depending on the SES indicator from aRR = 1.27 for low income (95% CI: 1.03-1.57) to aRR = 1.66 for low education (95% CI: 1.30-2.13). Migrant background was associated with ASM initiation after the first trimester (aRR 2.17; 95% CI 1.88-2.52). Low education was associated with the use of valproate during pregnancy in monotherapy (aRR 1.70; 95% CI 1.29-2.24) and in polytherapy (aRR 2.65; 95% CI 1.66-4.21). Low education was also associated with a 37% to 39% increased risk of switching from one ASM to another depending on the ASM used. For the other SES indicators, aRRs of switching varied from 1.16 (foreign origin; 95% CI 1.08-1.26) to 1.26 (not married or cohabiting; 95% CI 1.17-1.36). SIGNIFICANCE: Low SES was associated with riskier patterns of ASM use: discontinuation, late initiation, and switching during pregnancy. These findings may reflect unplanned pregnancies, disparities in access to preconception counseling, and suboptimal care.
Asunto(s)
Anticonvulsivantes , Epilepsia , Complicaciones del Embarazo , Humanos , Femenino , Epilepsia/tratamiento farmacológico , Epilepsia/epidemiología , Embarazo , Anticonvulsivantes/uso terapéutico , Adulto , Complicaciones del Embarazo/tratamiento farmacológico , Complicaciones del Embarazo/epidemiología , Estudios Transversales , Factores Socioeconómicos , Países Escandinavos y Nórdicos/epidemiología , Adulto Joven , Clase Social , Sistema de RegistrosRESUMEN
PURPOSE: This study aimed to describe recent trends in ADHD medication use in pregnancy in Norway and Sweden, including prevalence, individual characteristics, and patterns of use. METHODS: We studied ADHD medication use (amphetamine, dexamphetamine, methylphenidate, atomoxetine, lisdexamfetamine, guanfacine) by year and age in pregnancies from 2010 to 2019 identified from the medical birth registers (gestational age ≥ 22 weeks) linked to prescribed drug registers (Norway, N = 577,116; Sweden, N = 1,118,988). We compared characteristics of those who used any ADHD medication in pregnancy to no use in pregnancy. Discontinuation was defined as no use after first trimester. RESULTS: ADHD medication use increased from 2010 to 2019 by 3.0 users per 1000 pregnancies in Norway (from 2.5 to 5.5/1000) and by 6.3 per 1000 in Sweden (from 1.6 to 7.9/1000), mainly driven by methylphenidate and since 2015 by lisdexamfetamine. Medication use has increased among pregnant individuals of all age groups, with higher use among the youngest. Pregnant individuals who used ADHD medication were less likely to be married/cohabiting, more likely be nulliparous and to smoke. They had particularly high use of co-medication with antidepressants, anxiolytics/hypnotics, and opioids: 42% in Norway and 65% in Sweden used at least one additional class of psychotropic medication. Most individuals discontinued ADHD medication in pregnancy (85% Norway, 78% Sweden). CONCLUSION: ADHD medication use during pregnancy increased in Norway and Sweden in the last decade. However, discontinuation rates during pregnancy were high. Those who used ADHD medication had more risk factors for pregnancy complications including low parity, smoking, and other psychotropic drug use.
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Trastorno por Déficit de Atención con Hiperactividad , Estimulantes del Sistema Nervioso Central , Metilfenidato , Embarazo , Femenino , Humanos , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Estimulantes del Sistema Nervioso Central/uso terapéutico , Suecia/epidemiología , Dimesilato de Lisdexanfetamina/uso terapéutico , Prevalencia , Metilfenidato/uso terapéutico , Clorhidrato de Atomoxetina/uso terapéutico , Noruega/epidemiologíaRESUMEN
PURPOSE: To describe ADHD medication use trajectories around pregnancy in Norway and Sweden. METHODS: We identified pregnancies resulting in births using linked data from birth and prescribed drug registers of Norway (2006-2019, N = 813 107) and Sweden (2007-2018, N = 1 269 146). We restricted to women who filled prescriptions for ADHD medication during pregnancy or in the year before or after. We described exposure as use versus no use, and total amount of drug dispensed in defined daily doses (DDDs). Group-based trajectory modeling was used to identify distinct medication use trajectories. RESULTS: In total, 13 286 women (0.64%) filled a prescription for ADHD medication. We identified four trajectory groups: continuers (5.7%), interrupters (23.8%), discontinuers (49.5%), and late initiators (21.0%). Discontinuers were younger, continuers were older on average. More women continued medication in recent years (2014-2019). Most discontinuers (60.7%) were nulliparous; more initiators and continuers had one or multiple previous births, respectively. Continuers were least likely to live with a partner (65.8%). Discontinuers were least likely (24.7%) and continuers most likely (37.6%) to smoke at the beginning of pregnancy. More continuers used amphetamine derivatives and were most likely to use other psychotropics. On modeling continuers, we identified three dose-trajectory groups which suggested that most women reduced medication dose during pregnancy. CONCLUSIONS: Most pregnant women discontinued or interrupted their ADHD medication during pregnancy, but more continued in recent years. Continuers were more likely to have had previous births, less likely to have lived with a partner, and may have had additional comorbidities warranting the use of other psychotropics.
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Trastorno por Déficit de Atención con Hiperactividad , Humanos , Embarazo , Femenino , Suecia/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Noruega/epidemiologíaRESUMEN
BACKGROUND: Despite the widespread use, only sparse information is available on the safety of gabapentin during pregnancy. We sought to evaluate the association between gabapentin exposure during pregnancy and risk of adverse neonatal and maternal outcomes. METHODS AND FINDINGS: Using the United States Medicaid Analytic eXtract (MAX) dataset, we conducted a population-based study of 1,753,865 Medicaid-eligible pregnancies between January 2000 and December 2013. We examined the risk of major congenital malformations and cardiac defects associated with gabapentin exposure during the first trimester (T1), and the risk of preeclampsia (PE), preterm birth (PTB), small for gestational age (SGA), and neonatal intensive care unit admission (NICUa) associated with gabapentin exposure early, late, or both early and late in pregnancy. Gabapentin-unexposed pregnancies served as the reference. We estimated relative risks (RRs) and 95% confidence intervals (CIs) using fine stratification on the propensity score (PS) to control for over 70 confounders (e.g., maternal age, race/ethnicity, indications for gabapentin, other pain conditions, hypertension, diabetes, use of opioids, and specific morphine equivalents). We identified 4,642 pregnancies exposed in T1 (mean age = 28 years; 69% white), 3,745 exposed in early pregnancy only (28 years; 67% white), 556 exposed in late pregnancy only (27 years; 60% white), and 1,275 exposed in both early and late pregnancy (29 years; 75% white). The reference group consisted of 1,744,447 unexposed pregnancies (24 years; 40% white). The adjusted RR for major malformations was 1.07 (95% CI 0.94-1.21, p = 0.33) and for cardiac defects 1.12 (0.89-1.40, p = 0.35). Requiring ≥2 gabapentin dispensings moved the RR to 1.40 (1.03-1.90, p = 0.03) for cardiac defects. There was a higher risk of preterm birth among women exposed to gabapentin either late (RR, 1.28 [1.08-1.52], p < 0.01) or both early and late in pregnancy (RR, 1.22 [1.09-1.36], p < 0.001), SGA among women exposed to gabapentin early (1.17 [1.02-1.33], p = 0.02), late (1.39 [1.01-1.91], p = 0.05), or both early and late in pregnancy (RR, 1.32 [1.08-1.60], p < 0.01), and NICU admission among women exposed to gabapentin both early and late in pregnancy (RR, 1.35 [1.20-1.52], p < 0.001). There was no higher risk of preeclampsia among women exposed to gabapentin after adjustment. Study limitations include the potential for residual confounding and exposure misclassification. CONCLUSIONS: In this large population-based study, we did not find evidence for an association between gabapentin exposure during early pregnancy and major malformations overall, although there was some evidence of a higher risk of cardiac malformations. Maternal use of gabapentin, particularly late in pregnancy, was associated with a higher risk of PTB, SGA, and NICUa.
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Gabapentina/efectos adversos , Efectos Tardíos de la Exposición Prenatal/metabolismo , Anomalías Inducidas por Medicamentos/metabolismo , Adulto , Estudios de Cohortes , Femenino , Gabapentina/uso terapéutico , Humanos , Recién Nacido Pequeño para la Edad Gestacional , Preeclampsia/fisiopatología , Embarazo , Complicaciones del Embarazo , Primer Trimestre del Embarazo , Nacimiento Prematuro , Puntaje de Propensión , Riesgo , Estados UnidosRESUMEN
BACKGROUND: There has been concern that exposure to lithium early in pregnancy may be associated with a marked increase in the risk of Ebstein's anomaly (a right ventricular outflow tract obstruction defect) in infants and overall congenital cardiac defects, but data are conflicting and limited. METHODS: We conducted a cohort study involving 1,325,563 pregnancies in women who were enrolled in Medicaid and who delivered a live-born infant between 2000 and 2010. We examined the risk of cardiac malformations among infants exposed to lithium during the first trimester as compared with unexposed infants and, in secondary analyses, with infants exposed to another commonly used mood stabilizer, lamotrigine. Risk ratios and 95% confidence intervals were estimated with control for psychiatric and medical conditions, medications, and other potential confounders. RESULTS: Cardiac malformations were present in 16 of the 663 infants exposed to lithium (2.41%), 15,251 of the 1,322,955 nonexposed infants (1.15%), and 27 of the 1945 infants exposed to lamotrigine (1.39%). The adjusted risk ratio for cardiac malformations among infants exposed to lithium as compared with unexposed infants was 1.65 (95% confidence interval [CI], 1.02 to 2.68). The risk ratio was 1.11 (95% CI, 0.46 to 2.64) for a daily dose of 600 mg or less, 1.60 (95% CI, 0.67 to 3.80) for 601 to 900 mg, and 3.22 (95% CI, 1.47 to 7.02) for more than 900 mg. The prevalence of right ventricular outflow tract obstruction defects was 0.60% among lithium-exposed infants versus 0.18% among unexposed infants (adjusted risk ratio, 2.66; 95% CI, 1.00 to 7.06). Results were similar when lamotrigine-exposed infants were used as the reference group. CONCLUSIONS: Maternal use of lithium during the first trimester was associated with an increased risk of cardiac malformations, including Ebstein's anomaly; the magnitude of this effect was smaller than had been previously postulated. (Funded by the National Institute of Mental Health.).
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Antidepresivos/efectos adversos , Trastorno Bipolar/tratamiento farmacológico , Cardiopatías Congénitas/inducido químicamente , Compuestos de Litio/efectos adversos , Complicaciones del Embarazo/tratamiento farmacológico , Adulto , Anticonvulsivantes/efectos adversos , Anticonvulsivantes/uso terapéutico , Antidepresivos/uso terapéutico , Antimaníacos/efectos adversos , Antimaníacos/uso terapéutico , Estudios de Cohortes , Femenino , Cardiopatías Congénitas/epidemiología , Humanos , Lactante , Recién Nacido , Lamotrigina , Compuestos de Litio/uso terapéutico , Embarazo , Primer Trimestre del Embarazo , Prevalencia , Triazinas/efectos adversos , Triazinas/uso terapéutico , Adulto JovenRESUMEN
PURPOSE: Medication exposures in pregnancy are often defined by one or more prescription fills. Harmful effects could be underestimated if rapid discontinuation of use after pregnancy recognition is common. We used conception, a critical biological period, as an intervention in a novel application of interrupted time series analysis (ITSA). METHODS: Among 645 049 pregnancies from the Medical Birth Registry (2005-2015) linked to the Norwegian Prescription Database, we modeled the total number of prescription fills in the 12 weeks before and after estimated conception date with ITSA. We examined psychostimulants, antidepressants, antipsychotics, and antiepileptics (AEDs; separated by use for epilepsy or other indications). We used relative measures (%) to compare model coefficients. We also compared number of pregnancies defined as exposed when the earliest fill considered was 30 days before the last menstrual period (LMP -30 days), LMP, or estimated conception date (LMP +14 days). RESULTS: We observed a sudden decline in prescription fills from 2 weeks after conception and decreasing fills thereafter for psychostimulants, antidepressants, AEDs for other indications, and antipsychotics excluding incident users. Fills for AEDs for epilepsy did not fall after conception. Only 77% of pregnancies with fills for psychostimulants from LMP and 58% with fills from LMP -30 days had fills from conception. Similar figures for AEDs for epilepsy were 99% and 96%. CONCLUSIONS: This application shows that ITSA can help researchers understand rapid changes in patient behavior around conception that have consequences for exposure misclassification in pregnancy drug safety studies. ITSA results can help pharmacoepidemiologists guide study exposure definitions.
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Fármacos del Sistema Nervioso Central/uso terapéutico , Fertilización , Cumplimiento de la Medicación , Complicaciones del Embarazo/inducido químicamente , Anticonvulsivantes/uso terapéutico , Antidepresivos/uso terapéutico , Antipsicóticos/uso terapéutico , Fármacos del Sistema Nervioso Central/efectos adversos , Estimulantes del Sistema Nervioso Central/uso terapéutico , Bases de Datos Factuales , Prescripciones de Medicamentos , Femenino , Humanos , Análisis de Series de Tiempo Interrumpido , Noruega , Embarazo , Complicaciones del Embarazo/diagnóstico , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Factores de TiempoRESUMEN
PURPOSE: To describe recent international trends in antiepileptic drug (AED) use during pregnancy and individual patterns of use including discontinuation and switching. METHODS: We studied pregnancies from 2006 to 2016 within linked population-based registers for births and dispensed prescription drugs from Denmark, Finland, Iceland, Norway, Sweden, and New South Wales, Australia and claims data for public and private insurance enrollees in the United States. We examined the prevalence of AED use: the proportion of pregnancies with ≥1 prescription filled from 3 months before pregnancy until birth, and individual patterns of use by trimester. RESULTS: Prevalence of AED use in almost five million pregnancies was 15.3 per 1000 (n = 75 249) and varied from 6.4 in Sweden to 34.5 per 1000 in the publicly-insured US population. AED use increased in all countries in 2006-2012 ranging from an increase of 22% in Australia to 104% in Sweden, and continued to rise or stabilized in the countries in which more recent data were available. Lamotrigine, clonazepam, and valproate were the most commonly used AEDs in the Nordic countries, United States, and Australia, respectively. Among AED users, 31% only filled a prescription in the 3 months before pregnancy. Most filled a prescription in the first trimester (59%) but few filled prescriptions in every trimester (22%). CONCLUSIONS: Use of AEDs in pregnancy rose from 2006 to 2016. Trends and patterns of use of valproate and lamotrigine reflected the safety data available during this period. Many women discontinued AEDs during pregnancy while some switched to another AED.
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Anticonvulsivantes/uso terapéutico , Epilepsia/epidemiología , Cooperación del Paciente , Pautas de la Práctica en Medicina/estadística & datos numéricos , Complicaciones del Embarazo/epidemiología , Adulto , Epilepsia/tratamiento farmacológico , Femenino , Humanos , Nueva Gales del Sur/epidemiología , Pautas de la Práctica en Medicina/tendencias , Embarazo , Complicaciones del Embarazo/tratamiento farmacológico , Atención Prenatal , Prevalencia , Países Escandinavos y Nórdicos/epidemiología , Estados Unidos/epidemiologíaRESUMEN
PURPOSE: The purpose of the study is to develop an algorithm to identify pregnancies in administrative databases and apply it to assess pregnancy rates and outcomes in women prescribed isotretinoin or tretinoin. METHODS: Using the 2011 to 2015 Truven Health MarketScan Database, we identified pregnancies, including losses and terminations. In a cohort design, nonpregnant women filling a prescription for isotretinoin or tretinoin were matched to five women without either prescription. Women were followed for 365 days or until conception, medication discontinuation, or enrollment discontinuation ("prescription episode"). Rates of pregnancy, risks of pregnancy losses, and prevalence of infant malformations at birth were assessed by exposure. RESULTS: We identified 2 179 192 livebirths, 8434 stillbirths, 2521 mixed births, 415 110 spontaneous abortions, 124 556 elective terminations, and 8974 unspecified abortions. There were 86 834 isotretinoin and 973 587 tretinoin episodes, matched to 5 302 105 unexposed women. Pregnancy rates were 3 (isotretinoin), 19 (tretinoin), and 34 (unexposed) per 1000 person-years. Risk of spontaneous pregnancy losses were similar; however, terminations were more common in the isotretinoin-exposed (28% [95% CI: 21%-36%]) than the tretinoin-exposed (10% [95% CI: 9%-11%]) or unexposed pregnancies (6%). Malformations occurred in 4.5% (95% CI: 3.5%-5.6%) of the tretinoin-exposed pregnancies and 4.2% of the unexposed pregnancies (adjusted odds ratio: 1.16 [95% CI: 0.85-1.58]); isotretinoin-exposed births were too few to assess malformations. CONCLUSIONS: Administrative databases can complement risk evaluation and mitigation strategies (REMS) for known teratogens and contribute to safety surveillance for other medications. Here, isotretinoin-exposed pregnancy rates were low, but existent, and many pregnancies were terminated. Tretinoin exposure was not associated with a meaningfully elevated risk of losses or malformations as compared with unexposed pregnancies.
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Anomalías Inducidas por Medicamentos/epidemiología , Isotretinoína/efectos adversos , Resultado del Embarazo/epidemiología , Vigilancia de Productos Comercializados/métodos , Tretinoina/efectos adversos , Anomalías Inducidas por Medicamentos/etiología , Reclamos Administrativos en el Cuidado de la Salud/estadística & datos numéricos , Adolescente , Adulto , Bases de Datos Factuales/estadística & datos numéricos , Prescripciones de Medicamentos/estadística & datos numéricos , Femenino , Humanos , Recién Nacido , Exposición Materna/efectos adversos , Exposición Materna/estadística & datos numéricos , Persona de Mediana Edad , Embarazo , Índice de Embarazo , Prevalencia , Vigilancia de Productos Comercializados/estadística & datos numéricos , Estados Unidos/epidemiología , Adulto JovenRESUMEN
PURPOSE: Father's medication use is of interest in fertility studies and as negative control exposures in pregnancy medication safety studies. We sought to compare self-report to prescription records to understand how reliably each of these sources of information may be used. METHODS: We compared self-reported medication use in the 6 months prior to pregnancy from fathers participating in the Norwegian Mother and Child Cohort Study to records of dispensed prescriptions from the Norwegian Prescription Database that overlapped in time. Medications from 3 main categories were assessed: prescription medications used chronically, prescription medications used episodically, and over-the-counter/prescription medications (predominantly obtained without prescription). We calculated agreement between self-report and dispensing records using Cohen's kappa statistic. RESULTS: We included 42 848 pregnancies with the father's prescription data available for the 9 months before pregnancy. Prescription medications used chronically including antiepileptics, antipsychotics, and antidepressants showed substantial agreement between self-report and prescription records: kappa statistics 0.87, 0.63, and 0.74, respectively. Prescription medications used episodically like anti-infectives, opioids, anxiolytics, and hypnotics and sedatives showed worse agreement: kappa 0.19, 0.32, 0.40, 0.32. Over-the-counter/prescription medications like paracetamol and nonsteroidal anti-inflammatory drugs had slight agreement: kappa 0.02 and 0.20. CONCLUSIONS: There is good agreement between paternal self-report and prescription data for prescribed medications used chronically and substantially less for medications used episodically. Suboptimal agreement for episodic medications suggests poor recall (for questionnaires) or false positives due to noncompliance (prescription data). Not surprisingly, use of medications available both with and without a prescription is not well captured using prescription databases alone.
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Prescripciones de Medicamentos/estadística & datos numéricos , Medicamentos sin Prescripción/uso terapéutico , Exposición Paterna/estadística & datos numéricos , Medicamentos bajo Prescripción/uso terapéutico , Autoinforme/estadística & datos numéricos , Adulto , Estudios de Cohortes , Bases de Datos Factuales/estadística & datos numéricos , Padre/estadística & datos numéricos , Femenino , Humanos , Masculino , Noruega , EmbarazoRESUMEN
OBJECTIVE: We sought to determine whether midpregnancy antioxidant levels are associated with preeclampsia, overall and by timing of onset. STUDY DESIGN: We carried out a case-control study, nested within a cohort of 5337 pregnant women in Montreal, Quebec, Canada. Blood samples obtained at 24-26 weeks were assayed for nonenzymatic antioxidant levels among cases of preeclampsia (n = 111) and unaffected controls (n = 441). We excluded women diagnosed with gestational hypertension only. We used logistic regression with the z-score of each antioxidant level as the main predictor variable for preeclampsia risk. We further stratified early-onset (<34 weeks) and late-onset preeclampsia and carried out multinomial logistic regression. Finally, we assessed associations between antioxidant biomarkers and timing of onset (in weeks) by Cox regression, with appropriate selection weights. We summed levels of correlated biomarkers (r(2) > 0.3) and log-transformed positively skewed distributions. We adjusted for body mass index, nulliparity, preexisting diabetes, hypertension, smoking, and proxies for ethnicity and socioeconomic status. RESULTS: The odds ratios for α-tocopherol, α-tocopherol:cholesterol, lycopene, lutein, and carotenoids (sum of α-carotene, ß-carotene, anhydrolutein, α-cryptoxanthin, and ß-cryptoxanthin) suggested an inverse association between antioxidant levels and overall preeclampsia risk; however, only lutein was significantly associated with overall preeclampsia in adjusted models (odds ratio, 0.60; 95% confidence interval, 0.46-0.77) per SD. In multinomial logistic models, the relative risk ratio (RRR) estimates for the early-onset subgroup were farther from the null than those for the late-onset subgroup. The ratio of α-tocopherol to cholesterol and retinol were significantly associated with early- but not late-onset preeclampsia: RRRs (95% confidence intervals) for early-onset preeclampsia 0.67 (0.46-0.99) and 1.61 (1.12-2.33), respectively. Lutein was significantly associated with both early- and late-onset subtypes in adjusted models; RRRs 0.53 (0.35-0.80) and 0.62 (0.47-0.82), respectively. Survival analyses confirmed these trends. CONCLUSION: Most antioxidants were more strongly associated with early-onset preeclampsia, suggesting that oxidative stress may play a greater role in the pathophysiology of early-onset preeclampsia. Alternatively, reverse causality may explain this pattern. Lutein was associated with both early- and late-onset preeclampsia and may be a promising nutrient to consider in preeclampsia prevention trials, if this finding is corroborated.
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Antioxidantes/análisis , Preeclampsia/sangre , Adulto , Carotenoides/sangre , Estudios de Casos y Controles , Femenino , Humanos , Modelos Logísticos , Preeclampsia/epidemiología , Embarazo , Segundo Trimestre del Embarazo , Quebec/epidemiología , Medición de Riesgo , Adulto Joven , alfa-Tocoferol/sangreRESUMEN
BACKGROUND: Blinding is a fundamental design strengthening feature in randomized clinical trials. Blinding is particularly important in trials whose outcome measures include subjective assessment of signs and symptoms, such as trials investigating the post-thrombotic syndrome, a frequent chronic complication of deep vein thrombosis. PURPOSE: To determine whether strategies used to blind site investigators, research coordinators and patients were successful in a specific device trial, a multicenter trial of active versus placebo elastic compression stockings worn for 2 years to prevent post-thrombotic syndrome in patients with a first deep vein thrombosis (the SOX Trial). METHODS: Patients were randomized to the active or placebo stocking intervention, which were indistinguishable in appearance at baseline. Replacement stockings were shipped directly to patients' homes and were not worn to any of the study visits during the study. Guesstimates of treatment group assignment were completed by site investigators, research coordinators and patients at the end of study follow-up. Statistical assessments of blinding were performed using the James and Bang blinding indices. RESULTS: Overall rates of correct responses were 10.4% for site investigators, 17.8% for research coordinators and 29.4% for patients. James blinding index values suggest that blinding was achieved for site investigators, research coordinators and patients. The treatment specific Bang blinding index values suggest that blinding was achieved for site investigators and research coordinators, but detected possible unblinding and opposite guess for patients in the active and placebo elastic compression stocking groups, respectively. LIMITATIONS: Post-study assessment of blinding, as was done for the SOX Trial, cannot distinguish between degree of blinding and hunches about an intervention's efficacy. However, as rates of post-thrombotic syndrome along with adverse events in the SOX Trial were similar between treatment groups, it is unlikely that hunches would have interfered with our end-of-trial assessment for blinding. CONCLUSION: Blinding strategies used in our trial were successful overall and appeared to be most effective for site investigators and research coordinators. For patients, there may have been some degree of unblinding in the active stocking group. However, as the trial results were negative with active elastic compression stocking showing no benefit over placebo elastic compression stocking, this potential unblinding has minimal impact on the overall conclusions of the trial.
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Síndrome Postrombótico/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto/normas , Medias de Compresión , Trombosis de la Vena/terapia , Adulto , Anciano , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Efecto Placebo , Síndrome Postrombótico/etiología , Trombosis de la Vena/complicacionesRESUMEN
Importance: Increasing use of second-line noninsulin antidiabetic medication (ADM) in pregnant individuals with type 2 diabetes (T2D) may result in fetal exposure, but their teratogenic risk is unknown. Objective: To evaluate periconceptional use of second-line noninsulin ADMs and whether it is associated with increased risk of major congenital malformations (MCMs) in the infant. Design, Setting, and Participants: This observational population-based cohort study used data from 4 Nordic countries (2009-2020), the US MarketScan Database (2012-2021), and the Israeli Maccabi Health Services database (2009-2020). Pregnant women with T2D were identified and their live-born infants were followed until up to 1 year after birth. Exposure: Periconceptional exposure was defined as 1 or more prescription fill of sulfonylureas, dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists, and sodium-glucose cotransporter 2 (SGLT2) inhibitors, or insulin (active comparator) from 90 days before pregnancy to end of first trimester. Main Outcomes and Measures: Relative risks (RRs) and 95% CIs for MCMs were estimated using log-binomial regression models, adjusting for key confounders in each cohort and meta-analyzed. Results: Periconceptional exposure to second-line noninsulin ADMs differed between countries (32, 295, and 73 per 100â¯000 pregnancies in the Nordics, US, and Israel, respectively), and increased over the study period, especially in the US. The standardized prevalence of MCMs was 3.7% in all infants (n = 3â¯514â¯865), 5.3% in the infants born to women with T2D (n = 51â¯826), and among infants exposed to sulfonylureas was 9.7% (n = 1362); DPP-4 inhibitors, 6.1% (n = 687); GLP-1 receptor agonists, 8.3% (n = 938); SGLT2 inhibitors, 7.0% (n = 335); and insulin, 7.8% (n = 5078). Compared with insulin, adjusted RRs for MCMs were 1.18 (95% CI, 0.94-1.48), 0.83 (95% CI, 0.64-1.06), 0.95 (95% CI, 0.72-1.26), and 0.98 (95% CI, 0.65-1.46) for infants exposed to sulfonylureas, DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT2 inhibitors, respectively. Conclusions and Relevance: Use of second-line noninsulin ADMs is rapidly increasing for treatment of T2D and other indications, resulting in an increasing number of exposed pregnancies. Although some estimates were imprecise, results did not indicate a large increased risk of MCMs above the risk conferred by maternal T2D requiring second-line treatment. Although reassuring, confirmation from other studies is needed, and continuous monitoring will provide more precise estimates as data accumulate.
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Diabetes Mellitus Tipo 2 , Inhibidores de la Dipeptidil-Peptidasa IV , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Embarazo , Femenino , Humanos , Hipoglucemiantes/efectos adversos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/complicaciones , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Inhibidores del Cotransportador de Sodio-Glucosa 2/efectos adversos , Agonistas Receptor de Péptidos Similares al Glucagón , Estudios de Cohortes , Compuestos de Sulfonilurea/efectos adversos , Insulina/efectos adversos , Receptor del Péptido 1 Similar al Glucagón/agonistasRESUMEN
BACKGROUND: An increasing number of women of reproductive age are treated with attention-deficit hyperactivity disorder (ADHD) medication; however, patterns of ADHD medication use for women in the perinatal period have not been well described. OBJECTIVE: This study aimed to describe ADHD medication use patterns from 1 year before pregnancy to 1 year after delivery, and to describe sociodemographic characteristics and clinical features by medication trajectories. METHODS: The population-based cohort study included pregnancies in Denmark between 1997 and 2020, from the Medical Birth Register, by women who filled at least one prescription for ADHD medication from 12 months before pregnancy until 12 months after delivery. We applied group-based trajectory modeling to classify women into subgroups based on the identification of heterogeneous ADHD medication treatment patterns, and described the characteristics associated with these groups. RESULTS: Overall, we included 4717 pregnancies leading to liveborn singletons by 4052 mothers with a mean (standard deviation) age of 27.5 (5.6) years. We identified four treatment trajectories across pregnancy and the postpartum period: continuers (23.3%), discontinuers (41.8%), interrupters who ceased filling prescriptions during pregnancy but resumed postpartum (17.2%), and postpartum initiators (17.7%). Continuers were older at the time of conception, gave birth in more recent years, were more likely to smoke during pregnancy, and used other psychotropic medications during pregnancy. A large proportion of continuers used methylphenidate (89.1%) compared with the other groups (75.9-84.1%) and had switched ADHD medication type during the whole period (16.4% vs. 7.4-14.8%). CONCLUSION: We found that approximately 60% of women discontinued or interrupted their ADHD medication around pregnancy, and those who continued differed in sociodemographic and clinical factors that may reflect more severe ADHD.
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Trastorno por Déficit de Atención con Hiperactividad , Estimulantes del Sistema Nervioso Central , Metilfenidato , Embarazo , Humanos , Femenino , Adulto , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/complicaciones , Estudios de Cohortes , Metilfenidato/uso terapéutico , Sistema de Registros , Estimulantes del Sistema Nervioso Central/uso terapéuticoRESUMEN
Importance: Significant evidence gaps exist regarding the safety of smoking cessation pharmacotherapies during pregnancy, especially for the risk of congenital malformations. Consequently, professional bodies advise against the use of varenicline and bupropion and recommend caution with nicotine replacement therapy (NRT). Contemporary estimates of the use of smoking cessation pharmacotherapies during pregnancy are lacking. Objective: To quantify the proportion of individuals using prescribed smoking cessation pharmacotherapies during pregnancy and during the first trimester specifically, in 4 countries. Design, Setting, and Participants: This retrospective, population-based cohort study used linked birth records, hospital admission records, and dispensing records of prescribed medications from all pregnancies resulting in birth between 2015 and 2020 in New South Wales, Australia; New Zealand; Norway; and Sweden. Data analyses were conducted in October and November 2023. Exposure: Prescribed smoking cessation pharmacotherapy use (varenicline, NRT, and bupropion) during pregnancy was defined as days' supply overlapping the period from date of conception to childbirth. Main Outcomes and Measures: Prevalence of use among all pregnancies and pregnancies with maternal smoking were calculated. Among women who used a pharmacotherapy, the proportion of women with use during the first trimester of pregnancy was also calculated. Results: Among 1â¯700â¯638 pregnancies in 4 countries, 138â¯033 (8.1%) had maternal smoking and 729â¯498 (42.9%) were younger than 30 years. The prevalences ranged from 0.02% to 0.14% for varenicline, less than 0.01% to 1.86% for prescribed NRT, and less than 0.01% to 0.07% for bupropion. Among pregnant individuals who smoked, use of pharmacotherapies was up to 10 times higher, with maximum prevalences of 1.25% for varenicline in New South Wales, 11.39% for NRT in New Zealand, and 0.39% for bupropion in New Zealand. Use in the first trimester occurred among more than 90% of individuals using varenicline, approximately 60% among those using NRT, and 80% to 90% among those using bupropion. Conclusions and Relevance: In this cohort study of pregnant individuals in 4 high-income countries, the low prevalence of varenicline and bupropion use during pregnancy and higher prevalence of NRT use aligned with current clinical guidelines. As most use occurred in the first trimester, there is a need for evidence on the risk of congenital malformations for these medications.
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Bupropión , Complicaciones del Embarazo , Agentes para el Cese del Hábito de Fumar , Cese del Hábito de Fumar , Dispositivos para Dejar de Fumar Tabaco , Vareniclina , Humanos , Femenino , Embarazo , Cese del Hábito de Fumar/estadística & datos numéricos , Cese del Hábito de Fumar/métodos , Adulto , Estudios Retrospectivos , Agentes para el Cese del Hábito de Fumar/uso terapéutico , Vareniclina/uso terapéutico , Vareniclina/efectos adversos , Bupropión/uso terapéutico , Bupropión/efectos adversos , Nueva Zelanda/epidemiología , Dispositivos para Dejar de Fumar Tabaco/estadística & datos numéricos , Complicaciones del Embarazo/tratamiento farmacológico , Complicaciones del Embarazo/epidemiología , Suecia/epidemiología , Nueva Gales del Sur/epidemiología , Noruega/epidemiología , Adulto Joven , Fumar/epidemiología , Primer Trimestre del EmbarazoRESUMEN
Low birth weight raises neonatal risks and lifelong health issues and is linked to maternal medication use during pregnancy. We examined data from the Norwegian Mother, Father, and Child Cohort Study and the Medical Birth Registry of Norway, including 69,828 offspring with genotype data and 81,189 with maternal genotype data. We identified genetic risk variants in placental efflux transporters, calculated genetic scores based on alleles related to transporter activity, and assessed their interaction with prenatal use of antiseizure or antidepressant medication on offspring birth weight. Our study uncovered possible genetic variants in both offspring (rs3740066) and mothers (rs10248420; rs2235015) in placental efflux transporters (MRP2-ABCC2 and MDR1-ABCB1) that modulated the association between prenatal exposure to antiseizure medication and low birth weight in the offspring. Antidepressant exposure was associated with low birth weight, but there were no gene-drug interactions. The interplay between MRP2-ABCC2 and MDR1-ABCB1 variants and antiseizure medication may impact neonatal birth weight.
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Background: Antipsychotics are commonly prescribed to treat a range of psychiatric conditions in women of reproductive age and during pregnancy, including schizophrenia, bipolar disorder, anxiety, depression, autism spectrum disorder, and insomnia. This study aimed to evaluate whether children exposed to antipsychotic medication prenatally are at increased risk of specific neurodevelopmental disorders and learning difficulties. Methods: Our population-based cohort study used nationwide register data (1 January 2000-31 December 2020) on pregnant women diagnosed with a psychiatric disorder and their live-born singletons from Denmark, Finland, Iceland, Norway, and Sweden. Cox proportional hazard regression yielded propensity score-weighted hazard ratios (aHRs) and 95% confidence intervals (CIs) for risk of intellectual-, speech or language-, learning-developmental disorders, and a composite outcome of the listed disorders. We defined poor performance as scoring within the lowest quartile on national school tests in mathematics and language arts. We estimated propensity score-weighted risk ratios (aRRs) using Poisson regression. We analysed data from Denmark separately and pooled results using random effects meta-analysis. Findings: Among 213,302 children (median follow-up: 6.7 years), 11 626 (5.5%) were exposed to antipsychotics prenatally. Adjusted risk estimates did not suggest an increased risk of neurodevelopmental disorders: aHR of 1.06 (95% CI 0.94-1.20) for the composite outcome, or for poor academic performance: aRR of 1.04 (95% CI 0.91-1.18) in mathematics, and of 1.00 (95% CI 0.87-1.15) in language arts. Results were generally consistent across individual medications, trimesters of exposure, sibling- and sensitivity analyses. Interpretation: The findings of this large multinational cohort study suggest there is little to no increased risk of child neurodevelopmental disorders or learning difficulties after prenatal exposure to antipsychotics. Our findings can assist clinicians and women managing mental illness during pregnancy. Funding: This study was funded by the NordForsk Nordic Program on Health and Welfare (Nordic Pregnancy Drug Safety Studies, project No. 83539), by the Research Council of Norway (International Pregnancy Drug Safety Studies, project No. 273366) and by the Research Council of Norway through its Centres of Excellence funding scheme (project No. 262700), and UNSW Scientia Programme Awards (PS46019, PS46019-A).
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BACKGROUND AND OBJECTIVES: Valproate should be avoided in pregnancy, but it is the most effective drug for generalized epilepsies. Alternative treatment may require combinations of other drugs. Our objectives were to describe first trimester use of antiseizure medication (ASM) combinations that are relevant alternatives to valproate and determine whether specific combinations were associated with a lower risk of major congenital malformations (MCM) compared with valproate monotherapy. METHODS: We conducted a population-based cohort study using linked national registers from Denmark, Finland, Iceland, Norway, and Sweden and administrative health care data from the United States and New South Wales, Australia. We described first trimester use of ASM combinations among pregnant people with epilepsy from 2000 to 2020. We compared the risk of MCM after first trimester exposure to ASM combinations vs valproate monotherapy and low-dose valproate plus lamotrigine or levetiracetam vs high-dose valproate (≥1,000 mg/d). We used log-binomial regression with propensity score weights to calculate adjusted risk ratios (aRRs) and 95% CIs for each dataset. Results were pooled using fixed-effects meta-analysis. RESULTS: Among 50,905 pregnancies in people with epilepsy identified from 7.8 million total pregnancies, 788 used lamotrigine and levetiracetam, 291 used lamotrigine and topiramate, 208 used levetiracetam and topiramate, 80 used lamotrigine and zonisamide, and 91 used levetiracetam and zonisamide. After excluding pregnancies with use of other ASMs, known teratogens, or a child diagnosed with MCM of infectious or genetic cause, we compared 587 exposed to lamotrigine-levetiracetam duotherapy and 186 exposed to lamotrigine-topiramate duotherapy with 1959 exposed to valproate monotherapy. Pooled aRRs were 0.41 (95% CI 0.24-0.69) and 1.26 (0.71-2.23), respectively. Duotherapy combinations containing low-dose valproate were infrequent, and comparisons with high-dose valproate monotherapy were inconclusive but suggested a lower risk for combination therapy. Other combinations were too rare for comparative safety analyses. DISCUSSION: Lamotrigine-levetiracetam duotherapy in first trimester was associated with a 60% lower risk of MCM than valproate monotherapy, while lamotrigine-topiramate was not associated with a reduced risk. Duotherapy with lamotrigine and levetiracetam may be favored to treat epilepsy in people with childbearing potential compared with valproate regarding MCM, but whether this combination is as effective as valproate remains to be determined. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in people with epilepsy treated in the first trimester of pregnancy, the risk of major congenital malformations is lower with lamotrigine-levetiracetam duotherapy than with valproate alone, but similar with lamotrigine-topiramate.
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Epilepsia Generalizada , Ácido Valproico , Femenino , Humanos , Embarazo , Estudios de Cohortes , Lamotrigina/uso terapéutico , Levetiracetam , Topiramato , Ácido Valproico/efectos adversos , Zonisamida , Recién Nacido , Combinación de MedicamentosRESUMEN
Previous studies report an association between maternal diabetes mellitus (MDM) and attention-deficit/hyperactivity disorder (ADHD), often overlooking unmeasured confounders such as shared genetics and environmental factors. We therefore conducted a multinational cohort study with linked mother-child pairs data in Hong Kong, New Zealand, Taiwan, Finland, Iceland, Norway and Sweden to evaluate associations between different MDM (any MDM, gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (PGDM)) and ADHD using Cox proportional hazards regression. We included over 3.6 million mother-child pairs between 2001 and 2014 with follow-up until 2020. Children who were born to mothers with any type of diabetes during pregnancy had a higher risk of ADHD than unexposed children (pooled hazard ratio (HR) = 1.16, 95% confidence interval (CI) = 1.08-1.24). Higher risks of ADHD were also observed for both GDM (pooled HR = 1.10, 95% CI = 1.04-1.17) and PGDM (pooled HR = 1.39, 95% CI = 1.25-1.55). However, siblings with discordant exposure to GDM in pregnancy had similar risks of ADHD (pooled HR = 1.05, 95% CI = 0.94-1.17), suggesting potential confounding by unmeasured, shared familial factors. Our findings indicate that there is a small-to-moderate association between MDM and ADHD, whereas the association between GDM and ADHD is unlikely to be causal. This finding contrast with previous studies, which reported substantially higher risk estimates, and underscores the need to reevaluate the precise roles of hyperglycemia and genetic factors in the relationship between MDM and ADHD.
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Trastorno por Déficit de Atención con Hiperactividad , Diabetes Gestacional , Efectos Tardíos de la Exposición Prenatal , Humanos , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/genética , Femenino , Embarazo , Diabetes Gestacional/epidemiología , Niño , Masculino , Efectos Tardíos de la Exposición Prenatal/epidemiología , Estudios de Cohortes , Adulto , Factores de Riesgo , Madres , Modelos de Riesgos Proporcionales , Taiwán/epidemiología , Nueva Zelanda/epidemiología , Hong Kong/epidemiologíaRESUMEN
BACKGROUND: Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in hospitalized patients. Numerous randomized controlled trials (RCTs) show that using thromboprophylaxis in hospitalized patients at risk for VTE is safe, effective and cost-effective. Despite this, prophylactic therapies for VTE are underutilized. System-wide interventions may be more effective to improve the use of VTE prophylaxis than relying on individual providers' prescribing behaviors. OBJECTIVES: To assess the effects of interventions designed to increase the implementation of thromboprophylaxis in hospitalized adult medical and surgical patients at risk for venous thromboembolism (VTE), assessed in terms of: 1. Increase in the proportion of patients who receive prophylaxis and appropriate prophylaxis 2. Reduction in risk of symptomatic VTE3. Reduction in risk of asymptomatic VTE4. Safety of the intervention. SEARCH METHODS: The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Group's Specialised Register (last searched July 2010) and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) 2010, Issue 3. We searched the PubMed, EMBASE, and SCOPUS databases (19 April 2010) as well as the reference lists of relevant review articles. SELECTION CRITERIA: We included all studies whose interventions aimed to increase the use of prophylaxis and/or appropriate prophylaxis, decrease the proportion of symptomatic VTE, or decrease the proportion of asymptomatic VTE in hospitalized adult patients. We excluded studies that simply distributed published guidelines and studies whose interventions were not clearly described. DATA COLLECTION AND ANALYSIS: We collected the following outcomes: the proportion of patients who received prophylaxis (RP), the proportion of patients who received appropriate prophylaxis (RAP) (primary outcomes), and the occurrence of symptomatic VTE, asymptomatic VTE, and safety outcomes such as bleeding. We categorized interventions into education, alerts, and multifaceted interventions. We meta-analyzed RCTs and non-randomized studies (NRS) separately by random effects meta-analysis, and assessed heterogeneity using the I(2)statistic and subgroup analyses. Before analysis, we decided that results would be pooled if three or more studies were available for a particular intervention. We assessed publication bias using funnel plots and cumulative meta-analysis. MAIN RESULTS: We included a total of 55 studies. One of these reported data in patient-days and could not be quantitatively analyzed with the others. The 54 remaining studies (8 RCTs and 46 NRS) eligible for inclusion in our quantitative synthesis enrolled a total of 78,343 participants. Among RCTs, there were sufficient data to pool results for one primary outcome (received prophylaxis) for the 'alert' intervention. Alerts, such as computerized reminders or stickers on patients' charts, were associated with a risk difference (RD) of 13%, signifying an increase in the proportion of patients who received prophylaxis (95% confidence interval (CI) 1% to 25%). Among NRS, there were sufficient data to pool both primary outcomes for each intervention type. Pooled risk differences for received prophylaxis ranged from 8% to 17%, and for received appropriate prophylaxis ranged from 11% to 19%. Education and alerts were associated with statistically significant increases in prescription of appropriate prophylaxis, and multifaceted interventions were associated with statistically significant increases in prescription of any prophylaxis and appropriate prophylaxis. Multifaceted interventions had the largest pooled effects. I(2) results showed substantial statistical heterogeneity which was in part explained by patient types and type of hospital. A subgroup analysis showed that multifaceted interventions which included an alert may be more effective at improving rates of prophylaxis and appropriate prophylaxis than those without an alert. Results for VTE and safety outcomes did not show substantial benefits or harms, although most studies were underpowered to assess these outcomes. AUTHORS' CONCLUSIONS: We reviewed a large number of studies which implemented a variety of system-wide strategies aimed to improve thromboprophylaxis rates in many settings and patient populations. We found statistically significant improvements in prescription of prophylaxis associated with alerts (RCTs) and multifaceted interventions (RCTs and NRS), and improvements in prescription of appropriate prophylaxis in NRS with the use of education, alerts and multifaceted interventions. Multifaceted interventions with an alert component may be the most effective. Demonstrated sources of heterogeneity included patient types and type of hospital. The results of our review will help physicians, nurses, pharmacists, hospital administrators and policy makers make practical decisions about local adoption of specific system-wide measures to improve prevention of VTE, an important public health issue. We did not find a significant benefit for VTE outcomes; however, earlier RCTs assessing the efficacy of thromboprophylaxis which were powered to address these outcomes have demonstrated the benefit of prophylactic therapies and a favourable balance of benefits versus the increased risk of bleeding events.