Association of glucagon-like peptide-1 receptor agonists with serious liver events among patients with type 2 diabetes: A Scandinavian cohort study.

BACKGROUND AND AIMS: Clinical trials suggest that glucagon-like peptide-1 (GLP-1) receptor agonists may have beneficial effects on NAFLD, but the impact on hard hepatic end points is unknown. We assessed the association between the use of GLP-1 receptor agonists and the risk of serious liver events in routine clinical practice. APPROACH AND RESULTS: Cohort study using data from nationwide registers in Sweden, Denmark, and Norway, 2007-2020, including 91,479 initiators of GLP-1 receptor agonists and 244,004 initiators of the active comparator, dipeptidyl peptidase-4 inhibitors, without a history of chronic liver disease other than NAFLD/NASH. The primary outcome was serious liver events: a composite of incident compensated and decompensated cirrhosis and HCC. Secondary outcomes were the individual components of the primary outcome. Cox regression was used to estimate HRs, using propensity score weighting to control for confounding. Users of GLP-1 receptor agonists had 608 serious liver events (adjusted incidence rate: 16.9 events per 10,000 person-years), compared with 1770 events among users of dipeptidyl peptidase-4 inhibitors (19.2 events per 10,000 person-years). The adjusted HR was 0.85 (95% CI: 0.75 to 0.97), and the rate difference was -2.1 (-4.4 to 0.1) events per 10,000 person-years. In secondary outcome analyses, the adjusted HR was 0.85 (0.75 to 0.97) for compensated and decompensated cirrhosis and 1.05 (0.80 to 1.39) for HCC. CONCLUSIONS: The use of GLP-1 receptor agonists was associated with a significantly reduced risk of serious liver events, driven by a reduction of compensated and decompensated cirrhosis.

Antibiotic use during pregnancy in Sweden: A nationwide utilization study covering 2007-2019.

INTRODUCTION: Antibiotics are often prescribed during pregnancy. Assessing the current state of prenatal antibiotic use is therefore imperative for optimizing prescribing and identifying emerging research priorities. The study aimed to describe recent trends and patterns in antibiotic use during pregnancy among women who gave birth in Sweden, including user characteristics. MATERIAL AND METHODS: Population-based descriptive study using linked nationwide registers. All pregnancies delivered in Sweden from 2007 to 2019 were included. Prevalence of use was defined as the percentage of pregnancies during which at least one prescription forantibiotics was filled. Temporal trends in the prevalence of antibiotic use by calendar year, trimester and weeks of gestation were assessed from time series graphs. RESULTS: Prescriptions for systemic antibiotics were filled in 20.7% of 1 434 431 pregnancies overall, decreasing from 24.7% in 2007 to 18.0% in 2019. Phenoxymethylpenicillin (8.5%), pivmecillinam (6.5%), nitrofurantoin (4.7%), amoxicillin (1.6%) and cefadroxil (1.5%) use were the most prevalent. Their use decreased over the 13-year period, except for pivmecillinam, which increased from 4.0% to 7.4%. Prevalence of use was highest in the second trimester (9.5%), with weekly trends peaking at 13 and 34 weeks of gestation. Compared with non-users, antibiotic users more often belonged to the youngest and oldest age strata, carried multipleton pregnancies, had delivered before, had attained a lower education level and smoked in early pregnancy. A higher body mass index, asthma, chronic renal disease and diabetes mellitus were more prevalent among antibiotic users than among non-users. CONCLUSIONS: Although outpatient antibiotic use during pregnancy in Sweden has been declining, one in five pregnancies was exposed to systemic antibiotics.

Depression and anxiety-related disorders and suicide among Swedish male elite football players: a nationwide cohort study.

OBJECTIVE: To assess whether male elite football players, during and after their active career, were at increased risk of depression and anxiety-related disorders and suicide, as compared with the general male population. METHODS: We included male football players active in the Swedish top division 1924-2019 and general male population (matched to football players based on age and region of residence) aged <65 years in 1997. Using nationwide registers, we followed the football players from their first season in the top division (or the date of their first registered residency in Sweden) or 1 January 1997, and compared the risk of depression and anxiety-related disorders (captured through diagnoses from hospital admissions and outpatient visits, and use of prescription drugs) among football players versus controls. In a secondary analysis using data from death certificates, we compared the risk of suicide between football players and general population males who were alive in 1969 (when cause of death became available) . RESULTS: During follow-up through 31 December 2020, 504 (13.6%) of 3719 football players and 7455 (22.3%) of 33 425 general population males had a depression or anxiety-related disorder. In analyses accounting for age, region of residence and calendar time, the risk of anxiety and depression-related disorders was lower among football players versus general population males (HR 0.61, 95% CI 0.55 to 0.66). The protective association was attenuated with increasing age, and from around age 70 years the risk was similar in the two groups. The risk of suicide was lower among football players versus general population males (HR 0.48, 95% CI 0.32 to 0.72). CONCLUSIONS: In this nationwide cohort study in Sweden, elite male football players had a lower risk of depression and anxiety-related disorders and suicide as compared with the general population.

Use of DPP4 Inhibitors and GLP-1 Receptor Agonists and Risk of Intestinal Obstruction: Scandinavian Cohort Study.

BACKGROUND & AIMS: Concerns have been raised that the incretin-based diabetes drugs dipeptidyl peptidase 4 (DPP4) inhibitors and glucagon-like peptide 1 (GLP-1) receptor agonists may increase the risk of intestinal obstruction. We aimed to assess the association between use of DPP4 inhibitors and GLP-1 receptor agonists and the risk of intestinal obstruction. METHODS: Using data from nationwide registers in Sweden, Denmark, and Norway, 2013-2021, we conducted 2 cohort studies, one for DPP4 inhibitors and one for GLP-1 receptor agonists, to investigate the risk of intestinal obstruction as compared with an active comparator drug class (sodium-glucose co-transporter 2 [SGLT2] inhibitors). RESULTS: Among 19,0321 new users of DPP4 inhibitors (median (interquartile range [IQR]) follow-up time, 1.3 [0.6-2.6] years) and 139,315 new users of SGLT2 inhibitors (median [IQR] follow-up time, 0.8 [0.4-1.7] years), 919 intestinal obstruction events occurred. Use of DPP4 inhibitors, as compared with SGLT2 inhibitors, was not associated with a statistically significant increase in risk of intestinal obstruction (adjusted incidence rate, 2.0 vs 1.8 per 1000 person-years; hazard ratio, 1.13; 95% confidence interval, 0.96-1.34). Among 121,254 new users of GLP-1 receptor agonists (median [standard deviation] follow-up time, 0.9 [0.4-1.9] years) and 185,027 new users of SGLT2 inhibitors (median [IQR] follow-up time, 0.8 [0.4-1.8] years), 557 intestinal obstruction events occurred. Use of GLP-1 receptor agonists was not associated with a statistically significant increase in risk of intestinal obstruction (adjusted incidence rate, 1.3 vs 1.6 per 1000 person-years; hazard ratio, 0.83; 95% confidence interval, 0.69-1.01). CONCLUSIONS: In this analysis of nationwide data from 3 countries, previous safety signals indicating an increased risk of intestinal obstruction with use of DPP4 inhibitors and GLP-1 receptor agonists were not confirmed.

Selection of Comparator Group in Observational Drug Safety Studies: Alternatives to the Active Comparator New User Design.

A valid study design is essential when assessing the safety of drugs based on observational data. The comparator group is a key element of the design and can greatly influence the results. The active comparator new user design is a go-to design in observational drug safety research where a target trial of initiation of a study drug versus usual care is emulated. A comparison with another treatment that targets similar patients as the study drug and has no effect on the outcome has great potential to reduce bias. However, the active comparator new user design can be difficult to implement because no suitable comparator drug is available or because it requires extensive exclusion of study drug initiators. In this analysis, we evaluated alternative study designs that can be used in drug safety assessments when the active comparator new user design is not optimal. Using target trial emulation as a common framework, we defined and evaluated the following designs: traditional no use, no-use episodes, active comparator new user, prevalent new user, generalized prevalent new user, and hierarchical prevalent new user. We showed that all designs can be implemented by using sequential cohorts and simply altering the patient selection criteria, i.e., identifying increasingly restrictive cohorts. In this way, all designs are nested in each other and the differences between them can be demonstrated clearly. We concluded that many study-specific factors need to be considered when choosing a design, including indication, available comparator drugs, treatment patterns, potential effect modification, and sample size.

The comparative cardiovascular and renal effectiveness of sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists: A Scandinavian cohort study.

AIM: To assess the comparative cardiovascular and renal effectiveness of sodium-glucose co-transporter-2 (SGLT2) inhibitors versus glucagon-like peptide-1 (GLP-1) receptor agonists in routine clinical practice. MATERIALS AND METHODS: A cohort study of nationwide registers from Sweden, Denmark, and Norway, including 87 525 new users of SGLT2 inhibitors and 63 921 new users of GLP-1 receptor agonists, was conducted using data from 2013-2018. Co-primary outcomes, analysed using an intention-to-treat exposure definition, were major adverse cardiovascular events (MACE; myocardial infarction, stroke, and cardiovascular death), heart failure (hospitalization or death because of heart failure), and serious renal events (renal replacement therapy, hospitalization for renal events, and death from renal causes). RESULTS: Use of SGLT2 inhibitors versus GLP-1 receptor agonists was associated with a higher risk of MACE (adjusted incidence rate: 15.2 vs. 14.4 events per 1000 person-years; HR 1.07 [95% CI 1.01-1.15]), a similar risk of heart failure (6.0 vs. 6.0 events per 1000 person-years; HR 1.02 [0.92-1.12]), and a lower risk of serious renal events (2.9 vs. 4.0 events per 1000 person-years; HR 0.76 [0.66-0.87]). In as-treated analyses, the HR (95% CI) was 1.11 (1.00-1.24) for MACE, 0.88 (0.74-1.04) for heart failure, and 0.60 (0.47-0.77) for serious renal events. In secondary outcome analyses, use of SGLT2 inhibitors versus GLP-1 receptor agonists was not associated with statistically significant differences for the risk of myocardial infarction (HR 1.09 [95% CI 1.00-1.19]), cardiovascular death (HR 0.97 [95% CI 0.84-1.12]), death from renal causes (HR 0.75 [95% CI 0.41-1.35]), or any cause death (HR 1.01 [95% CI 0.94-1.09]), while the risk of stroke was higher (HR 1.14 [95% CI 1.03-1.26]), and the risk of renal replacement therapy (HR 0.74 [95% CI 0.56-0.97]) and hospitalization for renal events (HR 0.75 [95% CI 0.65-0.88]) were lower among users of SGLT2 inhibitors. CONCLUSIONS: Use of SGLT2 inhibitors versus GLP-1 receptor agonists was associated with a similar risk of heart failure and a lower risk of serious renal events, while use of GLP-1 receptor agonists versus SGLT2 inhibitors was associated with a slightly lower risk of MACE. In as-treated analyses, the associations with MACE and serious renal events increased in magnitude, and the HR for heart failure tended towards a protective association for SGLT2 inhibitors.

Association of SARS-CoV-2 Vaccination During Pregnancy With Pregnancy Outcomes.

Importance: Data about the safety of vaccines against SARS-CoV-2 during pregnancy are limited. Objective: To examine the risk of adverse pregnancy outcomes after vaccination against SARS-CoV-2 during pregnancy. Design, Setting, and Participants: This registry-based retrospective cohort study included 157 521 singleton pregnancies ending after 22 gestational weeks from January 1, 2021, until January 12, 2022 (Sweden), or January 15, 2022 (Norway). The Pregnancy Register in Sweden and the Medical Birth Registry of Norway were linked to vaccination and other registries for identification of exposure and background characteristics. Exposures: Data on mRNA vaccines-BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)-and 1 viral vector vaccine-AZD1222 (AstraZeneca)-were collected from national vaccination registries. Main Outcomes and Measures: The risk of preterm birth and stillbirth was evaluated using Cox regression models, with gestational day as the time metric and vaccination as a time-dependent exposure variable. The risk of small for gestational age, low Apgar score, and neonatal care admission was evaluated using logistic regression. Random-effects meta-analysis was used to combine results between countries. Results: Among the 157 521 singleton births included in the study (103 409 in Sweden and 54 112 in Norway), the mean maternal age at the time of delivery was 31 years, and 28 506 (18%) were vaccinated against SARS-CoV-2 (12.9% with BNT162b2, 4.8% with mRNA-1273, and 0.3% with AZD1222) while pregnant. A total of 0.7%, 8.3%, and 9.1% of individuals delivering were vaccinated during the first, second, and third trimester, respectively. Vaccination against SARS-CoV-2 was not significantly associated with increased risk of preterm birth (6.2 vs 4.9 per 10 000 pregnancy days; adjusted hazard ratio [aHR], 0.98 [95% CI, 0.91 to 1.05]; I2 = 0%; P for heterogeneity = .60), stillbirth (2.1 vs 2.4 per 100 000 pregnancy days; aHR, 0.86 [95% CI, 0.63 to 1.17]), small for gestational age (7.8% vs 8.5%; difference, -0.6% [95% CI, -1.3% to 0.2%]; adjusted OR [aOR], 0.97 [95% CI, 0.90 to 1.04]), low Apgar score (1.5% vs 1.6%; difference, -0.05% [95% CI, -0.3% to 0.1%]; aOR, 0.97 [95% CI, 0.87 to 1.08]), or neonatal care admission (8.5% vs 8.5%; difference, 0.003% [95% CI, -0.9% to 0.9%]; aOR, 0.97 [95% CI, 0.86 to 1.10]). Conclusions and Relevance: In this population-based study conducted in Sweden and Norway, vaccination against SARS-CoV-2 during pregnancy, compared with no SARS-CoV-2 vaccination during pregnancy, was not significantly associated with an increased risk of adverse pregnancy outcomes. The majority of the vaccinations were with mRNA vaccines during the second and third trimesters of pregnancy, which should be considered in interpreting the findings.

Use of incretin-based drugs and risk of cholangiocarcinoma: Scandinavian cohort study.

AIMS/HYPOTHESIS: Concerns have been raised regarding a potential association of use of the incretin-based drugs dipeptidyl peptidase 4 (DPP4) inhibitors and glucagon-like peptide-1 (GLP-1)-receptor agonists with risk of cholangiocarcinoma. We examined this association in nationwide data from three countries. METHODS: We used data from nationwide registers in Sweden, Denmark and Norway, 2007-2018, to conduct two cohort studies, one for DPP4 inhibitors and one for GLP-1-receptor agonists, to investigate the risk of incident cholangiocarcinoma compared with an active-comparator drug class (sulfonylureas). The cohorts included patients initiating treatment episodes with DPP4 inhibitors vs sulfonylureas, and GLP-1-receptor agonists vs sulfonylureas. We used Cox regression models, adjusted for potential confounders, to estimate hazard ratios from day 366 after treatment initiation to account for cancer latency. RESULTS: The main analyses of DPP4 inhibitors included 1,414,144 person-years of follow-up from 222,577 patients receiving DPP4 inhibitors (median [IQR] follow-up time, 4.5 [2.6-7.0] years) and 123,908 patients receiving sulfonylureas (median [IQR] follow-up time, 5.1 [2.9-7.8] years) during which 350 cholangiocarcinoma events occurred. Use of DPP4 inhibitors, compared with sulfonylureas, was not associated with a statistically significant increase in risk of cholangiocarcinoma (incidence rate 26 vs 23 per 100,000 person-years; adjusted HR, 1.15 [95% CI 0.90, 1.46]; absolute rate difference 3 [95% CI -3, 10] events per 100,000 person-years). The main analyses of GLP-1-receptor agonists included 1,036,587 person-years of follow-up from 96,813 patients receiving GLP-1-receptor agonists (median [IQR] follow-up time, 4.4 [2.4-6.9] years) and 142,578 patients receiving sulfonylureas (median [IQR] follow-up time, 5.5 [3.2-8.1] years) during which 249 cholangiocarcinoma events occurred. Use of GLP-1-receptor agonists was not associated with a statistically significant increase in risk of cholangiocarcinoma (incidence rate 26 vs 23 per 100,000 person-years; adjusted HR, 1.25 [95% CI 0.89, 1.76]; absolute rate difference 3 [95% CI -5, 13] events per 100,000 patient-years). CONCLUSIONS/INTERPRETATION: In this analysis using nationwide data from three countries, use of DPP4 inhibitors and GLP-1-receptor agonists, compared with sulfonylureas, was not associated with a significantly increased risk of cholangiocarcinoma.

Proton-Pump Inhibitor Use and the Risk of Community-Associated Clostridium difficile Infection.

BACKGROUND: Proton-pump inhibitors (PPIs) have been reported to increase the risk of community-associated Clostridium difficile infection (CDI), but the association remains disputed. METHODS: A nationwide cohort study among adults in Denmark, 2010-2013, linking register data on C. difficile testing, filled prescriptions, and patient characteristics. All incident episodes of community-associated CDI (ie, positive culture, molecular assay, or toxin test in individuals without previous hospitalization in the prior 12 weeks and without a positive test for C. difficile in the prior 8 weeks) were identified in the Danish National Microbiological Database. Self-controlled case-series analyses were used to estimate incidence rate ratios (IRRs) for community-associated CDI, comparing periods with and without exposure to PPIs. By design, models took fixed confounders such as chronic disease, genetics, and socioeconomic status into account; further, time-varying confounders, including hospital stay and antibiotic and corticosteroid use were adjusted for. RESULTS: 3583 episodes of community-associated CDI were identified, of which 964 occurred during current use of PPIs, 324 occurred 0-6 months after treatment cessation, 123 occurred 6-12 months after treatment cessation, and 2172 occurred during time periods without use of PPIs. The adjusted IRR was 2.03 (95% confidence interval, 1.74-2.36), comparing use of PPI with nonuse. The increased risk remained elevated in later time periods: 1.54 (1.31-1.80) for 0-6 months, 1.24 (1.00-1.53) for 6-12 months after current use. CONCLUSIONS: Use of PPIs was associated with moderately increased risk of community-associated CDI. The risk remained elevated up to 1 year after PPI treatment had ended.

Maternal Influenza A(H1N1) Immunization During Pregnancy and Risk for Autism Spectrum Disorder in Offspring : A Cohort Study.

BACKGROUND: There are concerns that influenza vaccine exposure during pregnancy may be associated with increased risk for autism spectrum disorder (ASD). OBJECTIVE: To examine the risk for ASD in offspring of mothers who were vaccinated against influenza A(H1N1)pdm09 ("swine flu") during pregnancy. DESIGN: Population-based cohort study using nationwide registers. SETTING: Seven health care regions in Sweden. PARTICIPANTS: Live births between October 2009 and September 2010, with follow-up through December 2016. In total, 39 726 infants were prenatally exposed to H1N1 vaccine (13 845 during the first trimester) and 29 293 infants were unexposed. MEASUREMENTS: Cox regression was used to estimate hazard ratios (HRs) for the primary outcome, ASD, before and after adjustment for potential confounders. The secondary outcome was autistic disorder (AD). RESULTS: Mean follow-up was 6.7 years in both unexposed and exposed children. During follow-up, 394 (1.0%) vaccine-exposed and 330 (1.1%) unexposed children had a diagnosis of ASD. In adjusted analyses, prenatal exposure to H1N1 vaccination was not associated with a later diagnosis of ASD (adjusted HR [aHR], 0.95 [95% CI, 0.81 to 1.12]) or AD (aHR, 0.96 [CI, 0.80 to 1.16]). The 6-year standardized cumulative incidence difference between the unexposed and exposed children was 0.04% (CI, -0.09% to 0.17%) for ASD and 0.02% (CI, -0.09% to 0.14%) for AD. Restricting the analysis to vaccination in the first trimester of pregnancy did not influence risk estimates (aHR, 0.92 [CI, 0.74 to 1.16] for ASD and 0.91 [CI, 0.70 to 1.18] for AD). LIMITATION: Data on H1N1 influenza infection are lacking. CONCLUSION: This large cohort study found no association between maternal H1N1 vaccination during pregnancy and risk for ASD in the offspring. PRIMARY FUNDING SOURCE: Swedish Research Council.

Quadrivalent HPV Vaccination and the Risk of Adverse Pregnancy Outcomes.

BACKGROUND: The quadrivalent human papillomavirus (HPV) vaccine is recommended for all girls and women 9 to 26 years of age. Some women will have inadvertent exposure to vaccination during early pregnancy, but few data exist regarding the safety of the quadrivalent HPV vaccine in this context. METHODS: We assessed a cohort that included all the women in Denmark who had a pregnancy ending between October 1, 2006, and November 30, 2013. Using nationwide registers, we linked information on vaccination, adverse pregnancy outcomes, and potential confounders among women in the cohort. Women who had vaccine exposure during the prespecified time windows were matched for propensity score in a 1:4 ratio with women who did not have vaccine exposure during the same time windows. Outcomes included spontaneous abortion, stillbirth, major birth defect, small size for gestational age, low birth weight, and preterm birth. RESULTS: In matched analyses, exposure to the quadrivalent HPV vaccine was not associated with significantly higher risks than no exposure for major birth defect (65 cases among 1665 exposed pregnancies and 220 cases among 6660 unexposed pregnancies; prevalence odds ratio, 1.19; 95% confidence interval [CI], 0.90 to 1.58), spontaneous abortion (20 cases among 463 exposed pregnancies and 131 cases among 1852 unexposed pregnancies; hazard ratio, 0.71; 95% CI, 0.45 to 1.14), preterm birth (116 cases among 1774 exposed pregnancies and 407 cases among 7096 unexposed pregnancies; prevalence odds ratio, 1.15; 95% CI, 0.93 to 1.42), low birth weight (76 cases among 1768 exposed pregnancies and 277 cases among 7072 unexposed pregnancies; prevalence odds ratio, 1.10; 95% CI, 0.85 to 1.43), small size for gestational age (171 cases among 1768 exposed pregnancies and 783 cases among 7072 unexposed pregnancies; prevalence odds ratio, 0.86; 95% CI, 0.72 to 1.02), or stillbirth (2 cases among 501 exposed pregnancies and 4 cases among 2004 unexposed pregnancies; hazard ratio, 2.43; 95% CI, 0.45 to 13.21). CONCLUSIONS: Quadrivalent HPV vaccination during pregnancy was not associated with a significantly higher risk of adverse pregnancy outcomes than no such exposure. (Funded by the Novo Nordisk Foundation and the Danish Medical Research Council.).

Maternal Glycemic Control in Type 1 Diabetes and the Risk for Preterm Birth: A Population-Based Cohort Study.

Background: Maternal type 1 diabetes (T1D) has been linked to preterm birth and other adverse pregnancy outcomes. How these risks vary with glycated hemoglobin (or hemoglobin A1c [HbA1c]) levels is unclear. Objective: To examine preterm birth risk according to periconceptional HbA1c levels in women with T1D. Design: Population-based cohort study. Setting: Sweden, 2003 to 2014. Patients: 2474 singletons born to women with T1D and 1 165 216 reference infants born to women without diabetes. Measurements: Risk for preterm birth (<37 gestational weeks). Secondary outcomes were neonatal death, large for gestational age, macrosomia, infant birth injury, hypoglycemia, respiratory distress, 5-minute Apgar score less than 7, and stillbirth. Results: Preterm birth occurred in 552 (22.3%) of 2474 infants born to mothers with T1D versus 54 287 (4.7%) in 1 165 216 infants born to mothers without diabetes. The incidence of preterm birth was 13.2% in women with a periconceptional HbA1c level below 6.5% (adjusted risk ratio [aRR] vs. women without T1D, 2.83 [95% CI, 2.28 to 3.52]), 20.6% in those with a level from 6.5% to less than 7.8% (aRR, 4.22 [CI, 3.74 to 4.75]), 28.3% in those with a level from 7.8% to less than 9.1% (aRR, 5.56 [CI, 4.84 to 6.38]), and 37.5% in those with a level of 9.1% or higher (aRR, 6.91 [CI, 5.85 to 8.17]). The corresponding aRRs for medically indicated preterm birth (n = 320) were 5.26 (CI, 3.83 to 7.22), 7.42 (CI, 6.21 to 8.86), 11.75 (CI, 9.72 to 14.20), and 17.51 (CI, 14.14 to 21.69), respectively. The corresponding aRRs for spontaneous preterm birth (n = 223) were 1.81 (CI, 1.31 to 2.52), 2.86 (CI, 2.38 to 3.44), 2.88 (CI, 2.23 to 3.71), and 2.80 (CI, 1.94 to 4.03), respectively. Increasing HbA1c levels were associated with the study's secondary outcomes: large for gestational age, hypoglycemia, respiratory distress, low Apgar score, neonatal death, and stillbirth. Limitation: Because HbA1c levels were registered annually at routine visits, they were not available for all pregnant women with T1D. Conclusion: The risk for preterm birth was strongly linked to periconceptional HbA1c levels. Women with HbA1c levels consistent with recommended target levels also were at increased risk. Primary Funding Source: Swedish Diabetes Foundation.

Long-Term Risk of Cardiovascular Death With Use of Clarithromycin and Roxithromycin: A Nationwide Cohort Study.

Recent studies have raised concern that macrolide antibiotics may be associated with an increased long-term risk of cardiovascular death. We examined the 1-year risk associated with treatment with clarithromycin (n = 187,887) or roxithromycin (n = 698,899) compared with penicillin V (n = 3,473,081), matched 1:4 on propensity score, in a nationwide, registry-based cohort study in Danish outpatients, 1997-2011. Among clarithromycin courses, the rate ratio for cardiovascular death was 1.24 (95% confidence interval (CI): 0.96, 1.59). Among roxithromycin courses, the rate ratio was 0.99 (95% CI: 0.86, 1.16). In analyses by time after treatment start, the rate ratio associated with clarithromycin was 1.66 (95% CI: 0.98, 2.79) during days 0-7. This was attenuated in later time periods (days 8-89, rate ratio = 1.30, 95% CI: 0.88, 1.94; and days 90-364, rate ratio = 0.96, 95% CI: 0.63, 1.47). For roxithromycin, the rate ratios were 0.88 (95% CI: 0.59, 1.32) during days 0-7, 1.17 (95% CI: 0.92, 1.48) during days 8-89, and 0.88 (95% CI: 0.70, 1.10) during days 90-364. We found no increased risk of cardiovascular death in a general outpatient population. With clarithromycin, we observed a transient increased risk during days 0-7 after treatment start, which corresponds to the period of active treatment. This association was absent in later time periods, which is consistent with no long-term toxicity resulting in cardiovascular death.

Concomitant use of low-dose methotrexate and NSAIDs and the risk of serious adverse events among patients with rheumatoid arthritis.

PURPOSE: Case reports and pharmacokinetic studies have suggested that concomitant use of low-dose methotrexate and nonsteroidal anti-inflammatory drugs (NSAIDs) may be associated with increased risk of methotrexate toxicity. This study aimed to investigate the risk of serious adverse events associated with concomitant use of low-dose methotrexate and NSAIDs, compared with use of methotrexate alone, among patients with rheumatoid arthritis. METHODS: The study was conducted as a register-based cohort study in Denmark, 2004 to 2015, including episodes of concomitant use of methotrexate and NSAIDs (n = 21 536) and control episodes of use of methotrexate alone (n = 21 725). The primary outcome was the composite end point any serious adverse event, including liver toxicity, acute renal failure, and cytopenia. Secondary outcomes were the individual outcome components. Analyses were conducted using proportional-hazards regression, with adjustment using inverse-probability-of-treatment weighting based on propensity scores. RESULTS: During follow-up, 110 cases of the primary outcome occurred during concomitant use of methotrexate and NSAIDs (unadjusted incidence rate 12.1 per 1000 person-years) and 129 during control episodes (11.0 per 1000 person-years). Concomitant use of methotrexate and NSAIDs was associated with a significantly increased risk of any serious adverse event (weighted hazard ratio 1.40; 95% CI, 1.07-1.82). In secondary analyses, concomitant use of methotrexate and NSAIDs was associated with a significantly increased risk of acute renal failure and cytopenia. CONCLUSIONS: Concomitant use of low-dose methotrexate and NSAIDs was associated with a significantly increased risk of serious adverse events, expanding on the evidence base for current regulatory recommendations that advocate caution when low-dose methotrexate and NSAID are coprescribed.

Ondansetron in pregnancy and risk of adverse fetal outcomes.

BACKGROUND: Ondansetron is frequently used to treat nausea and vomiting during pregnancy, but the safety of this drug for the fetus has not been well studied. METHODS: We investigated the risk of adverse fetal outcomes associated with ondansetron administered during pregnancy. From a historical cohort of 608,385 pregnancies in Denmark, women who were exposed to ondansetron and those who were not exposed were included, in a 1:4 ratio, in propensity-score-matched analyses of spontaneous abortion (1849 exposed women vs. 7396 unexposed women), stillbirth (1915 vs. 7660), any major birth defect (1233 vs. 4932), preterm delivery (1792 vs. 7168), and birth of infants at low birth weight and small for gestational age (1784 vs. 7136). In addition, estimates were adjusted for hospitalization for nausea and vomiting during pregnancy (as a proxy for severity) and the use of other antiemetics. RESULTS: Receipt of ondansetron was not associated with a significantly increased risk of spontaneous abortion, which occurred in 1.1% of exposed women and 3.7% of unexposed women during gestational weeks 7 to 12 (hazard ratio, 0.49; 95% confidence interval [CI], 0.27 to 0.91) and in 1.0% and 2.1%, respectively, during weeks 13 to 22 (hazard ratio, 0.60; 95% CI, 0.29 to 1.21). Ondansetron also conferred no significantly increased risk of stillbirth (0.3% for exposed women and 0.4% for unexposed women; hazard ratio, 0.42; 95% CI, 0.10 to 1.73), any major birth defect (2.9% and 2.9%, respectively; prevalence odds ratio, 1.12; 95% CI, 0.69 to 1.82), preterm delivery (6.2% and 5.2%; prevalence odds ratio, 0.90; 95% CI, 0.66 to 1.25), delivery of a low-birth-weight infant (4.1% and 3.7%; prevalence odds ratio, 0.76; 95% CI, 0.51 to 1.13), or delivery of a small-for-gestational-age infant (10.4% and 9.2%; prevalence odds ratio, 1.13; 95% CI, 0.89 to 1.44). CONCLUSIONS: Ondansetron taken during pregnancy was not associated with a significantly increased risk of adverse fetal outcomes. (Funded by the Danish Medical Research Council.).

Use of azithromycin and death from cardiovascular causes.

BACKGROUND: Azithromycin use is associated with an increased risk of death from cardiovascular causes among patients at high baseline risk. Whether azithromycin confers a similar risk in the unselected general population is unknown. METHODS: We conducted a nationwide historical cohort study involving Danish adults (18 to 64 years of age), linking registry data on filled prescriptions, causes of death, and patient characteristics for the period from 1997 through 2010. We estimated rate ratios for death from cardiovascular causes, comparing 1,102,050 episodes of azithromycin use with no use of antibiotic agents (matched in a 1:1 ratio according to propensity score, for a total of 2,204,100 episodes) and comparing 1,102,419 episodes of azithromycin use with 7,364,292 episodes of penicillin V use (an antibiotic with similar indications; analysis was conducted with adjustment for propensity score). RESULTS: The risk of death from cardiovascular causes was significantly increased with current use of azithromycin (defined as a 5-day treatment episode), as compared with no use of antibiotics (rate ratio, 2.85; 95% confidence interval [CI], 1.13 to 7.24). The analysis relative to an antibiotic comparator included 17 deaths from cardiovascular causes during current azithromycin use (crude rate, 1.1 per 1000 person-years) and 146 during current penicillin V use (crude rate, 1.5 per 1000 person-years). With adjustment for propensity scores, current azithromycin use was not associated with an increased risk of cardiovascular death, as compared with penicillin V (rate ratio, 0.93; 95% CI, 0.56 to 1.55). The adjusted absolute risk difference for current use of azithromycin, as compared with penicillin V, was -1 cardiovascular death (95% CI, -9 to 11) per 1 million treatment episodes. CONCLUSIONS: Azithromycin use was not associated with an increased risk of death from cardiovascular causes in a general population of young and middle-aged adults. (Funded by the Danish Medical Research Council.).

Use of selective serotonin reuptake inhibitors during pregnancy and risk of autism.

BACKGROUND: Studies have raised concern about an association between the use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy and an increased risk of autism spectrum disorders in the offspring. METHODS: We conducted a cohort study of all singleton live births in Denmark from 1996 through 2005 (626,875 births), with follow-up through 2009. Using Danish population registries, we linked information on maternal use of SSRIs before and during pregnancy, autism spectrum disorders diagnosed in the offspring, and a range of potential confounders. We used a survival analysis of the time to diagnosis in the offspring with Poisson regression to estimate rate ratios of autism spectrum disorders according to maternal use of SSRIs. RESULTS: During 5,057,282 person-years of follow-up, we identified 3892 cases of autism spectrum disorder (incidence rate, 77.0 per 100,000 person-years). A total of 52 cases during 42,400 person-years of follow-up involved offspring of women who were exposed to SSRIs during their pregnancy (incidence rate, 122.6 per 100,000 person-years). As compared with no use of SSRIs both before and during pregnancy, use during pregnancy was not associated with a significantly increased risk of autism spectrum disorders (fully adjusted rate ratio, 1.20; 95% confidence interval [CI], 0.90 to 1.61). Among women who received SSRIs before pregnancy but not during pregnancy, the corresponding fully adjusted rate ratio was 1.46 (95% CI, 1.17 to 1.81). CONCLUSIONS: We did not detect a significant association between maternal use of SSRIs during pregnancy and autism spectrum disorder in the offspring. On the basis of the upper boundary of the confidence interval, our study could not rule out a relative risk up to 1.61, and therefore the association warrants further study. (Funded by the Danish Health and Medicines Authority.).

Use of oral fluconazole during pregnancy and the risk of birth defects.

BACKGROUND: Case reports suggest that long-term, high-dose fluconazole treatment for severe fungal infections during pregnancy causes a pattern of birth defects. It is unclear whether commonly used lower doses increase the risk of specific birth defects. METHODS: In a registry-based cohort of liveborn infants in Denmark, we evaluated first-trimester oral fluconazole exposure and the risk of birth defects overall and of birth defects previously linked to azole antifungal agents. RESULTS: The majority of fluconazole-exposed pregnancies were in women who received common therapeutic doses of 150 mg (56% of pregnancies) or 300 mg (31%). Oral fluconazole exposure was not associated with an increased risk of birth defects overall (210 birth defects among 7352 fluconazole-exposed pregnancies [prevalence, 2.86%] and 25,159 birth defects among 968,236 unexposed pregnancies [prevalence, 2.60%]; adjusted prevalence odds ratio, 1.06; 95% confidence interval [CI], 0.92 to 1.21). In addition, oral fluconazole exposure was not associated with a significantly increased risk of 14 of 15 types of birth defects previously linked to azole antifungal agents: craniosynostosis, other craniofacial defects, middle-ear defects, cleft palate, cleft lip, limb defects, limb-reduction defects, polydactyly, syndactyly, diaphragmatic hernia, heart defects overall, pulmonary-artery hypoplasia, ventricular septal defects, and hypoplastic left heart. A significantly increased risk of tetralogy of Fallot was observed (7 cases in fluconazole-exposed pregnancies [prevalence, 0.10%] as compared with 287 cases in unexposed pregnancies [prevalence, 0.03%]; adjusted prevalence odds ratio, 3.16; 95% CI, 1.49 to 6.71). CONCLUSIONS: Oral fluconazole was not associated with a significantly increased risk of birth defects overall or of 14 of the 15 specific birth defects of previous concern. Fluconazole exposure may confer an increased risk of tetralogy of Fallot. (Funded by the Danish Medical Research Council.).

Association Between Use of Oral Fluconazole During Pregnancy and Risk of Spontaneous Abortion and Stillbirth.

IMPORTANCE: Vaginal candidiasis is common during pregnancy. Although intravaginal formulations of topical azole antifungals are first-line treatment for pregnant women, oral fluconazole is often used despite limited safety information. OBJECTIVE: To study the association between oral fluconazole exposure during pregnancy and the risk of spontaneous abortion and stillbirth. DESIGN, SETTING, AND PARTICIPANTS: Nationwide register-based cohort study in Denmark, 1997-2013. From a cohort of 1,405,663 pregnancies, oral fluconazole-exposed pregnancies were compared with up to 4 unexposed pregnancies matched on propensity score, maternal age, calendar year, and gestational age (based on gestational age at first day of treatment with eligible controls surviving through this date). To test for confounding by indication, pregnancies exposed to intravaginal formulations of topical azoles were used as an additional comparator group. EXPOSURES: Filled prescriptions for oral fluconazole were obtained from the National Prescription Register. MAIN OUTCOMES AND MEASURES: Hazard ratios (HRs) for spontaneous abortion and stillbirth, estimated using proportional hazards regression. RESULTS: Among 3315 women exposed to oral fluconazole from 7 through 22 weeks' gestation, 147 experienced a spontaneous abortion, compared with 563 among 13,246 unexposed matched women. There was a significantly increased risk of spontaneous abortion associated with fluconazole exposure (HR, 1.48; 95% CI, 1.23-1.77). Among 5382 women exposed to fluconazole from gestational week 7 to birth, 21 experienced a stillbirth, compared with 77 among 21,506 unexposed matched women. There was no significant association between fluconazole exposure and stillbirth (HR, 1.32 [95% CI, 0.82-2.14]). Using topical azole exposure as the comparison, 130 of 2823 women exposed to fluconazole vs 118 of 2823 exposed to topical azoles had a spontaneous abortion (HR, 1.62 [95% CI, 1.26-2.07]); 20 of 4301 women exposed to fluconazole vs 22 of 4301 exposed to topical azoles had a stillbirth (HR, 1.18 [95% CI, 0.64-2.16]). CONCLUSIONS AND RELEVANCE: In this nationwide cohort study in Denmark, use of oral fluconazole in pregnancy was associated with a statistically significant increased risk of spontaneous abortion compared with risk among unexposed women and women with topical azole exposure in pregnancy. Until more data on the association are available, cautious prescribing of fluconazole in pregnancy may be advisable. Although the risk of stillbirth was not significantly increased, this outcome should be investigated further.