Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort study

OBJECTIVE

To investigate whether use of glucagon-like peptide 1 (GLP1) receptor agonists is associated with increased risk of thyroid cancer.

DESIGN

Scandinavian cohort study.

SETTING

Denmark, Norway, and Sweden, 2007-21.

PARTICIPANTS

Patients who started GLP1 receptor agonist treatment were compared with patients who started dipeptidyl peptidase 4 (DPP4) inhibitor treatment, and in an additional analysis, patients who started sodium-glucose cotransporter 2 (SGLT2) inhibitor treatment.

MAIN OUTCOME MEASURES

Thyroid cancer identified from nationwide cancer registers. An active-comparator new user study design was used to minimise risks of confounding and time related biases from using real world studies of drug effects. Cox regression was used to estimate hazard ratios, controlling for potential confounders with propensity score weighting.

RESULTS

The mean follow-up time was 3.9 years (standard deviation 3.5 years) in the GLP1 receptor agonist group and 5.4 years (standard deviation 3.5 years) in the DPP4 inhibitor group. 76 of 145 410 patients (incidence rate 1.33 events per 10 000 person years) treated with GLP1 receptor agonists and 184 of 291 667 patients (incidence rate 1.46 events per 10 000 person years) treated with DPP4 inhibitors developed thyroid cancer. GLP1 receptor agonist use was not associated with increased risk of thyroid cancer (hazard ratio 0.93, 95% confidence interval 0.66 to 1.31; rate difference -0.13, 95% confidence interval -0.61 to 0.36 events per 10 000 person years). The hazard ratio for medullary thyroid cancer was 1.19 (0.37 to 3.86). In the additional analysis comparing the GLP1 receptor agonist group with the SGLT2 inhibitor group, the hazard ratio for thyroid cancer was 1.16 (0.65 to 2.05).

CONCLUSIONS

In this large cohort study using nationwide data from three countries, GLP1 receptor agonist use was not associated with a substantially increased risk of thyroid cancer over a mean follow-up of 3.9 years. In the main analysis comparing GLP1 receptor agonists with DPP4 inhibitors, the upper limit of the confidence interval was consistent with no more than a 31% increase in relative risk.

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.

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.

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.

Neurodegenerative disease among male elite football (soccer) players in Sweden: a cohort study

BACKGROUND

Football (soccer) players might be at increased risk of neurodegenerative disease, which has led to questions regarding the safety of the sport and recent measures introduced by football associations to reduce heading of the ball. We aimed to assess the risk of neurodegenerative disease among male football players in the Swedish top division Allsvenskan, compared with matched controls.

METHODS

In this cohort study, we identified all male football players (amateurs and professionals) who had played at least one game in Allsvenskan from Aug 1, 1924 to Dec 31, 2019 and excluded players whose personal identity number could not be retrieved or be identified in the Total Population Register, and those who were not born in Sweden and who had immigrated to the country after age 15 years. Football players were matched with up to ten controls from the general population according to sex, age, and region of residence. We used nationwide registers to compare the risk of neurodegenerative disease (diagnoses recorded in death certificates, during hospital admissions and outpatient visits, or use of prescription drugs for dementia) among football players versus controls. We also assessed each type of neurodegenerative disease (Alzheimer's disease and other dementias, motor neuron disease, and Parkinson's disease) separately, and compared the risk of neurodegenerative disease among outfield players versus goalkeepers.

FINDINGS

Of 7386 football players who had played at least one game in the top Swedish division between Aug 1, 1924, and Dec 31, 2019, 182 players were excluded for an unretrievable personal identity number, and 417 were excluded due to their number not being identified in the Total Population Register. After a further exclusion of 780 players and 11 627 controls who were born outside of Sweden and who had immigrated to the country after age 15 years, 6007 football players (510 goalkeepers) were included in the study population along with 56 168 matched controls. During follow-up to Dec 31, 2020, 537 (8·9%) of 6007 football players and 3485 (6·2%) of 56 168 controls were diagnosed with neurodegenerative disease. The risk of neurodegenerative disease was higher among football players than controls (hazard ratio [HR] 1·46 [95% CI 1·33-1·60]). Alzheimer's disease and other dementias were more common among football players than controls (HR 1·62 [95% CI 1·47-1·78]), significant group differences were not observed for motor neuron disease (HR 1·27 [0·73-2·22]), and Parkinson's disease was less common among football players (HR 0·68 [0·52-0·89]). The risk of neurodegenerative disease was higher for outfield players than controls (HR 1·50 [95% CI 1·36-1·65]) but not for goalkeepers versus controls (HR 1·07 [0·78-1·47]), and outfield players had a higher risk of neurodegenerative disease than did goalkeepers (HR 1·43 [1·03-1·99]). All-cause mortality was slightly lower among football players than controls (HR 0·95 [95% CI 0·91-0·99]).

INTERPRETATION

In this cohort study, male football players who had played in the Swedish top division had a significantly increased risk of neurodegenerative disease compared with population controls. The risk increase was observed for Alzheimer's disease and other dementias but not for other types of neurodegenerative disease, and among outfield players, but not among goalkeepers. Our study expands on the data that can be used to assess and manage risks in the sport.

FUNDING

Karolinska Institutet, The Swedish Research Council for Sport Science, Folksam Research Foundation, Hedberg Foundation, Neurofonden, and Åhlen Foundation.

Prenatal and Infant Exposure to Acid-Suppressive Medications and Risk of Allergic Diseases in Children

Importance

Existing observational data have indicated positive associations of acid-suppressive medication (ASM) use in prenatal and early life with allergic diseases in children; however, no study to date has accounted for confounding by indication or within-familial factors.

Objective

To evaluate the association of prenatal or infant exposure to ASMs with risk of allergic diseases in children.

Design, Setting, and Participants

This nationwide, cohort study included data from South Korea's National Health Insurance Service mother-child-linked database from January 1, 2007, to December 31, 2020. Participants included mother-child pairs of neonates born from April 1, 2008, to December 31, 2019.

Exposures

Prenatal and infant exposure to ASMs (histamine 2 receptor antagonists [H2RAs] and proton pump inhibitors [PPIs]).

Main Outcomes and Measures

Composite and individual outcomes of allergic diseases (asthma, allergic rhinitis, atopic dermatitis, and food allergy) in children (followed up to 13 years of age) were assessed. The ASM-exposed individuals were compared with unexposed individuals in propensity score (PS)-matched and sibling-matched analyses to control for various potential confounders and within-familial factors. Hazard ratios (HRs) with 95% CIs were estimated using Cox proportional hazards regression models.

Results

The study included 4 149 257 mother-child pairs. Prenatal exposure analyses included 808 067 PS-matched pairs (763 755 received H2RAs, 36 529 received PPIs) among women with a mean (SD) age of 31.8 (4.2) years. The PS-matched HR was 1.01 (95% CI, 1.01-1.02) for allergic diseases overall (asthma: HR, 1.02 [95% CI, 1.01-1.03]; allergic rhinitis: HR, 1.02 [95% CI, 1.01-1.02]; atopic dermatitis: HR, 1.02 [95% CI, 1.01-1.02]; food allergy: HR, 1.03 [95% CI, 0.98-1.07]); in sibling-matched analyses, the HRs were similar to those of PS-matched analyses but were not significant (allergic diseases: HR, 1.01; 95% CI, 0.997-1.01). Infant exposure analyses included 84 263 PS-matched pairs (74 188 received H2RAs, 7496 received PPIs). The PS-matched HR was 1.06 (95% CI, 1.05-1.07) for allergic diseases overall (asthma: HR, 1.16 [95% CI, 1.14-1.18]; allergic rhinitis: HR, 1.02 [95% CI, 1.01-1.03]; atopic dermatitis: HR, 1.05 [95% CI, 1.02-1.08]; food allergy: HR, 1.28 [95% CI, 1.10-1.49]); asthma risk (HR, 1.13; 95% CI, 1.09-1.17) remained significantly higher among children exposed to ASMs during infancy in sibling-matched analyses. The findings were similar for H2RAs and PPIs analyzed separately and were robust across all sensitivity analyses.

Conclusions and Relevance

The findings of this cohort study suggest that there is no association between prenatal exposure to ASMs and allergic diseases in offspring. However, infant exposure to ASMs was associated with a higher risk of developing asthma, although the magnitude was more modest than previously reported. Clinicians should carefully weigh the benefits of prescribing ASMs to children, accompanied by subsequent close monitoring for any clinically relevant safety signals.

Sodium-Glucose Cotransporter 2 Inhibitor Treatment and Risk of Atrial Fibrillation: Scandinavian Cohort Study

OBJECTIVE

To assess the association between use of sodium-glucose cotransporter 2 (SGLT2) inhibitors and the risk of new-onset atrial fibrillation (AF) in routine clinical practice.

RESEARCH DESIGN AND METHODS

We used nationwide registers in Denmark, Norway, and Sweden from 2013 to 2018 in order to include patients without a history of AF who were newly prescribed an SGLT2 inhibitor or an active comparator (glucagon-like peptide 1 [GLP-1] receptor agonist). We performed a cohort study to assess new-onset AF in intention-to-treat analyses using Cox regression, adjusted for baseline covariates with propensity score weighting.

RESULTS

We identified 79,343 new users of SGLT2 inhibitors (59.2% dapagliflozin, 40.0% empagliflozin, 0.8% canagliflozin, <0.1% ertugliflozin) and 57,613 new users of GLP-1 receptor agonists. Mean age of the study cohort was 61 years and 60% were men. The adjusted incidence rate of new-onset AF was 8.6 per 1,000 person-years for new users of SGLT2 inhibitors compared with 10.0 per 1,000 person-years for new users of GLP-1 receptor agonists. The adjusted hazard ratio (aHR) was 0.89 (95% CI 0.81-0.96), and the rate difference was 1.4 fewer events per 1,000 person-years (95% CI 0.6-2.1). Using an as-treated exposure definition, the aHR for new-onset AF was 0.87 (95% CI 0.76-0.99). No statistically significant heterogeneity of the aHRs was observed between subgroups of patients with and without a history of heart failure or major cardiovascular disease.

CONCLUSIONS

In this cohort study using nationwide data from three countries, use of SGLT2 inhibitors, compared with GLP-1 receptor agonists, was associated with a modestly reduced risk of new-onset AF.

In-utero antibiotic exposure and subsequent infections in infancy: a register-based cohort study with sibling analysis

BACKGROUND

Prenatal antibiotic use, the ensuing maternal dysbiosis, and subsequent acquisition of altered microbiota in early life have been linked to the offspring's increased susceptibility to childhood infections. However, infection risks during the first year of life associated with in-utero antibiotic exposure have not been comprehensively explored.

OBJECTIVE

To investigate the associations between exposure to antibiotics in utero and subsequent infections during infancy and whether such associations differ by antibiotic class.

STUDY DESIGN

All data were retrieved from Swedish population-based registers. Singletons live-born between 2006 and 2018 were followed up from birth to their first birthday. Exposure was maternal filling of at least 1 antibiotic prescription between the last menstrual period and delivery. Outcomes were the infants' antimicrobial prescription fills, incident infections diagnosed in specialist care, and deaths with infections indicated as underlying or contributing causes ("infection-related deaths"). Birth year, birth season, maternal age, place of residence, parity, comorbidity indicator, body mass index, proxies for general health status, education level, and smoking status were considered covariates. Poisson regression was used to estimate crude and adjusted incidence rate ratios with 95% confidence intervals for the number of antimicrobial prescriptions filled to the infant. Cox regression was used to estimate crude and adjusted hazard ratios with 95% confidence intervals for incident infections diagnosed in specialist care and at death. Sibling analyses were used to account for shared familial factors. Sensitivity of the results to exposure definition and perinatal factors prognostic for the outcomes were assessed in supplementary analyses.

RESULTS

Of 1,347,018 infants in the full cohort, 294,657 (21.9%) were exposed to antibiotics in utero. There were 677,430 antimicrobial prescriptions filled (1.380 per 1000 person-days), 423,705 incident infections diagnosed in specialist care (0.870 per 1000 person-days), and 2800 infection-related deaths (0.006 deaths per 1000 person-days) during follow-up. Compared to unexposed, infants exposed to antibiotics in utero had higher rates of antimicrobial prescription fills (adjusted incidence rate ratio, 1.34; 95% confidence interval, 1.33-1.34), incident infections diagnosed in specialist care (adjusted hazard ratio, 1.28; 95% confidence interval, 1.27-1.29), and infection-related mortality (adjusted hazard ratio, 1.15; 95% confidence interval, 1.05-1.25). For antimicrobial prescriptions and infections diagnosed in specialist care, associations were consistent across most antibiotic classes but were attenuated in the sibling analyses: adjusted incidence rate ratio of 1.05 (95% confidence interval, 1.04-1.06) and adjusted hazard ratio of 1.05 (95% confidence interval, 1.03-1.07), respectively. No association with infant mortality was found in the sibling cohort (adjusted hazard ratio, 0.93; 95% confidence interval, 0.81-1.08).

CONCLUSION

The minor associations between exposure to antibiotics in utero and infections during infancy were partly explained by shared familial factors and did not differ across frequently used antibiotic classes.

Use of sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists according to the 2019 ESC guidelines and the 2019 ADA/EASD consensus report in a national population of patients with type 2 diabetes

AIMS

To assess treatment eligibility for, and received treatment with, sodium-glucose co-transporter 2 inhibitors (SGLT2) and glucagon-like peptide-1 (GLP-1) receptor agonists according to the 2019 ADA/EASD consensus report and the 2019 ESC guidelines in a nationwide sample of patients with type 2 diabetes.

METHODS AND RESULTS

Both sets of guidelines included the treatment indications of heart failure, chronic kidney disease and atherosclerotic cardiovascular disease while only the 2019 ESC guidelines also recommended treatment based on high or very high cardiovascular risk. The analyses included 435 000 patients with type 2 diabetes identified from the Swedish National Diabetes Register (2020-2021). According to the 2019 ESC guidelines, 79.5% were recommended any of the two drugs (SGLT2 inhibitors: 37.2%; SGLT2 inhibitors or GLP-1 receptor agonists: 40.9%; GLP-1 receptor agonists: 1.4%). According to the 2019 ADA/EASD consensus report, 48.8% were recommended any of the two drugs (SGLT2 inhibitors: 37.2%; GLP-1 receptor agonists: 11.6%). Of those who had been recommended any of the two drugs, 33·7% had received the recommended treatment according to the 2019 ESC guidelines and 25·4% according to the 2019 ADA/EASD consensus report.

CONCLUSIONS

In this nationwide study, the proportion of patients with type 2 diabetes who were recommended treatment with an SGLT2 inhibitor or a GLP-1 receptor agonist was approximately 80% according to the 2019 ESC guidelines and around half according to the 2019 ADA/EASD consensus report. Uptake of these recommendations in routine clinical practice was limited.

Alcohol related disorders among elite male football players in Sweden: nationwide cohort study

OBJECTIVES

To assess whether male elite football players are at increased risk of alcohol related disorders compared with men from the general population, and whether such an increased risk would vary on the basis of calendar year of the first playing season in the top tier of competition, age, career length, and goal scoring abilities.

DESIGN

Nationwide cohort study.

SETTING

Sweden, 1924-2020.

PARTICIPANTS

6007 male football players who had played in the Swedish top division, Allsvenskan, from 1924 to 2019 and 56 168 men from the general population matched to players based on age and region of residence.

MAIN OUTCOME MEASURES

Primary outcome was alcohol related disorders (diagnoses recorded in death certificates, during hospital admissions and outpatient visits, or use of prescription drugs for alcohol addiction); secondary outcome was disorders related to misuse of other drugs.

RESULTS

During follow-up up to 31 December 2020, 257 (4.3%) football players and 3528 (6.3%) men from the general population received diagnoses of alcohol related disorders. In analyses accounting for age, region of residence, and calendar time, risk of alcohol related disorders was lower among football players than among men from the general population (hazard ratio 0.71, 95% confidence interval 0.62 to 0.81). A reduced risk of alcohol related disorders was observed for football players who played their first season in the top tier in the early 1960s and later, while no significant difference versus men from the general population was seen in the risk for football players from earlier eras. The hazard ratio was lowest at around age 35 years, and then increased with age; at around age 75 years, football players had a higher risk of alcohol related disorders than men from the general population. No significant association was seen between goal scoring, number of games, and seasons played in the top tier and the risk of alcohol related disorders. Risk of disorders related to other drug misuse was significantly lower among football players than the general population (hazard ratio 0.22, 95% confidence interval 0.15 to 0.34).

CONCLUSIONS

In this nationwide cohort study, male football players who had played in the Swedish top tier of competition had a significantly lower risk of alcohol related disorders than men from the general population.

Association between proton pump inhibitor use and risk of pneumonia in children: nationwide self-controlled case series study in Sweden

OBJECTIVE

To evaluate the association between use of proton pump inhibitors (PPIs) and risk of pneumonia in children.

DESIGN

Nationwide register-based self-controlled case series study.

SETTING

Sweden, July 2006 to December 2016.

PARTICIPANTS

Children aged <18 years who were treated with PPIs and had a hospitalisation or hospital emergency care visit for pneumonia within 1 year before and 2 years after PPI initiation.

MAIN OUTCOMES AND MEASURES

The primary analysis examined the risk of pneumonia during the risk period (ongoing PPI treatment), the pre-exposure period (≤30 days preceding PPI treatment) and the postexposure period (days 1-365 after PPI discontinuation), comparing to the unexposed period. Conditional Poisson regression was used to estimate incidence rate ratios (IRRs) and 95% CIs.

RESULTS

A total of 2356 cases of pneumonia were included. Compared with the unexposed period, the risk of pneumonia was significantly increased during ongoing PPI treatment, with an adjusted IRR of 1.40 (95% CI 1.21 to 1.62). The risk of pneumonia was also increased in the pre-exposure period (adjusted IRR, 1.80, 95% CI 1.51 to 2.13), but not in the postexposure period (adjusted IRR 0.98, 95% CI 0.89 to 1.08). Dividing the risk period by time since treatment initiation, the increased risk of pneumonia was highest in the first 30 days (adjusted IRR 1.63, 95% CI 1.35 to 1.97), remained during days 31-90 (adjusted IRR 1.32, 95% CI 1.04 to 1.69), but waned in days ≥91 (IRR 1.06, 95% CI 0.79 to 1.41).

CONCLUSIONS AND RELEVANCE

An increased risk of pneumonia was observed both immediately before and immediately after PPI initiation. This pattern of association can likely be explained by an underlying risk of pneumonia due to factors transiently present at the time around PPI initiation. Thus, our findings do not support a causal relationship between PPI use and risk of pneumonia.

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.

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.

Proton pump inhibitor use and risk of depression and anxiety in children: nationwide cohort study

Although some data have linked proton pump inhibitor (PPI) use to risk of depression and anxiety, there are no studies investigating this safety issue in children. This study investigated the association between PPI use and risk of depression and anxiety in children. We conducted a nationwide register‐based cohort study in Sweden, July 1, 2007, to December 31, 2016. Following matching on age and propensity score, we included 29,320 pairs of PPI initiators and noninitiators among children aged 7–17 years old. The primary analysis examined the risk of incident depression and anxiety, a composite outcome defined as a diagnosis of depression, anxiety, or a prescription for an antidepressant. Children who initiated PPI use had higher hazards for risk of depression and anxiety compared with noninitiators (hazard ratios [HRs], 2.61; 95% confidence interval [CI], 2.32–2.94). In analyses of the timing of depression and anxiety onset after PPI initiation, the HRs were 3.71 (95% CI, 2.17–6.34) for 1–30 days, 3.47 (95% CI, 2.33–5.18) for 31–90 days, 2.71 (2.04–3.60) for 91–180 days, 2.52 (2.00–3.16) for 181–365 days, and 2.34 (1.94–2.82) for 366–730 days. Significant associations were observed across all age groups. The magnitude of the association increased with longer duration of PPI use (p for trend < 0.0001). The association was consistent through all sensitivity analyses, including high‐dimensional propensity score matching (HR, 2.31, 95% CI, 2.05–2.61). PPI use was associated with increased risk of depression and anxiety in children. Further investigation is warranted to confirm or refute this potential association.

SARS-CoV-2 and pregnancy outcomes under universal and non-universal testing in Sweden: register-based nationwide cohort study

OBJECTIVE

To assess associations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and pregnancy outcomes considering testing policy and test-positivity-to-delivery interval.

DESIGN

Nationwide cohort study.

SETTING

Sweden.

POPULATION

From the Pregnancy-Register we identified 88 593 singleton births, 11 March 2020-31 January 2021, linked to data on SARS-CoV-2-positivity from the Public Health Agency, and information on neonatal care admission from the Neonatal Quality Register. Adjusted odds ratios (aORs) were estimated stratified by testing-policy and test-positivity-to-delivery interval.

MAIN OUTCOME MEASURES

Five-minute Apgar score, neonatal care admission, stillbirth and preterm birth.

RESULTS

During pregnancy, SARS-CoV-2 test-positivity was 5.4% (794/14 665) under universal testing and 1.9% (1402/73 928) under non-universal testing. There were generally lower risks associated with SARS-CoV-2 under universal than non-universal testing. In women testing positive >10 days from delivery, generally no significant differences in risk were observed under either testing policy. Neonatal care admission was more common (15.3% versus 8.0%; aOR 2.24, 95% CI 1.62-3.11) in women testing positive ≤10 days before delivery under universal testing. There was no significant association with 5-minute Apgar score below 7 (1.0% versus 1.7%; aOR 0.64, 95% CI 0.24-1.72) or stillbirth (0.3% versus 0.4%; aOR 0.72, 95% CI 0.10-5.20). Compared with term births (2.1%), test-positivity was higher in medically indicated preterm birth (5.7%; aOR 2.70, 95% CI 1.60-4.58) but not significantly increased in spontaneous preterm birth (2.3%; aOR 1.12, 95% CI 0.62-2.02).

CONCLUSIONS

Testing policy and timing of test-positivity impact associations between SARS-CoV-2-positivity and pregnancy outcomes. Under non-universal testing, women with complications near delivery are more likely to be tested than women without complications, thereby inflating any association with adverse pregnancy outcomes compared with findings under universal testing.

TWEETABLE ABSTRACT

Testing policy and time from SARS-CoV-2 infection to delivery influence the association with pregnancy outcomes.

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.

Association Between Proton Pump Inhibitor Use and Risk of Asthma in Children

IMPORTANCE

The use of proton pump inhibitors (PPIs) in children has increased substantially in recent years, concurrently with emerging concerns that these drugs may increase the risk of asthma. Whether PPI use in the broad pediatric population is associated with increased risk of asthma is not known.

OBJECTIVE

To investigate the association between PPI use and risk of asthma in children.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide cohort study collected registry data in Sweden from January 1, 2007, to December 31, 2016. Children and adolescents 17 years or younger were matched by age and propensity score into 80 870 pairs of those who initiated PPI use and those who did not. Data were analyzed from February 1 to September 1, 2020.

EXPOSURES

Initiation of PPI use.

MAIN OUTCOMES AND MEASURES

The primary analysis examined the risk of incident asthma with a median follow-up to 3.0 (interquartile range, 2.1-3.0) years. Cox proportional hazards regression was used to estimate hazard ratios (HRs).

RESULTS

Among the 80 870 pairs (63.0% girls; mean [SD] age, 12.9 [4.8] years), those who initiated PPI use had a higher incidence rate of asthma (21.8 events per 1000 person-years) compared with noninitiators (14.0 events per 1000 person-years), with an HR of 1.57 (95% CI, 1.49-1.64). The risk of asthma was significantly increased across all age groups and was highest for infants and toddlers with an HR of 1.83 (95% CI, 1.65-2.03) in the group younger than 6 months and 1.91 (95% CI, 1.65-2.22) in the group 6 months to younger than 2 years (P < .001 for interaction). The HRs for individual PPIs were 1.64 (95% CI, 1.50-1.79) for esomeprazole, 1.49 (95% CI, 1.25-1.78) for lansoprazole, 1.43 (95% CI, 1.35-1.51) for omeprazole, and 2.33 (95% CI, 1.30-4.18) for pantoprazole. In analyses of the timing of asthma onset after PPI initiation, the HRs were 1.62 (95% CI, 1.42-1.85) for 0 to 90 days, 1.73 (95% CI, 1.52-1.98) for 91 to 180 days, and 1.53 (95% CI, 1.45-1.62) for 181 days to end of follow-up. The association was consistent through all sensitivity analyses, including high-dimensional propensity score matching (HR, 1.48; 95% CI, 1.41-1.55).

CONCLUSIONS AND RELEVANCE

In this cohort study, initiation of PPI use compared with nonuse was associated with an increased risk of asthma in children. Proton pump inhibitors should be prescribed to children only when clearly indicated, weighing the potential benefit against potential harm.

Direct oral anticoagulant use and risk of severe COVID-19

BACKGROUND

Hypercoagulability and thromboembolism are prominent features of severe COVID-19, and ongoing anticoagulant use might be protective.

METHODS

We conducted a nationwide register-based cohort study in Sweden, February through May, 2020, to assess whether ongoing direct oral anticoagulant (DOAC) use was associated with reduced risk of hospital admission for laboratory-confirmed COVID-19, or a composite of intensive care unit (ICU) admission or death due to laboratory-confirmed COVID-19.

RESULTS

DOAC use (n = 103 703) was not associated with reduced risk of hospital admission for COVID-19 (adjusted hazard ratio [aHR] [95% confidence interval] 1.00 [0.75-1.33] vs. nonuse atrial fibrillation comparator [n = 36 875]; and aHR 0.94 [0.80-1.10] vs. nonuse cardiovascular disease comparator [n = 355 699]), or ICU admission or death due to COVID-19 (aHRs 0.76 [0.51-1.12], and 0.90 [0.71-1.15], respectively).

CONCLUSION

Ongoing DOAC use was not associated with reduced risk of severe COVID-19, indicating that prognosis would not be modified by early outpatient DOAC initiation.

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.

Use of Pregabalin and Worsening Heart Failure: A Nationwide Cohort Study

INTRODUCTION

Concerns regarding the increased risk of worsening heart failure with pregabalin have been raised. We assessed the association between use of pregabalin and risk of worsening heart failure in routine clinical practice.

METHODS

We conducted a population-based cohort study in Denmark using data from nationwide registers, from 1 January 2008 to 31 December 2017. The study population consisted of patients 50 years of age or older with a diagnosis of heart failure who were new users of pregabalin or gabapentin (active comparator). We matched a total of 1395 new users of pregabalin to 1395 new users of gabapentin on a propensity score based on 55 covariates. Using proportional hazards regression, we estimated hazard ratios (HRs) for worsening heart failure (hospitalization with, or death from, heart failure) within 90 days of the start of treatment.

RESULTS

We observed 33 patients with worsening heart failure among users of pregabalin [incidence rate (IR) 105.7 per 1000 person-years] versus 43 patients among users of gabapentin (IR 133.8 per 1000 person-years), corresponding to an HR of 0.79 [95% confidence interval (CI) 0.50-1.23]. The corresponding absolute risk difference was - 28.6 (95% CI - 66.8 to 31.3) per 1000 person-years. In sensitivity analysis using duloxetine as an alternative active comparator, including 847 new users of pregabalin and 847 new users of duloxetine, the results were similar (HR 1.08, 95% CI 0.60-1.94).

CONCLUSIONS

The present study found no evidence to support an association between the use of pregabalin and increased risk of worsening heart failure, compared with gabapentin and duloxetine.

Association Between Proton Pump Inhibitor Use and Risk of Fracture in Children

IMPORTANCE

Proton pump inhibitor (PPI) use has been linked to increased risk of fracture in adults. Despite a trend in prescription of PPIs in children, there is scarce evidence regarding this safety concern in pediatric patients.

OBJECTIVE

To evaluate the association between PPI use and risk of fracture in children.

DESIGN

This nationwide register-based cohort study included data from Sweden from July 2006 to December 2016. Children younger than 18 years who initiated PPI use were matched on propensity score and age with those who did not initiate PPI use.

EXPOSURE

Initiation of PPI use.

MAIN OUTCOMES AND MEASURES

Cox regression was adopted to estimate hazard ratios (HRs) for a first fracture of any type and 5 subtypes of fracture, with follow-up for up to 5 years. To address potential residual confounding, high-dimensional propensity score matching and a direct comparison with histamine-2 receptor antagonists were performed.

RESULTS

There were a total of 115 933 pairs of children included. During a mean (SD) of 2.2 (1.6) years of follow-up, 5354 and 4568 cases of any fracture occurred among those who initiated PPIs vs those who did not, respectively (20.2 vs 18.3 events per 1000 person-years; hazard ratio [HR], 1.11 [95% CI, 1.06-1.15]). Use of PPIs was associated with increased risk of upper-limb fracture (HR, 1.08 [95% CI, 1.03-1.13]), lower-limb fracture (HR, 1.19 [95% CI, 1.10-1.29]), and other fractures (HR, 1.51 [95% CI, 1.16-1.97]) but not head fracture (HR, 0.93 [95% CI, 0.76-1.13]) or spine fracture (HR, 1.31 [95% CI, 0.95-1.81]). The HRs for fracture according to cumulative duration of PPI use were 1.08 (95% CI, 1.03-1.13) for 30 days or less, 1.14 (95% CI, 1.09-1.20) for 31 to 364 days, and 1.34 (95% CI, 1.13-1.58) for 365 days or more. The association was consistent in most sensitivity analyses, including high-dimensional propensity score matching (HR, 1.10 [95% CI, 1.06-1.15]), although the analysis of PPI vs histamine-2 receptor antagonist did not reach statistical significance (HR, 1.06 [95% CI, 0.97-1.15]).

CONCLUSIONS AND RELEVANCE

In this large pediatric cohort, PPI use was associated with a small but significant increased risk of any fracture. Risk of fracture should be taken into account when weighing the benefits and risks of PPI treatment in children.

Use of Glucagon-Like Peptide 1 Receptor Agonists and Risk of Serious Renal Events: Scandinavian Cohort Study

OBJECTIVE

To assess the association between use of glucagon-like peptide 1 (GLP-1) receptor agonists and risk of serious renal events in routine clinical practice.

RESEARCH DESIGN AND METHODS

This was a cohort study using an active-comparator, new-user design and nationwide register data from Sweden, Denmark, and Norway during 2010-2016. The cohort included 38,731 new users of GLP-1 receptor agonists (liraglutide 92.5%, exenatide 6.2%, lixisenatide 0.7%, and dulaglutide 0.6%), matched 1:1 on age, sex, and propensity score to a new user of the active comparator, dipeptidyl peptidase 4 (DPP-4) inhibitors. The main outcome was serious renal events, a composite including renal replacement therapy, death from renal causes, and hospitalization for renal events. Secondary outcomes were the individual components of the main outcome. Hazard ratios (HRs) were estimated using Cox models and an intention-to-treat exposure definition. Mean (SD) follow-up time was 3.0 (1.7) years.

RESULTS

Mean (SD) age of the study population was 59 (10) years, and 18% had cardiovascular disease. A serious renal event occurred in 570 users of GLP-1 receptor agonists (incidence rate 4.8 events per 1,000 person-years) and in 722 users of DPP-4 inhibitors (6.3 events per 1,000 person-years, HR 0.76 [95% CI 0.68-0.85], absolute difference -1.5 events per 1,000 person-years [-2.1 to -0.9]). Use of GLP-1 receptor agonists was associated with a significantly lower risk of renal replacement therapy (HR 0.73 [0.62-0.87]) and hospitalization for renal events (HR 0.73 [0.65-0.83]) but not death from renal causes (HR 0.72 [0.48-1.10]). When we used an as-treated exposure definition in which patients were censored at treatment cessation or switch to the other study drug, the HR for the primary outcome was 0.60 (0.49-0.74).

CONCLUSIONS

In this large cohort of patients seen in routine clinical practice in three countries, use of GLP-1 receptor agonists, as compared with DPP-4 inhibitors, was associated with a reduced risk of serious renal events.

Use of sodium-glucose co-transporter 2 inhibitors and risk of serious renal events: Scandinavian cohort study

OBJECTIVE

To assess the association between use of sodium-glucose co-transporter 2 (SGLT2) inhibitors and risk of serious renal events in data from routine clinical practice.

DESIGN

Cohort study using an active comparator, new user design and nationwide register data.

SETTING

Sweden, Denmark, and Norway, 2013-18.

PARTICIPANTS

Cohort of 29 887 new users of SGLT2 inhibitors (follow-up time: dapagliflozin 66.1%; empagliflozin 32.6%; canagliflozin 1.3%) and 29 887 new users of an active comparator, dipeptidyl peptidase-4 inhibitors, matched 1:1 on the basis of a propensity score with 57 variables. Mean follow-up time was 1.7 (SD 1.0) years.

EXPOSURES

SGLT2 inhibitors versus dipeptidyl peptidase-4 inhibitors, defined by filled prescriptions and analysed according to intention to treat.

MAIN OUTCOME MEASURES

The main outcome was serious renal events, a composite including renal replacement therapy, death from renal causes, and hospital admission for renal events. Secondary outcomes were the individual components of the main outcome.

RESULTS

The mean age of the study population was 61.3 (SD 10.5) years; 11 108 (19%) had cardiovascular disease, and 1974 (3%) had chronic kidney disease. Use of SGLT2 inhibitors, compared with dipeptidyl peptidase-4 inhibitors, was associated with a reduced risk of serious renal events (2.6 events per 1000 person years versus 6.2 events per 1000 person years; hazard ratio 0.42 (95% confidence interval 0.34 to 0.53); absolute difference -3.6 (-4.4 to -2.8) events per 1000 person years). In secondary outcome analyses, the hazard ratio for use of SGLT2 inhibitors versus dipeptidyl peptidase-4 inhibitors was 0.32 (0.22 to 0.47) for renal replacement therapy, 0.41 (0.32 to 0.52) for hospital admission for renal events, and 0.77 (0.26 to 2.23) for death from renal causes. In sensitivity analyses in each of the Swedish and Danish parts of the cohort, the model was further adjusted for glycated haemoglobin and estimated glomerular filtration rate (Sweden and Denmark) and for blood pressure, body mass index, and smoking (Sweden only); in these analyses, the hazard ratio moved from 0.41 (0.26 to 0.66) to 0.50 (0.31 to 0.81) in Sweden and from 0.42 (0.32 to 0.56) to 0.55 (0.41 to 0.74) in Denmark.

CONCLUSIONS

In this analysis using nationwide data from three countries, use of SGLT2 inhibitors, compared with dipeptidyl peptidase-4 inhibitors, was associated with a significantly reduced risk of serious renal events.

Association of Maternal Gastric Bypass Surgery With Offspring Birth Defects

This cohort study uses Swedish Medical Birth Register data to investigate risk of birth defects in infants born to women who had Roux-en-Y bariatric surgery between 2007 and 2014.

Use of tumour necrosis factor-α inhibitors and the risk of serious infection in paediatric inflammatory bowel disease in Denmark: a nationwide cohort study

BACKGROUND

Studies have shown an association between use of tumour necrosis factor-α (TNFα) inhibitors and increased risk of serious infection in adult inflammatory bowel disease (IBD). However, data on this topic for paediatric patients are scarce and inconclusive. The aim of this study was to investigate whether there is an association between the use of TNFα inhibitors and the risk of serious infection in children with IBD.

METHODS

In this nationwide Danish cohort study, we searched health registers (from Jan 1, 2007, to Dec 31, 2016) to identify episodes of children and adolescents (<18 years) with at least two recorded IBD diagnoses in specialist care. We categorised follow-up time in mutually exclusive episodes of incident TNFα inhibitor use or no TNFα inhibitor use from specialist care records. We used Cox proportional hazards models to estimate hazard ratios (HRs), adjusting using propensity score weighting for demographic characteristics, comorbidities, treatment history, health-care use, and indicators of disease severity. The primary outcome, incident serious infection, was defined as infection requiring a stay in hospital and was identified through hospital records.

FINDINGS

Among 2817 paediatric patients with IBD, we identified 618 episodes of incident TNFα inhibitor use and 2925 episodes of no TNFα inhibitor use. In the cohort of exposed and not exposed episodes that was propensity-score weighted, 53·9% were of male sex, the mean age was 15·1 (SD 1·7) years, 69·9% had Crohn's disease, and 30·1% had ulcerative colitis or IBD-unclassified; median follow-up was 1·4 years (IQR 0·4-3·0). The weighted incidence of serious infection was 54·6 events per 1000 patient-years for the TNFα inhibitor episodes and 61·9 events per 1000 patient-years for the no-use episodes. The weighted HR of serious infection associated with TNFα inhibitor use was 0·81 (95% CI 0·54-1·21).

INTERPRETATION

There was no significant association between use of TNFα inhibitors and the risk of serious infection in children with IBD, and, based on the upper bound of the confidence interval, a relatively small risk increase seems unlikely, contrary to previous findings in adults. Observational data such as these can support paediatric clinical practice.

FUNDING

Swedish Research Council, Frimurare Barnhuset Foundation, and the Åke Wiberg Foundation.

Use of sodium glucose cotransporter 2 inhibitors and risk of major cardiovascular events and heart failure: Scandinavian register based cohort study

OBJECTIVE

To investigate the cardiovascular effectiveness of sodium glucose cotransporter 2 (SGLT2) inhibitors in routine clinical practice.

DESIGN

Cohort study using data from nationwide registers and an active-comparator new-user design.

SETTING

Denmark, Norway, and Sweden, from April 2013 to December 2016.

PARTICIPANTS

20 983 new users of SGLT2 inhibitors and 20 983 new users of dipeptidyl peptidase 4 (DPP4) inhibitors, aged 35-84, matched by age, sex, history of major cardiovascular disease, and propensity score.

MAIN OUTCOME MEASURES

Primary outcomes were major cardiovascular events (composite of myocardial infarction, stroke, and cardiovascular death) and heart failure (hospital admission for heart failure or death due to heart failure). Secondary outcomes were the individual components of the cardiovascular composite and any cause death. In the primary analyses, patients were defined as exposed from treatment start throughout follow-up (analogous to intention to treat); additional analyses were conducted with an as-treated exposure definition. Cox regression was used to estimate hazard ratios.

RESULTS

Mean age of the study cohort was 61 years, 60% were men, and 19% had a history of major cardiovascular disease. Of the total 27 416 person years of follow-up in the SGLT2 inhibitor group, 22 627 (83%) was among patients who initiated dapagliflozin, 4521 (16%) among those who initiated empagliflozin, and 268 (1%) among those who initiated canagliflozin. During follow-up, 467 SGLT2 inhibitor users (incidence rate 17.0 events per 1000 person years) and 662 DPP4 inhibitor users (18.0) had a major cardiovascular event, whereas 130 (4.7) and 265 (7.1) had a heart failure event, respectively. Hazard ratios were 0.94 (95% confidence interval 0.84 to 1.06) for major cardiovascular events and 0.66 (0.53 to 0.81) for heart failure. Hazard ratios were consistent among subgroups of patients with and without history of major cardiovascular disease and with and without history of heart failure. Hazard ratios for secondary outcomes, comparing SGLT2 inhibitors with DPP4 inhibitors, were 0.99 (0.85 to 1.17) for myocardial infarction, 0.94 (0.77 to 1.15) for stroke, 0.84 (0.65 to 1.08) for cardiovascular death, and 0.80 (0.69 to 0.92) for any cause death. In the as-treated analyses, hazard ratios were 0.84 (0.72 to 0.98) for major cardiovascular events, 0.55 (0.42 to 0.73) for heart failure, 0.93 (0.76 to 1.14) for myocardial infarction, 0.83 (0.64 to 1.07) for stroke, 0.67 (0.49 to 0.93) for cardiovascular death, and 0.75 (0.61 to 0.91) for any cause death.

CONCLUSIONS

In this large Scandinavian cohort, SGLT2 inhibitor use compared with DPP4 inhibitor use was associated with reduced risk of heart failure and any cause death, but not with major cardiovascular events in the primary intention-to-treat analysis. In the additional as-treated analyses, the magnitude of the association with heart failure and any cause death became larger, and a reduced risk of major cardiovascular events that was largely driven by the cardiovascular death component was observed. These data help inform patients, practitioners, and authorities regarding the cardiovascular effectiveness of SGLT2 inhibitors in routine clinical practice.

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.

Use of liraglutide and risk of major cardiovascular events: a register-based cohort study in Denmark and Sweden

BACKGROUND

Trial evidence shows that the glucagon-like peptide-1 receptor agonist liraglutide significantly reduces the risk of major cardiovascular events among patients with type 2 diabetes who have established cardiovascular disease or are at high cardiovascular risk. We aimed to assess the cardiovascular effectiveness of liraglutide in routine clinical practice.

METHODS

We used data from nationwide registers in Denmark and Sweden for the period from Jan 1, 2010, to Dec 31, 2016, to investigate the risk of major cardiovascular events associated with use of liraglutide, compared with an active comparator drug class, dipeptidyl peptidase-4 (DPP-4) inhibitors, in patients with type 2 diabetes. The cohort included incident users of liraglutide or DPP-4 inhibitors, who were also using metformin at baseline, matched 1:1 on age, sex, and propensity score. The main outcome was major cardiovascular events, a composite outcome consisting of myocardial infarction, stroke, and cardiovascular death. Other outcomes assessed were the individual components of the main composite outcome, heart failure, death from any cause, and an expanded composite major cardiovascular events outcome that also included other ischaemic heart disease, coronary revascularisation, and peripheral arterial disease.

FINDINGS

The study population consisted of 23 402 users of liraglutide and 23 402 matched users of DPP-4 inhibitors; patients were followed up for a mean of 3·3 years (SD 2·0). A major cardiovascular event occurred in 1132 users of liraglutide (incidence rate 14·0 per 1000 person-years) and in 1141 users of DPP-4 inhibitors (15·4 per 1000 person-years; hazard ratio [HR] 0·90, 95% CI 0·83-0·98). The HRs were 0·81 (0·71-0·92) for patients with a history of major cardiovascular disease and 0·96 (0·86-1·06) for patients without such a history (p=0·057 [test of homogeneity], suggesting no statistical evidence of heterogeneity). Compared with use of DPP-4 inhibitors, use of liraglutide was associated with a significantly lower risk of cardiovascular death (HR 0·78, 95% CI 0·68-0·91), but no significant differences were identified for risk of myocardial infarction (0·94, 0·84-1·06) or stroke (0·88, 0·77-1·01). Furthermore, use of liraglutide was associated with a significantly lower risk of death from any cause (HR 0·83, 95% CI 0·77-0·90), but no significant differences were identified for risk of heart failure (0·90, 0·80-1·03) or for the expanded major cardiovascular events outcome (0·95, 0·89-1·01).

INTERPRETATION

In this large Scandinavian cohort, use of liraglutide, as compared with use of DPP-4 inhibitors, was associated with significantly reduced risk of major cardiovascular events. Patients with history of cardiovascular disease seemed to derive the largest benefit from treatment with liraglutide. These data provide support for the cardiovascular effectiveness of liraglutide in routine clinical practice.

FUNDING

Swedish Heart-Lung Foundation, Novo Nordisk Foundation, and Swedish Society for Medical Research.

Association between use of azathioprine and risk of acute pancreatitis in children with inflammatory bowel disease: a Swedish-Danish nationwide cohort study

BACKGROUND

Studies have shown an association between use of azathioprine and increased risk of acute pancreatitis in adult inflammatory bowel disease. However, whether an association exists among paediatric patients is not known. We aimed to investigate whether use of azathioprine is associated with the risk of acute pancreatitis in children with inflammatory bowel disease.

METHODS

We did a nationwide register-based cohort study in Sweden (2006-16) and Denmark (2000-16). All paediatric patients (<18 years of age) with inflammatory bowel disease during the study period were identified through hospital records. Episodes of incident azathioprine use and no use of any thiopurine were matched (1:1) using propensity scores, controlling for sociodemographic characteristics, comorbidities, previous treatment, indicators of disease severity, and health care use. Incident acute pancreatitis (physician-assigned diagnosis with ICD-10 code K85) occurring in the 90 days following treatment initiation were identified through outpatient and inpatient hospital records.

FINDINGS

We identified 3574 azathioprine episodes and 18 700 no-use episodes, which resulted in 3374 pairs after propensity score matching; baseline characteristics in the matched cohort were well balanced. Among the matched azathioprine episodes, mean age was 14·3 years (SD 3·1), 1854 (54·9%) were male, 1923 (57·0%) had Crohn's disease, and 1451 (43·0%) had ulcerative colitis or unclassified inflammatory bowel disease. Within the first 90 days following initiation of azathioprine, 40 acute pancreatitis events occurred (incidence rate 49·1 events per 1000 person-years) compared with six events in the no-use group (8·4 events per 1000 person-years). Azathioprine use was associated with an increased risk of acute pancreatitis (incidence rate ratio 5·82 [95% CI 2·47-13·72]; absolute difference 1·0 [95% CI 0·3-2·6] events per 100 patients) during the 90-day risk period.

INTERPRETATION

Use of azathioprine was associated with an increased risk of acute pancreatitis in children with inflammatory bowel disease during the first 90 days following treatment initiation, suggesting the need for regular and rigorous monitoring. The risk of acute pancreatitis needs to be considered when deciding on optimal treatment strategies.

FUNDING

Swedish Research Council, Frimurare Barnhuset Foundation, and the Åke Wiberg Foundation.

Sodium glucose cotransporter 2 inhibitors and risk of serious adverse events: nationwide register based cohort study

OBJECTIVE

To assess the association between the use of sodium glucose cotransporter 2 (SGLT2) inhibitors and seven serious adverse events of current concern.

DESIGN

Register based cohort study.

SETTING

Sweden and Denmark from July 2013 to December 2016.

PARTICIPANTS

A propensity score matched cohort of 17 213 new users of SGLT2 inhibitors (dapagliflozin, 61%; empagliflozin, 38%; canagliflozin, 1%) and 17 213 new users of the active comparator, glucagon-like peptide 1 (GLP1) receptor agonists.

MAIN OUTCOME MEASURES

The primary outcomes were lower limb amputation, bone fracture, diabetic ketoacidosis, acute kidney injury, serious urinary tract infection, venous thromboembolism, and acute pancreatitis, as identified from hospital records. Hazard ratios and 95% confidence intervals were estimated by using Cox proportional hazards models.

RESULTS

Use of SGLT2 inhibitors, as compared with GLP1 receptor agonists, was associated with an increased risk of lower limb amputation (incidence rate 2.7 v 1.1 events per 1000 person years, hazard ratio 2.32, 95% confidence interval 1.37 to 3.91) and diabetic ketoacidosis (1.3 v 0.6, 2.14, 1.01 to 4.52) but not with bone fracture (15.4 v 13.9, 1.11, 0.93 to 1.33), acute kidney injury (2.3 v 3.2, 0.69, 0.45 to 1.05), serious urinary tract infection (5.4 v 6.0, 0.89, 0.67 to 1.19), venous thromboembolism (4.2 v 4.1, 0.99, 0.71 to 1.38) or acute pancreatitis (1.3 v 1.2, 1.16, 0.64 to 2.12).

CONCLUSIONS

In this analysis of nationwide registers from two countries, use of SGLT2 inhibitors, as compared with GLP1 receptor agonists, was associated with an increased risk of lower limb amputation and diabetic ketoacidosis, but not with other serious adverse events of current concern.

Periconception glycaemic control in women with type 1 diabetes and risk of major birth defects: population based cohort study in Sweden

OBJECTIVE

To examine the association between maternal type 1 diabetes and the risk of major birth defects according to levels of glycated haemoglobin (HbA1C) within three months before or after estimated conception.

DESIGN

Population based historical cohort study using nationwide health registers.

SETTING

Sweden, 2003-15.

PARTICIPANTS

2458 singleton liveborn infants of mothers with type 1 diabetes and a glycated haemoglobin measurement within three months before or after estimated conception and 1 159 865 infants of mothers without diabetes.

MAIN OUTCOME MEASURES

Major cardiac and non-cardiac birth defects according to glycated haemoglobin levels.

RESULTS

122 cases of major cardiac defects were observed among 2458 infants of mothers with type 1 diabetes. Compared with 15 cases of major cardiac defects per 1000 infants of mothers without diabetes, the rates among infants of mothers with type 1 diabetes were 33 per 1000 for a glycated haemoglobin level of <6.5% (adjusted risk ratio 2.17, 95% confidence interval 1.37 to 3.42), 49 per 1000 for 6.5% to <7.8% (3.17, 2.45 to 4.11), 44 per 1000 for 7.8% to <9.1% (2.79, 1.90 to 4.12), and 101 per 1000 for ≥9.1% (6.23, 4.32 to 9.00). The corresponding adjusted risk differences were 17 (5 to 36), 32 (21 to 46), 26 (13 to 46), and 77 (49 to 118) cases of major cardiac defects per 1000 infants, respectively. 50 cases of major non-cardiac defects were observed among infants of mothers with type 1 diabetes. Compared with 18 cases of major non-cardiac defects per 1000 infants of mothers without diabetes, the rates among infants of mothers with type 1 diabetes were 22 per 1000 for a glycated haemoglobin level of <6.5% (adjusted risk ratio 1.18, 0.68 to 2.07), 19 per 1000 for 6.5% to <7.8% (1.01, 0.66 to 1.54), 17 per 1000 for 7.8% to <9.1% (0.89, 0.46 to 1.69), and 32 per 1000 for ≥9.1% (1.68, 0.85 to 3.33).

CONCLUSION

Among liveborn infants of mothers with type 1 diabetes, increasingly worse glycaemic control in the three months before or after estimated conception was associated with a progressively increased risk of major cardiac defects. Even with glycated haemoglobin within target levels recommended by guidelines (<6.5%), the risk of major cardiac defects was increased more than twofold. The risk of major non-cardiac defects was not statistically significantly increased at any of the four glycated haemoglobin levels examined; the study had limited statistical power for this outcome and was based on live births only.

Oral Fluconazole in Pregnancy and Risk of Stillbirth and Neonatal Death

This pharmacoepidemiology study uses Swedish and Norwegian registry data to investigate associations between fluconazole use during pregnancy and subsequent stillbirth and neonatal 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.

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.

Fluoroquinolone use and risk of aortic aneurysm and dissection: nationwide cohort study

OBJECTIVE

To investigate whether oral fluoroquinolone use is associated with an increased risk of aortic aneurysm or dissection.

DESIGN

Nationwide historical cohort study using linked register data on patient characteristics, filled prescriptions, and cases of aortic aneurysm or dissection.

SETTING

Sweden, July 2006 to December 2013.

PARTICIPANTS

360 088 treatment episodes of fluoroquinolone use (78%ciprofloxacin) and propensity score matched comparator episodes of amoxicillin use (n=360 088).

MAIN OUTCOME MEASURES

Cox regression was used to estimate hazard ratios for a first diagnosis of aortic aneurysm or dissection, defined as admission to hospital or emergency department for, or death due to, aortic aneurysm or dissection, within 60 days from start of treatment.

RESULTS

Within the 60 day risk period, the rate of aortic aneurysm or dissection was 1.2 cases per 1000 person years among fluoroquinolone users and 0.7 cases per 1000 person years among amoxicillin users. Fluoroquinolone use was associated with an increased risk of aortic aneurysm or dissection (hazard ratio 1.66 (95% confidence interval 1.12 to 2.46)), with an estimated absolute difference of 82 (95% confidence interval 15 to 181) cases of aortic aneurysm or dissection by 60 days per 1 million treatment episodes. In a secondary analysis, the hazard ratio for the association with fluoroquinolone use was 1.90 (1.22 to 2.96) for aortic aneurysm and 0.93 (0.38 to 2.29) for aortic dissection.

CONCLUSIONS

In a propensity score matched cohort, fluoroquinolone use was associated with an increased risk of aortic aneurysm or dissection. This association appeared to be largely driven by aortic aneurysm.

Human papillomavirus vaccination of adult women and risk of autoimmune and neurological diseases

BACKGROUND

Since 2006, human papillomavirus (HPV) vaccines have been introduced in many countries worldwide. Whilst safety studies have been reassuring, focus has been on the primary target group, the young adolescent girls. However, it is also important to evaluate safety in adult women where background disease rates and safety issues could differ significantly.

OBJECTIVE

We took advantage of the unique Danish and Swedish nationwide healthcare registers to conduct a cohort study comparing incidence rate ratios (RRs) of 45 preselected serious chronic diseases in quadrivalent HPV (qHPV)-vaccinated and qHPV-unvaccinated adult women 18-44 years of age.

METHODS

We used Poisson regression to estimate RRs according to qHPV vaccination status with two-sided 95% confidence intervals (95% CIs).

RESULTS

The study cohort comprised 3 126 790 women (1 195 865 [38%] Danish and 1 930 925 [62%] Swedish) followed for 16 386 459 person-years. Vaccine uptake of at least one dose of qHPV vaccine was 8% in the cohort: 18% amongst Danish women and 2% amongst Swedish. We identified seven adverse events with statistically significant increased risks following vaccination-Hashimoto's thyroiditis, coeliac disease, localized lupus erythematosus, pemphigus vulgaris, Addison's disease, Raynaud's disease and other encephalitis, myelitis or encephalomyelitis. After taking multiple testing into account and conducting self-controlled case series analyses, coeliac disease (RR 1.56 [95% confidence interval 1.29-1.89]) was the only remaining association.

CONCLUSION

Unmasking of conditions at vaccination visits is a plausible explanation for the increased risk associated with qHPV in this study because coeliac disease is underdiagnosed in Scandinavian populations. In conclusion, our study of serious adverse event rates in qHPV-vaccinated and qHPV-unvaccinated adult women 18-44 years of age did not raise any safety issues of concern.

Risk of major congenital malformations in relation to maternal overweight and obesity severity: cohort study of 1.2 million singletons

Objective To estimate the risks of major congenital malformations in the offspring of mothers who are underweight (body mass index (BMI) <18.5), overweight (BMI 25 to <30), or in obesity classes I (BMI 30 to <35), II (35 to <40), or III (≥40) compared with offspring of normal weight mothers (BMI 18.5 to <25) in early pregnancy.Design Population based cohort study.Setting Nationwide Swedish registries.Participants 1 243 957 liveborn singleton infants from 2001 to 2014 in Sweden. Data on maternal and pregnancy characteristics were obtained by individual record linkages.Exposure Maternal BMI at the first prenatal visit.Main outcome measures Offspring with any major congenital malformation, and subgroups of organ specific malformations diagnosed during the first year of life. Risk ratios were estimated using generalised linear models adjusted for maternal factors, sex of offspring, and birth year.Results A total of 43 550 (3.5%) offspring had any major congenital malformation, and the most common subgroup was for congenital heart defects (n=20 074; 1.6%). Compared with offspring of normal weight mothers (risk of malformations 3.4%), the proportions and adjusted risk ratios of any major congenital malformation among the offspring of mothers with higher BMI were: overweight, 3.5% and 1.05 (95% confidence interval 1.02 to 1.07); obesity class I, 3.8% and 1.12 (1.08 to 1.15), obesity class II, 4.2% and 1.23 (1.17 to 1.30), and obesity class III, 4.7% and 1.37 (1.26 to 1.49). The risks of congenital heart defects, malformations of the nervous system, and limb defects also progressively increased with BMI from overweight to obesity class III. The largest organ specific relative risks related to maternal overweight and increasing obesity were observed for malformations of the nervous system. Malformations of the genital and digestive systems were also increased in offspring of obese mothers.Conclusions Risks of any major congenital malformation and several subgroups of organ specific malformations progressively increased with maternal overweight and increasing severity of obesity. For women who are planning pregnancy, efforts should be encouraged to reduce adiposity in those with a BMI above the normal range.

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.).

Neuraminidase inhibitors during pregnancy and risk of adverse neonatal outcomes and congenital malformations: population based European register study

Objective To evaluate the possible effects of exposure to neuraminidase inhibitors during embryo-fetal life with respect to adverse neonatal outcomes and congenital malformations.Design Population based multinational observational cohort study and meta-analysis.Setting National registers covering information on maternal healthcare, births, and prescriptions in Denmark, Norway, and Sweden and the EFEMERIS database from the Haute-Garonne district in France.Participants All women together with their singleton infants born between 1 January 2008 and 31 December 2010. Only infants born at 154 days of gestation or later were included. Infants were defined as exposed if the women filled a prescription during pregnancy for either of the two neuraminidase inhibitors oseltamivir or zanamivir.Main outcomes Low birth weight, low Apgar score, preterm birth, small for gestational age birth, stillbirth, neonatal mortality, neonatal morbidity, and congenital malformations. Crude and adjusted hazard ratios of preterm birth were estimated using Cox regression models. Crude and adjusted odds ratios for other outcomes were estimated by logistic regression models.Results The study included 5824 (0.8%) exposed women and their infants and 692 232 who were not exposed. Exposure to neuraminidase inhibitors in utero was not associated with increased risks of any of the investigated neonatal outcomes, including low birth weight (adjusted odds ratio 0.77, 95% confidence interval 0.65 to 0.91), low Apgar score (adjusted odds ratio 0.87, 0.67 to 1.14), preterm birth (adjusted hazard ratio 0.97, 0.86 to 1.10), small for gestational age birth (adjusted odds ratio 0.72, 0.59 to 0.87), stillbirth (adjusted odds ratio 0.81, 0.51 to 1.30), neonatal mortality (adjusted odds ratio 1.13, 0.56 to 2.28), and neonatal morbidity (adjusted odds ratio 0.92, 0.86 to 1.00). No increased risk of congenital malformations overall associated with maternal exposure was observed during the first trimester (adjusted odds ratio 1.06, 0.77 to 1.48). Similarly, no significantly increased risks of any of the outcomes were observed in an analysis restricted to oseltamivir alone.Conclusions This large multinational register study found no increased risks of adverse neonatal outcomes or congenital malformations associated with exposure to neuraminidase inhibitors during embryo-fetal life. The results support previously reported findings that the use of neuraminidase inhibitors is not associated with increased risks of adverse fetal or neonatal outcomes.

Oral fluoroquinolone use and serious arrhythmia: bi-national cohort study

OBJECTIVE

To evaluate if oral fluoroquinolone use is associated with an increased risk of serious arrhythmia.

DESIGN

Bi-national cohort study, linking register data on filled prescriptions, cases of serious arrhythmia, and patient characteristics.

SETTING

Denmark, 1997-2011; Sweden, 2006-13.

PARTICIPANTS

The study cohort was derived from a source population of all Danish and Swedish adults, aged 40 to 79 years. 909,656 courses of fluoroquinolone use (ciprofloxacin 82.6%, norfloxacin 12.1%, ofloxacin 3.2%, moxifloxacin 1.2%, and other fluoroquinolones 0.9%) and 909,656 courses of penicillin V use, matched 1:1 on propensity score, were included.

MAIN OUTCOME MEASURE

The main outcome was risk of serious arrhythmia (fatal and non-fatal), comparing courses of fluoroquinolone use with courses of penicillin V use (an antibiotic with no pro-arrhythmic effect). The risk period of interest was current use, defined as days 0-7 of treatment. Subgroup analyses were conducted according to country, sex, age, underlying cardiovascular disease, concomitant use of drugs known to increase the risk of torsades de pointes, fluoroquinolone type, and levels of arrhythmia risk score.

RESULTS

144 cases of serious arrhythmia occurred during follow-up, 66 among current fluoroquinolone users (incidence rate 3.4 per 1000 person years) and 78 among current penicillin users (4.0 per 1000 person years); comparing oral fluoroquinolone treatment with penicillin V, the rate ratio was 0.85 (95% confidence interval 0.61 to 1.18). Compared with penicillin V, the absolute risk difference was -13 (95% confidence interval -35 to 16) cases of serious arrhythmia per 1,000,000 courses of fluoroquinolones. The risk of serious arrhythmia was not statistically significantly increased in any of the subgroups, including analyses by fluoroquinolone type.

CONCLUSIONS

Contrary to previous reports, oral fluoroquinolone treatment was not associated with an increased risk of serious arrhythmia in the general adult populations of Denmark and Sweden. Given the statistical power of the study, even small increases in relative and absolute risk could be ruled out. Since ciprofloxacin was the most commonly used fluoroquinolone in our study, we cannot exclude that intraclass differences influence the risk of serious arrhythmia associated with other less frequently used fluoroquinolones.

Maternal use of oral contraceptives and risk of birth defects in Denmark: prospective, nationwide cohort study

STUDY QUESTION

Is oral contraceptive use around the time of pregnancy onset associated with an increased risk of major birth defects?

METHODS

In a prospective observational cohort study, data on oral contraceptive use and major birth defects were collected among 880,694 live births from Danish registries between 1997 and 2011. We conservatively assumed that oral contraceptive exposure lasted up to the most recently filled prescription. The main outcome measure was the number of major birth defects throughout one year follow-up (defined according to the European Surveillance of Congenital Anomalies classification). Logistic regression estimated prevalence odds ratios of any major birth defect as well as categories of birth defect subgroups.

STUDY ANSWER AND LIMITATIONS

Prevalence of major birth defects (per 1000 births) was consistent across each oral contraceptive exposure group (25.1, never users; 25.0, use >3 months before pregnancy onset (reference group); 24.9, use 0-3 months before pregnancy onset (that is, recent use); 24.8, use after pregnancy onset). No increase in prevalence of major birth defects was seen with oral contraceptive exposure among women with recent use before pregnancy (prevalence odds ratio 0.98 (95% confidence interval 0.93 to 1.03)) or use after pregnancy onset (0.95 (0.84 to 1.08)), compared with the reference group. There was also no increase in prevalence of any birth defect subgroup (for example, limb defects). It is unknown whether women took oral contraceptives up to the date of their most recently filled prescription. Also, the rarity of birth defects made disaggregation of the results difficult. Residual confounding was possible, and the analysis lacked information on folate, one of the proposed mechanisms.

WHAT THIS STUDY ADDS

Oral contraceptive exposure just before or during pregnancy does not appear to be associated with an increased risk of major birth defects.

FUNDING, COMPETING INTERESTS, DATA SHARING

BMC was funded by the Harvard T H Chan School of Public Health's Maternal Health Task Force and Department of Epidemiology Rose Traveling Fellowship; training grant T32HD060454 in reproductive, perinatal, and paediatric epidemiology and award F32HD084000 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development; and grant T32CA09001 from the National Cancer Institute. The authors have no competing interests or additional data to share.