Fifteen-year temporal changes in rates of acute kidney injury among children in Denmark

BACKGROUND

We aimed to examine temporal changes in the annual rate of acute kidney injury (AKI) in Danish children and associated changes in patient characteristics including potential underlying risk factors.

METHODS

In this population-based cohort study, we used plasma creatinine measurements from Danish laboratory databases to identify AKI episodes in children aged 0-17 years from 2007 to 2021. For each child, the first AKI episode per calendar year was included. We estimated the annual crude and sex- and age-standardized AKI rate as the number of children with an AKI episode divided by the total number of children as reported by census numbers. Using Danish medical databases, we assessed patient characteristics including potential risk factors for AKI, such as use of nephrotoxic medication, surgery, sepsis, and perinatal factors.

RESULTS

In total, 14,200 children contributed with 16,345 AKI episodes over 15 years. The mean annual AKI rate was 148 (95% CI: 141-155) per 100,000 children. From 2007 to 2021, the annual AKI rate demonstrated minor year-to-year variability without any discernible overall trend. The highest AKI rate was recorded in 2007 at 174 (95% CI: 161-187) per 100,000 children, while the lowest rate occurred in 2012 at 129 (95% CI: 118-140) per 100,000 children. In 2021, the AKI rate was 148 (95% CI: 141-155) per 100,000 children. Characteristics of children with AKI were similar throughout the study period.

CONCLUSION

The rate of AKI among Danish children was stable from 2007 to 2021 with little variation in patient characteristics over time.

Predicting the risks of kidney failure and death in adults with moderate to severe chronic kidney disease: multinational, longitudinal, population based, cohort study

OBJECTIVE

To train and test a super learner strategy for risk prediction of kidney failure and mortality in people with incident moderate to severe chronic kidney disease (stage G3b to G4).

DESIGN

Multinational, longitudinal, population based, cohort study.

SETTINGS

Linked population health data from Canada (training and temporal testing), and Denmark and Scotland (geographical testing).

PARTICIPANTS

People with newly recorded chronic kidney disease at stage G3b-G4, estimated glomerular filtration rate (eGFR) 15-44 mL/min/1.73 m2.

MODELLING

The super learner algorithm selected the best performing regression models or machine learning algorithms (learners) based on their ability to predict kidney failure and mortality with minimised cross-validated prediction error (Brier score, the lower the better). Prespecified learners included age, sex, eGFR, albuminuria, with or without diabetes, and cardiovascular disease. The index of prediction accuracy, a measure of calibration and discrimination calculated from the Brier score (the higher the better) was used to compare KDpredict with the benchmark, kidney failure risk equation, which does not account for the competing risk of death, and to evaluate the performance of KDpredict mortality models.

RESULTS

67 942 Canadians, 17 528 Danish, and 7740 Scottish residents with chronic kidney disease at stage G3b to G4 were included (median age 77-80 years; median eGFR 39 mL/min/1.73 m2). Median follow-up times were five to six years in all cohorts. Rates were 0.8-1.1 per 100 person years for kidney failure and 10-12 per 100 person years for death. KDpredict was more accurate than kidney failure risk equation in prediction of kidney failure risk: five year index of prediction accuracy 27.8% (95% confidence interval 25.2% to 30.6%) versus 18.1% (15.7% to 20.4%) in Denmark and 30.5% (27.8% to 33.5%) versus 14.2% (12.0% to 16.5%) in Scotland. Predictions from kidney failure risk equation and KDpredict differed substantially, potentially leading to diverging treatment decisions. An 80-year-old man with an eGFR of 30 mL/min/1.73 m2 and an albumin-to-creatinine ratio of 100 mg/g (11 mg/mmol) would receive a five year kidney failure risk prediction of 10% from kidney failure risk equation (above the current nephrology referral threshold of 5%). The same man would receive five year risk predictions of 2% for kidney failure and 57% for mortality from KDpredict. Individual risk predictions from KDpredict with four or six variables were accurate for both outcomes. The KDpredict models retrained using older data provided accurate predictions when tested in temporally distinct, more recent data.

CONCLUSIONS

KDpredict could be incorporated into electronic medical records or accessed online to accurately predict the risks of kidney failure and death in people with moderate to severe CKD. The KDpredict learning strategy is designed to be adapted to local needs and regularly revised over time to account for changes in the underlying health system and care processes.

Acute Kidney Injury Duration and 20-Year Risks of CKD and Cardiovascular Disease

Introduction

Acute kidney injury (AKI) is associated with chronic kidney disease (CKD) and cardiovascular disease (CVD); however, it is unclear whether AKI duration affects the long-term risks of CKD and CVD. Therefore, we performed a population-based cohort study examining the associations between AKI duration and CKD and CVD.

Methods

We identified patients with laboratory-recorded AKI in Denmark from 1990 through 2018. AKIs were categorized as rapid reversal AKI (≤48 hours), persistent AKI (2-7 days), and acute kidney disease (AKD) (>7 days). We estimated 20-year risks and adjusted hazard ratios (aHRs) of incident CKD and CVD.

Results

The study comprised 169,582 patients with AKI, with 100,478 and 76,838 included in the analysis of CKD and CVD, respectively. The 20-year risks of CKD were 26.3%, 29.5%, and 28.7% for rapid reversal AKI, persistent AKI, and AKD, respectively. Compared with rapid reversal AKI, aHRs were 1.13 (95% confidence interval [CI], 1.08-1.19) for persistent AKI and 1.36 (95% CI, 1.30-1.41) for AKD. Risks and rates of overall CVD were similar for rapid reversal AKI, persistent AKI, and AKD. However, persistent AKI was associated with a slightly increased aHR of heart failure (1.09; 95% CI, 1.02-1.16), and aHRs of heart failure, ischemic heart disease, and peripheral artery disease were slightly increased for AKD (1.09 [95% CI, 1.03-1.15], 1.11 [95% CI, 1.03-1.19], and 1.10 [95% CI, 1.02-1.17], respectively).

Conclusion

AKI duration was associated with development of CKD, but not overall CVD; however, rates of heart failure, ischemic heart disease, and peripheral artery disease increased slightly with AKI duration.

Proton pump inhibitors and the risk of acute kidney injury in cancer patients receiving immune checkpoint inhibitors: A Danish population-based cohort study

Previous studies have suggested that the use of proton pump inhibitors (PPIs) more than doubles the risk of acute kidney injury (AKI) in cancer patients receiving immune checkpoint inhibitors (ICIs). However, this association may be confounded. Therefore, we conducted a register-based cohort study to examine the risk of AKI in users and nonusers of PPIs among cancer patients treated with ICIs in Denmark from 2011 through 2021 while accounting for a comprehensive range of potential confounders. PPI use was determined based on redeemed prescriptions of PPIs before ICI initiation. We identified laboratory-recorded AKI events within the first year after ICI initiation. We estimated the risks and hazard ratios (HRs) of AKI while accounting for a comprehensive range of confounders (including comorbidities and comedication) by propensity score weighting. Furthermore, we performed an additional per-protocol analysis while accounting for informative censoring by weighting. We identified 10 200 cancer patients including 2749 (27%) users, 6214 (61%) nonusers, and 1237 (12%) former users of PPIs. PPI users had an increased risk of AKI compared to nonusers (1-year risk, 24.7% vs 19.9%; HR, 1.42 [95% confidence interval (CI), 1.29-1.56]); however, this association attenuated when accounting for confounders (weighted 1-year risk, 24.2% vs 23.8%; weighted HR, 1.06 [95% CI, 0.93-1.21]). In the per-protocol analysis, the crude HR was 1.86 (95% CI, 1.63-2.12), while the weighted HR was 1.24 (95% CI, 1.03-1.49). Thus, the association between PPI use and AKI could largely be explained by confounding, suggesting that previous studies may have overestimated the association.

Recovery of kidney function after acute kidney disease-a multi-cohort analysis

BACKGROUND

There are no consensus definitions for evaluating kidney function recovery after acute kidney injury (AKI) and acute kidney disease (AKD), nor is it clear how recovery varies across populations and clinical subsets. We present a federated analysis of four population-based cohorts from Canada, Denmark and Scotland, 2011-18.

METHODS

We identified incident AKD defined by serum creatinine changes within 48 h, 7 days and 90 days based on KDIGO AKI and AKD criteria. Separately, we applied changes up to 365 days to address widely used e-alert implementations that extend beyond the KDIGO AKI and AKD timeframes. Kidney recovery was based on resolution of AKD and a subsequent creatinine measurement below 1.2× baseline. We evaluated transitions between non-recovery, recovery and death up to 1 year; within age, sex and comorbidity subgroups; between subset AKD definitions; and across cohorts.

RESULTS

There were 464 868 incident cases, median age 67-75 years. At 1 year, results were consistent across cohorts, with pooled mortalities for creatinine changes within 48 h, 7 days, 90 days and 365 days (and 95% confidence interval) of 40% (34%-45%), 40% (34%-46%), 37% (31%-42%) and 22% (16%-29%) respectively, and non-recovery of kidney function of 19% (15%-23%), 30% (24%-35%), 25% (21%-29%) and 37% (30%-43%), respectively. Recovery by 14 and 90 days was frequently not sustained at 1 year. Older males and those with heart failure or cancer were more likely to die than to experience sustained non-recovery, whereas the converse was true for younger females and those with diabetes.

CONCLUSION

Consistently across multiple cohorts, based on 1-year mortality and non-recovery, KDIGO AKD (up to 90 days) is at least prognostically similar to KDIGO AKI (7 days), and covers more people. Outcomes associated with AKD vary by age, sex and comorbidities such that older males are more likely to die, and younger females are less likely to recover.

Effect of surgery versus chemotherapy in pancreatic cancer patients: a target trial emulation

PURPOSE

To estimate the causal effect of surgery vs chemotherapy on survival in patients with T1-3NxM0 pancreatic cancer in a rigorous framework addressing selection bias and immortal time bias.

METHODS

We used population-based Danish healthcare registries to conduct a cohort study emulating a hypothetical randomized trial to estimate the absolute difference in survival, comparing surgery with chemotherapy. We included pancreatic cancer patients diagnosed during 2008-2021. Exposure was surgery or chemotherapy initiated within a 16-week grace period after diagnosis. At the time of diagnosis, data of each patient was duplicated; one copy was assigned to the surgery protocol and one copy to the chemotherapy protocol of the hypothetical trial. Copies were censored when the assigned treatment deviated from the observed treatment. To account for informative censoring, uncensored patients were weighted according to confounders. For comparison, we also applied a more conventional analysis using propensity score-based inverse probability weighting.

RESULTS

We included 1,744 patients with a median age of 68 years; 73.6% underwent surgery and 18.6% had chemotherapy without surgery. 7.8% received no treatment. The 3-year survival was 39.7% (95% CI 36.7% to 42.6%) after surgery and 22.7% (95% CI: 17.7% to 28.4%) after chemotherapy, corresponding to an absolute difference of 17.0% (95% CI: 10.8% to 23.1%). In the conventional survival analysis, this difference was 23.0% (95% CI: 17.0% to 29.0%).

CONCLUSION

Surgery was superior to chemotherapy in achieving long-term survival for pancreatic cancer. The difference comparing surgery and chemotherapy was substantially smaller when using the clone-censor-weight approach than conventional survival analysis.

Risk factor analysis for a rapid progression of chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a growing global health concern. Identifying individuals in routine clinical care with new onset CKD at high risk of rapid progression of the disease is imperative to guide allocation of prophylactic interventions, but community-based data are limited. We aimed to examine the risk of rapid progression, kidney failure, hospitalisation and death among adults with incident CKD stage G3 and to clarify the association between predefined risk markers and rapid CKD progression.

METHODS

Using plasma creatinine measurements for the entire Danish population from both hospitals and primary care, we conducted a nationwide, population-based cohort study, including adults in Denmark with incident CKD stage G3 in 2017-2020. We estimated 3-year risks of rapid progression (defined by a confirmed decline in estimated glomerular filtration rate of ≥5 ml/min/1.73 m2/year), kidney failure, all-cause hospitalisation and death. To examine risk markers, we constructed a heat map showing the risk of rapid progression based on predefined markers: albuminuria, sex, diabetes and hypertension/cardiovascular disease.

RESULTS

Among 133 443 individuals with incident CKD stage G3, the 3-year risk of rapid progression was 14.6% (95% confidence interval (CI): 14.4-14.8). The 3-year risks of kidney failure, hospitalisation and death were 0.3% (95% CI: 0.3-0.4), 53.3% (95% CI: 53.0-53.6) and 18.1% (95% CI: 17.9-18.4), respectively. In the heat map, the 3-year risk of rapid progression ranged from 7% in females without albuminuria, hypertension/cardiovascular disease or diabetes, to 46-47% in males and females with severe albuminuria, hypertension/cardiovascular disease and diabetes.

CONCLUSION

This population-based study shows that CKD stage G3 is associated with considerable morbidity in a community-based setting and underscores the need for optimised prophylactic interventions among such patients. Moreover, our data highlight the potential of using easily accessible markers in routine clinical care to identify individuals who are at high risk of rapid progression.

Oral anticoagulant treatment and risk of kidney disease-a nationwide, population-based cohort study

Background

Direct oral anticoagulants (DOACs) are recommended as first-line treatment of atrial fibrillation. Whether DOAC use is associated with lower risks of kidney complications compared with vitamin K antagonists (VKAs) remains unclear. We examined this association in a nationwide, population-based cohort study.

Methods

We conducted a cohort study including patients initiating oral anticoagulant treatment within 3 months after an atrial fibrillation diagnosis in Denmark during 2012-18. Using routinely collected creatinine measurements from laboratory databases, we followed patients in an intention-to-treat approach for acute kidney injury (AKI) and chronic kidney disease (CKD) progression. We used propensity-score weighting to balance baseline confounders, computed weighted risks and weighted hazard ratios (HRs) with 95% confidence intervals (CIs) comparing DOACs with VKAs. We performed several subgroup analyses and a per-protocol analysis.

Results

We included 32 781 persons with atrial fibrillation initiating oral anticoagulation (77% initiating DOACs). The median age was 75 years, 25% had a baseline estimated glomerular filtration rate <60 mL/min/1.73 m2, and median follow-up was 2.3 (interquartile range 1.1-3.9) years. The weighted 1-year risks of AKI were 13.6% in DOAC users and 15.0% in VKA users (HR 0.86, 95% CI 0.82; 0.91). The weighted 5-year risks of CKD progression were 13.9% in DOAC users and 15.4% in VKA users (HR 0.85, 95% CI 0.79; 0.92). Results were similar across subgroups and in the per-protocol analysis.

Conclusions

Initiation of DOACs was associated with a decreased risk of AKI and CKD progression compared with VKAs. Despite the potential limitations of observational studies, our findings support the need for increased clinical awareness to prevent kidney complications among patients who initiate oral anticoagulants.

Regional variation in incidence and prognosis of acute kidney injury

BACKGROUND

Examining regional variation in acute kidney injury (AKI) and associated outcomes may reveal inequalities and possibilities for optimization of the quality of care. Using the Danish medical databases, we examined regional variation in the incidence, follow-up, and prognosis of AKI in Denmark.

METHODS

Patients with one or more AKI episodes in 2017 were identified using population-based creatinine measurements covering all Danish residents. Crude and sex-and-age-standardized incidence rates of AKI were estimated using census statistics for each municipality. Adjusted hazard ratios (aHR) of chronic kidney disease (CKD), all-cause death, biochemical follow-up, and outpatient contact with a nephrology department after AKI were estimated across geographical regions and categories of municipalities, accounting for differences in demographics, comorbidities, medication use, lifestyle and social factors, and baseline kidney function.

RESULTS

We identified 63 382 AKI episodes in 58 356 adults in 2017. The regional standardized AKI incidence rates ranged from 12.9 to 14.9 per 1 000 person-years. Compared with the Capital Region of Denmark, the aHRs across regions ranged from 1.04 to 1.25 for CKD, from 0.97 to 1.04 for all-cause death, from 1.09 to 1.15 for biochemical follow-up, and from 1.08 to 1.49 for outpatient contact with a nephrology department after AKI. Similar variations were found across municipality categories.

CONCLUSIONS

Within the uniform Danish healthcare system, we found modest regional variation in AKI incidence. The mortality after AKI was similar; however, CKD, biochemical follow-up, and nephrology follow-up after AKI varied across regions and municipality categories.

Performance of the race-free CKD-EPI creatinine-based eGFR equation in a Danish cohort with measured GFR

Background

In 2021, an updated Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for estimated glomerular filtration rate (eGFR) without a coefficient for race (CKD-EPI21) was developed. The performance of this new equation has yet to be examined among specific patient groups.

Methods

We compared the performances of the new CKD-EPI21 equation and the 2009 equation assuming non-Black race (CKD-EPI09-NB) in patients with GFR measured by chromium-51-EDTA plasma clearance at Aarhus University Hospital in Denmark during 2010-18. We examined bias, accuracy, precision and correct classification of chronic kidney disease (CKD) stage using chromium-51-EDTA clearance as the reference standard. We assessed the performance in the total cohort, cancer patients and potential living kidney donors. We also assessed the performance stratified by CKD stage in the total cohort.

Results

In this predominantly white population, the CKD-EPI21 equation performed slightly better than the CKD-EPI09-NB equation in both the total cohort (N = 4668), and in cancer patients (N = 3313) and potential living kidney donors (N = 239). In the total cohort, the CKD-EPI21 equation demonstrated a slightly lower median absolute bias (-0.2 versus -4.4 mL/min/1.73 m2), and a similar accuracy, precision and correct classification of CKD stage compared with the CKD-EPI09-NB equation. When stratified by CKD stage, the CKD-EPI09-NB equation performed slightly better than the CKD-EPI21 equation among patients with a measured GFR (mGFR) <60 mL/min/1.73 m2.

Conclusions

In a selected cohort of Danish patients with mGFR, the CKD-EPI21 equation performed slightly better than the CKD-EPI09-NB equation except for patients with a mGFR <60 mL/min/1.73 m2, where CKD-EPI09-NB performed slightly better although the differences were considered clinically insignificant.

Ten-year trends in incidence and prevalence of atrial fibrillation and flutter in Denmark according to demographics, ethnicity, educational level, and area of residence (2009-2018)

BACKGROUND

Atrial fibrillation is the most common cardiac arrhythmia and a major global health burden. Updated trends in the epidemiology of atrial fibrillation or flutter (AF) are needed.

METHODS

Using the Danish Heart Statistics, we investigated nationwide trends 2009-2018 in incidence rate and prevalence of AF according to age as well as age-standardized incidence rate (ASIR) and prevalence (ASP) of AF according to sex, ethnicity, educational level, and area of residence. Comparing year 2018 to 2009, we calculated stratum-specific ASIR ratios (ASIRR) and changes in ASP.

RESULTS

During 2009-2015 the ASIR for AF increased for both men and women, followed by a decline from 2015-2018. Overall, this resulted in a 9% increase among men (ASIRR: 1.09, 95% CI: 1.06-1.12), but no change among women (ASIRR: 1.00, 95% CI: 0.97-1.04). The ASP increased by 29% among men and 26% among women. An increase in ASIR was observed in all ethnic groups except men of Far Eastern ethnicity. Lower educational level was associated with greater increases in both ASIR and ASP. ASIR and ASP differed slightly between the Danish regions but increased in all of them.

CONCLUSIONS

During 2009-2018 the incidence and prevalence of AF in Denmark increased although the increase in incidence was transient among women. Factors associated with higher incidence were male sex, higher age, Danish and Western ethnicity as well as Middle Eastern/North African ethnicity among women, and lower educational level. Within Denmark, we observed only minor regional differences in AF incidence and prevalence.

Prenatal, Intrapartum, and Neonatal Factors Increase the Risk of Eosinophilic Esophagitis

INTRODUCTION

Early-life exposures have been associated with an increased risk of eosinophilic esophagitis (EoE); however, most studies to date have been conducted at referral centers and are subject to recall bias. By contrast, we conducted a nationwide, population-based and registry-based case-control study of prenatal, intrapartum, and neonatal exposures, using data collected prospectively through population-based Danish health and administrative registries.

METHODS

We ascertained all EoE cases in Denmark (birth years 1997-2018). Cases were sex and age matched to controls (1:10) using risk-set sampling. We obtained data on prenatal, intrapartum, and neonatal factors, i.e., pregnancy complications, mode of delivery, gestational age at delivery, birthweight (expressed as a z-score), and neonatal intensive care unit (NICU) admission. We used conditional logistic regression to compute the crude and adjusted odds ratios (aOR) of EoE in relation to each prenatal, intrapartum, and neonatal factor, thus providing an estimate of incidence density ratios with 95% confidence intervals (CI).

RESULTS

In the 393 cases and 3,659 population controls included (median age at index date, 11 years [interquartile range, 6-15]; 69% male), we observed an association between gestational age and EoE, peaking at 33 vs 40 weeks (aOR 3.6 [95% CI 1.8-7.4]), and between NICU admission and EoE (aOR 2.8 [95% CI 1.2-6.6], for a NICU hospitalization of 2-3 weeks vs no admission). In interaction analyses, we observed a stronger association between NICU admission and EoE in infants born at term than in preterm infants (aOR 2.0 [95% CI 1.4-2.9] for term infants and aOR 1.0 [95% CI 0.5-2.0] for preterm infants). We also observed an association between pregnancy complications and EoE (aOR 1.4 [95% CI 1.0-1.9]). Infants who were very growth restricted at birth had an increased rate of EoE (aOR 1.4 [95% CI: 1.0-1.9] for a z-score of -1.5 vs a z-score of 0). Mode of delivery was not associated with EoE.

DISCUSSION

Prenatal, intrapartum, and neonatal factors, particularly preterm birth and NICU admission, were associated with development of EoE. Further research is needed to elucidate the mechanisms underlying the observed associations.

Ability of the DANCAMI to predict the risk ischemic stroke and mortality in patients with atrial fibrillation/flutter

OBJECTIVES

Comparison of the danish comorbidity index for acute myocardial infarction (DANCAMI), the charlson comorbidity index (CCI), the elixhauser comorbidity index (ECI), and the CHA2DS2-VASc score to predict ischemic stroke, cardiovascular mortality, and all-cause mortality after atrial fibrillation/flutter.

MATERIALS AND METHODS

A population-based cohort study of all Danish patients with incident atrial fibrillation/flutter during 2000-2020 (n=361,901). C-Statistics were used to evaluate the discriminatory performance for predicting 1 and 5-year risks of the outcomes for a baseline model (including age and sex) +/- the individual indices.

RESULTS

For the DANCAMI, the 5-year risk did not increase with comorbidity burden for ischemic stroke (5.9% for low vs. 5.6% for severe) but did increase for cardiovascular mortality (10% for low vs. 16% for severe) and all-cause mortality (33% for low vs. 61% for severe). C-Statistics for predicting 5-year ischemic stroke risk were similar for all models (0.64). C-Statistics for predicting 5-year cardiovascular mortality risk were also similar for the baseline (0.76), the DANCAMI (0.77), the CCI (0.76), the ECI (0.76), and the CHA2DS2-VASc (0.76) models. C-Statistics for predicting 5-year all-cause mortality risk were lower for the baseline (0.71) and the CHA2DS2-VASc (0.71) models than for the DANCAMI (0.75), the CCI (0.74), and the ECI (0.74) models. The 1-year C-Statistics were comparable.

CONCLUSION

The DANCAMI predicted ischemic stroke and cardiovascular mortality risks similar to the CCI, the ECI, and the CHA2DS2-VASc. The DANCAMI predicted all-cause mortality risk similar to the CCI and the ECI, but better than the baseline and the CHA2DS2-VASc.

Long-term risk of benign prostatic hyperplasia-related surgery and acute urinary retention in men treated with 5-alpha reductase inhibitor versus alpha-blocker monotherapy in routine clinical care

OBJECTIVES

To assess the risk of benign prostatic hyperplasia (BPH)-related surgery and acute urinary retention (AUR) in men treated with 5-alpha-reductase inhibitor (5-ARI) versus alpha-blocker monotherapy in routine clinical care over 15 years of follow-up.

METHODS

Using population-based Danish Health registries, we identified all new-users of 5-ARI or alpha-blocker monotherapy in Denmark, 1997-2017. We defined an index date 180 days after the date of first prescription and included men who redeemed at least one additional prescription before the index date. We used multiple imputation to replace missing prostate-specific antigen values. We performed propensity score-weighted Cox regression to estimate weighted hazard ratios (wHRs) and cumulative incidence function to estimate weighted cumulative risks of BPH-related surgery and AUR in intention to treat (ITT) and per protocol (PP) analyses.

RESULTS

We included 18,421 and 95,984 men treated with 5-ARI and alpha-blocker monotherapy, respectively. Overall, treatment with 5-ARI monotherapy was associated with a reduced risk of BPH-related surgery (ITT wHR = 0.73 (95% confidence interval [CI]: 0.68-0.78), PP wHR = 0.77 (95% CI: 0.70-0.84) and AUR (ITT wHR = 0.73 (95% CI: 0.67-0.78), PP wHR = 0.75 (95% CI: 0.66-0.84). The 15-year risk of BPH-related surgery in men treated with 5-ARI versus alpha-blocker monotherapy was 14.8% (95% CI: 14.1%-15.5%) versus 19.1% (95% CI: 18.7%-19.5%) in the ITT analysis and 13.8% (95% CI: 12.6%-14.9%) versus 17.5% (95% CI: 16.9%-18.0%) in the PP analysis. The 15-year risk of AUR in men treated with 5-ARI versus alpha-blocker was 13.0% (95% CI: 12.3%-13.6%) versus 16.6% (95% CI: 16.3%-17.0%) in the ITT analysis and 12.6% (95%: 11.3%-14.0%) versus 16.9% (95% CI: 16.3%-17.6%) in the PP analysis.

CONCLUSION

Treatment with 5-ARI versus alpha-blocker monotherapy in routine clinical care was associated with a reduced risk of BPH-related surgery and AUR for up to 15 years of follow-up. After 15 years of follow-up, the relative risk reduction was 21%-25% and the absolute risk reduction was 4%.

Epidemiology of male osteoporosis in Denmark (1996-2018)

Osteoporosis in men may be underdiagnosed. One in four men in Denmark will develop osteoporosis after age of 50 years, with fracture as a common presenting symptom.

PURPOSE

The aim of this study was to describe epidemiology of male osteoporosis in Denmark.

METHODS

In this nationwide registry-based cohort study, we identified men with osteoporosis, 50 years or older, residing in Denmark, during the years 1996-2018. Osteoporosis was defined as one of the following: a hospital diagnosis of osteoporosis; a hospital diagnosis of osteoporosis fracture; or an outpatient dispensing of an anti-osteoporosis medication. We reported annual incidence and prevalence and described the distribution of fractures, comorbidities, socioeconomic status, and initiation of anti-osteoporosis therapy among men with osteoporosis. Selected characteristics were also described among men without osteoporosis of similar age.

RESULTS

There were 171,186 men fulfilling the study criteria for osteoporosis. The overall age-standardized incidence rate of osteoporosis was 8.6 per 1000 person-years (95% confidence interval (CI), 8.5-8.6), varying between 7.7 and 9.7, while the prevalence increased from 4.3% (95% CI, 4.2-4.3) to 7.1% (95% CI, 7.0-7.1) during the 22-year period. The remaining-lifetime risk of developing osteoporosis after age of 50 years was close to 30%. The proportion of men initiating anti-osteoporosis treatment within 1 year of diagnosis increased from 6.9% to 29.8%. Men with osteoporosis had more comorbidities and redeemed more medication than did men without osteoporosis of similar age.

CONCLUSION

Osteoporosis among men may be undertreated despite increasing treatment initiation.

Acute urinary retention in men: 21-year trends in incidence, subsequent benign prostatic hyperplasia-related treatment and mortality: A Danish population-based cohort study

OBJECTIVE

To examine trends in incidence of acute urinary retention, subsequent benign prostatic hyperplasia-related treatment and mortality in the era of medical therapy for benign prostatic hyperplasia. Additionally, to compare mortality with the general population.

MATERIALS AND METHODS

We conducted a Danish nationwide registry-based study including 70,775 men aged 45 years or older with a first hospitalization for acute urinary retention during 1997-2017. We computed annual standardized incidence rates, subsequent 1-year cumulative incidence of benign prostatic hyperplasia-related surgical and medical treatment, and standardized 3-month and 1-year mortality rates. Finally, we compared standardized all-cause and cause-specific mortality ratios with the general population.

RESULTS

The standardized incidence rate of acute urinary retention per 1000 person-years increased transiently from 2.34 to 3.42 during 1997-2004, but gradually declined to 2.95 in 2017. The 1-year cumulative incidence of benign prostatic hyperplasia-related surgery declined from 31.2% to 19.8% and 20.5% to 7.7% after spontaneous and precipitated acute urinary retention, respectively. During 1997-2017, the standardized 1-year mortality declined from 22.2% to 17.2%. Compared with the general population, mortality was 4-5 times higher after 3 months and 2-3 times higher after 1 year of acute urinary retention. The cause-specific standardized mortality ratios were particularly high for deaths attributable to malignancies, urogenital disease, certain infections, chronic pulmonary disease, and diabetes.

CONCLUSION

During 1997-2017, we observed a transient increase in the incidence of acute urinary retention. The subsequent use of benign prostatic hyperplasia-related surgery declined considerably and mortality continued to be high, mainly because of deaths from malignancies, urogenital disease, infections, and preexisting comorbidity.

Defining measures of kidney function in observational studies using routine health care data: methodological and reporting considerations

The availability of electronic health records and access to a large number of routine measurements of serum creatinine and urinary albumin enhance the possibilities for epidemiologic research in kidney disease. However, the frequency of health care use and laboratory testing is determined by health status and indication, imposing certain challenges when identifying patients with kidney injury or disease, when using markers of kidney function as covariates, or when evaluating kidney outcomes. Depending on the specific research question, this may influence the interpretation, generalizability, and/or validity of study results. This review illustrates the heterogeneity of working definitions of kidney disease in the scientific literature and discusses advantages and limitations of the most commonly used approaches using 3 examples. We summarize ways to identify and overcome possible biases and conclude by proposing a framework for reporting definitions of exposures and outcomes in studies of kidney disease using routinely collected health care data.

Routine Clinical Care Creatinine Data in Denmark - An Epidemiological Resource for Nationwide Population-Based Studies of Kidney Disease

PURPOSE

Creatinine data are key in identifying acute and chronic kidney disease. In Denmark, routine clinical care creatinine data have been collected regionally in the Clinical Laboratory Information System Research Database (LABKA) since the 1990s and nationwide in the Register of Laboratory Results for Research (RLRR) since 2013. Here we describe the geographical coverage of the databases and characteristics of Danish individuals with creatinine tests. This information is pivotal for the design and interpretation of studies using these data to examine kidney disease epidemiology.

PATIENTS AND METHODS

We included all creatinine tests in LABKA and RLRR from 1990 through 2018. The daily number of creatinine tests by municipality and region of residence were plotted and geographical coverage was ascertained. In addition, we characterized a contemporary cohort of creatinine-tested individuals in 2016-2018.

RESULTS

During 1990-2018, 61,011,941 creatinine tests were available for 4,647,966 unique Danish residents. The North Denmark Region was the first region to achieve complete reporting in November 2004, and nationwide reporting was complete starting in October 2015. In each year from 2016 to 2018, more than a third of Danish residents had a recorded creatinine measurement, with the highest proportion of tested individuals aged 77-87 years and the lowest proportion aged 3-5 years. During 2016-2018, the creatinine-tested cohort had a median age of 53 years (IQR, 35-67 years) and included 54.3% women. The most common comorbidity was a hospital-based diagnosis of hypertension (12.0%), and the most common prescription drug was angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (15.8%).

CONCLUSION

In combination, the population-based LABKA and RLRR databases provide regional creatinine data with long follow-up and nationwide data for the Danish population. There was considerable variation in the time of complete geographical coverage by region, which needs to be considered when using these data for studies on kidney disease epidemiology.

Kidney function before and after acute kidney injury: a nationwide population-based cohort study

Background

Acute kidney injury (AKI) is a common and serious condition defined by a rapid decline in kidney function. Data on changes in long-term kidney function following AKI are sparse and conflicting. Therefore, we examined the changes in estimated glomerular filtration rate (eGFR) from before to after AKI in a nationwide population-based setting.

Methods

Using Danish laboratory databases, we identified individuals with first-time AKI defined by an acute increase in plasma creatinine (pCr) during 2010 to 2017. Individuals with three or more outpatient pCr measurements before and after AKI were included and cohorts were stratified by baseline eGFR (≥/<60 mL/min/1.73 m²). Linear regression models were used to estimate and compare individual eGFR slopes and eGFR levels before and after AKI.

Results

Among individuals with a baseline eGFR ≥60 mL/min/1.73 m² (n = 64 805), first-time AKI was associated with a median difference in eGFR level of -5.6 mL/min/1.73 m² [interquartile range (IQR) -16.1 to 1.8] and a median difference in eGFR slope of -0.4 mL/min/1.73 m²/year (IQR -5.5 to 4.4). Correspondingly, among individuals with a baseline eGFR <60 mL/min/1.73 m² (n = 33 267), first-time AKI was associated with a median difference in eGFR level of -2.2 mL/min/1.73 m² (IQR -9.2 to 4.3) and a median difference in eGFR slope of 1.5 mL/min/1.73 m²/year (IQR -2.9 to 6.5).

Conclusion

Among individuals with first-time AKI surviving to have repeated outpatient pCr measurements, AKI was associated with changes in eGFR level and eGFR slope for which the magnitude and direction depended on baseline eGFR.

Postoperative complications, mortality, and quality of in-hospital care among hip fracture patients with Parkinson's disease

AIM

The aim of this study was to investigate the association between Parkinson's disease (PD) and postoperative complications, mortality, and quality of in-hospital care in patients with hip fracture.

METHODS

We included patients aged 65+ years with an incident hip fracture from 2004-2017, registered in the Danish Multidisciplinary Hip Fracture Registry. Patients with PD were identified using diagnosis codes prior to hip fracture. Using log-binomial regression, we calculated both 30-day crude and adjusted risk ratios (aRR) with 95% confidence intervals (CIs) for the following outcomes: any hospital-treated infections, pneumonia, urinary tract infection, sepsis, community-treated infections, cardiovascular events, mortality, and fulfilment of quality indicators of in-hospital care. Analyses were adjusted for age, sex and Charlson comorbidity index score.

RESULTS

We identified 77,550 hip fracture patients of which 1,915 had PD. Compared to non-PD, patients with PD had higher risk of any hospital-treated - (aRR = 1.27 (CI: 1.10-1.45) and community-treated infection (aRR = 1.22 (CI: 1.13-1.32)), pneumonia (aRR = 1.38 (1.11-1.69)), urinary tract infection (aRR of 1.58 (CI: 1.28-1.92)) and sepsis (aRR = 1.18 (CI: 0.67-1.89)), but a reduced risk of cardiovascular events (aRR = 0.59 (CI: 0.41-0.82)). The aRR for 30-day mortality was 1.11 (CI: 0.97-1.27) for PD vs non-PD patients, and the aHR for 1-year mortality was 1.19 (CI: 1.09-1.30). The aRRs for fulfillment of all relevant quality indicators was about 1 for PD vs non-PD patients.

CONCLUSION

Hip fracture patients with PD have a higher risk of infections and mortality within 30 days after surgery after adjustment for sex, age, and comorbidity. They do, however, receive comparable quality of in-hospital care after hip fracture compared to non-PD patients.

Defining Baseline Creatinine for Identification of AKI in Population-Based Laboratory Databases: A Danish Nationwide Cohort Study

Background

The baseline creatinine level is central in the Kidney Disease Improving Global Outcomes (KDIGO) criteria of AKI, but baseline creatinine is often inconsistently defined or unavailable in AKI research. We examined the rate, characteristics, and 30-day mortality of AKI in five AKI cohorts created using different definitions of baseline creatinine.

Methods

This nationwide cohort study included all individuals aged ≥18 years in Denmark with a creatinine measurement in 2017. Applying the KDIGO criteria, we created four AKI cohorts using four different baseline definitions (most recent, mean, or median value of outpatient creatinine 365-368 days before, or median value 90-98 days before, if available, otherwise median value 365-391 days before) and one AKI cohort not using a baseline value. AKI rate and the distribution of age, sex, baseline creatinine, and comorbidity were described for each AKI cohort, and the 30-day all-cause mortality was estimated using the Kaplan-Meier method.

Results

The study included 2,095,850 adults with at least one creatinine measurement in 2017. The four different baseline definitions identified between 61,189 and 62,597 AKI episodes. The AKI rate in these four cohorts was 13-14 per 1000 person-years, and 30-day all-cause mortality was 17%-18%. The cohort created without using a baseline creatinine included 37,659 AKI episodes, corresponding to an AKI rate of 8.2 per 1000 person-years and a 30-day mortality of 23%. All five cohorts were similar regarding age, sex, and comorbidity.

Conclusions

In a population-based setting with available outpatient baseline creatinine, different baseline creatinine definitions revealed comparable AKI cohorts, whereas the lack of a baseline creatinine when defining AKI led to a smaller AKI cohort with a higher mortality. These findings underscore the importance of availability and consistent use of an outpatient baseline creatinine, particulary in studies of community-acquired AKI.

Ranitidine and Risk of Bladder and Kidney Cancer: A Population-Based Cohort Study

BACKGROUND

In 2019, ranitidine was withdrawn due to high levels of N-nitrosodimethylamine, a probable human carcinogen. The risk of bladder and kidney cancer in ranitidine users, however, remains unclear.

METHODS

In a Danish nationwide cohort study, we included adults (18 years or older) without previous cancer, who between 1996 and 2008 redeemed at least two prescriptions for ranitidine and, as two separate comparison cohorts, patients with at least two prescriptions for other H2-receptor antagonists (H2-blockers), or proton pump inhibitors (PPI). Follow-up for bladder or kidney cancer started at date of the second prescription and continued to date of cancer, death, emigration, or December 31, 2018, whichever occurred first. We used propensity scores for ranitidine use to compute stabilized inverse probability of treatment (sIPT) weights and used Cox regression to compute crude and weighted HRs.

RESULTS

We identified 31,393 initiators of ranitidine, 65,384 initiating other H2-blockers, and 509,849 initiating PPI. Compared with other H2-blockers, the crude HR for bladder cancer was 1.33 [95% confidence interval (CI): 1.15-1.55], but sIPT weighting attenuated this to 1.11 (95% CI: 0.95-1.29). Compared with PPI initiators, the weighted HR was 1.24 (95% CI: 1.04-1.48). For kidney cancer, the weighted HR was 0.89 (95% CI: 0.72-1.10) compared with users of H2-blockers and 0.87 (95% CI: 0.67-1.13) compared with users of PPI.

CONCLUSIONS

Our findings did not suggest a substantial increase in bladder or kidney cancer occurrence in ranitidine users.

IMPACT

These findings are reassuring for previous ranitidine users.

Ranitidine Use and Risk of Upper Gastrointestinal Cancers

BACKGROUND

The discovery that ranitidine is contaminated with N-nitrosodimethylamine, a suspected human carcinogen, raises the hypothesis of a gastrointestinal carcinogenic effect; however, evidence remains inconclusive.

METHODS

We used the nationwide Danish Prescription Registry to identify a cohort of incident ranitidine users and two active comparator cohorts comprising users of other histamine-2 receptor blockers (H2RB) and users of proton pump inhibitors (PPI). All Danish adults with a first prescription of ranitidine, other H2RBs, or PPIs in 1996 through 2008 were followed virtually completely through 2018 for incidence of esophageal, stomach, liver, and pancreatic cancers. We used Cox regression with propensity-score weighting to calculate hazard ratios and 10-year cumulative risk with 95% confidence intervals.

RESULTS

We ascertained 276 newly diagnosed esophageal, 342 stomach, 133 hepatocellular, and 517 pancreatic cancers among ranitidine users during follow-up (median 14 years). In comparison with use of other H2RBs or PPIs, we found no consistent evidence of increased HRs or excess 10-year cumulative risk of any upper gastrointestinal cancer following ranitidine use. We observed no association after restriction to subjects with at least 5 or 10 prescriptions or those with 10 prescriptions and at least 10 years of follow-up.

CONCLUSIONS

Our large prospective study using high-quality prescription and cancer incidence data, with two active comparator groups, provides no compelling evidence that ranitidine increases the risk of upper gastrointestinal cancers.

IMPACT

Our results, which do not support any carcinogenic effect on esophagus, stomach, liver or pancreas, should be reassuring for millions of concerned past users of ranitidine.

Osteonecrosis of the jaw among patients with cancer treated with denosumab or zoledronic acid: Results of a regulator-mandated cohort postauthorization safety study in Denmark, Norway, and Sweden

BACKGROUND

Osteonecrosis of the jaw (ONJ) is an adverse effect of antiresorptive treatment. This study estimated incidence proportions and incidence rates of ONJ in cancer patients with bone metastases from solid tumors treated for the prevention of skeletal-related events in routine clinical practice.

METHODS

This cohort study in Denmark, Norway, and Sweden in 2011-2018 included 3 treatment cohorts: a denosumab inception cohort (DEIC), a zoledronic acid inception cohort (ZAIC), and a denosumab-switch cohort (DESC). The authors estimated 1- to 5-year incidence proportions and incidence rates of ONJ overall, by cancer site (breast, prostate, or other solid tumor), and by country. ONJ diagnoses were confirmed by adjudication.

RESULTS

There were 1340 patients in the DEIC, 1352 in the ZAIC, and 408 in the DESC. The median ages of the 3 cohorts were 70, 69, and 70 years, respectively; the proportions of men were 72.6%, 53.8%, and 48.3%, respectively; and the median follow-up was 19.8, 12.9, and 13.3 months, respectively. The 5-year incidence proportions of ONJ were 5.7% (95% confidence interval [CI], 4.4%-7.3%) in the DEIC, 1.4% (95% CI, 0.8%-2.3%) in the ZAIC, and 6.6% (95% CI, 4.2%-10.0%) in the DESC. The corresponding ONJ incidence rates per 100 person-years were 3.0 (95% CI, 2.3-3.7), 1.0 (95% CI, 0.6-1.5), and 4.3 (95% CI, 2.8-6.3). Incidence proportions and incidence rates were highest in patients with prostate cancer and in Denmark.

CONCLUSIONS

This study provides estimates of the risk of medically confirmed ONJ among patients initiating denosumab or zoledronic acid in routine clinical practice in 3 Scandinavian countries. The results varied by cancer site and by country.

LAY SUMMARY

Denosumab and zoledronic acid reduce the risk of bone fractures, pain, and surgery in patients with advanced cancers involving bone. Osteonecrosis of the jaw (ONJ)-death of a jawbone-is a known side effect of treatment with denosumab or zoledronic acid. The authors examined almost 2900 denosumab- or zoledronic acid-treated patients with cancer in Denmark, Norway, and Sweden. Over the course of 5 years, ONJ developed in 5.7% of the patients whose initial treatment was denosumab, in 1.4% of the patients whose initial treatment was zoledronic acid, and in 6.6% of the patients who switched from zoledronic acid to denosumab.

Statin but not Aspirin Treatment is Associated with Reduced Cardiovascular Risk in Patients with Diabetes without Obstructive Coronary Artery Disease

AIMS

Patients with diabetes and no obstructive coronary artery disease (CAD) as assessed by coronary angiography (CAG) are frequently treated with aspirin and statins. We examined the effectiveness of aspirin and statin treatment on cardiovascular and bleeding incidence in patients with diabetes and absent obstructive CAD.

METHODS AND RESULTS

The study included patients with diabetes and absent obstructive CAD as assessed by CAG from 2003 to 2016 in Western Denmark. We stratified patients by aspirin and statin treatment within 6 months after CAG in two separate analyses. Outcomes were MACE (major adverse cardiovascular events, a composite of myocardial infarction, ischaemic stroke, and death) and bleeding (aspirin only). To account for confounding, we used propensity score-based weights to estimate the inverse probability of treatment-weighted hazard ratios (HRIPTW). We included 4,124 patients with diabetes but without CAD as assessed by CAG, among whom 2,474 (60%) received aspirin and 2,916 (71%) received statin treatment within 6 months following CAG. Median follow-up was 4.9 years. Aspirin did not reduce 10-year MACE (21.3% vs 21.8%, HRIPTW 1.01, 95% confidence interval (CI) 0.82-1.25), all-cause death (HRIPTW 0.96, 95% CI 0.74-1.23), or bleeding (HRIPTW 0.95, 95% CI 0.73-1.23), compared to those not receiving aspirin treatment. Statin treatment reduced MACE (25% vs. 37%, HRIPTW 0.58, 95% CI 0.48-0.70) compared to those not receiving statin treatment.

CONCLUSION

Among patients with diabetes and no obstructive CAD, aspirin neither reduced MACE nor increased bleeding. In contrast, statin treatment was associated with a major reduction in risk of MACE.

Identification of Patients with CKD in Medical Databases: A Comparison of Different Algorithms

BACKGROUND AND OBJECTIVES

Despite CKD consensus definitions, epidemiologic studies use multiple different algorithms to identify CKD. We aimed to elucidate if this affects the patient characteristics and the estimated prevalence and prognosis of CKD by applying six different algorithms to identify CKD in population-based medical databases and compare the cohorts.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients with CKD in Northern Denmark (2009-2016) were identified using six different algorithms: five were laboratory based defined by (1) one measured outpatient eGFR <60 ml/min per 1.73 m² (single test, n=103,435), (2) two such findings ≥90 days apart (Kidney Disease Improving Global Outcomes, n=84,688), (3) two such findings ≥90 days apart with no eGFR >60 ml/min per 1.73 m² observed in-between (Kidney Disease Improving Global Outcomes, persistent, n=68,994), (4) two such findings ≥90 and <365 days apart (Kidney Disease Improving Global Outcomes, time limited, n=75,031), and (5) two eGFRs <60 ml/min per 1.73 m² or two urine albumin-creatinine ratios >30 mg/g ≥90 days apart (Kidney Disease Improving Global Outcomes, eGFR/albuminuria, n=100,957). The sixth included patients identified by reported in- and outpatient hospital International Classification of Diseases diagnoses of CKD (hospital-diagnosed, n=27,947). For each cohort, we estimated baseline eGFR, CKD prevalence, and 1-year mortality using the Kaplan-Meier method.

RESULTS

The five different laboratory-based algorithms resulted in large differences in the estimated prevalence of CKD from 4637-8327 per 100,000 population. In contrast, 1-year mortality varied only slightly (7%-9%). Baseline eGFR levels at diagnosis were comparable (53-56 ml/min per 1.73 m²), whereas median time since first recorded eGFR <60 ml/min per 1.73 m² varied from 0 months (single-test) to 17 months (Kidney Disease Improving Global Outcomes, persistent). The hospital-diagnosed algorithm yielded markedly lower CKD prevalence (775 per 100,000 population), a lower baseline eGFR (47 ml/min per 1.73 m²), longer time since first eGFR <60 ml/min per 1.73 m² (median 70 months), and much higher 1-year mortality (22%).

CONCLUSIONS

Population prevalence of CKD identified in medical databases greatly depends on the applied algorithm to define CKD. Despite these differences, laboratory-based algorithms produce cohorts with similar prognosis.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_03_11_CJN15691020_final.mp3.

SARS-CoV-2 infection and adverse outcomes in users of ACE inhibitors and angiotensin-receptor blockers: a nationwide case-control and cohort analysis

OBJECTIVE

To examine the impact of ACE inhibitor (ACE-I)/angiotensin receptor blocker (ARB) use on rate of SARS-CoV-2 infection and adverse outcomes.

METHODS

This nationwide case-control and cohort study included all individuals in Denmark tested for SARS-CoV-2 RNA with PCR from 27 February 2020 to 26 July 2020. We estimated confounder-adjusted ORs for a positive test among all SARS-CoV-2 tested, and inverse probability of treatment weighted 30-day risk and risk ratios (RRs) of hospitalisation, intensive care unit (ICU) admission and mortality comparing current ACE-I/ARB use with calcium channel blocker (CCB) use and with non-use.

RESULTS

The study included 13 501 SARS-CoV-2 PCR-positive and 1 088 695 PCR-negative individuals. Users of ACE-I/ARB had a marginally increased rate of a positive PCR when compared with CCB users (aOR 1.17, 95% CI 1.00 to 1.37), but not when compared with non-users (aOR 1.00 95% CI 0.92 to 1.09).Among PCR-positive individuals, 1466 (11%) were ACE-I/ARB users. The weighted risk of hospitalisation was 36.5% in ACE-I/ARB users and 43.3% in CCB users (RR 0.84, 95% CI 0.70 to 1.02). The risk of ICU admission was 6.3% in ACE-I/ARB users and 5.4% in CCB users (RR 1.17, 95% CI 0.64 to 2.16), while the 30-day mortality was 12.3% in ACE-I/ARB users and 13.9% in CCB users (RR 0.89, 95% CI 0.61 to 1.30). The associations were similar when ACE-I/ARB users were compared with non-users.

CONCLUSIONS

ACE-I/ARB use was associated neither with a consistently increased rate nor with adverse outcomes of SARS-CoV-2 infection. Our findings support the current recommendation of continuing use of ACE-Is/ARBs during the SARS-CoV-2 pandemic.

TRIAL REGISTRATION NUMBER

EUPAS34887.

Association of α1-Blocker Receipt With 30-Day Mortality and Risk of Intensive Care Unit Admission Among Adults Hospitalized With Influenza or Pneumonia in Denmark

IMPORTANCE

Alpha 1-adrenergic receptor blocking agents (α1-blockers) have been reported to have protective benefits against hyperinflammation and cytokine storm syndrome, conditions that are associated with mortality in patients with coronavirus disease 2019 and other severe respiratory tract infections. However, studies of the association of α1-blockers with outcomes among human participants with respiratory tract infections are scarce.

OBJECTIVE

To examine the association between the receipt of α1-blockers and outcomes among adult patients hospitalized with influenza or pneumonia.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used data from Danish national registries to identify individuals 40 years and older who were hospitalized with influenza or pneumonia between January 1, 2005, and November 30, 2018, with follow-up through December 31, 2018. In the main analyses, patients currently receiving α1-blockers were compared with those not receiving α1-blockers (defined as patients with no prescription for an α1-blocker filled within 365 days before the index date) and those currently receiving 5α-reductase inhibitors. Propensity scores were used to address confounding factors and to compute weighted risks, absolute risk differences, and risk ratios. Data were analyzed from April 21 to December 21, 2020.

EXPOSURES

Current receipt of α1-blockers compared with nonreceipt of α1-blockers and with current receipt of 5α-reductase inhibitors.

MAIN OUTCOMES AND MEASURES

Death within 30 days of hospital admission and risk of intensive care unit (ICU) admission.

RESULTS

A total of 528 467 adult patients (median age, 75.0 years; interquartile range, 64.4-83.6 years; 273 005 men [51.7%]) were hospitalized with influenza or pneumonia in Denmark between 2005 and 2018. Of those, 21 772 patients (4.1%) were currently receiving α1-blockers compared with a population of 22 117 patients not receiving α1-blockers who were weighted to the propensity score distribution of those receiving α1-blockers. In the propensity score-weighted analyses, patients receiving α1-blockers had lower 30-day mortality (15.9%) compared with patients not receiving α1-blockers (18.5%), with a corresponding risk difference of -2.7% (95% CI, -3.2% to -2.2%) and a risk ratio (RR) of 0.85 (95% CI, 0.83-0.88). The risk of ICU admission was 7.3% among patients receiving α1-blockers and 7.7% among those not receiving α1-blockers (risk difference, -0.4% [95% CI, -0.8% to 0%]; RR, 0.95 [95% CI, 0.90-1.00]). A comparison between 18 280 male patients currently receiving α1-blockers and 18 228 propensity score-weighted male patients currently receiving 5α-reductase inhibitors indicated that those receiving α1-blockers had lower 30-day mortality (risk difference, -2.0% [95% CI, -3.4% to -0.6%]; RR, 0.89 [95% CI, 0.82-0.96]) and a similar risk of ICU admission (risk difference, -0.3% [95% CI, -1.4% to 0.7%]; RR, 0.96 [95% CI, 0.83-1.10]).

CONCLUSIONS AND RELEVANCE

This cohort study's findings suggest that the receipt of α1-blockers is associated with protective benefits among adult patients hospitalized with influenza or pneumonia.

Neoadjuvant breast cancer treatment response; tumor size evaluation through different conventional imaging modalities in the NeoDense study

BACKGROUND

Neoadjuvant chemotherapy (NACT) is offered to an increasing number of breast cancer (BC) patients, and comprehensive monitoring of treatment response is of utmost importance. Several imaging modalities are available to follow tumor response, although likely to provide different clinical information. We aimed to examine the association between early radiological response by three conventional imaging modalities and pathological complete response (pCR). Further, we investigated the agreement between these modalities pre-, during, and post-NACT, and the accuracy of predicting pathological residual tumor burden by these imaging modalities post-NACT.

MATERIAL AND METHODS

This prospective Swedish cohort study included 202 BC patients assigned to NACT (2014-2019). Breast imaging with clinically used modalities: mammography, ultrasound, and tomosynthesis was performed pre-, during, and post-NACT. We investigated the agreement of tumor size by the different imaging modalities, and their accuracy of tumor size estimation. Patients with a radiological complete response or radiological partial response (≥30% decrease in tumor diameter) during NACT were classified as radiological early responders.

RESULTS

Patients with an early radiological response by ultrasound had 2.9 times higher chance of pCR than early radiological non-responders; the corresponding relative chance for mammography and tomosynthesis tumor size measures was 1.8 and 2.8, respectively. Post-NACT, each modality, separately, could accurately estimate tumor size (within 5 mm margin compared to pathological evaluation) in 43-46% of all tumors. The diagnostic precision in predicting pCR post-NACT was similar between the three imaging modalities; however, tomosynthesis had slightly higher specificity and positive predictive values.

CONCLUSION

Breast imaging modalities correctly estimated pathological tumor size in less than half of the tumors. Based on this finding, predicting residual tumor size post-NACT is challenging using conventional imaging. Patients with early radiological non-response might need improved monitoring during NACT and be considered for changed treatment plans.

The DANish Comorbidity Index for Acute Myocardial Infarction (DANCAMI): Development, Validation and Comparison with Existing Comorbidity Indices

Objective

To develop and validate the DANish Comorbidity index for Acute Myocardial Infarction (DANCAMI) for adjustment of comorbidity burden in studies of myocardial infarction prognosis.

Methods

Using medical registries, we identified patients with first-time myocardial infarction in Denmark during 2000–2013 (n=36,685). We developed comorbidity indices predicting 1-year all-cause mortality from all comorbidities (DANCAMI) and restricted to non-cardiovascular comorbidities (rDANCAMI). For variable selection, we eliminated comorbidities stepwise using hazard ratios from multivariable Cox models. We compared DANCAMI/rDANCAMI with Charlson and Elixhauser comorbidity indices using standard performance measures (Nagelkerke’s R², Harrell’s C-statistic, the Integrated Discrimination Improvement, and the continuous Net Reclassification Index). We assessed the significance of the novel DANCAMI variables not included in the Charlson Comorbidity Index. External validation was performed in patients with myocardial infarction in New Zealand during 2007–2016 (n=75,069).

Results

The DANCAMI included 24 comorbidities. The rDANCAMI included 17 non-cardiovascular comorbidities. In the Danish cohort, the DANCAMI indices outperformed both the Charlson and the Elixhauser comorbidity indices on all performance measures. The DANCAMI indices included multiple variables that were significant predictors of 1-year mortality even after controlling for all variables in the Charlson Comorbidity Index. These novel variables included valvular heart disease (hazard ratio for 1-year mortality=1.25, 95% CI: 1.14–1.35), coagulopathy (1.13, 95% CI: 1.05–1.22), alcohol and drug abuse (1.35, 95% CI: 1.15–1.58), schizophrenia (1.60, 95% CI: 1.46–1.76), affective disorder (1.29, 95% CI: 1.22–1.36), epilepsy (1.26, 95% CI: 1.05–1.50), neurodegenerative disorder (1.30, 95% CI: 1.10–1.54) and chronic pancreatitis (1.71, 95% CI: 1.14–2.56). The results were supported by the external validation in New Zealand.

Conclusion

DANCAMI assessed comorbidity burden of patients with first-time myocardial infarction, outperformed existing comorbidity indices, and was generalizable to patients outside Denmark. DANCAMI is recommended as a standard approach for comorbidity adjustment in studies of myocardial infarction prognosis.

Positive Predictive Value of Benign Prostatic Hyperplasia and Acute Urinary Retention in the Danish National Patient Registry: A Validation Study

Background and Aim

Benign prostatic hyperplasia comprises a significant burden to ageing men due to frequently associated lower urinary tract symptoms and the risk of developing serious complications, such as acute urinary retention. Healthcare databases are a valuable source of epidemiological research; however, continuous validation of definitions is imperative. We examined the positive predictive values of International Classification of Diseases, 10th Revision (ICD-10), diagnostic coding for benign prostatic hyperplasia and acute urinary retention in men in the Danish National Patient Registry.

Methods

We investigated a random sample of 100 men diagnosed with benign prostatic hyperplasia and 100 men diagnosed with acute urinary retention between 2011 and 2017 in the Central Denmark Region. Using medical record review as reference standard, we estimated the positive predictive value with corresponding 95% confidence intervals (CI) overall and stratified by age, type of hospital (university hospital vs regional hospital), type of hospital contact (inpatient, outpatient or emergency room), calendar year group (2011–2013, 2014–2017), and department (department of urology, geriatrics, endocrinology or emergency room).

Results

Medical records were available for all 200 sampled patients. We found an overall positive predictive value (PPV) of 95% (95% CI: 89–98%) for benign prostatic hyperplasia and 98% (95% CI: 93–99%) for acute urinary retention. The PPVs were consistent across age, type of hospital, type of hospital contact, calendar year group, and department.

Conclusion

The PPVs of ICD-10 codes for benign prostatic hyperplasia and acute urinary retention recorded in the Danish National Patient Registry are high.

Acute pancreatitis: 31-Year trends in incidence and mortality - A Danish population-based cohort study

BACKGROUND

Objectives: Increasing incidence rates and declining mortality rates have made acute pancreatitis a common cause of hospitalization. We aimed to examine 31-year trends in first-time hospitalization for acute pancreatitis, the subsequent short-term and long-term mortality, and the prognostic impacts of age, sex, and comorbidity.

METHODS

In this nationwide Danish population-based cohort study of 47,711 incident cases, we computed the annual sex-specific age-standardized incidence rates of acute pancreatitis for 1988-2018. Among patients with incident hospitalization for acute pancreatitis, we computed sex-specific 30-day and 31-365-day mortality rates, stratified them, and performed proportional-hazards regression to estimate mortality rate ratios adjusted for sex, age, and comorbidity, measured by Charlson Comorbidity Index categories.

RESULTS

From 1988 to 2018, the standardized incidence rate of acute pancreatitis per 100,000 person-years increased by 29% for men (28.8-37.0%) and by 148% for women (15.7-38.9%). Among patients with pancreatitis, the 30-day mortality declined from 10.0% in those diagnosed in 1988-1992 to 6.3% for those diagnosed in 2013-2017. The corresponding 31-365 day mortality increased from 5.5% to 6.0%. In comparing periods 1988-1992 and 2013-17, the adjusted 30-day mortality rate ratio was 0.36 (95% confidence interval: 0.32-0.41) and the adjusted 31-365 day mortality rate ratio was 0.64 (95% confidence interval: 0.56-0.74). Comorbidity was a strong predictor of mortality among patients with pancreatitis.

CONCLUSIONS

Over the 31 years of observations, annual rates of acute pancreatitis more than doubled among women, converging with those among men. The comorbidity burden was a strong prognostic factor for short and long-term mortality. Treatments for acute pancreatitis should focus on existing comorbidities.

Renin-Angiotensin System Blockers and Adverse Outcomes of Influenza and Pneumonia: A Danish Cohort Study

Background Angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) may worsen the prognosis of coronavirus disease 2019, but any association could be confounded by the cardiometabolic conditions indicating ACE-I/ARB use. We therefore examined the impact of ACE-Is/ARBs on respiratory tract infection outcomes. Methods and Results This cohort study included all adult patients hospitalized with influenza or pneumonia from 2005 to 2018 in Denmark using population-based medical databases. Thirty-day mortality and risk of admission to the intensive care unit in ACE-Is/ARBs users was compared with nonusers and with users of calcium channel blockers. We used propensity scores to handle confounding and computed propensity score-weighted risks, risk differences (RDs), and risk ratios (RRs). Of 568 019 patients hospitalized with influenza or pneumonia, 100 278 were ACE-I/ARB users and 37 961 were users of calcium channel blockers. In propensity score-weighted analyses, ACE-I/ARB users had marginally lower 30-day mortality than users of calcium channel blockers (13.9% versus 14.5%; RD, -0.6%; 95% CI, -1.0 to -0.1; RR, 0.96; 95% CI, 0.93-0.99), and a lower risk of admission to the intensive care unit (8.0% versus 9.6%; RD, -1.6%; 95% CI, -2.0 to -1.2; RR, 0.83; 95% CI, 0.80-0.87). Compared with nonusers, current ACE-I/ARB users had lower mortality (RD, -2.4%; 95% CI, -2.8 to -2.0; RR, 0.85; 95% CI, 0.83-0.87), but similar risk of admission to the intensive care unit (RD, 0.4%; 95% CI, 0.0-0.7; RR, 1.04; 95% CI, 1.00-1.09). Conclusions Among patients with influenza or pneumonia, ACE-I/ARB users had no increased risk of admission to the intensive care unit and slightly reduced mortality after controlling for confounding.

Risk of Anemia in Patients with Newly Identified Chronic Kidney Disease - A Population-Based Cohort Study

Purpose

Anemia is prevalent in patients with chronic kidney disease (CKD), but the longitudinal risk of anemia in patients with newly identified CKD is unknown. We therefore examined the risks of experiencing anemia in persons with newly identified CKD.

Patients and Methods

This cohort study included adult patients with newly identified CKD stages 3–5 defined by an estimated glomerular filtration rate (eGFR) level <60 mL/min/1.73m² (at least two measurements ≥90 days apart) ascertained from a population-based registry with complete laboratory test results in Northern Denmark (population ~2.2 million) during 2009–2016. We calculated 1) cumulative incidence (risk) of anemia [hemoglobin <12/<13 g/dl in women/men] by CKD stage, and 2) adjusted hazard ratios (HRs) of anemia using Cox regression analyses.

Results

We identified 55,940 distinct individuals with newly identified CKD stages 3–5 and no prevalent anemia [n=41,958 patients in stage 3a, n=17,875 in stage 3b, n=5182 in stage 4, and n=931 in stage 5]. After one year, 42.3% (95%-confidence interval [CI]: 41.9–42.7) of patients with CKD stages 3–5 had newly measured anemia, increasing to 67.7% (95%-CI: 67.2–68.2) after five years. The absolute and relative anemia risk increased markedly with higher CKD stages. The adjusted HR of any anemia was 5.42 (95%-CI: 5.09–5.77) in patients with CKD stage 5 compared to patients with CKD stage 3a.

Conclusion

Patients with newly identified CKD stages 3–5 have a substantial risk of anemia, increasing with higher CKD stages. This study underlines that clinical awareness of anemia risk is important in patients with newly identified or progressed CKD.

Statin use and breast cancer recurrence in postmenopausal women treated with adjuvant aromatase inhibitors: a Danish population-based cohort study

Purpose

To examine the association between statin use and risk of breast cancer recurrence in a national Danish cohort of postmenopausal breast cancer patients receiving aromatase inhibitors (AI) in the adjuvant setting.

Patients and methods

We enrolled all postmenopausal patients diagnosed with stage I–III estrogen receptor positive breast cancer during the years 2007–2017, assigned adjuvant AI treatment, and registered in both the Danish Breast Cancer Group database and the Danish Cancer Registry. We ascertained incident statin exposure (≥ 1 prescription post-diagnosis) from the Danish National Prescription Registry and modeled statins as a time-varying exposure lagged by 6 months. Follow-up began 7 months after diagnosis and continued to the first event of recurrence, death, emigration, 5 years elapsed, or 25th September 2018. We estimated incidence rates of recurrence at 5 years and used Cox regression models to compute crude and adjusted hazard ratios (HRs) with 95% confidence intervals (95% CI), comparing statin exposure with non-exposure.

Results

We enrolled 14,773 eligible patients. During the 5 years of follow-up, there were 32 recurrences in 3163 person-years of follow-up among statin-exposed patients, and 612 recurrences in 45,655 person-years among unexposed patients (incidence rate per 1000 person-years: 10.12 [95% CI 6.92–14.28] and 13.40 [95% CI 12.36–14.51], respectively). In multivariable models, any statin exposure was associated with a reduced rate of 5-year breast cancer recurrence (adjusted HR 0.72 [95% CI 0.50–1.04]). Considering only lipophilic statins as exposure the results were similar (adjusted HR 0.70 [95% CI 0.48–1.02]).

Conclusions

Statin use was associated with a reduced risk of breast cancer recurrence among postmenopausal patients diagnosed with early stage breast cancer who received adjuvant AI therapy.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05749-5) contains supplementary material, which is available to authorized users.

Overall risk and risk factors for metachronous peritoneal metastasis after colorectal cancer surgery: a nationwide cohort study

Background

This study aimed to identify the cumulative incidence and risk factors of metachronous peritoneal metastasis (M‐PM) from colorectal cancer in patients who had intended curative treatment.

Methods

Patients with colorectal cancer were identified using the Danish Colorectal Cancer Group database for 2006–2015. The Danish Pathology Registry and the Danish National Patient Registry were used to identify M‐PM to 2017. Risk factors were estimated by multivariable absolute risk regression, treating death and other cancers as competing risks. Overall risk and risk differences (RDs) were estimated at 1, 3 and 5 years.

Results

In 22 586 patients with colorectal cancer, the overall risk of M‐PM was reported to be 0·9 (95 per cent c.i. 0·8 to 1·0) per cent at 1 year, 1·9 (1·8 to 2·1) per cent at 3 years and 2·2 (2·0 to 2·4) per cent at 5 years. Advanced tumour category ((y)pT4 versus (y)pT1) increased the RD of both M‐PM (2·9 (95 per cent c.i. 2·1 to 3·7) at 1 year and 6·0 (4·9 to 7·2) at 3 years) and lymph node involvement ((y)pN2 versus (y)pN0) (2·5 (1·8 to 3·2) at year and 4·3 (3·2 to 5·3) at 3 years). No further increase in risk was observed at 5 years. In a subanalysis, tumour‐involved resection margin (R1 versus R0) was associated with M‐PM with a RD of 3·9 (1·6 to 6·2) at 1 year and 5·9 (2·6 to 9·3) at 3 years.

Conclusion

The overall risk of M‐PM in patients with colorectal cancer is low, but is increased in advanced T and N status. Follow‐up of at least 3 years after colorectal cancer surgery may be necessary, given the potential curative treatment of early diagnosed M‐PM.

Mammographic density is a potential predictive marker of pathological response after neoadjuvant chemotherapy in breast cancer

Background

Our aim is to study if mammographic density (MD) prior to neoadjuvant chemotherapy is a predictive factor in accomplishing a pathological complete response (pCR) in neoadjuvant-treated breast cancer patients.

Methods

Data on all neoadjuvant treated breast cancer patients in Southern Sweden (2005–2016) were retrospectively identified, with patient and tumor characteristics retrieved from their medical charts. Diagnostic mammograms were used to evaluate and score MD as categorized by breast composition with the Breast Imaging-Reporting and Data System (BI-RADS) 5th edition. Logistic regression was used in complete cases to assess the odds ratios (OR) for pCR compared to BI-RADS categories (a vs b-d), adjusting for patient and pre-treatment tumor characteristics.

Results

A total of 302 patients were included in the study population, of which 57 (18.9%) patients accomplished pCR following neoadjuvant chemotherapy. The number of patients in the BI-RADS category a, b, c, and d were separately 16, 120, 140, and 26, respectively. In comparison to patients with BI-RADS breast composition a, patients with denser breasts had a lower OR of accomplishing pCR: BI-RADS b 0.32 (95%CI 0.07–0.1.5), BI-RADS c 0.30 (95%CI 0.06–1.45), and BI-RADS d 0.06 (95%CI 0.01–0.56). These associations were measured with lower point estimates, but wider confidence interval, in premenopausal patients; OR of accomplishing pCR for BI-RADS d in comparison to BI-RADS a: 0.03 (95%CI 0.00–0.76).

Conclusions

The likelihood of accomplishing pCR is indicated to be lower in breast cancer patients with higher MD, which need to be analysed in future studies for improved clinical decision-making regarding neoadjuvant treatment.

Acute pancreatitis as an early marker of pancreatic cancer and cancer stage, treatment, and prognosis

BACKGROUND

We aimed to examine the association between acute pancreatitis, a potential early symptom of pancreatic cancer, and pancreatic cancer stage, treatment, and prognosis.

METHODS

We conducted a cohort study of patients diagnosed with pancreatic cancer during 2004-2017 using population-based registry data from Denmark and Surveillance, Epidemiology, and End Results (SEER) data linked with Medicare claims from the United States (US), which include individuals aged 65 + . We ascertained information on acute pancreatitis diagnoses up to 90 days before pancreatic cancer and followed them for a maximum of five years. We assessed overall survival difference at 30 days, six months, and one, three and five years, comparing patients with and without coexistence of acute pancreatitis. Secondary outcomes were cancer stage and treatment.

RESULTS

We identified 12,522 Danish and 37,552 US patients with pancreatic cancer (median age 71 and 78 years, respectively). In the Danish cohort, 1.4 % had acute pancreatitis before pancreatic cancer vs. 5.9 % in the US cohort. After five years of follow-up, the survival difference was 6.1 % (95 % CI: [-0.4 %, 12.6 %]) in Danish and 1.7 % (95 % CI: [0.8 %, 2.7 %]) in US patients, comparing patients with and without acute pancreatitis. Patients with acute pancreatitis had lower prevalence of metastatic tumors at diagnosis (Denmark: 42.5 % vs. 48.7 %; US: 34.4 % vs. 45.9 %) and higher resection frequencies (Denmark: 20.1 % vs. 12.1 %; US: 16.1 % vs.11.3 %) than patients without acute pancreatitis.

CONCLUSIONS

Pancreatic cancer patients with acute pancreatitis diagnosed up to 90 days before cancer diagnosis had earlier stage at diagnosis and better survival than patients without acute pancreatitis.

Comparison of Risk of Osteoporotic Fracture in Denosumab vs Alendronate Treatment Within 3 Years of Initiation

IMPORTANCE

Head-to-head randomized clinical trials showed greater efficacy of denosumab vs alendronate in improving bone mineral density. Although there is an association of changes in bone mineral density with reductions in fracture risk, the magnitude of the association is not well established.

OBJECTIVE

To compare the risk of hip and any fracture in patients treated with denosumab and alendronate in routine practice settings.

DESIGN, SETTING, AND PARTICIPANTS

This Danish nationwide, population-based, historical cohort study of a population with universal access to health care used prospectively collected, individually linked data from Danish health registries with complete follow-up. Cohorts consisted of 92 355 individuals 50 years or older who were new users of denosumab (n = 4624) or alendronate (n = 87 731) from May 2010 to December 2017 after at least 1 year without an antiosteoporosis medication dispensing.

EXPOSURES

Initiation of denosumab or alendronate.

MAIN OUTCOMES AND MEASURES

The primary outcome was hospitalization for hip fracture, and the secondary outcome was hospitalization for any fracture. Inverse probability of treatment weights and the intention-to-treat approach were used to calculate cumulative incidences and adjusted hazard ratios (aHRs) with 95% CIs.

RESULTS

Of the 92 355 included patients, 75 046 (81.3%) were women, and the mean (SD) age was 71 (10) years. The denosumab cohort had a lower proportion of men than the alendronate cohort (12.7% [589] vs 19.0% [16 700]), while age distributions were similar in the 2 cohorts. Within 3 years of follow-up, initiation of denosumab or alendronate was associated with cumulative incidences of 3.7% and 3.1%, respectively, for hip fracture and 9.0% and 9.0%, respectively, for any fracture. Overall, the aHRs for denosumab vs alendronate were 1.08 (95% CI, 0.92-1.28) for hip fracture and 0.92 (95% CI, 0.83-1.02) for any fracture. The aHR of denosumab vs alendronate for hip fracture was 1.07 (95% CI, 0.85-1.34) among patients with a history of any fracture and 1.05 (95% CI, 0.83-1.32) among patients without history of fracture. The aHR for any fracture for denosumab vs alendronate was 0.84 (95% CI, 0.71-0.98) among patients with a history of any fracture and 0.77 (95% CI, 0.64-0.93) among patients with no history of fracture.

CONCLUSIONS AND RELEVANCE

Treatment with denosumab and alendronate was associated with similar risks of hip or any fracture over a 3-year period, regardless of fracture history.

β-Blocker Use in Pregnancy and the Risk for Congenital Malformations: An International Cohort Study

BACKGROUND

β-Blockers are a class of antihypertensive medications that are commonly used in pregnancy.

OBJECTIVE

To estimate the risks for major congenital malformations associated with first-trimester exposure to β-blockers.

DESIGN

Cohort study.

SETTING

Health registries in the 5 Nordic countries and the U.S. Medicaid database.

PATIENTS

Pregnant women with a diagnosis of hypertension and their offspring.

MEASUREMENTS

First-trimester exposure to β-blockers was assessed. Outcomes were any major congenital malformation, cardiac malformations, cleft lip or palate, and central nervous system (CNS) malformations. Propensity score stratification was used to control for potential confounders.

RESULTS

Of 3577 women with hypertensive pregnancies in the Nordic cohort and 14 900 in the U.S. cohort, 682 (19.1%) and 1668 (11.2%), respectively, were exposed to β-blockers in the first trimester. The pooled adjusted relative risk (RR) and risk difference per 1000 persons exposed (RD1000) associated with β-blockers were 1.07 (95% CI, 0.89 to 1.30) and 3.0 (CI, -6.6 to 12.6), respectively, for any major malformation; 1.12 (CI, 0.83 to 1.51) and 2.1 (CI, -4.3 to 8.4) for any cardiac malformation; and 1.97 (CI, 0.74 to 5.25) and 1.0 (CI, -0.9 to 3.0) for cleft lip or palate. For CNS malformations, the adjusted RR was 1.37 (CI, 0.58 to 3.25) and the RD1000 was 1.0 (CI, -2.0 to 4.0) (based on U.S. cohort data only).

LIMITATION

Analysis was restricted to live births, exposure was based on dispensed medication, and cleft lip or palate and CNS malformations had few outcomes.

CONCLUSION

The results suggest that maternal use of β-blockers in the first trimester is not associated with a large increase in the risk for overall malformations or cardiac malformations, independent of measured confounders.

PRIMARY FUNDING SOURCE

The Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Söderström König Foundation.

Sampling strategies for selecting general population comparison cohorts

Background

For a patient cohort, access to linkable population-based registries permits sampling of a comparison cohort from the general population, thereby contributing to the understanding of the disease in a population context. However, sampling without replacement in random order can lead to immortal time bias by conditioning on the future.

Aim

We compared the following strategies for sampling comparison cohorts in matched cohort studies with respect to time to ischemic stroke and mortality: sampling without replacement in random order; sampling with replacement; and sampling without replacement in chronological order.

Methods

We constructed index cohorts of individuals from the Danish general population with no particular trait, except being alive and without ischemic stroke on the index date. We also constructed index cohorts of persons aged >50 years from the general population. We then applied the sampling strategies to sample comparison cohorts (5:1 or 1:1) from the Danish general population and compared outcome risks between the index and comparison cohorts. Finally, we sampled comparison cohorts for a heart failure cohort using each strategy.

Results

We observed increased outcome risks in comparison cohorts sampled 5:1 without replacement in random order compared to the index cohorts. However, these increases were minuscule unless index persons were aged >50 years. In this setting, sampling without replacement in chronological order failed to sample a sufficient number of comparators, and the mortality risks in these comparison cohorts were lower than in the index cohorts. Sampling 1:1 showed no systematic difference between comparison and index cohorts. When we sampled comparison cohorts for the heart failure patients, we observed a pattern similar to when index persons were aged >50 years.

Conclusion

When index persons were aged >50 years, ie, had high outcome risks, sampling 5:1 without replacement introduced bias. Sampling with replacement or 1:1 did not introduce bias.

Acute Pancreatitis and Pancreatic Cancer Risk: A Nationwide Matched-Cohort Study in Denmark

BACKGROUND & AIMS

Acute pancreatitis may be a risk factor for pancreatic cancer; however, findings from studies on this association are conflicting. We investigated the association between acute pancreatitis and increased risk of pancreatic cancer.

METHODS

We conducted a nationwide, population-based, matched cohort study of all patients admitted to a hospital in Denmark with a diagnosis of acute pancreatitis from January 1, 1980, through October 31, 2012. As many as 5 individuals from the general population without acute pancreatitis were matched for age and sex to each patient with acute pancreatitis. Pancreatic cancer risk was expressed as hazard ratios (HRs) with 95% confidence intervals (CIs), calculated using the Cox proportional hazards model. Cox models were stratified by age, sex, and year of pancreatitis diagnosis and adjusted for alcohol- and smoking-related conditions, and Charlson Comorbidity Index score.

RESULTS

We included 41,669 patients diagnosed with incident acute pancreatitis and 208,340 comparison individuals. Patients with acute pancreatitis had an increased risk of pancreatic cancer compared with the age- and sex-matched general population throughout the follow-up period. The risk decreased over time but remained high after more than 5 years of follow-up (adjusted HR 2.02; 95% CI 1.57-2.61). Two- and 5-year absolute risks of pancreatic cancer among patients with acute pancreatitis were 0.70% (95% CI 0.62%-0.78%) and 0.87% (95% CI 0.78%-0.97), respectively.

CONCLUSIONS

In a nationwide, population-based, matched cohort study, we observed an association between a diagnosis of acute pancreatitis and long-term risk of pancreatic cancer.