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.

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.

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.

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.

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.

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.

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.

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.

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.

Maternal and Infant Antibiotic and Acid Suppressant Use and Risk of Eosinophilic Esophagitis.

Importance: Eosinophilic esophagitis (EoE), a chronic disease with significant patient and health care burden, has increased rapidly in incidence across many countries. Elucidating risk factors for disease development is a priority for health care practitioners and patients. Objective: To evaluate the association of maternal and infant use of antibiotics and acid suppressants with the development of EoE. Design, Setting, and Participants: This was a population-based, case-control study of pediatric EoE (1996-2019) in Denmark using pathology, prescription, birth, inpatient, and outpatient health registry data and with complete ascertainment of all EoE cases among Danish residents born between 1997 and 2018. Study data were analyzed from September 2020 to August 2023. Exposures: Maternal and infant use of antibiotics and acid suppressants, examining medication class, timing, and frequency of use. Main Outcome and Measure: Development of EoE. Results: Included in the study was a total of 392 cases and 3637 sex- and year of birth-matched controls with a median (IQR) age of 11.0 (6.0-15.0) years, 2772 male individuals (68.8%), and 1257 female individuals (31.2%). Compared with children with no antibiotic prescriptions filled during infancy, those with any use of an antibiotic had an associated 40% increase in risk of EoE (adjusted odds ratio [aOR], 1.4; 95% CI, 1.1-1.7). Those with 3 or more prescriptions had an associated 80% increase in risk of EoE (aOR, 1.8; 95% CI, 1.3-2.5). Frequency of maternal antibiotic use was associated with an increased risk (1 prescription: aOR, 1.4; 95% CI, 1.0-1.8; 3≤ prescriptions: aOR, 2.1; 95% CI, 1.4-3.2). Risk was highest for use in the third trimester and in the first 6 months from birth. Any acid suppressant use in infancy was associated with increased risk of EoE (aOR, 15.9; 95% CI, 9.1-27.7). Restriction of cases to those diagnosed at 5 years or older yielded similar results (aOR, 11.6; 95% CI, 5.5-24.8). For maternal use, 3 or more prescriptions were associated with an increased risk of EoE for her offspring (aOR, 5.1; 95% CI, 1.8-14.8). Conclusions and Relevance: Maternal and infant antibiotic use were associated with increased risk of developing EoE, in a dose-response manner, and the magnitude of association was highest for exposure near the time of delivery. Increased risk was also observed with maternal and infant acid suppressant use. Exposure during early life, a period of known developmental susceptibility, may confer the greatest risk and opportunity for risk mitigation.

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.

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.

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%.

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.

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.

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.

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.

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.

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.