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.

Preadmission morbidity and healthcare utilization among older adults with potentially avoidable hospitalizations: a Danish case-control study

PURPOSE

Examine preadmission diagnoses, medication use, and preadmission healthcare utilization among older adults prior to first potentially avoidable hospitalizations.

METHODS

A nationwide population-based case-control study using Danish healthcare data. All Danish adults aged ≥ 65 years who had a first potentially avoidable hospitalization from January 1995 through March 2019 (n = 725,939) were defined as cases, and 1:1 age- and sex-matched general population controls (n = 725,939). Preadmission morbidity and healthcare utilization were assessed based on a complete hospital diagnosis history within 10 years prior, and all medication use and healthcare contacts 1 year prior. Using log-binomial regression, we calculated adjusted prevalence ratios (PR) with 95% confidence intervals (CI).

RESULTS

Included cases and controls had a median age of 78 years and 59% were female. The burden of preadmission morbidity was higher among cases than controls. The strongest associations were observed for preadmission chronic lung disease (PR 3.8, CI 3.7-3.8), alcohol-related disease (PR 3.1, CI 3.0-3.2), chronic kidney disease (PR 2.4, CI 2.4-2.5), psychiatric disease (PR 2.2, CI 2.2-2.3), heart failure (PR 2.2, CI 2.2-2.3), and previous hospital contacts with infections (PR 2.2, CI 2.2-2.3). A high and accelerating number of healthcare contacts was observed during the months preceding the potentially avoidable hospitalization (having over 5 GP contacts 1 month prior, PR 3.0, CI 3.0-3.0).

CONCLUSION

A high number of healthcare contacts and preadmission morbidity and medication use, especially chronic lung, heart, and kidney disease, alcohol-related or psychiatric disease including dementia, and previous infections are strongly associated with potentially avoidable hospitalizations.

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.

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.

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.

Kidney disease and risk of dementia: a Danish nationwide cohort study

OBJECTIVES

It is unclear whether kidney disease is a risk factor for developing dementia. We examined the association between kidney disease and risk of future dementia.

DESIGN AND SETTING

Nationwide historical registry-based cohort study in Denmark based on data from 1 January 1995 until 31 December 2016.

PARTICIPANTS

All patients diagnosed with kidney disease and matched general population cohort without kidney disease (matched 1:5 on age, sex and year of kidney disease diagnosis).

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause dementia and its subtypes: Alzheimer's disease, vascular dementia and other specified or unspecified dementia. We computed 5-year cumulative incidences (risk) and hazard ratios (HRs) for outcomes using Cox regression analyses.

RESULTS

The study cohort comprised 82 690 patients with kidney disease and 413 405 individuals from the general population. Five-year and ten-year mortality rates were twice as high in patients with kidney disease compared with the general population. The 5-year risk for all-cause dementia was 2.90% (95% confidence interval: 2.78% to 3.08%) in patients with kidney disease and 2.98% (2.92% to 3.04%) in the general population. Compared with the general population, the adjusted HRs for all-cause dementia in patients with kidney disease were 1.06 (1.00 to 1.12) for the 5-year follow-up and 1.08 (1.03 to 1.12) for the entire study period. Risk estimates for dementia subtypes differed substantially and were lower for Alzheimer's disease and higher for vascular dementia.

CONCLUSIONS

Patients diagnosed with kidney disease have a modestly increased rate of dementia, mainly driven by vascular dementia. Moreover, patients with kidney disease may be underdiagnosed with dementia due to high mortality and other comorbidities of higher priority.

Lessons Learned Using Real-World Data to Emulate Randomized Trials: A Case Study of Treatment Effectiveness for Newly Diagnosed Immune Thrombocytopenia

Regulatory agencies are increasingly considering real-world evidence (RWE) to support label expansions of approved medicines. We conducted a comparative effectiveness study to emulate a proposed randomized trial of romiplostim vs. standard-of-care (SOC) therapy among patients with recently diagnosed (≤12 months) immune thrombocytopenia (ITP), that could support expansion of the romiplostim label. We discuss challenges that we encountered and solutions that were developed to address those challenges. Study size was a primary concern, particularly for romiplostim initiators, given the rarity of ITP and the stringent trial eligibility criteria. For this reason, we leveraged multiple data sources (Nordic Country Patient Registry for Romiplostim; chart review study of romiplostim initiators in Europe; Flatiron Health EMR linked with MarketScan claims). Additionally, unlike the strictly controlled clinical trial setting, platelet counts were not measured at regular intervals in the observational data sources, and therefore the end point of durable platelet response often used in trials could not be reliably measured. Instead, the median platelet count was chosen as the primary end point. Ultimately, while we observed a slightly higher median platelet count in the romiplostim group vs. SOC, precision was limited because of small study size (median difference was 11 × 10⁹ /L (95% CI: -59, 81)). We underscore the importance of conducting comprehensive feasibility assessments to identify fit-for-purpose data sources with sufficient sample size, data elements, and follow-up. Beyond technical challenges, we also discuss approaches to increase the credibility of RWE, including systematic incorporation of clinical expertise into study design decisions, and separation between decision makers and the data.

Risk factors of hospitalisation for thrombosis in adults with primary immune thrombocytopenia, including disease-specific treatments: a French nationwide cohort study

We aimed to assess the risk factors of venous thrombosis (VT) and arterial thrombosis (AT) in adults with primary immune thrombocytopenia (ITP), particularly in relation to treatments. The population comprised all incident primary ITP adults in France between 2009 and 2017 (FAITH cohort; NCT03429660) built in the national health database. Outcomes were the first hospitalisation for VT and AT. Multivariable Cox regression models included baseline risk factors, time-varying exposure to ITP drugs, splenectomy and to cardiovascular drugs. The cohort included 10 039 patients. A higher risk of hospitalisation for VT was observed with older age, history of VT, history of cancer, splenectomy [hazard ratio (HR) 3·23, 95% confidence interval (CI) 2·26-4·61], exposure to corticosteroids (HR 3·55, 95% CI 2·74-4·58), thrombopoietin-receptor agonists (TPO-RAs; HR 2·28, 95% CI 1·59-3·26) and intravenous immunoglobulin (IVIg; HR 2·10, 95% CI 1·43-3·06). A higher risk of hospitalisation for AT was observed with older age, male sex, a history of cardiovascular disease, splenectomy (HR 1·50, 95% CI 1·12-2·03), exposure to IVIg (HR 1·85, 95% CI 1·36-2·52) and TPO-RAs (HR 1·64, 95% CI 1·26-2·13). Rituximab was not associated with an increased risk. These findings help to estimate the risk of thrombosis in adult patients with ITP and to select treatment.

The association between initial opioid type and long-term opioid use after hip fracture surgery in elderly opioid-naïve patients

Objectives Long-term opioid use after hip fracture surgery has been demonstrated in previously opioid-naïve elderly patients. It is unknown if the opioid type redeemed after hip surgery is associated with long-term opioid use. The aim of this study was to examine the association between the opioid type redeemed within the first three months after hip fracture surgery and opioid use 3-12 months after the surgery. Methods A nationwide population-based cohort study was conducted using data from Danish health registries (2005-2015). Previously opioid-naïve patients registered in the Danish Multidisciplinary Hip Fracture Registry, aged ≥65 years, who redeemed ≥1 opioid prescription within three months after the surgery, were included. Long-term opioid use was defined as ≥1 redeemed prescription within each of three three-month periods within the year after hip fracture surgery. The proportion with long-term opioid use after surgery, conditioned on nine-month survival, was calculated according to opioid types within three months after surgery. Adjusted odds ratios (aOR) for different opioid types were computed by logistic regression analyses with 95% confidence intervals (CI) using morphine as reference. Subgroup analyses were performed according to age, comorbidity and calendar time before and after 2010. Results The study included 26,790 elderly, opioid-naïve patients with opioid use within three months after hip fracture surgery. Of these patients, 21% died within nine months after the surgery. Among the 21,255 patients alive nine months after surgery, 15% became long-term opioid users. Certain opioid types used within the first three months after surgery were associated with long-term opioid use compared to morphine (9%), including oxycodone (14%, aOR; 1.76, 95% CI 1.52-2.03), fentanyl (29%, aOR; 4.37, 95% CI 3.12-6.12), codeine (13%, aOR; 1.55, 95% CI 1.14-2.09), tramadol (13%, aOR; 1.56, 95% CI 1.35-1.80), buprenorphine (33%, aOR; 5.37, 95% CI 4.14-6.94), and >1 opioid type (27%, aOR; 3.83, 95% CI 3.31-4.44). The proportion of long-term opioid users decreased from 18% before 2010 to 13% after 2010. Conclusions The findings suggest that use of certain opioid types after hip fracture surgery is more associated with long-term opioid use than morphine and the proportion initiating long-term opioid use decreased after 2010. The findings suggest that some elderly, opioid-naïve patients appear to be presented with untreated pain conditions when seen in the hospital for a hip fracture surgery. Decisions regarding the opioid type prescribed after hospitalization for hip fracture surgery may be linked to different indication for pain treatment, emphasizing the likelihood of careful and conscientious opioid prescribing behavior.

Renin-angiotensin system blockers and 1-year mortality in patients with post-operative acute kidney injury

BACKGROUND

Angiotensin-converting enzyme inhibitor (ACE-I) and angiotensin-receptor blocker (ARB) users may be associated with increased mortality in patients with post-operative acute kidney injury (AKI), but data are limited. We studied whether users of ACE-I/ARBs with AKI after colorectal cancer surgery (CRC) were associated with increased 1-year mortality after AKI.

METHODS

This population-based cohort study in Northern Denmark included patients with AKI within 7 days after CRC surgery during 2005-2014. From reimbursed prescriptions, patients were classified as ACE-I/ARB current, former, or non-users. We computed the cumulative 30-day and 1-year mortality after AKI with 95% confidence intervals (95% CI) using the Kaplan-Meier method (1-survival function). Hazard ratios (HRs) comparing mortality in current and former users with non-users were computed by Cox proportional hazards regression analyses, controlling for potential confounders.

RESULTS

We identified 10 713 CRC surgery patients. A total of 2000 patients had AKI and were included. Thirty-day mortality was 16.5% (95% CI 13.7-19.8), 16.2% (95% CI 11.3-22.8), and 13.4% (95% CI 11.6-15.4) for current, former, and non-users. Adjusted HR was 1.26 (95% CI 0.96-1.65) and 1.19 (95% CI 0.78-1.82) for current and former users compared with non-users. One-year mortality rates were 26.4% (95% CI 22.9-30.4), 29.8% (95% CI 23.2-37.8), and 24.7% (95% CI 22.4-27.2) in current, former, and non-users. Compared with non-users, the adjusted 1-year HR for death in current and former users were 1.29 (95% CI 0.96-1.73) and 1.11 (95% CI 0.91-1.35).

CONCLUSION

Based on our findings, current users of ACE-I/ARB may possibly have a small increase in mortality rate in the year after post-operative AKI, although the degree of certainty is low.

Readmission of older acutely admitted medical patients after short-term admissions in Denmark: a nationwide cohort study

Background

Knowledge of unplanned readmission rates and prognostic factors for readmission among older people after early discharge from emergency departments is sparse. The aims of this study were to examine the unplanned readmission rate among older patients after short-term admission, and to examine risk factors for readmission including demographic factors, comorbidity and admission diagnoses.

Methods

This cohort study included all medical patients aged ≥65 years acutely admitted to Danish hospitals between 1 January 2013 and 30 June 2014 and surviving a hospital stay of ≤24 h. Data on readmission within 30 days, comorbidity, demographic factors, discharge diagnoses and mortality were obtained from the Danish National Registry of Patients and the Danish Civil Registration System. We examined risk factors for readmission using a multivariable Cox regression to estimate adjusted hazard ratios (aHR) with 95% confidence intervals (CI) for readmission.

Results

A total of 93,306 patients with a median age of 75 years were acutely admitted and discharged within 24 h, and 18,958 (20.3%; 95% CI 20.1 - 20.6%) were readmitted with a median time to readmission of 8 days (IQR 3 - 16 days). The majority were readmitted with a new diagnosis. Male sex (aHR 1.15; 1.11 - 1.18) and a Charlson Comorbidity Index ≥3 (aHR 2.28; 2.20 - 2.37) were associated with an increased risk of readmission. Discharge diagnoses associated with increased risk of readmission were heart failure (aHR 1.26; 1.12 - 1.41), chronic obstructive pulmonary disease (aHR 1.33; 1.25 - 1.43), dehydration (aHR 1.28; 1.17 - 1.39), constipation (aHR 1.26; 1.14 - 1.39), anemia (aHR 1.45; 1.38 - 1.54), pneumonia (aHR 1.15; 1.06 - 1.25), urinary tract infection (aHR 1.15; 1.07 - 1.24), suspicion of malignancy (aHR 1.51; 1.37 - 1.66), fever (aHR 1.52; 1.33 - 1.73) and abdominal pain (aHR 1.12; 1.05 - 1.19).

Conclusions

One fifth of acutely admitted medical patients aged ≥65 were readmitted within 30 days after early discharge. Male gender, the burden of comorbidity and several primary discharge diagnoses were risk factors for readmission.

Considerations for pharmacoepidemiological analyses in the SARS-CoV-2 pandemic

The coronavirus disease 2019 (COVID-19) pandemic has triggered several hypotheses regarding use of specific medicines and risk of infection as well as prognosis. Under these unique circumstances, rapid answers require quick engagement in data collection and analyses; however, appropriate design and conduct of pharmacoepidemiologic studies are needed to generate valid and reliable evidence. In this paper, endorsed by the International Society for Pharmacoepidemiology, we provide methodological considerations for the conduct of pharmacoepidemiological studies in relation to the pandemic across eight domains: (1) timeliness of evidence, including the need to prioritise some questions over others in the acute phase of the pandemic; (2) the need to align observational and interventional research on efficacy; (3) the specific challenges related to "real-time epidemiology" during an ongoing pandemic; (4) what design to use to answer a specific question; (5) considerations on the definition of exposures; (6) what covariates to collect; (7) considerations on the definition of outcomes; and (8) the need for transparent reporting.

The Validity of Registered Synchronous Peritoneal Metastases from Colorectal Cancer in the Danish Medical Registries

Introduction

Treatment options for peritoneal metastases (PM) from colorectal cancer (CRC) have increased, their efficiency should be monitored. For this purpose, register-based data on PM can be used, if valid.

Purpose

We aimed to evaluate the completeness and positive predictive value (PPV) of synchronous peritoneal metastases (S-PM) registered among CRC patients in the Danish National Patient Register (DNPR) and/or the Danish National Pathology Register (the DNPatR) using the Danish Colorectal Cancer Group database (DCCG) as a reference.

Patients and Methods

We identified Danish patients with newly diagnosed primary CRC in the DCCG during 2014–2015. S-PM were routinely registered in the DCCG. We excluded patients with non-CRC cancers and identified S-PM using all three registries. We estimated the completeness and the PPV of registered S-PM in the DNPR, the DNPatR and the DNPR and/or the DNPatR (DNPR/DNPatR) in combination using the DCCG as the reference. We stratified by age, gender, WHO performance status, tumour location and distant metastases to liver and/or lungs.

Results

We identified 9142 patients with CRC in DCCG. In DCCG, 366 patients were registered with S-PM, among whom 213 in DCCG only, whereas 153 in DCCG and in at least one of DNPR and/or DNPatR. In DNPR/DNPatR, S-PM was registered with a completeness of 42% [95% CI: 37–47] and a PPV of 60% [95% CI: 54–66]. In the DNPR only, the completeness was 32% [95% CI: 27–37] and the PPV 57% [95% CI: 50–64]. The completeness in the DNPatR was 19% [95% CI: 15–23] and the PPV was 76% [95% CI: 68–85]. In the DNPR/DNPatR patients aged <60 years (57% [95% CI: 46–69]), patients with WHO performance status 0 (46% [95% CI: 37–54]) and patients with no distant metastases (58% [95% CI: 50–65]) were registered with a higher completeness.

Conclusion

Our algorithm demonstrates that the DNPR/DNPatR captures less than half of CRC patients with S-PM. Potential candidates for curative treatment options are registered with a higher completeness. Clinicians should be encouraged to register the presence of S-PM to increase the validity of register-based S-PM data.

Prognostic impact of elevated lactate levels on mortality in critically ill patients with and without preadmission metformin treatment: a Danish registry-based cohort study

BACKGROUND

Lactate is a robust prognostic marker for the outcome of critically ill patients. Several small studies reported that metformin users have higher lactate levels at ICU admission without a concomitant increase in mortality. However, this has not been investigated in a larger cohort. We aimed to determine whether the association between lactate levels around ICU admission and mortality is different in metformin users compared to metformin nonusers.

METHODS

This cohort study included patients admitted to ICUs in northern Denmark between January 2010 and August 2017 with any circulating lactate measured around ICU admission, which was defined as 12 h before until 6 h after admission. The association between the mean of the lactate levels measured during this period and 30-day mortality was determined for metformin users and nonusers by modelling restricted cubic splines obtained from a Cox regression model.

RESULTS

Of 37,293 included patients, 3183 (9%) used metformin. The median (interquartile range) lactate level was 1.8 (1.2-3.2) in metformin users and 1.6 (1.0-2.7) mmol/L in metformin nonusers. Lactate levels were strongly associated with mortality for both metformin users and nonusers. However, the association of lactate with mortality was different for metformin users, with a lower mortality rate in metformin users than in nonusers when admitted with similar lactate levels. This was observed over the whole range of lactate levels, and consequently, the relation of lactate with mortality was shifted rightwards for metformin users.

CONCLUSION

In this large observational cohort of critically ill patients, early lactate levels were strongly associated with mortality. Irrespective of the degree of hyperlactataemia, similar lactate levels were associated with a lower mortality rate in metformin users compared with metformin nonusers. Therefore, lactate levels around ICU admission should be interpreted according to metformin use.

Intubation rate, duration of noninvasive ventilation and mortality after noninvasive neurally adjusted ventilatory assist (NIV-NAVA)

BACKGROUND

Asynchrony is a common problem in patients treated with noninvasive ventilation (NIV). Neurally adjusted ventilatory assist (NAVA) has shown to improve patient-ventilator interaction. However, it is unknown whether NIV-NAVA improves outcomes compared to noninvasive pressure support (NIV-PS).

METHODS

This observational cohort study included patients 18 years or older receiving noninvasive ventilation using an oro-nasal face mask for more than 2 hours in a Danish ICU. The study included a NIV-NAVA cohort (year 2013-2015) and two comparison cohorts: (a) a historical NIV-PS cohort (year 2011-2012) before the implementation of NIV-NAVA at the ICU in 2013, and (b) a concurrent NIV-PS cohort (year 2013-2015). Outcomes of NIV-NAVA (intubation rate, duration of NIV and 90-day mortality) were assessed and compared using multivariable linear and logistic regression adjusted for relevant confounders.

RESULTS

The study included 427 patients (91 in the NIV-NAVA, 134 in the historic NIV-PS and 202 in the concurrent NIV-PS cohort). Patients treated with NIV-NAVA did not have improved outcome after adjustment for measured confounders. Actually, there were statistically imprecise higher odds for intubation in NIV-NAVA patients compared with both the historical [OR 1.48, CI (0.74-2.97)] and the concurrent NIV-PS cohort [OR 1.67, CI (0.87-3.19)]. NIV-NAVA might also have a longer length of NIV [63%, CI (19%-125%)] and [139%, CI (80%-213%)], and might have a higher 90-day mortality [OR 1.24, CI (0.69-2.25)] and [OR 1.39, CI (0.81-2.39)]. Residual confounding cannot be excluded.

CONCLUSION

This present study found no improved clinical outcomes in patients treated with NIV-NAVA compared to NIV-PS.

One-year mortality among non-surgical patients with hematological malignancies admitted to the intensive care unit: a Danish nationwide population-based cohort study

PURPOSE

Contemporary data on mortality of hematological patients admitted to the intensive care unit (ICU) are missing. In a Danish nationwide set-up, we assessed 30-day and 1-year mortality in this population including impact of age and comorbidity, with non-hematological patients as reference.

METHODS

This population-based cohort study included all non-surgical patients > 15 years of age admitted to an ICU in Denmark between 2010 and 2015. Data on hematological malignancies were obtained from the Danish Hematological Database, and information on the Charlson Comorbidity Index was obtained from the Danish National Patient Registry. Thirty-day and 1-year mortality was estimated using the Kaplan-Meier method. We used Cox proportional hazards regression to estimate hazard ratios.

RESULTS

We included 2122 ICU patients with a hematological malignancy and 88,951 non-hematological ICU patients. The 30-day mortality was 44% (95% confidence interval: 42-47%) among hematological patients and 27% (27-27%) among non-hematological patients. Similarly, 1-year mortality was 66% (64-68%) and 37% (37-37%), respectively. The corresponding hazard ratio with adjustment for age, sex, and comorbidity was 1.62 (1.54-1.71). Excess mortality was observed in all subgroups of age or of comorbidity. For example, the 1-year mortality for patients with Charlson Comorbidity Index Score > 3: 70% (66-74%) among hematological patients and 62% (61-63%) among non-hematological patients.

CONCLUSION

ICU patients with hematological malignancy had higher mortality than other ICU patients. However, one third of critically ill patients with a hematological malignancy is alive 1 year after ICU admission.

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.

Non-obstetric abdominal surgery during pregnancy and birth outcomes: A Danish registry-based cohort study

INTRODUCTION

Surgery during pregnancy may increase the risk of adverse birth outcomes. In this nationwide registry-based cohort study including women aged 15-54 years with singleton birth or miscarriage, we examined the association between non-obstetric abdominal surgery during pregnancy and the birth outcomes small-for-gestational-age (SGA), preterm birth, and miscarriage.

MATERIAL AND METHODS

The study used data on births or miscarriages from the large national Danish registries in 1997-2015. We calculated absolute risks and risk differences for the main outcomes and used Cox regression analysis with non-obstetric abdominal surgery as a time-varying exposure, adjusting for maternal age, year of last menstrual period, major abdominal surgery before pregnancy, maternal smoking status, rheumatoid arthritis, diabetes and inflammatory bowel disease. Our main outcome measures were risks and hazard ratios (HRs) for SGA, very preterm or preterm birth, and miscarriage after gestational week 7 overall, stratified by calendar year, and, for SGA, trimester of pregnancy. Finally, absolute risk of miscarriage stratified by time since surgery.

RESULTS

Absolute risks in surgically treated vs untreated were 3.4% vs 2.7% for SGA (adjusted HR 1.3, 95% CI 1.1-1.5), 2.2% vs 0.8% for very preterm birth (adjusted HR 2.8, 95% CI 2.2-3.5), 8.3% vs 4.3% for preterm birth (adjusted HR 2.1, 95% CI 1.9-2.3), and 8.2% vs 6.1% for miscarriage (adjusted HR 3.1, 95% CI 2.7-3.5). For miscarriage, the risk was highest the first week after surgery and levelled out after 2 weeks.

CONCLUSIONS

Surgery during pregnancy is associated with an increased risk of SGA, very preterm birth, preterm birth and miscarriage, and the risk of miscarriage is highest the first week after surgery.

Renin-angiotensin system blocker use and the risk of acute kidney injury after colorectal cancer surgery: a population-based cohort study

OBJECTIVES

It is unknown whether preoperative use of ACE inhibitors (ACE-I) or angiotensin receptor blockers (ARBs) affects the risk of acute kidney injury (AKI) after colorectal cancer (CRC) surgery. We assessed the impact of preoperative ACE-I/ARB use on risk of AKI after CRC surgery.

DESIGN

Observational cohort study. Patients were divided into three exposure groups-current, former and non-users-through reimbursed prescriptions within 365 days before the surgery. AKI within 7 days after surgery was defined according to the current Kidney Disease Improving Global Outcome consensus criteria.

SETTING

Population-based Danish medical databases.

PARTICIPANTS

A total of 9932 patients undergoing incident CRC surgery during 2005-2014 in northern Denmark were included through the Danish Colorectal Cancer Group Database.

OUTCOME MEASURE

We computed cumulative incidence proportions (risk) of AKI with 95% CIs for current, former and non-users of ACE-I/ARB, including death as a competing risk. We compared current and former users with non-users by computing adjusted risk ratios (aRRs) using log-binomial regression adjusted for demographics, comorbidities and CRC-related characteristics. We stratified the analyses of ACE-I/ARB users to address any difference in impact within relevant subgroups.

RESULTS

Twenty-one per cent were ACE-I/ARB current users, 6.4% former users and 72.3% non-users. The 7-day postoperative AKI risk for current, former and non-users was 26.4% (95% CI 24.6% to 28.3%), 25.2% (21.9% to 28.6%) and 17.8% (17.0% to 18.7%), respectively. The aRRs of AKI were 1.20 (1.09 to 1.32) and 1.16 (1.01 to 1.34) for current and former users, compared with non-users. The relative risk of AKI in current compared with non-users was consistent in all subgroups, except for higher aRR in patients with a history of hypertension.

CONCLUSIONS

Being a current or former user of ACE-I/ARBs is associated with an increased risk of postoperative AKI compared with non-users. Although it may not be a drug effect, users of ACE-I/ARBs should be considered a risk group for postoperative AKI.

Preadmission use of antidepressants and risk of complications and death after colorectal cancer surgery: a nationwide population-based cohort study

AIM

Few studies have evaluated how preadmission use of antidepressants affects outcomes in colorectal cancer (CRC) patients after they have undergone surgery. Therefore, our aim is to examine whether preadmission use of antidepressants increased the risk of complications and death in patients who underwent CRC surgery.

METHOD

Using the Danish Colorectal Cancer Group Database we identified patients who underwent CRC surgery in Denmark from 2005 to 2012. We identified prescriptions for antidepressants redeemed within 1 year prior to surgery and categorized patients as current users (≤ 90 days), former users (91-365 days) and nonusers. All patients were followed from surgery to 30 days thereafter or to death. We calculated 30-day rates of complications, intensive care unit (ICU) admission and mortality and compared these between users and nonusers using logistic and Cox regression adjusting for potential confounders.

RESULTS

Of 27 374 patients, 8.9% were current users and 3.0% were former users. Antidepressant users were older and had more comorbidity but a similar cancer stage. Compared with nonusers, current users had a higher risk of postoperative reoperation [adjusted odds ratio (aORs) = 1.15 (95% CI 1.02-1.30)], medical complications [aORs = 1.41 (95% CI 1.25-1.60)] and increased ICU admission rate [adjusted hazard ratio (aHR) = 1.32 (95% CI 1.21-1.45)]. The 30-day mortality was 11.4% for current users, 9.1% for former users and 6.2% for nonusers [aHR = 1.34 (95% CI 1.17-1.53) for current vs nonusers].

CONCLUSION

Patients with preadmission use of antidepressants had a higher risk of complications and ICU admission, and higher 30-day mortality following CRC surgery than nonusers.

Opioid use after hip fracture surgery: A Danish nationwide cohort study from 2005 to 2015

BACKGROUND

There is currently a knowledge gap regarding persistent opioid use after hip fracture surgery. Thus, opioid use within a year after hip fracture surgery in patients with/without opioid use before surgery was examined.

METHODS

This population-based cohort study included all patients (aged ≥ 65) undergoing primary hip fracture surgery in Denmark (2005-2015) identified from the Danish Multidisciplinary Hip Fracture Database. Opioid use was assessed from The Danish National Health Service Prescription Database as redeemed prescriptions. The proportion of patients with ≥1 opioid prescription was computed within 6 months before surgery and each of four 3-month periods (quarters) after surgery, among patients alive first day in each period. Proportion differences (95% CI) were calculated for each quarter compared to before surgery. Proportions were calculated for users and nonusers before surgery, including initiators after first quarter.

RESULTS

This study included 69,456 patients. Proportion differences of opioid users were 35.0 (95% CI 34.5-35.5), 7.0 (95% CI 6.5-7.5), 2.9 (95% CI 2.4-3.4) and 1.4 percentage-points (95% CI 0.9-1.9) the four quarters after surgery compared to before. Among opioid nonusers before surgery, 54.7% (95% CI 54.3-55.1), 21.8% (95% CI 21.4-22.2), 17.8% (95% CI 17.4-18.2) and 16.8% (95% CI 16.4-17.2) were opioid users in 1st-4th quarter after surgery. However, 8.5% (95% CI 8.2-8.7) of the nonusers before surgery in 4th quarter initiated opioid use more than a quarter after surgery.

CONCLUSIONS

The proportion of opioid users increased after hip fracture surgery and was 1.4 percentage-points increased in fourth quarter compared to before. Of opioid nonusers before surgery, 16.8% were opioid users fourth quarter after surgery.

SIGNIFICANCE

Opioid use 1 year after hip fracture surgery is common, both in patients who were opioid users and nonusers before the surgery. These significant findings point out the need for indication of benefits and risks of opioid use in the acute and long-term management of patients undergoing hip fracture surgery.

Acute kidney injury and 1-year mortality after colorectal cancer surgery: a population-based cohort study

OBJECTIVES

Acute kidney injury (AKI) is a frequent postoperative complication, but the mortality impact within different postoperative time frames and severities of AKI are poorly understood. We examined the occurrence of postoperative AKI among colorectal cancer (CRC) surgery patients and the impact of AKI on mortality during 1 year after surgery.

DESIGN

Observational cohort study. We defined the exposure, AKI, as a 50% increase in plasma creatinine or initiation of renal replacement therapy within 7 days after surgery or an absolute increase in creatinine of 26 µmol/L within 48 hours.

SETTING

Population-based Danish medical databases.

PARTICIPANTS

A total of 6580 patients undergoing CRC surgery in Northern Denmark during 2005-2011 were included from the Danish Colorectal Cancer Group database.

OUTCOMES MEASURE

Occurrence of AKI and 8-30, 31-90 and 91-365 days mortality in patient with or without AKI.

RESULTS

AKI occurred in 1337 patients (20.3%) of the 6580 patients who underwent CRC surgery. Among patients with AKI, 8-30, 31-90 and 91-365 days mortality rates were 10.1% (95% CI 8.6% to 11.9%), 7.8% (95% CI 6.4% to 9.5%) and 12.0% (95% CI 10.3% to 14.2%), respectively. Compared with patients without AKI, AKI was associated with increased 8-30 days mortality (adjusted HR (aHR)=4.01,95% CI 3.11 to 5.17) and 31-90 days mortality (aHR 2.08,95% CI 1.60 to 2.69), while 91-365 days aHR was 1.12 (95% CI 0.89 to 1.41). We observed no major differences in stratified analyses.

CONCLUSIONS

AKI after surgery for CRC is a frequent postoperative complication associated with a substantially increased 90-day mortality. AKI should be considered a potential target for reducing 90-day mortality.

Survival after bone metastasis by primary cancer type: a Danish population-based cohort study

OBJECTIVE

In the 10 most common primary types with bone metastases, we aimed to examine survival, further stratifying on bone metastases only or with additional synchronous metastases.

METHODS

We included all patients aged 18 years and older with incident hospital diagnosis of solid cancer between 1994 and 2010, subsequently diagnosed with BM until 2012. We followed patients from date of bone metastasis diagnosis until death, emigration or 31 December 2012, whichever came first. We computed 1-year, 3-year and 5-year survival (%) and the corresponding 95% CIs stratified on primary cancer type. Comparing patients with bone metastasis only and patients with other synchronous metastases, we estimated crude and adjusted HRs and corresponding 95% CI for mortality.

RESULTS

We included 17 251 patients with bone metastasis. The most common primary cancer types with bone metastasis were prostate (34%), breast (22%) and lung (20%). One-year survival after bone metastasis diagnosis was lowest in patients with lung cancer (10%, 95% CI 9% to 11%) and highest in patients with breast cancer (51%, 50% to 53%). At 5 years of follow-up, only patients with breast cancer had over 10% survival (13%, 11% to 14%). The risk of mortality was increased for the majority of cancer types among patients with bone and synchronous metastases compared with bone only (adjusted relative risk 1.29-1.57), except for cervix, ovarian and bladder cancer.

CONCLUSIONS

While patients with bone metastases after most primary cancers have poor survival, one of ten patients with bone metastasis from breast cancer survived 5 years.

Metformin use and risk of lactic acidosis in people with diabetes with and without renal impairment: a cohort study in Denmark and the UK

AIMS

To assess risk of lactic acidosis among metformin users compared with other glucose-lowering agent users, according to renal function.

METHODS

Using routine registries and databases, we conducted a cohort study. Of 43 580 metformin and 37 788 other glucose-lowering agent users in northern Denmark and 102 688 metformin and 28 788 other glucose-lowering agent users in the UK during 2001-2011, we identified lactic acidosis using diagnostic codes. We calculated the incidence rates of lactic acidosis in metformin and other glucose-lowering agent users overall and according to baseline estimated GFR (eGFR) levels.

RESULTS

In Denmark, the incidence rates of lactic acidosis were 11.6 (95% CI 7.0-18.1) and 1.8 (95% CI 0.4-5.4) per 100 000 person-years of metformin use and of other glucose-lowering agent use, respectively. In the UK, the corresponding lactic acidosis incidence rates were 6.8 (95% CI 4.6-9.6) and 1.0 (95% CI 0.01-5.7) per 100 000 person-years of metformin use and of other glucose-lowering agent use. The incidence rates increased with decreasing baseline eGFR in both countries. Of the metformin-exposed people with lactic acidosis, 37% in Denmark and 34% in the UK experienced a decline in renal function in the year before the diagnosis.

CONCLUSIONS

Risk of lactic acidosis was higher in metformin users than in other glucose-lowering agent users, and increased with decreasing eGFR, although this could be attributable to surveillance bias; however, diagnosed lactic acidosis was rare and can occur regardless of renal function.

Impact of body mass index on risk of acute kidney injury and mortality in elderly patients undergoing hip fracture surgery

The literature is limited regarding risk factors for acute kidney injury (AKI) and mortality in hip fracture patients, although AKI is common in these patients. While obese patients were at increased risk of AKI, underweight patients with and without AKI had elevated mortality for up to 1 year after hip fracture surgery, compared with normal-weight patients.

INTRODUCTION

This study aimed to examine risk of postoperative AKI and subsequent mortality, by body mass index (BMI) level, in hip fracture surgery patients aged 65 and over.

METHODS

A regional cohort study using medical databases was used. We included all patients who underwent surgery to repair a hip fracture during the years 2005-2011 (n = 13,529) at hospitals in Northern Denmark. We calculated cumulative risk of AKI by BMI level during 5 days postsurgery and subsequent short-term (6-30 days postsurgery) and long-term (31-365 days post-surgery) mortality. We calculated crude and adjusted hazard ratios (aHRs) for AKI and death with 95% confidence intervals (CIs), comparing underweight, overweight, and obese patients with normal-weight patients.

RESULTS

Risks of AKI within five postoperative days were 11.9, 10.1, 12.5, and 17.9% for normal-weight, underweight, overweight, and obese patients, respectively. Among those who developed AKI, short-term mortality was 14.1% for normal-weight patients compared to 23.1% for underweight (aHR 1.7 (95% CI 1.2-2.4)), 10.7% for overweight (aHR 0.9 (95% CI 0.6-1.1)), and 15.2% for obese (aHR 0.9 (95% CI 0.6-1.4)) patients. Long-term mortality was 24.5% for normal-weight, 43.8% for underweight (aHR 1.6 (95% CI 1.0-2.6)), 20.5% for overweight (aHR 0.8 (95% CI 0.6-1.2)), and 21.4% for obese (aHR 1.1 (95% CI 0.7-1.8) AKI patients. Similar associations between BMI and mortality were observed among patients without postoperative AKI, although the absolute mortality risk estimates by BMI were considerably lower in patients without than in those with AKI.

CONCLUSIONS

Obese patients were at increased risk of AKI compared with normal-weight patients. Among patients with and without postoperative AKI, overweight and obesity were not associated with mortality. Compared to normal-weight patients, underweight patients had elevated mortality for up to 1 year after hip fracture surgery irrespective of the presence of AKI. The absolute mortality risks were higher in all BMI groups with the presence of AKI.

Preadmission use of selective serotonin reuptake inhibitors and short-term mortality in diabetic patients hospitalized due to stroke

BACKGROUND

Patients with diabetes have an increased risk of stroke with a poor prognosis. Moreover, diabetic patients are at increased risk of depression and therefore likely to use selective serotonin reuptake inhibitors (SSRIs). We examined whether preadmission SSRI use was associated with increased mortality in diabetic patients hospitalized due to stroke.

METHODS

Population-based medical databases were used to identify all first-time stroke-related hospitalizations and subsequent mortality in diabetic patients in Denmark between 2004 and 2012 (n = 12 620). Based on redeemed prescriptions, SSRI use was categorized as current (new or long term), former or nonuse, and absolute 30-day mortality and mortality rate ratios (MRRs) were computed using Cox regression controlling for confounding factors.

RESULTS

Amongst SSRI nonusers, 30-day stroke mortality was 15.8% (10.4% for ischaemic stroke, 41.8% for intracerebral haemorrhage and 27.3% for subarachnoid haemorrhage). Amongst current SSRI users, 30-day stroke mortality was 23.3% (17.1% for ischaemic stroke, 50.7% for intracerebral haemorrhage and 28.6% for subarachnoid haemorrhage). Current SSRI use was associated with increased 30-day stroke mortality compared with nonuse [adjusted MRR 1.3, 95% confidence interval (CI) 1.1-1.5], with the highest risk observed amongst new users (MRR 1.5, 95% CI 1.2-1.8). Overall stroke mortality was driven by increased mortality due to ischaemic stroke, with adjusted MRRs of 1.3 (95% CI 1.1-1.7) for current users and 1.7 (95% CI 1.2-2.4) for new users. Propensity score-matched results were similar and robust across subgroups.

CONCLUSION

In patients with diabetes, preadmission SSRI use was associated with increased mortality following ischaemic stroke, compared with nonuse.

Preadmission Use of Glucocorticoids and 30-Day Mortality After Stroke

BACKGROUND AND PURPOSE

The prognostic impact of glucocorticoids on stroke mortality remains uncertain. We, therefore, examined whether preadmission use of glucocorticoids is associated with short-term mortality after ischemic stroke, intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH).

METHODS

We conducted a nationwide population-based cohort study using medical registries in Denmark. We identified all patients with a first-time inpatient diagnosis of stroke between 2004 and 2012. We categorized glucocorticoid use as current use (last prescription redemption ≤90 days before admission), former use, and nonuse. Current use was further classified as new or long-term use. We used Cox regression to compute 30-day mortality rate ratios with 95% confidence intervals (CIs), controlling for confounders.

RESULTS

We identified 100 042 patients with a first-time stroke. Of these, 83 735 patients had ischemic stroke, 11 779 had ICH, and 4528 had SAH. Absolute mortality risk was higher for current users compared with nonusers for ischemic stroke (19.5% versus 10.2%), ICH (46.5% versus 34.4%), and SAH (35.0% versus 23.2%). For ischemic stroke, the adjusted 30-day mortality rate ratio was increased among current users compared with nonusers (1.58, 95% CI: 1.46-1.71), driven by the effect of glucocorticoids among new users (1.80, 95% CI: 1.62-1.99). Current users had a more modest increase in the adjusted 30-day mortality rate ratio for hemorrhagic stroke (1.26, 95% CI: 1.09-1.45 for ICH and 1.40, 95% CI: 1.01-1.93 for SAH) compared with nonusers. Former use was not substantially associated with mortality.

CONCLUSIONS

Preadmission use of glucocorticoids was associated with increased 30-day mortality among patients with ischemic stroke, ICH, and SAH.

Preadmission use of ACE inhibitors or angiotensin receptor blockers and short-term mortality after stroke

BACKGROUND AND AIM

The prognostic impact of ACE inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) on stroke mortality remains unclear. We aimed to examine whether prestroke use of ACE-Is or ARBs was associated with improved short-term mortality following ischaemic stroke, intracerebral haemorrhage (ICH) and subarachnoid haemorrhage (SAH).

METHODS

We conducted a nationwide population-based cohort study using medical registries in Denmark. We identified all first-time stroke patients during 2004-2012 and their comorbidities. We defined ACE-I/ARB use as current use (last prescription redemption <90 days before admission for stroke), former use and non-use. Current use was further classified as new or long-term use. We used Cox regression modelling to compute 30-day mortality rate ratios (MRRs) with 95% CIs, controlling for potential confounders.

RESULTS

We identified 100 043 patients with a first-time stroke. Of these, 83 736 patients had ischaemic stroke, 11 779 had ICH, and 4528 had SAH. For ischaemic stroke, the adjusted 30-day MRR was reduced in current users compared with non-users (0.85, 95% CI 0.81 to 0.89). There was no reduction in the adjusted 30-day MRR for ICH (0.95, 95% CI 0.87 to 1.03) or SAH (1.01, 95% CI 0.84 to 1.21), comparing current users with non-users. No association with mortality was found among former users compared with non-users. No notable modification of the association was observed within sex or age strata.

CONCLUSIONS

Current use of ACE-Is/ARBs was associated with reduced 30-day mortality among patients with ischaemic stroke. We found no association among patients with ICH or SAH.

Impact of preadmission treatment with calcium channel blockers or beta blockers on short-term mortality after stroke: a nationwide cohort study

Background

The prognostic impact of preadmission use of calcium channel blockers (CCBs) and beta blockers (BBs) on stroke mortality remains unclear. We aimed to examine whether preadmission use of CCBs or BBs was associated with improved short-term mortality following ischemic stroke, intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH).

Methods

We conducted a nationwide population-based cohort study using Danish medical registries. We identified all patients with a first-time inpatient diagnosis of stroke between 2004 and 2012 and their comorbidities. We defined CCB/BB use as current use, former use, or non-use. Current use was further classified as new or long-term use. We used Cox regression modeling to compute 30-day mortality rate ratios (MRRs) with 95% confidence intervals (CIs), controlling for potential confounders.

Results

We identified 100,043 patients with a first-time stroke. Of these, 83,736 (83.7%) patients had ischemic stroke, 11,779 (11.8%) had ICH, and 4,528 (4.5%) had SAH. Comparing current users of CCBs or BBs with non-users, we found no association with mortality for ischemic stroke [adjusted 30-day MRR = 0.99 (95% CI: 0.94-1.05) for CCBs and 1.01 (95% CI: 0.96-1.07) for BBs], ICH [adjusted 30-day MRR = 1.05 (95% CI: 0.95-1.16) for CCBs and 0.95 (95% CI: 0.87-1.04) for BBs], or SAH [adjusted 30-day MRR = 1.05 (95% CI: 0.85-1.29) for CCBs and 0.89 (95% CI: 0.72-1.11) for BBs]. Former use of CCBs or BBs was not associated with mortality.

Conclusions

Preadmission use of CCBs or BBs was not associated with 30-day mortality following ischemic stroke, ICH, or SAH.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0279-3) contains supplementary material, which is available to authorized users.

Chronic liver disease and 90-day mortality in 21,359 patients following peptic ulcer bleeding--a Nationwide Cohort Study

BACKGROUND

Bleeding is a serious and frequent complication of peptic ulcer disease. Hepatic dysfunction can cause coagulopathy and increases the risk of peptic ulcer bleeding. However, whether chronic liver disease increases mortality after peptic ulcer bleeding remains unclear.

AIM

To examine the prognostic impact of chronic liver disease on mortality after peptic ulcer bleeding.

METHODS

We used population-based medical registries to conduct a cohort study of all Danish residents hospitalised with incident peptic ulcer bleeding from 2004 through 2011. We identified patients diagnosed with liver cirrhosis or non-cirrhotic chronic liver disease before their admission for peptic ulcer bleeding. We then computed 90-day mortality after peptic ulcer bleeding based on the Kaplan-Meier method (1 - survival function) and used a Cox regression model to estimate mortality rate ratios (MRRs), controlling for potential confounders.

RESULTS

We identified 21,359 patients hospitalised with peptic ulcer bleeding. Among these, 653 (3.1%) had a previous diagnosis of liver cirrhosis and 474 (2.2%) had a history of non-cirrhotic chronic liver disease. Patients with liver cirrhosis and non-cirrhotic chronic liver disease had a cumulative 90-day mortality of 25.3% and 20.7%, respectively, compared to 18.3% among patients without chronic liver disease. Liver cirrhosis was associated with an adjusted 90-day MRR of 2.38 (95% CI: 2.02-2.80), compared to 1.49 (95% CI: 1.22-1.83) among patients with non-cirrhotic chronic liver disease.

CONCLUSION

Patients with chronic liver disease, particularly liver cirrhosis, are at increased risk of death within 90 days after hospitalisation for peptic ulcer bleeding compared to patients without chronic liver disease.

Kidney disease and risk of venous thromboembolism: a nationwide population-based case-control study

BACKGROUND

Chronic kidney disease is associated with hemostatic derangements, including both procoagulant activity and platelet dysfunction, which may influence the risk of venous thromboembolism. However, data associating kidney disease with risk of venous thromboembolism are sparse.

OBJECTIVES

We examined whether kidney disease is associated with increased risk of venous thromboembolism.

METHODS

We conducted this nationwide case-control study using data from medical databases. We included 128,096 patients with a hospital diagnosis of VTE in Denmark between 1980 and 2010 (54,473 had pulmonary embolism and 73,623 had deep venous thrombosis only) and 642,426 age- and gender-matched population controls based on risk-set sampling. We identified all previous hospital diagnoses of kidney disease, including nephrotic syndrome, glomerulonephritis without nephrotic syndrome, hypertensive nephropathy, chronic pyelonephritis/interstitial nephritis, polycystic kidney disease, diabetic nephropathy, or other kidney diseases. We used conditional logistic regression models to compute odds ratios (ORs) for venous thromboembolism with adjustment for potential confounders.

RESULTS

Kidney disease was associated with an adjusted OR for venous thromboembolism ranging from 1.41 (95% CI, 1.22-1.63) for hypertensive nephropathy to 2.89 (95% CI, 2.26-3.69) for patients with nephrotic syndrome. The association was strongest within the first 3 months after a diagnosis of chronic kidney disease (adjusted OR for nephrotic syndrome = 23.23; 95% CI, 8.58-62.89), gradually declining thereafter. The risk, however, remained elevated for more than 5 years, especially in patients with nephrotic syndrome and glomerulonephritis.

CONCLUSIONS

Kidney diseases, in particular nephrotic syndrome and glomerulonephritis, were associated with an increased risk of venous thromboembolism.

Risk and prognosis of cancer in patients with nephrotic syndrome

BACKGROUND

Nephrotic syndrome may be a marker of occult cancer, but population-based studies of this association are lacking. Therefore, we examined the risk and prognosis of cancer in patients with nephrotic syndrome.

METHODS

We conducted this population-based cohort study in Denmark, including all individuals diagnosed with nephrotic syndrome between 1980 and 2010 without a preceding cancer history. We computed the 5-year risk of cancer accounting for competing risk by death and standardized incidence ratios (SIRs) of cancer in patients with nephrotic syndrome relative to the general population. We compared the 5-year mortality for patients with cancer after nephrotic syndrome with that for a cancer cohort without a history of nephrotic syndrome using Cox regression adjusted for age, gender, and comorbidity.

RESULTS

Of 4293 individuals with nephrotic syndrome, 338 developed an incident cancer during a median follow-up of 5.7 years. The 5-year risk of any cancer was 4.7% in patients with nephrotic syndrome, a 73% increased risk (SIR, 1.73; 95% confidence interval [CI], 1.55-1.92). The association was most pronounced for lung cancer, kidney cancer, lymphoma, and multiple myeloma. It was highest within 1 year of nephrotic syndrome diagnosis (SIR, 4.49; 95% CI, 3.68-5.42), but remained increased beyond 1 year (SIR, 1.34; 95% CI, 1.17-1.53). The 5-year mortality after cancer was 68.5% in patients with cancer with nephrotic syndrome and 63.4% in the cancer comparison cohort (adjusted hazard ratio, 1.20; 95% CI, 1.02-1.42).

CONCLUSIONS

Nephrotic syndrome is a marker of occult solid tumors and hematologic malignancies and is associated with a worsened cancer prognosis.

Sodium phosphate does not increase risk for acute kidney injury after routine colonoscopy, compared with polyethylene glycol

BACKGROUND & AIMS

Oral sodium phosphate (OSP) is a common bowel purgative administered before colonoscopy; the Food and Drug Administration has warned against its use because of concerns about acute kidney injury (AKI) from the absorbed phosphate and dystrophic calcification. However, it is not clear if OSP is associated with AKI in the general population or in high-risk subgroups undergoing colonoscopy. We estimated the risk of AKI among patients undergoing a screening colonoscopy using OSP vs polyethylene glycol (PEG) for bowel cleansing in a large, US-based claims database.

METHODS

We used an insurance database to identify a cohort of patients ages 50 to 75 years who underwent screening colonoscopies as outpatients from January 2000 through November 2008 (before the Food and Drug Administration warning), receiving OSP (n = 121,266) or PEG (n = 429,430) within 30 days beforehand, without prior use of either drug. We collected data from patients for 6 months afterward to identify those who developed AKI or renal failure, or received dialysis. Adjusted and propensity score-matched hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. We investigated the effects in subgroups with higher AKI risk (patients with chronic kidney disease, kidney stones, hypertension, or diabetes, or using antihypertensive or nonsteroidal anti-inflammatory drugs).

RESULTS

AKI occurred in 0.2% of OSP users and in 0.3% of PEG users (adjusted HR, 0.86; 95% CI, 0.75-0.99). OSP users matched well with PEG users, producing similar estimates (HR, 0.85; 95% CI, 0.72-1.01). We did not observe a consistent increase in the risk of AKI or other outcomes in any subgroups analyzed.

CONCLUSIONS

In a large database analysis, we did not associate administration of OSP before colonoscopy with increased risk of postprocedure AKI, even in high-risk clinical subgroups.

Psychiatric diagnoses and psychoactive medication use among nonsurgical critically ill patients receiving mechanical ventilation

IMPORTANCE

The relationship between critical illness and psychiatric illness is unclear.

OBJECTIVE

To assess psychiatric diagnoses and medication prescriptions before and after critical illness.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study in Denmark of critically ill patients in 2006-2008 with follow-up through 2009, and 2 matched comparison cohorts from hospitalized patients and from the general population.

EXPOSURES

Critical illness defined as intensive care unit admission with mechanical ventilation.

MAIN OUTCOMES AND MEASURES

Adjusted prevalence ratios (PRs) of psychiatrist-diagnosed psychiatric illnesses and prescriptions for psychoactive medications in the 5 years before critical illness. For patients with no psychiatric history, quarterly cumulative incidence (risk) and adjusted hazard ratios (HRs) for diagnoses and medications in the following year, using Cox regression.

RESULTS

Among 24,179 critically ill patients, 6.2% had 1 or more psychiatric diagnoses in the prior 5 years vs 5.4% for hospitalized patients (adjusted PR, 1.31; 95% CI, 1.22-1.42; P<.001) and 2.4% for the general population (adjusted PR, 2.57; 95% CI, 2.41-2.73; P<.001). Five-year preadmission psychoactive prescription rates were similar to hospitalized patients: 48.7% vs 48.8% (adjusted PR, 0.97; 95% CI, 0.95-0.99; P<.001) but were higher than the general population (33.2%; adjusted PR, 1.40; 95% CI, 1.38-1.42; P<.001). Among the 9912 critical illness survivors with no psychiatric history, the absolute risk of new psychiatric diagnoses was low but higher than hospitalized patients: 0.5% vs 0.2% over the first 3 months (adjusted HR, 3.42; 95% CI, 1.96-5.99; P <.001), and the general population cohort (0.02%; adjusted HR, 21.77; 95% CI, 9.23-51.36; P<.001). Risk of new psychoactive medication prescriptions was also increased in the first 3 months: 12.7% vs 5.0% for the hospital cohort (adjusted HR, 2.45; 95% CI, 2.19-2.74; P<.001) and 0.7% for the general population (adjusted HR, 21.09; 95% CI, 17.92-24.82; P<.001). These differences had largely resolved by 9 to 12 months after discharge.

CONCLUSIONS AND RELEVANCE

Prior psychiatric diagnoses are more common in critically ill patients than in hospital and general population cohorts. Among survivors of critical illness, new psychiatric diagnoses and psychoactive medication use is increased in the months after discharge. Our data suggest both a possible role of psychiatric disease in predisposing patients to critical illness and an increased but transient risk of new psychiatric diagnoses and treatment after critical illness.

Hospitalization with acute exacerbation of chronic obstructive pulmonary disease and associated health resource utilization: a population-based Danish cohort study

OBJECTIVE

Health resource utilization (HRU) and outcomes associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are not well described. Therefore, a population-based cohort study was conducted to characterize patients hospitalized with AECOPD with regard to HRU, mortality, recurrence, and predictors of readmission with AECOPD.

METHODS

Using Danish healthcare databases, this study identified COPD patients with at least one AECOPD hospitalization between 2005-2009 in Northern Denmark. Hospitalized AECOPD patients' HRU, in-hospital mortality, 30-day, 60-day, 90-day, and 180-day post-discharge mortality and recurrence risk, and predictors of readmission with AECOPD in the year following study inclusion were characterized.

RESULTS

This study observed 6612 AECOPD hospitalizations among 3176 prevalent COPD patients. Among all AECOPD hospitalizations, median length of stay was 6 days (interquartile range [IQR] 3-9 days); 5 days (IQR 3-9) among those without ICU stay and 11 days (IQR 7-20) among the 8.6% admitted to the ICU. Mechanical ventilation was provided to 193 (2.9%) and non-invasive ventilation to 479 (7.2%) admitted patients. In-hospital mortality was 5.6%. Post-discharge mortality was 4.2%, 7.8%, 10.5%, and 17.4% at 30, 60, 90, and 180 days, respectively. Mortality and readmission risk increased with each AECOPD hospitalization experienced in the first year of follow-up. Readmission at least twice in the first year of follow-up was observed among 286 (9.0%) COPD patients and was related to increasing age, male gender, obesity, asthma, osteoporosis, depression, myocardial infarction, diabetes I and II, any malignancy, and hospitalization with AECOPD or COPD in the prior year.

LIMITATIONS

The study included only hospitalized AECOPD patients among prevalent COPD patients. Furthermore, information was lacking on clinical variables.

CONCLUSION

These findings indicate that AECOPD hospitalizations are associated with substantial mortality and risk of recurrence.

Hospital visits among women with skeletal-related events secondary to breast cancer and bone metastases: a nationwide population-based cohort study in Denmark

Objective

Skeletal-related events (SREs) among women with breast cancer may be associated with considerable use of health-care resources. We characterized inpatient and outpatient hospital visits in a national population-based cohort of Danish women with SREs secondary to breast cancer and bone metastases.

Methods

We identified first-time breast cancer patients with bone metastases from 2003 through 2009 who had a subsequent SRE (defined as pathologic fracture, spinal cord compression, radiation therapy, or surgery to bone). Hospital visits included the number of inpatient hospitalizations, length of stay, number of hospital outpatient clinic visits, and emergency room visits. The number of hospital visits was assessed for a pre-SRE period (90 days prior to the diagnostic period), a diagnostic period (14 days prior to the SRE), and a post-SRE period (90 days after the SRE). Patients who experienced more than one SRE during the 90-day post-SRE period were defined as having multiple SREs and were followed until 90 days after the last SRE.

Results

We identified 569 women with SREs secondary to breast cancer with bone metastases. The majority of women had multiple SREs (73.1%). A total of 20.9% and 33.4% of women with single and multiple SREs died in the post-SRE period, respectively. SREs were associated with a large number of hospital visits in the diagnostic period, irrespective of the number and type of SREs. Women with multiple SREs generally had a higher number of visits compared to those with a single SRE in the post-SRE period, eg, median length of hospitalization was 5 days (interquartile range 0–15) for women with a single SRE and 13 days (interquartile range 4–30) for women with multiple SREs.

Conclusion

SREs secondary to breast cancer and bone metastases were associated with substantial use of hospital resources.

Type 2 diabetes and 1-year mortality in intensive care unit patients

BACKGROUND

Data on the prognostic impact of diabetes and diabetic complications in intensive care unit (ICU) patients are limited and inconsistent. We, therefore, examined mortality in ICU patients with type 2 diabetes with and without pre-existing heart and kidney diseases compared with nondiabetic patients.

DESIGN

We conducted this population-based cohort study in Northern Denmark during 2005-2011. We included all ICU patients aged 40 years or older from the 17 ICUs in the area and identified type 2 diabetes by either a filled prescription for an antidiabetic drug, a previous diagnosis of diabetes, or an elevated glycosylated haemoglobin level. Diabetic patients were disaggregated according to pre-existing diagnoses of heart disease (myocardial infarction or heart failure) and kidney disease. We estimated 1-year mortality by the Kaplan-Meier method and hazard ratios of death (HRs) during follow-up using Cox regression, controlling for confounding factors and stratified by relevant subgroups.

RESULTS

Among 45 018 ICU patients, 7219 (16·0%) had type 2 diabetes. Overall, 1-year mortality was 36·0% in ICU patients with type 2 diabetes, rising to 54·6% in patients with pre-existing heart and kidney diseases, compared with 29·1% in nondiabetic patients. Comparing diabetic with nondiabetic patients, the adjusted 0- to 30-day HR was 1·20 (95% confidence interval (CI): 1·13-1·26) and 1·19 (95% CI: 1·10-1·28) during the 31- to 365-day follow-up period. Pre-existing kidney disease further increased the impact of diabetes, while heart disease alone had no such effect.

CONCLUSIONS

ICU patients with type 2 diabetes had higher 1-year mortality compared with nondiabetic ICU patients, particularly those with pre-existing kidney disease.

Validity of the coding for intensive care admission, mechanical ventilation, and acute dialysis in the Danish National Patient Registry: a short report

BACKGROUND

Large health care databases provide a cost-effective data source for observational research in the intensive care unit (ICU) if the coding is valid. The aim of this study was to investigate the accuracy of the recorded coding of ICU admission, mechanical ventilation, and acute dialysis in the population-based Danish National Patient Registry (DNPR).

METHODS

We conducted the study in the North Denmark Region, including seven ICUs. From the DNPR we selected a total of 150 patients with an ICU admission by the following criteria: (1) 50 patients randomly selected among all patients registered with an ICU admission code, (2) 50 patients with an ICU admission code and a concomitant code for mechanical ventilation, and (3) 50 patients with an ICU admission code and a concomitant code for acute dialysis. Using the medical records as gold standard we estimated the positive predictive value (PPV) for each of the three procedure codes.

RESULTS

We located 147 (98%) of the 150 medical records. Of these 147 patients, 141 (95.9%; 95% confidence interval [CI]: 91.8-98.3) had a confirmed ICU admission according to their medical records. Among patients, who were selected only on the coding for ICU admission, the PPV for ICU admission was 87.2% (95% CI: 75.6-94.5). For the mechanical ventilation code, the PPV was 100% (95% CI: 95.1-100). Forty-nine of 50 patients with the coding for acute dialysis received this treatment, corresponding to a PPV of 98.0% (95% CI: 91.0-99.8).

CONCLUSION

We found a high PPV for the coding of ICU admission and even higher PPVs for mechanical ventilation, and acute dialysis in the DNPR. The DNPR is a valuable data source for observational studies of ICU patients.

Methods to assess seasonal effects in epidemiological studies of infectious diseases--exemplified by application to the occurrence of meningococcal disease

Seasonal variation in occurrence is a common feature of many diseases, especially those of infectious origin. Studies of seasonal variation contribute to healthcare planning and to the understanding of the aetiology of infections. In this article, we provide an overview of statistical methods for the assessment and quantification of seasonality of infectious diseases, as exemplified by their application to meningococcal disease in Denmark in 1995-2011. Additionally, we discuss the conditions under which seasonality should be considered as a covariate in studies of infectious diseases. The methods considered range from the simplest comparison of disease occurrence between the extremes of summer and winter, through modelling of the intensity of seasonal patterns by use of a sine curve, to more advanced generalized linear models. All three classes of method have advantages and disadvantages. The choice among analytical approaches should ideally reflect the research question of interest. Simple methods are compelling, but may overlook important seasonal peaks that would have been identified if more advanced methods had been applied. For most studies, we suggest the use of methods that allow estimation of the magnitude and timing of seasonal peaks and valleys, ideally with a measure of the intensity of seasonality, such as the peak-to-low ratio. Seasonality may be a confounder in studies of infectious disease occurrence when it fulfils the three primary criteria for being a confounder, i.e. when both the disease occurrence and the exposure vary seasonally without seasonality being a step in the causal pathway. In these situations, confounding by seasonality should be controlled as for any confounder.