Low Completeness of Bacteraemia Registration in the Danish National Patient Registry

Detection of infections by computerized capture of peaks in longitudinally measured C-reactive protein levels

We developed four algorithms for the automatic capture of C-reactive protein (CRP) peaks in 296 adult patients with acute myeloid leukemia who had bloodstream infection (BSI) episodes, negative blood cultures (BCs) or possible infections where no BCs were performed. The algorithms detected CRP peaks for 418-446 of the 586 documented BSI episodes (71.3-76.1%) and 2714-3118 of the 4382 negative BCs (61.9-71.2%). The four algorithms captured 382-789 CRP peaks in which there were neither BSI episodes nor negative BCs. We conclude that automatic capture of CRP peaks is a tool for the monitoring of BSI episodes and possibly other infections in patients with acute myeloid leukemia.

Impact of C-reactive protein and albumin levels on short, medium, and long term mortality in patients with diffuse large B-cell lymphoma

Objectives and study design: In this population-based study of 602 patients, we amended C-reactive protein (CRP) and plasma albumin (PA) levels around the diagnosis of diffuse large B-cell lymphoma (DLBCL) to the International Prognostic Index (IPI) and assessed 0-90, 91-365, and +365-day survival.Results: The CRP did not contribute to the IPI's prognostic or discriminatory ability, regardless of time period, particularly not in models with PA. In contrast, the PA was an important contributor, especially in the 0-90 day period, but also up to one year after the diagnosis. For day 0-90, the model with the IPI only had an Area Under the Receiver Operating Characteristics (AUROC) of 0.742, whereas the IPI with PA as a continuous variable rendered an AUROC of 0.841. Especially the lower PA quartile (18-32 g/L) contributed to the worse prognosis.Conclusions: The amendment of PA to the IPI may significantly improve the short-term prognostic and discriminative ability.Key messagesThe amendment of the plasma albumin (PA) level to the International Prognostic Index significantly improved the prediction of mortality up to one year after the diagnosis of diffuse large B-cell lymphoma.It was especially the lower quartile of the PA level (18-32 g/L) that contributed to the worse prognosis.

Decrease in All-Cause 30-Day Mortality after Bacteraemia over a 15-Year Period: A Population-Based Cohort Study in Denmark in 2000-2014

INTRODUCTION

Bacteraemia is a frequent infectious condition that strongly affects morbidity and mortality. The incidence is increasing worldwide. This study explores all-cause 30-day mortality after bacteraemia in two out of Denmark's five healthcare regions with approximately 2.4 million inhabitants.

METHODS

Clinically significant bacteraemia episodes (n = 55,257) were identified from a geographically well-defined background population between 2000 and 2014, drawing on population-based data regarding bacterial species and vital status. All-cause 30-day mortality was assessed in relation to bacteraemia episodes, number of patients with analysed blood cultures and the background population.

RESULTS

We observed a decreasing trend of all-cause 30-day mortality between 2000 and 2014, both in relation to the number of bacteraemia episodes and the background population. Mortality decreased from 22.7% of the bacteraemia episodes in 2000 to 17.4% in 2014 (annual IRR [95% CI]: 0.983 [0.979-0.987]). In relation to the background population, there were 41 deaths per 100,000 inhabitants in 2000, decreasing to 39 in 2014 (annual IRR [95% CI]: 0.988 [0.982-0.993]). Numbers of inhabitants, bacteraemia episodes, and analysed persons having BCs increased during the period.

CONCLUSIONS

All-cause 30-day mortality in patients with bacteraemia decreased significantly over a 15-year period.

Longitudinal trajectory patterns of plasma albumin and C-reactive protein levels around diagnosis, relapse, bacteraemia, and death of acute myeloid leukaemia patients

Background

No study has evaluated C-reactive protein (CRP) and plasma albumin (PA) levels longitudinally in patients with acute myeloid leukaemia (AML).

Methods

We studied defined events in 818 adult patients with AML in relation to 60,209 CRP and PA measures. We investigated correlations between CRP and PA levels and daily CRP and PA levels in relation to AML diagnosis, AML relapse, or bacteraemia (all ±30 days), and death (─30–0 days).

Results

On the AML diagnosis date (D0), CRP levels increased with higher WHO performance score (PS), e.g. patients with PS 3/4 had 68.1 mg/L higher CRP compared to patients with PS 0, adjusted for relevant covariates. On D0, the PA level declined with increasing PS, e.g. PS 3/4 had 7.54 g/L lower adjusted PA compared to PS 0. CRP and PA levels were inversely correlated for the PA interval 25–55 g/L (R = − 0.51, p < 10–5), but not for ≤24 g/L (R = 0.01, p = 0.57). CRP increases and PA decreases were seen prior to bacteraemia and death, whereas no changes occurred up to AML diagnosis or relapse. CRP increases and PA decreases were also found frequently in individuals, unrelated to a pre-specified event.

Conclusions

PA decrease is an important biomarker for imminent bacteraemia in adult patients with AML.

Variation in Proportion of Blood Cultures Obtained for Children With Skin and Soft Tissue Infections

OBJECTIVES

To identify variation in the proportion of blood cultures obtained for pediatric skin and soft tissue infections (SSTIs) among children's hospitals.

METHODS

We conducted a retrospective cohort study using the Pediatric Health Information System database, which we queried for emergency department (ED)-only and hospital encounters between 2012 and 2017 for children aged 2 months to 18 years with diagnosis codes for SSTI. The primary outcome was proportion of SSTI encounters during which blood cultures were obtained. Encounters with and without blood cultures were compared for length of stay, costs, and 30-day ED revisit and readmission rates, adjusted for patient factors and hospital clustering. We also identified encounters with bacteremia using billing codes for septicemia and bacteremia.

RESULTS

We identified 239 954 ED-only and 49 291 hospital SSTI encounters among 38 hospitals. Median proportions of ED-only and hospital encounters with blood cultures were 3.2% (range: 1%- 11%) and 51.6% (range: 25%-81%), respectively. Adjusted ED-only encounters with versus without blood culture had higher costs ($1266 vs $460, P < .001), higher ED revisit rates (3.6% vs 2.9%, P < .001), and higher admission rates (2.0% vs 0.9%, P < .001). Hospital encounters with blood culture had longer length of stay (2.3 vs 2.0 days, P < .001), higher costs ($5254 vs $4425, P < .001), and higher readmission rates (0.8% vs 0.7%, P = .027). The overall proportion of encounters with bacteremia was 0.6% for ED-only encounters and 1.0% for hospital encounters.

CONCLUSIONS

Despite multiple studies in which low clinical value was demonstrated and current Infectious Diseases Society of America guidelines arguing against the practice, blood cultures were obtained frequently for children hospitalized with SSTIs, with substantial variation across institutions. Few bacteremic encounters were identified.

Contacting out-of-hours primary care or emergency medical services for time-critical conditions - impact on patient outcomes

BACKGROUND

Out-of-hours (OOH) healthcare services in Western countries are often differentiated into out-of-hours primary healthcare services (OOH-PC) and emergency medical services (EMS). Call waiting time, triage model and intended aims differ between these services. Consequently, the care pathway and outcome could vary based on the choice of entrance to the healthcare system. We aimed to investigate patient pathways and 1- and 1-30-day mortality, intensive care unit (ICU) stay and length of hospital stay for patients with acute myocardial infarction (AMI), stroke and sepsis in relation to the OOH service that was contacted prior to the hospital contact.

METHODS

Population-based observational cohort study during 2016 including adult patients from two Danish regions with an OOH service contact on the date of hospital contact. Patients <18 years were excluded. Data was retrieved from OOH service databases and national registries, linked by a unique personal identification number. Crude and adjusted logistic regression analyses were performed to assess mortality in relation to contacted OOH service with OOH-PC as the reference and cox regression analysis to assess risk of ICU stay.

RESULTS

We included 6826 patients. AMI and stroke patients more often contacted EMS (52.1 and 54.1%), whereas sepsis patients predominately called OOH-PC (66.9%). Less than 10% (all diagnoses) of patients contacted both OOH-PC & EMS. Stroke patients with EMS or OOH-PC & EMS contacts had higher likelihood of 1- and 1-30-day mortality, in particular 1-day (EMS: OR = 5.33, 95% CI: 2.82-10.08; OOH-PC & EMS: OR = 3.09, 95% CI: 1.06-9.01). Sepsis patients with EMS or OOH-PC & EMS contacts also had higher likelihood of 1-day mortality (EMS: OR = 2.22, 95% CI: 1.40-3.51; OOH-PC & EMS: OR = 2.86, 95% CI: 1.56-5.23) and 1-30-day mortality. Risk of ICU stay was only significantly higher for stroke patients contacting EMS (EMS: HR = 2.38, 95% CI: 1.51-3.75). Stroke and sepsis patients with EMS contact had longer hospital stays.

CONCLUSIONS

More patients contacted OOH-PC than EMS. Sepsis and stroke patients contacting EMS solely or OOH-PC & EMS had higher likelihood of 1- and 1-30-day mortality during the subsequent hospital contact. Our results suggest that patients contacting EMS are more severely ill, however OOH-PC is still often used for time-critical conditions.

Cerebrospinal fluid pleocytosis level as a diagnostic predictor? A cross-sectional study

BACKGROUND

Lumbar puncture with quantification of leukocytes and differential count of cellular subsets in the cerebrospinal fluid is a standard procedure in cases of suspected neuroinfectious conditions. However, a number of non-infectious causes may result in a low leukocyte number (0-1000 cells/ml). We wanted to assess the diagnostic diversity of unselected adult patients with pleocytosis in the cerebrospinal fluid.

METHODS

The study is based on data from cerebrospinal fluid (CSF) analyses of all adult patients (15 years or older) admitted to a large university hospital in Denmark during a two-year period (2008-2009). Data from the local patient administrative system supplied with data from patient charts were combined with laboratory data.

RESULTS

A total of 5390 cerebrospinal fluid samples from 3290 patients were included. Pleocytosis >5 leucocytes/μl was found in samples from 262 patients of which 106 (40.5%) were caused by infection of the central nervous system (CNS), 20 (7.6%) by infection outside CNS, 79 (30.2%) due to non-infectious neurological diseases, 23 (8.8%) by malignancy, and 34 (13.0%) caused by other conditions. Significantly higher mean CSF leukocytes was found in patients suffering from CNS infection (mean 1135 cells/μl, p-value <0.0001).

CONCLUSIONS

CNS infection, non-infectious neurological disease, malignancy, and infection outside CNS can cause pleocytosis of the cerebrospinal fluid. Leukocyte counts above 100/μl is mainly caused by CNS infection, whereas the number of differential diagnoses is higher if the CSF leukocyte counts is below 50/μl. These conditions are most commonly caused by non-infectious neurological diseases including seizures.

Gram-negative bacteremia as a clinical marker of occult malignancy

OBJECTIVES

Gram-negative bacteremia may be a harbinger of occult cancer. We examined the risk of cancer following hospitalization with bacteremia.

METHODS

Using medical databases, we conducted a nationwide population-based cohort study of all Danes with a discharge diagnosis of Gram-negative bacteremia during 1994-2013. We calculated absolute risks and standardized incidence ratios (SIRs) of cancer, comparing the observed risk to that expected in the general population.

RESULTS

We observed 1379 cancers vs. 988 expected among 11,753 patients with Gram-negative bacteremia, corresponding to an overall SIR of 1.40 (95% confidence interval (CI): 1.32-1.47). During the first 6 months following the bacteremia diagnosis, the SIR for cancer was 3.33-fold (95% CI: 2.99-3.69) increased, corresponding to an absolute risk of 3.05%. The increased risk stemmed mainly from higher than expected occurrence of gastrointestinal cancer (3- to 13-fold higher), genitourinary cancer (4- to 10-fold higher), non-Hodgkin lymphoma (5-fold higher), non-specified metastatic cancer (5-fold higher), and breast and lung cancer (2-fold higher). The 6-12 months SIR for any cancer was 1.46 (95% CI: 1.22-1.72), and beyond 1 year of follow-up, the SIR declined to 1.13 (95% CI: 1.05-1.20).

CONCLUSIONS

Gram-negative bacteremia is a clinical marker of occult cancer.

Risk and prognosis of bacteremia and fungemia among first-time kidney transplant recipients: a population-based cohort study

BACKGROUND

Bacterial infections are common complications in kidney transplant recipients (KTRs). Little is known about incidence rates of bacteremia and fungemia (BAF) in KTRs.

METHODS

In this population-based cohort study, we used medical and administrative registries to identify episodes of BAF among KTRs in the Central Denmark and North Denmark Regions during 1995-2010. KTRs were followed from the date of their first transplantation to the earliest of BAF, graft loss, death, emigration or 31 December 2010. We calculated incidence rates of first BAF episode overall and stratified by time from transplantation. Potential risk factors were assessed using Cox regression analysis. The Kaplan-Meier analysis was used to estimate 30- and 90-day mortality.

RESULTS

Among 612 KTRs, we identified 138 first episodes of bacteremia during 2397 person-years of follow-up (PYFU). The overall incidence rate (IR) was 5.8 BAF episodes per 100 PYFU (95% confidence interval [CI]: 4.9-6.8). The incidence rate declined from 84.0 per 100 PYFU (95% CI: 61.6-114.5) during post-transplant day 0-30 to 2.3 per 100 PYFU (95% CI: 1.7-3.0) from post-transplant day 365 and onwards. Hospital-onset BAF comprised 39% of the episodes of BAF. The most frequently isolated microorganisms were Escherichia coli and Klebsiella species causing 49 (35.5%) and 29 (21.0%) episodes of BAF, respectively. The 30-day mortality was 2.1% (95% CI: 0.7-6.6).

CONCLUSIONS

While the risk of BAF in KTRs was high, thirty-day mortality was low. After the first post-transplant year, the IR of bacteremia was substantially lower than in the immediate post-transplant period.

The Danish National Patient Registry: a review of content, data quality, and research potential

Background

The Danish National Patient Registry (DNPR) is one of the world’s oldest nationwide hospital registries and is used extensively for research. Many studies have validated algorithms for identifying health events in the DNPR, but the reports are fragmented and no overview exists.

Objectives

To review the content, data quality, and research potential of the DNPR.

Methods

We examined the setting, history, aims, content, and classification systems of the DNPR. We searched PubMed and the Danish Medical Journal to create a bibliography of validation studies. We included also studies that were referenced in retrieved papers or known to us beforehand. Methodological considerations related to DNPR data were reviewed.

Results

During 1977–2012, the DNPR registered 8,085,603 persons, accounting for 7,268,857 inpatient, 5,953,405 outpatient, and 5,097,300 emergency department contacts. The DNPR provides nationwide longitudinal registration of detailed administrative and clinical data. It has recorded information on all patients discharged from Danish nonpsychiatric hospitals since 1977 and on psychiatric inpatients and emergency department and outpatient specialty clinic contacts since 1995. For each patient contact, one primary and optional secondary diagnoses are recorded according to the International Classification of Diseases. The DNPR provides a data source to identify diseases, examinations, certain in-hospital medical treatments, and surgical procedures. Long-term temporal trends in hospitalization and treatment rates can be studied. The positive predictive values of diseases and treatments vary widely (<15%–100%). The DNPR data are linkable at the patient level with data from other Danish administrative registries, clinical registries, randomized controlled trials, population surveys, and epidemiologic field studies – enabling researchers to reconstruct individual life and health trajectories for an entire population.

Conclusion

The DNPR is a valuable tool for epidemiological research. However, both its strengths and limitations must be considered when interpreting research results, and continuous validation of its clinical data is essential.