Iron, haemochromatosis genotypes, and risk of infections: a cohort study of 142,188 general population individuals.

It is unclear whether risk of infection is increased in individuals with hereditary haemochromatosis and in individuals with low or high plasma iron, transferrin saturation, or ferritin. Therefore, we tested whether high and low iron, transferrin saturation, and ferritin are associated with risk of infections observationally and genetically through HFE genotypes. We studied 142,188 Danish general population individuals. Iron, transferrin saturation, and ferritin were measured in 136,656, 136,599, and 38,020 individuals, respectively. HFE was genotyped for C282Y and H63D in 132,542 individuals. Median follow-up after study enrolment was 8 years(range:0-38years) for hospital and emergency room admissions with infections(n=20,394 individuals) using the National Patient Register, covering all Danish hospitals. Hazard ratios for any infection were 1.20(95%CI:1.12-1.28) and 1.14(1.07-1.22) in individuals with plasma iron≤5th or ≥95th percentile compared to individuals with iron from 26th-74th percentiles. Findings for transferrin saturation were similar, while infection risk was not increased in individuals with ferritin≤5th or ≥95th percentile. Hazard ratios in C282Y homozygotes versus non-carriers were 1.40(1.16-1.68) for any infection, 1.69(1.05-2.73) for sepsis, and 2.34(1.41-3.90) for death from infectious disease. Risk of infection was increased in C282Y homozygotes with normal plasma iron, transferrin saturation, or ferritin, and in C282Y homozygotes without liver disease, diabetes, and/or heart failure. In summary, low and high plasma iron and transferrin saturation were independently associated with increased infection risk. C282Y homozygotes had increased risk of any infection, sepsis, and death from infections. Even C282Y homozygotes with normal iron, transferrin saturation, or ferritin, not currently recommended for genotyping, had increased infection risk.

Ultrasound in predicting improvement in dyspnoea after therapeutic thoracentesis in patients with recurrent unilateral pleural effusion.

Background: In patients with recurrent pleural effusion, therapeutic thoracentesis is one way of relief. Correct prediction of which patients will experience relief following drainage may support the management of these patients. This study aimed to assess the association between ultrasound (US) characteristics and a relevant improvement in dyspnoea immediately following drainage. Methods: In a prospective, observational study, patients with recurrent unilateral pleural effusion underwent US evaluation of effusion characteristics and diaphragm movement measured by M-mode and the Area method before and right after drainage. The level of dyspnoea was assessed using the modified Borg scale (MBS). A minimal important improvement in dyspnoea was defined as delta MBS ≥ 1. Results: In the 104 patients included, 53% had a minimal important improvement in dyspnoea following thoracentesis. We found no association between US-characteristics, including diaphragm shape or movement (M-mode or the Area method), and a decrease in dyspnoea following drainage. Baseline MBS score ≥ 4 and a fully drained effusion were significant correlated with a minimal important improvement in dyspnoea (OR 3.86 (1.42-10.50), p = 0.01 and 2.86 (1.03-7.93), p = 0.04, respectively). Conclusions: In our study population, US-characteristics including assessment of diaphragm movement or shape was not associated with a minimal important improvement in dyspnoea immediately following thoracentesis.

Pleural disease.

The incidence of pleural disease is increasing and the mortality and morbidity is high. Many recent RCTs have resulted in evidence-based guidelines published in 2023, pointing towards a more individualized and specialized management. Most patients with pleural disease are admitted at the A and E but can be managed in outpatient clinics. Thus, there is a need to establish specialized, multidisciplinary pleural clinics to ensure optimal, individualized and evidence-based management of the increasing number of patients with pleural disease in Denmark, as argued in this review.

Glucose phosphate isomerase deficiency demasked by whole-genome sequencing: a case report.

BACKGROUND: Glucose-6-phosphate isomerase deficiency is a rare genetic disorder causing hereditary nonspherocytic hemolytic anemia. It is the second most common glycolytic enzymopathy in red blood cells. About 90 cases are reported worldwide, with symptoms including chronic hemolytic anemia, jaundice, splenomegaly, gallstones, cholecystitis, and in severe cases, neurological impairments, hydrops fetalis, and neonatal death. CASE PRESENTATION: This paper details the case of the first Danish patient diagnosed with glucose-6-phosphate isomerase deficiency. The patient, a 27-year-old white female, suffered from lifelong anemia of unknown origin for decades. Diagnosis was established through whole-genome sequencing, which identified two GPI missense variants: the previously documented variant p.(Thr224Met) and a newly discovered variant p.(Tyr341Cys). The pathogenicity of these variants was verified enzymatically. CONCLUSIONS: Whole-genome sequencing stands as a potent tool for identifying hereditary anemias, ensuring optimal management strategies.

Ultrasound in the Diagnosis of Non-Expandable Lung: A Prospective Observational Study of M-Mode, B-Mode, and 2D-Shear Wave Elastography.

BACKGROUND: Non-expandable lung (NEL) has severe implications for patient symptoms and impaired lung function, as well as crucial implications for the management of malignant pleural effusion (MPE). Indwelling pleural catheters have shown good symptom relief for patients with NEL; hence, identifying patients early in their disease is vital. With the inability of the lung to achieve pleural apposition following thoracentesis and the formation of a hydropneumothorax, traditionally, chest X-ray and clinical symptoms have been used to make the diagnosis following thoracentesis. It is our aim to investigate whether ultrasound measurement of lung movement during respiration can predict NEL before thoracentesis, thereby aiding clinicians in their planning for the optimal treatment of affected patients. METHODS: A total of 49 patients were consecutively included in a single-centre trial performed at a pleural clinic. Patients underwent protocolled ultrasound assessment pre-thoracentesis with measurements of lung and diaphragm movement and shear wave elastography measurements of the pleura and pleural effusion at the planned site of thoracentesis. RESULTS: M-mode measurements of lung movement provided the best diagnostic ROC-curve results, with an AUC of 0.81. Internal validity showed good results utilising the calibration belt test and Brier test. CONCLUSION: M-mode measurement of lung movement shows promise in diagnosing NEL before thoracentesis in patients with known or suspected MPE. A validation cohort is needed to confirm the results.

The Danish national haemoglobinopathy screening programme: Report from 16 years of screening in a low-prevalence, non-endemic region.

The Danish national haemoglobinopathy screening programme seeks to determine parental haemoglobinopathy carrier state antenatally. In this retrospective register-based study, we evaluated the 16-year trajectory of this programme, utilising the Danish Red Blood Cell Centre's laboratory database, covering approximately 77% of the Danish population. During the study period, we observed a substantial increase in annual diagnostic examinations performed, from 389 in 2007 to 3030 in 2022. Women constituted 88% of these cases, aligning with the emphasis of the screening programme. Of these, 54% of women of reproductive age (15-40 years) and 10% of women >40 years were specified as pregnant. During our study period, 61 children were born with a severe haemoglobinopathy, out of which 23 children were born from mothers not residing in Denmark during their first trimester thus not included in the screening programme. Prenatal invasive testing was performed for 60 fetuses, identifying 12 with homozygous or compound heterozygous haemoglobinopathy. The Danish haemoglobinopathy screening programme has provided screening, information and reproductive choices for numerous families. During the study period, screening for haemoglobinopathies has been steadily increasing and is expected to continue to increase. Awareness of and adherence to the screening programme is subject of further investigation and optimisation.

Social inequalities in the risk of giving birth to a small for gestational age child in Sweden 2010-16: a cross-sectional study adopting an intersectional approach.

BACKGROUND: Well-established associations exist between the risk of small for gestational age (SGA) and unidimensional sociodemographic factors. We investigated social inequalities in SGA risk and adopted an intersectional approach that simultaneously considers different social categories. By doing so, we could assess heterogeneities in SGA risk within unidimensional sociodemographic categories. METHODS: We included all live 679 694 singleton births in Sweden between 2010 and 2016. The outcome was SGA, and the exposures were age, maternal educational level, dichotomous migration status and civil status. Thirty-six possible combinations of these factors constituted the exposure in an intersectional model. We present odds ratios (ORs) with 95% confidence intervals (95% CIs) and the area under the receiver operating characteristic curve (AUC)-a measurement of discriminatory accuracy (i.e. the ability to discriminate the babies born SGA from those who are not). RESULTS: Women with low education and women born outside Sweden had ORs of 1.46 (95% CI 1.38-1.54) and 1.50 (95% CI 1.43-1.56) in unidimensional analyses, respectively. Among women aged under 25 with low education who were born outside Sweden and unmarried, the highest OR was 3.06 (2.59-3.63). The discriminatory accuracy was low for both the unidimensional model that included all sociodemographic factors (AUC 0. 563) and the intersectional model (AUC 0.571). CONCLUSIONS: The intersectional approach revealed a complex sociodemographic pattern of SGA risk. Sociodemographic factors have a low accuracy in identifying SGA at the individual level, even when quantifying their multi-dimensional intersections. This cautions against interventions targeted to individuals belonging to socially defined groups to reduce social inequalities in SGA risk.

Clinical characteristics of chylothorax: results from the International Collaborative Effusion database.

Background: Chylothorax is an uncommon medical condition for which limited data are available regarding the contemporary aetiology, management and outcomes. The goal of this study was to better define these poorly characterised features. Methods: The medical records of adult patients diagnosed with chylothorax at 12 centres across Europe, America and South Africa from 2009-2021 were retrospectively reviewed. Descriptive and inferential statistics were performed. Results: 77 patients (median age 69 years, male to female ratio 1.5) were included. Subacute dyspnoea was the most typical presenting symptom (66%). The commonest cause of chylothorax was malignancy (68.8%), with lymphoma accounting for 62% of these cases. Other aetiologies were trauma (13%), inflammatory/miscellaneous conditions (11.7%) and idiopathic cases (6.5%). At the initial thoracentesis, the pleural fluid appeared milky in 73%, was exudative in 89% and exhibited triglyceride concentrations >100 mg·dL-1 in 88%. Lymphangiography/lymphoscintigraphy were rarely ordered (3%), and demonstration of chylomicrons in pleural fluid was never ascertained. 67% of patients required interventional pleural procedures. Dietary measures were infrequently followed (36%). No patient underwent thoracic duct ligation or embolisation. Morbidity included infections (18%), and thrombosis in malignant aetiologies (16%). The 1-year mortality was 47%. Pleural fluid protein >3.5 mg·dL-1 (sub-distribution hazard ratio (SHR) 4.346) or lactate dehydrogenase <500 U·L-1 (SHR 10.21) increased the likelihood of effusion resolution. Pleural fluid protein ≤3.5 mg·dL-1 (HR 4.047), bilateral effusions (HR 2.749) and a history of respiratory disease (HR 2.428) negatively influenced survival. Conclusion: Chylothoraces have a poor prognosis and most require pleural interventions. Despite the standard recommendations, lymphatic imaging is seldom used, nor are dietary restrictions followed.

A Novel ß-Globin Variant, Hb Raklev [ß 75(E19) HBB:c.227T > A (Leu→Gln)].

We present a new hemoglobin variant, Hb Raklev, characterized by the substitution of leucine with glutamine at position 75 in the ß-globin chain. This variant was discovered inadvertently during an HbA1c evaluation using high performance liquid chromatography in a symptomless 54-year-old Caucasian woman, with the same variant also identified in her 16-year-old daughter. Purification of the hemoglobin revealed possibly diminished 2,3-bisphosphoglycerate (2,3-BPG) sensitivity, which may result in heightened oxygen affinity. Notably, two variants have been previously documented at this location: the unstable Hb Atlanta and the high-affinity Hb Pasadena.

A Novel Approach to Predicting Early Pregnancy Outcomes Dynamically in a Prospective Cohort Using Repeated Ultrasound and Serum Biomarkers.

This study aimed to develop a dynamic model for predicting outcome during the first trimester of pregnancy using baseline demographic data and serially collected blood samples and transvaginal sonographies. A prospective cohort of 203 unselected women with an assumed healthy pregnancy of < 8 weeks' gestation was followed fortnightly from 4-14 weeks' gestation until either miscarriage or confirmed first trimester viability. The main outcome was development of a model to predict outcome from gestational age-dependent hazard ratios using both baseline and updated serial data from each visit. Secondary outcomes were descriptions of risk factors for miscarriage. The results showed that 18% of the women experienced miscarriages. A fetal heart rate detected before 8 weeks' gestation indicated a 90% (95% CI 85-95%) chance of subsequent delivery. Maternal age (≥ 35 years), insufficient crown-rump-length (CRL) and mean gestational sac diameter (MSD) development, and presence of bleeding increased the risk of miscarriage. Serum biomarkers, including hCG, progesterone, and estradiol, were found to impact the risk of miscarriage with estradiol as the most important. The best model to predict miscarriage was a combination of maternal age, vaginal bleeding, CRL, and hCG. The second-best model was the sonography-absent model of maternal age, bleeding, hCG, and estradiol. This study suggests that combining maternal age, and evolving data from hCG, estradiol, CRL, and bleeding could be used to predict fetal outcome during the first trimester of pregnancy.Trial registration ClinicalTrials.gov identifier: NCT02761772.

Investigation and outcomes in patients with nonspecific pleuritis: results from the International Collaborative Effusion database.

Introduction: We present findings from the International Collaborative Effusion database, a European Respiratory Society clinical research collaboration. Nonspecific pleuritis (NSP) is a broad term that describes chronic pleural inflammation. Various aetiologies lead to NSP, which poses a diagnostic challenge for clinicians. A significant proportion of patients with this finding eventually develop a malignant diagnosis. Methods: 12 sites across nine countries contributed anonymised data on 187 patients. 175 records were suitable for analysis. Results: The commonest aetiology for NSP was recorded as idiopathic (80 out of 175, 44%). This was followed by pleural infection (15%), benign asbestos disease (12%), malignancy (6%) and cardiac failure (6%). The malignant diagnoses were predominantly mesothelioma (six out of 175, 3.4%) and lung adenocarcinoma (four out of 175, 2.3%). The median time to malignant diagnosis was 12.2 months (range 0.8-32 months). There was a signal towards greater asbestos exposure in the malignant NSP group compared to the benign group (0.63 versus 0.27, p=0.07). Neither recurrence of effusion requiring further therapeutic intervention nor initial biopsy approach were associated with a false-negative biopsy. A computed tomography finding of a mass lesion was the only imaging feature to demonstrate a significant association (0.18 versus 0.01, p=0.02), although sonographic pleural thickening also suggested an association (0.27 versus 0.09, p=0.09). Discussion: This is the first multicentre study of NSP and its associated outcomes. While some of our findings are reflected by the established body of literature, other findings have highlighted important areas for future research, not previously studied in NSP.

Additional Up-Front Thoracic Ultrasound in the Workup of Patients with Unilateral Pleural Effusion: A Prospective Observational Pilot Study.

BACKGROUND: In patients with pleural effusion, specific ultrasound characteristics are associated with pleural malignancy. OBJECTIVES: This study aimed to evaluate the added value of an additional, up-front, systematic thoracic ultrasound (TUS) to standard imaging in patients with unilateral pleural effusion of unknown cause in a clinical setting. METHODS: In a prospective observational pilot study, patients referred for workup and thoracentesis of a unilateral pleural effusion received up-front TUS following a set protocol in addition to available imaging and US guiding the thoracentesis or diagnostic puncture. The primary outcome was the proportion of cases where systematic TUS changed the planned diagnostic workup. Follow-up took place 26 weeks after inclusion. RESULTS: From February to December 2020, 55 patients were included. Thirty-six (65%) patients had other chest imaging available before TUS. Twenty-one (38%) were diagnosed with malignant pleural effusion. Three patients (5%) had clinically relevant changes in the diagnostic workup after additional systematic TUS. CONCLUSIONS: Additional up-front, systematic TUS had limited clinically relevant effect on the planned diagnostic workup in patients with unilateral pleural effusion in a setting where chest CT scans often are available at referral.

Implementation of universal umbilical cord pH analysis in Denmark. A national register-based study.

INTRODUCTION: Umbilical cord blood gas analysis provides information about intrapartum hypoxia and is considered an important measure of quality in maternity care. Universal measurement of umbilical cord pH (UC-pH), as part of umbilical cord blood gas analysis, has been recommended in Denmark since 2009. The recommendation is that UC-pH is measured from the umbilical cord artery (pHUA ) and vein (pHUV ). The aim of this study was to evaluate the national implementation of universal measurement of UC-pH. MATERIAL AND METHODS: The study consisted of two parts. First, an evaluation of the implementation, that is, the proportion of births with measured UC-pH since the recommendation was introduced. Second, an evaluation of the cases in which UC-pH was missing. This analysis only involved births with gestational age ≥35 + 0 weeks. RESULTS: In the period 2009 to 2018 there were 560 889 singleton, live births with registered gestational age in Denmark. The proportion of births with measured pHUA and pHUV increased from 12.4% in 2009 to 82.8% in 2015 and then declined to 76.9% in 2018 (p < 0.001). When comparing the group with missing pH from one or both vessels to the group with both pHUA and pHUV we found lower occurrence of pregnancy and births complications in the first group, body mass index ≥35 (unadjusted RR: 0.89, 95% CI: 0.85-0.93), pregnancy induced medical conditions (RR: 0.86, 95% CI: 0.84-0.89), fetal distress during birth (RR: 0.77, 95% CI: 0.76-0.79), emergency cesarean section (RR: 0.80, 95% CI: 0.78-0.83) and serious births events (RR: 0.80, 95% CI: 0.74-0.86). In contrast, the occurrence of placental insufficiency (RR: 1.07, 95% CI: 1.03-1.11), small for gestational age (RR: 1.36, 95% CI: 1.30-1.43, for <2.3th percentile), hypothermia treatment (RR: 1.60, 95% CI: 1.21-2.14) and neonatal death (RR: 1.96, 95% CI: 1.40-2.74) were higher in the group without measured pHUA and pHUV . CONCLUSIONS: The use of UC-pH measurement has increased markedly in Denmark since universal measurement was recommended in 2009. Missing UC-pH from one or both vessels was associated with less complicated pregnancies and with small for gestational age, hypothermia treatment and neonatal death.

Inhaled Corticosteroids in Patients with Chronic Obstructive Pulmonary Disease and Risk of Acquiring Streptococcus pneumoniae Infection. A Multiregional Epidemiological Study.

Background: Inhaled corticosteroids (ICS) are associated with an increased risk of clinical pneumonia among patients with chronic obstructive pulmonary disease (COPD). It is unknown whether the risk of microbiologically verified pneumonia such as pneumococcal pneumonia is increased in ICS users. Methods: The study population consists of all COPD patients followed in outpatient clinics in eastern Denmark during 2010-2017. ICS use was categorized into four categories based on accumulated use. A Cox proportional hazard regression model was used adjusting for age, body mass index, sex, airflow limitation, use of oral corticosteroids, smoking, and year of cohort entry. A propensity score matched analysis was performed for sensitivity analyses. Findings: A total of 21,438 patients were included. Five hundred and eighty-two (2.6%) patients acquired a positive lower airway tract sample with S. pneumoniae during follow-up. In the multivariable analysis ICS-use was associated with a dose-dependent risk of S. pneumoniae as follows: low ICS dose: HR 1.11, 95% CI 0.84 to 1.45, p = 0.5; moderate ICS dose: HR 1.47, 95% CI 1.13 to 1.90, p = 0.004; high ICS dose: HR 1.77, 95% CI 1.38 to 2.29, p < 0.0001, compared to no ICS use. Sensitivity analyses confirmed these results. Interpretation: Use of ICS in patients with severe COPD was associated with an increased and dose-dependent risk of acquiring S. pneumoniae, but only for moderate and high dose. Caution should be taken when administering high dose of ICS to patients with COPD. Low dose of ICS seemed not to carry this risk.

Preterm birth in the Nordic countries-Capacity, management and outcome in neonatal care.

AIM: Organisation of care, perinatal and neonatal management of very preterm infants in the Nordic regions were hypothesised to vary significantly. The aim of this observational study was to test this hypothesis. METHODS: Information on preterm infants in the 21 greater healthcare regions of Denmark, Finland, Iceland, Norway and Sweden was gathered from national registers in 2021. Preterm birth rates, case-mix, perinatal interventions, neonatal morbidity and survival to hospital discharge in very (<32 weeks) and extremely preterm infants (<28 weeks of gestational age) were compared. RESULTS: Out of 287 642 infants born alive, 16 567 (5.8%) were preterm, 2389 (0.83%) very preterm and 800 (0.28%) were extremely preterm. In very preterm infants, exposure to antenatal corticosteroids varied from 85% to 98%, live births occurring at regional centres from 48% to 100%, surfactant treatment from 28% to 69% and use of mechanical ventilation varied from 13% to 77% (p < 0.05 for all comparisons). Significant regional variations within and between countries were also seen in capacity in neonatal care, case-mix and number of admissions, whereas there were no statistically significant differences in survival or major neonatal morbidities. CONCLUSION: Management of very preterm infants exhibited significant regional variations in the Nordic countries.

Prediction of Time to Next Therapeutic Thoracentesis and Identification of Risk Factors of Rapid Pleural Fluid Recurrence: A Prospective Observational Study.

BACKGROUND: The value of pre-booked repeated thoracentesis in patients with recurrent pleural effusion is reliant on the estimation of time to next drainage. Identifying factors associated with rapid pleural fluid recurrence could be supportive. OBJECTIVE: We aimed to evaluate the ability of the patient and physician to predict the time to next therapeutic thoracentesis and to identify characteristics associated with rapid pleural fluid recurrence. METHOD: In a prospective, observational study, patients with recurrent unilateral pleural effusion and the physician were to predict the time to next symptom-guided therapeutic thoracentesis. Primary outcome was difference between days to actual thoracentesis and days predicted by the patient and the physician. Factors associated with pleural fluid recurrence within 60-day follow-up were assessed using Cox regression analysis. RESULTS: A total of 98 patients were included, 71% with malignant pleural effusion. Patients' and physicians' predictions numerically deviated by 6 days from the actual number of days to re-thoracentesis (IQR 2-12 and 2-13, respectively). On multivariate analyses, factors associated with increased hazard of pleural fluid recurrence included daily fluid production (HR 1.35 [1.16-1.59], p > 0.001) and large effusion size (HR 2.76 [1.23-6.19], p = 0.01). Septations were associated with decreased hazard (HR 0.48 [0.24-0.96], p = 0.04). CONCLUSION: Patients and physicians were equally unable to predict the time to next therapeutic thoracentesis. Daily fluid production and large effusion size were associated with increased risk of rapid pleural fluid recurrence, while septations were associated with a decreased risk. This may guide patients and physicians in when to expect a need for therapeutic thoracentesis.

Suspected Lung Cancer with Suspicious Liver Lesions: Diagnostic Yield and Safety of Same-Day Bronchoscopy and Liver Biopsy in the Hands of a Pulmonologist.

BACKGROUND: Bronchoscopy and endobronchial ultrasound (EBUS) are standard procedures for the diagnosis and staging of patients suspected of lung cancer. If the patient simultaneously presents with suspicious liver lesions, it is tradition to refer the patient to a radiologist for ultrasound-guided percutaneous liver biopsy. OBJECTIVE: The aim of this study was to investigate the results and complications when the pulmonologist performs all three procedures in the same setting. METHODS: We retrospectively identified patients who during 2018-2020 underwent invasive workup of suspected lung cancer and liver metastases with percutaneous liver lesion biopsy with or without same-day endoscopy (bronchoscopy and EBUS). We compared diagnostic yield and safety of liver lesion biopsy stratified by same-day endoscopy or not. RESULTS: In total, 89 patients were included, of whom 28 patients (31%) underwent same-day endoscopy. All liver lesion biopsies were fine-needle aspiration biopsies performed by experienced pulmonologists. No complications were reported, and overall diagnostic yield was 88%. The diagnostic yield was significantly lower in the same-day endoscopy group (71% vs. 95%), and undergoing endoscopy was significantly associated with having fewer liver lesions, higher prevalence of lung cancer, and lower overall prevalence of a malignant diagnosis. CONCLUSION: Liver biopsy in the same session as endoscopy during lung cancer workup was feasible and safe. Confounding by indication was present in our study.

Neonatal Phototherapy and Clinical Characteristics: The Danish National Patient Registry 2000-2016.

Purpose: Phototherapy is the standard treatment for neonatal hyperbilirubinemia. It is important to collect data on phototherapy to support research related to the efficacy and safety of phototherapy. We explored the registration of phototherapy in the Danish National Patient Registry (DNPR) and the clinical characteristics of neonates treated with phototherapy. Methods: We identified children born alive in Denmark from 1 January 2000 through 30 November 2016 from the DNPR (N=1,044,502). We calculated the proportion of children registered that received phototherapy during the neonatal period and examined temporal trends, both nationwide and at the level of individual hospitals. In a sub-cohort of children born at Aarhus University Hospital (AUH) in 2002-2016 (N=71,781), we analyzed the proportions of children registered that received phototherapy, according to sex, gestational age, birth weight, and neonatal characteristics, like Apgar score, birth asphyxia, and infections. Results: We identified 11,295 (1.1%) registered that received phototherapy. The proportions of children registered that received phototherapy differed among hospitals (range: 0 to 4.1%). Nationwide registration was low during the study period, but it increased to 1.8% in 2016. For the AUH sub-cohort the proportion of children registered with phototherapy averaged 4.4% (N=3182, range:3.9-5.1%). The proportion of children registered with phototherapy was inversely correlated with gestational age and birth weight, and positively correlated with neonatal characteristics, including low Apgar score, birth asphyxia, and infections. Conclusion: Phototherapy was under-reported in the DNPR and the proportions of children registered that received phototherapy differed among hospitals. The non-compulsory policy for reporting treatment and care in hospitals to the DNPR might explain the variation. The most consistent reporting was observed among children born in an university hospital, where 4.4% of children registered that received phototherapy, and phototherapy was inversely associated with gestational age, birth weight, and positively associated with clinical characteristics like birth asphyxia, and infections.