Prediction model for future OHCAs based on geospatial and demographic data: An observational study.

This study used demographic data in a novel prediction model to identify areas with high risk of out-of-hospital cardiac arrest (OHCA) in order to target prehospital preparedness. We combined data from the nationwide Danish Cardiac Arrest Registry with geographical- and demographic data on a hectare level. Hectares were classified in a hierarchy according to characteristics and pooled to square kilometers (km2). Historical OHCA incidence of each hectare group was supplemented with a predicted annual risk of at least 1 OHCA to ensure future applicability. We recorded 19,090 valid OHCAs during 2016 to 2019. The mean annual OHCA rate was highest in residential areas with no point of public interest and 100 to 1000 residents per hectare (9.7/year/km2) followed by pedestrian streets with multiple shops (5.8/year/km2), areas with no point of public interest and 50 to 100 residents (5.5/year/km2), and malls with a mean annual incidence per km2 of 4.6. Other high incidence areas were public transport stations, schools and areas without a point of public interest and 10 to 50 residents. These areas combined constitute 1496 km2 annually corresponding to 3.4% of the total area of Denmark and account for 65% of the OHCA incidence. Our prediction model confirms these areas to be of high risk and outperforms simple previous incidence in identifying future risk-sites. Two thirds of out-of-hospital cardiac arrests were identified in only 3.4% of the area of Denmark. This area was easily identified as having multiple residents or having airports, malls, pedestrian shopping streets or schools. This result has important implications for targeted intervention such as automatic defibrillators available to the public. Further, demographic information should be considered when implementing such interventions.

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

OBJECTIVE: To train and test a super learner strategy for risk prediction of kidney failure and mortality in people with incident moderate to severe chronic kidney disease (stage G3b to G4). DESIGN: Multinational, longitudinal, population based, cohort study. SETTINGS: Linked population health data from Canada (training and temporal testing), and Denmark and Scotland (geographical testing). PARTICIPANTS: People with newly recorded chronic kidney disease at stage G3b-G4, estimated glomerular filtration rate (eGFR) 15-44 mL/min/1.73 m2. MODELLING: The super learner algorithm selected the best performing regression models or machine learning algorithms (learners) based on their ability to predict kidney failure and mortality with minimised cross-validated prediction error (Brier score, the lower the better). Prespecified learners included age, sex, eGFR, albuminuria, with or without diabetes, and cardiovascular disease. The index of prediction accuracy, a measure of calibration and discrimination calculated from the Brier score (the higher the better) was used to compare KDpredict with the benchmark, kidney failure risk equation, which does not account for the competing risk of death, and to evaluate the performance of KDpredict mortality models. RESULTS: 67 942 Canadians, 17 528 Danish, and 7740 Scottish residents with chronic kidney disease at stage G3b to G4 were included (median age 77-80 years; median eGFR 39 mL/min/1.73 m2). Median follow-up times were five to six years in all cohorts. Rates were 0.8-1.1 per 100 person years for kidney failure and 10-12 per 100 person years for death. KDpredict was more accurate than kidney failure risk equation in prediction of kidney failure risk: five year index of prediction accuracy 27.8% (95% confidence interval 25.2% to 30.6%) versus 18.1% (15.7% to 20.4%) in Denmark and 30.5% (27.8% to 33.5%) versus 14.2% (12.0% to 16.5%) in Scotland. Predictions from kidney failure risk equation and KDpredict differed substantially, potentially leading to diverging treatment decisions. An 80-year-old man with an eGFR of 30 mL/min/1.73 m2 and an albumin-to-creatinine ratio of 100 mg/g (11 mg/mmol) would receive a five year kidney failure risk prediction of 10% from kidney failure risk equation (above the current nephrology referral threshold of 5%). The same man would receive five year risk predictions of 2% for kidney failure and 57% for mortality from KDpredict. Individual risk predictions from KDpredict with four or six variables were accurate for both outcomes. The KDpredict models retrained using older data provided accurate predictions when tested in temporally distinct, more recent data. CONCLUSIONS: KDpredict could be incorporated into electronic medical records or accessed online to accurately predict the risks of kidney failure and death in people with moderate to severe CKD. The KDpredict learning strategy is designed to be adapted to local needs and regularly revised over time to account for changes in the underlying health system and care processes.

Overweight in childhood and consumer purchases in a Danish cohort.

BACKGROUND: Prevention and management of childhood overweight involves the entire family. We aimed to investigate purchase patterns in households with at least one member with overweight in childhood by describing expenditure on different food groups. METHODS: This Danish register-based cohort study included households where at least one member donated receipts concerning consumers purchases in 2019-2021 and at least one member had their Body mass index (BMI) measured in childhood within ten years prior to first purchase. A probability index model was used to evaluate differences in proportion expenditure spent on specific food groups. RESULTS: We identified 737 households that included a member who had a BMI measurement in childhood, 220 with overweight and 517 with underweight or normal weight (reference households). Adjusting for education, income, family type, and urbanization, households with a member who had a BMI classified as overweight in childhood had statistically significant higher probability of spending a larger proportion of expenditure on ready meals 56.29% (95% CI: 51.70;60.78) and sugary drinks 55.98% (95% CI: 51.63;60.23). Conversely, they had a statistically significant lower probability of spending a larger proportion expenditure on vegetables 38.44% (95% CI: 34.09;42.99), compared to the reference households. CONCLUSION: Households with a member with BMI classified as overweight in childhood spent more on unhealthy foods and less on vegetables, compared to the reference households. This study highlights the need for household/family-oriented nutrition education and intervention.

Comparative responses to 17 different antidepressants in major depressive disorder: Results from a 2-year long-term nation-wide population-based study emulating a randomized trial.

BACKGROUND: Long-term studies comparing nonresponse to antidepressants for major depressive disorder (MDD) are lacking. AIMS: To present systematic population-based nation-wide register data on comparative 2-year non-response within six antidepressant drug classes and 17 different antidepressants in patients with MDD. METHOD: The study included all 106,920 patients in Denmark with a first main index diagnosis of MDD at a psychiatric hospital inpatient or outpatient contact and who subsequently had a purchase of an antidepressant in the period from 1995 to 2018. Non-response to first antidepressant within a 2-year study period was defined as switch to or add-on of another antidepressant, antipsychotic medication, lithium, or hospitalization. Analyses emulated a targeted trial in populations standardized according to age, sex, socioeconomic status, and comorbidity with psychiatric and physical disorders. RESULTS: Compared with sertraline, there was no difference for citalopram (RR: 1.00 [95% CI: 0.98-1.02]) but fluoxetine (1.13 [95% CI: 1.10-1.17]), paroxetine (1.06 [95% CI: 1.01-1.10]) and escitalopram (1.22 [95% CI: 1.18-1.25]) were associated with higher risk ratio of non-responses. Within selective noradrenaline reuptake inhibitors, sertraline outperformed reboxetine; within serotonin-norepinephrine reuptake inhibitors, venlafaxine outperformed duloxetine; within noradrenergic and specific serotonergic antidepressants, mirtazapine outperformed mianserin and within the class of other antidepressants, sertraline outperformed agomelatine and vortioxetine. Within tricyclic antidepressants, compared to amitriptyline, nortriptyline, dosulepin, and clomipramine had higher non-response, whereas there was no difference for imipramine. CONCLUSIONS: These analyses emulating a randomized trial of "real world" observational register-based data show that 2-year long-term non-responses to some antidepressants within six different drug classes are increased over others.

Estimation of separable direct and indirect effects in a continuous-time illness-death model.

In this article we study the effect of a baseline exposure on a terminal time-to-event outcome either directly or mediated by the illness state of a continuous-time illness-death process with baseline covariates. We propose a definition of the corresponding direct and indirect effects using the concept of separable (interventionist) effects (Robins and Richardson in Causality and psychopathology: finding the determinants of disorders and their cures, Oxford University Press, 2011; Robins et al. in arXiv:2008.06019 , 2021; Stensrud et al. in J Am Stat Assoc 117:175-183, 2022). Our proposal generalizes Martinussen and Stensrud (Biometrics 79:127-139, 2023) who consider similar causal estimands for disentangling the causal treatment effects on the event of interest and competing events in the standard continuous-time competing risk model. Unlike natural direct and indirect effects (Robins and Greenland in Epidemiology 3:143-155, 1992; Pearl in Proceedings of the seventeenth conference on uncertainty in artificial intelligence, Morgan Kaufmann, 2001) which are usually defined through manipulations of the mediator independently of the exposure (so-called cross-world interventions), separable direct and indirect effects are defined through interventions on different components of the exposure that exert their effects through distinct causal mechanisms. This approach allows us to define meaningful mediation targets even though the mediating event is truncated by the terminal event. We present the conditions for identifiability, which include some arguably restrictive structural assumptions on the treatment mechanism, and discuss when such assumptions are valid. The identifying functionals are used to construct plug-in estimators for the separable direct and indirect effects. We also present multiply robust and asymptotically efficient estimators based on the efficient influence functions. We verify the theoretical properties of the estimators in a simulation study, and we demonstrate the use of the estimators using data from a Danish registry study.

Association between mortality and phone-line waiting time for non-urgent medical care: a Danish registry-based cohort study.

BACKGROUND AND IMPORTANCE: Telephone calls are often patients' first healthcare service contact, outcomes associated with waiting times are unknown. OBJECTIVES: Examine the association between waiting time to answer for a medical helpline and 1- and 30-day mortality. DESIGN, SETTING AND PARTICIPANTS: Registry-based cohort study using phone calls data (January 2014 to December 2018) to the Capital Region of Denmark's medical helpline. The service refers to hospital assessment/treatment, dispatches ambulances, or suggests self-care guidance. EXPOSURE: Waiting time was grouped into the following time intervals in accordance with political service targets for waiting time in the Capital Region: <30 s, 0:30-2:59, 3-9:59, and ≥10 min. OUTCOME MEASURES AND ANALYSIS: The association between time intervals and 1- and 30-day mortality per call was calculated using logistic regression with strata defined by age and sex. MAIN RESULTS: In total, 1 244 252 callers were included, phoning 3 956 243 times, and 78% of calls waited <10 min. Among callers, 30-day mortality was 1% (16 560 deaths). For calls by females aged 85-110 30-day mortality increased with longer waiting time, particularly within the first minute: 9.6% for waiting time <30 s, 10.8% between 30 s and 1 minute and 9.1% between 1 and 2 minutes. For calls by males aged 85-110 30-day mortality was 11.1%, 12.9% and 11.1%, respectively. Additionally, among calls with a Charlson score of 2 or higher, longer waiting times were likewise associated with increased mortality. For calls by females aged 85-110 30-day mortality was 11.6% for waiting time <30 s, 12.9% between 30 s and 1 minute and 11.2% between 1 and 2 minutes. For calls by males aged 85-110 30-day mortality was 12.7%, 14.1% and 12.6%, respectively. Fewer ambulances were dispatched with longer waiting times (4%/2%) with waiting times <30 s and >10 min. CONCLUSION: Longer waiting times for telephone contact to a medical helpline were associated with increased 1- and 30-day mortality within the first minute, especially among elderly or more comorbid callers.

Vitamin D Status During Adolescence and the Impact of Lifestyle Changes: 2 Years' Follow-up From the Fit Futures Study.

CONTEXT: Longitudinal data regarding vitamin D status in adolescence is scarce. This study presents population-based data from an Arctic adolescent population (n = 589) at 16 and 18 years. OBJECTIVE: The aims of this study were to investigate changes in vitamin D status during 2 years in adolescence, and whether lifestyle changes were associated with serum 25-hydroxyvitamin D (s-25(OH)D) at follow-up. METHODS: Fit Futures is a longitudinal study at 69°N in Norway. Participants had their s-25(OH)D levels analyzed in their first and third year of upper secondary school (median age 16 and 18 years), in Fit Futures 1 (FF1) and Fit Futures 2 (FF2), respectively. Self-reported lifestyle habits were registered through questionnaires. The association between lifestyle changes and s-25(OH)D levels at follow-up were calculated by regression analyses, controlling for baseline s-25(OH)D levels. RESULTS: Longitudinal data were available for 309 girls and 280 boys. The proportion of adolescents with s-25(OH)D <50 nmol/L were 73.7% in FF1 and 77.1% in FF2, while the proportion <30 nmol/L constituted 35.7% in FF1 and 40.9% in FF2. Of those with s-25(OH)D <30 nmol/L (severe vitamin D deficiency) in FF1, 73.3% remained severely deficient in FF2. Among boys, an increase in UV exposure was significantly associated with higher s-25(OH)D levels in FF2 (beta; CI [nmol/L] 12.9; 9.1, 16.7). In girls, decreased vitamin/mineral supplement intake was significantly associated with lower s-25(OH)D at FF2 (-6.7; -10.2, -3.1), while increased UV (10.8; 7.0, 14.7) and combined hormonal contraceptive exposure (12.1; 6.0, 18.1) in FF2 was significantly associated with higher s-25(OH)D levels in FF2. CONCLUSION: Severe vitamin D deficiency was prevalent throughout adolescence. Lifestyle changes may alter s-25(OH)D levels in this age group.

Risk of ankylosis of avulsed teeth immediately replanted or stored under favorable storage conditions before replantation: A long-term clinical study.

BACKGROUND/AIM: There are few long-term clinical follow-up studies on human teeth replanted immediately or after storage in a suitable storage medium prior to replantation. This study aimed to assess the risk of ankylosis in avulsed human teeth replanted immediately or after storage in physiological media for a short time. MATERIAL: Data from 116 patients with 145 replanted avulsed permanent teeth were selected from a comprehensive dental trauma database in Copenhagen University Hospital. The following teeth were selected: Group 1 comprised 36 teeth replanted immediately (dry time <6 min; wet time <6 min). Group 2 comprised 61 teeth replanted after physiologic storage media (saliva and saline) (dry time <6 min; wet time >5 min; wet time ranged from 7 to 170 min, and mean wet time was 59 min). Group 3 (control) included 48 teeth replanted after dry storage (dry time > 60 min). METHOD: Clinical and radiographic registrations were carried out according to a standardized protocol; follow-up ranged from 7 months to 23 years. Ankylosis was diagnosed by percussion test and radiographs and related to the conditions prior to replantation and stage of root development. RESULTS: The overall risk of ankylosis was 17.2% [95% CI: 4.61; 29.79] for immediately replanted teeth, 55.3% [95% CI: 42.54; 68.00] for teeth stored in physiologic media before replantation, and 85.7% [95% CI: 75.70; 95.73] for teeth stored dry more than 1 h. Mature teeth showed a significantly higher risk of ankylosis than immature teeth. CONCLUSION: This clinical long-term study has verified earlier experimental studies showing that immediate reimplantation has the lowest risk of ankylosis. Physiologic storage media are good alternatives that also reduce the risk of ankylosis compared to dry storage, where ankylosis is more likely although not always seen. Mature teeth are significantly more likely to develop ankylosis.

Venous thromboembolism with use of hormonal contraception and non-steroidal anti-inflammatory drugs: nationwide cohort study.

OBJECTIVE: To study the influence of concomitant use of hormonal contraception and non-steroidal anti-inflammatory drugs (NSAIDs) on the risk of venous thromboembolism. DESIGN: Nationwide cohort study. SETTING: Denmark through national registries. PARTICIPANTS: All 15-49 year old women living in Denmark between 1996 and 2017 with no medical history of any venous or arterial thrombotic event, cancer, thrombophilia, hysterectomy, bilateral oophorectomy, sterilisation, or infertility treatment (n=2 029 065). MAIN OUTCOME MEASURE: A first time discharge diagnosis of lower limb deep venous thrombosis or pulmonary embolism. RESULTS: Among 2.0 million women followed for 21.0 million person years, 8710 venous thromboembolic events occurred. Compared with non-use of NSAIDs, use of NSAIDs was associated with an adjusted incidence rate ratio of venous thromboembolism of 7.2 (95% confidence interval 6.0 to 8.5) in women not using hormonal contraception, 11.0 (9.6 to 12.6) in women using high risk hormonal contraception, 7.9 (5.9 to 10.6) in those using medium risk hormonal contraception, and 4.5 (2.6 to 8.1) in users of low/no risk hormonal contraception. The corresponding numbers of extra venous thromboembolic events per 100 000 women over the first week of NSAID treatment compared with non-use of NSAIDs were 4 (3 to 5) in women not using hormonal contraception, 23 (19 to 27) in women using high risk hormonal contraception, 11 (7 to 15) in those using medium risk hormonal contraception, and 3 (0 to 5) in users of low/no risk hormonal contraception. CONCLUSIONS: NSAID use was positively associated with the development of venous thromboembolism in women of reproductive age. The number of extra venous thromboembolic events with NSAID use compared with non-use was significantly larger with concomitant use of high/medium risk hormonal contraception compared with concomitant use of low/no risk hormonal contraception. Women needing both hormonal contraception and regular use of NSAIDs should be advised accordingly.

Risk of first-time major cardiovascular event among individuals with newly diagnosed type 2 diabetes: data from Danish registers.

AIMS/HYPOTHESIS: We aimed to examine whether individuals with initial omission of glucose-lowering drug treatment (GLDT), including those achieving initial remission of type 2 diabetes, may experience a higher risk of major adverse cardiovascular events (MACE) compared with well-controlled individuals on GLDT after a new type 2 diabetes diagnosis in real-world clinical practice. Furthermore, we examined whether a higher risk could be related to lower initiation of statins and renin-angiotensin system inhibitors (RASi). METHODS: In this cohort study, we used Danish registers to identify individuals with a first measured HbA1c between 48 and 57 mmol/mol (6.5-7.4%) from 2014 to 2020. Six months later, we divided participants into four groups according to GLDT and achieved HbA1c (<48 vs ≥48 mmol/mol [6.5%]): well-controlled and poorly controlled on GLDT; remission and persistent type 2 diabetes not on GLDT. We reported how much the standardised 5 year risk of MACE could be reduced for each group if initiation of statins and RASi was the same as in the well-controlled group on GLDT. RESULTS: We included 14,221 individuals. Compared with well-controlled participants on GLDT, the 5 year standardised risk of MACE was higher in the three other exposure groups: by 3.3% (95% CI 1.6, 5.1) in the persistent type 2 diabetes group not on GLDT; 2.0% (95% CI 0.4, 3.7) in the remission group not on GLDT; and 3.5% (95% CI 1.3, 5.7) in the poorly controlled group on GLDT. Fewer individuals not on GLDT initiated statins and RASi compared with individuals on GLDT. If initiation of statins and RASi had been the same as in the well-controlled group on GLDT, participants not on GLDT could have reduced their risk of MACE by 2.1% (95% CI 1.2, 2.9) in the persistent type 2 diabetes group and by 1.1% (95% CI 0.4, 1.9) in the remission group. CONCLUSIONS/INTERPRETATION: Compared with well-controlled individuals on GLDT, individuals not on initial GLDT had a higher 5 year risk of MACE, even among those achieving remission of type 2 diabetes. This may be related to lower use of statins and RASi.

Risk of Worsening Heart Failure and All-Cause Mortality Following COVID-19 Vaccination in Patients With Heart Failure: A Nationwide Real-World Safety Study.

BACKGROUND: Patients with heart failure are vulnerable to the SARS-CoV-2 infection. However, limited evidence exists on the safety of the SARS-CoV-2 mRNA vaccines in this patient population. The objective of this study was to investigate the risk of all-cause mortality, worsening heart failure, venous thromboembolism, and myocarditis associated with the mRNA vaccines in patients with heart failure. METHODS: Using Danish nationwide registries, 2 cohorts were constructed: (1) all prevalent heart failure patients in 2019 aged 40 to 95 years and (2) all prevalent heart failure patients in 2021 aged 40 to 95 years, who were vaccinated with either of the 2 mRNA vaccines (BNT162B2 or mRNA-1273). The patients in the 2 cohorts were matched 1:1 using exact exposure matching on age, sex, and duration of heart failure. To estimate standardized absolute risks, outcome-specific Cox regression analyses were performed. RESULTS: The total study population comprised 101 786 patients. The median age of the study population was 74 years (interquartile range, 66-81). The standardized risk of all-cause mortality within 90 days was 2.23% (95% CI, 2.10%-2.36%) in the vaccinated cohort and 2.56% (95% CI, 2.43%-2.70%) in the unvaccinated cohort (90-day risk difference, -0.33% [95% CI, -0.52% to -0.15%]). The standardized risk of worsening heart failure within 90 days was 1.10% (95% CI, -1.01% to 1.19%) in the 2021 (vaccinated) cohort and 1.08% (95% CI, 0.99%-1.17%) in the 2019 (unvaccinated) cohort (risk difference, 0.02% [95% CI, -0.11% to 0.15%]). No significant differences were found regarding venous thromboembolism or myocarditis. CONCLUSIONS: Receiving an mRNA vaccine was not associated with an increased risk of worsening heart failure, myocarditis, venous thromboembolism, or all-cause mortality.

The risk of healing complications in primary teeth with root fractures: A retrospective cohort study.

BACKGROUND/AIM: Primary teeth are frequently affected by traumatic dental injuries. Root fractures are rare and have a reported incidence of 2% in the primary dentition. Hence, there is limited evidence on this topic. This study aims to evaluate the risk of healing complications in primary teeth with root fracture and to identify possible sequelae in the permanent dentition following root fracture in the primary dentition. MATERIALS AND METHODS: A retrospective analysis of a cohort of 53 patients with 74 root fractured primary teeth. The standard follow-up program included clinical and radiographic examination after 4 weeks, 8 weeks, 6 months, and 1 year after the trauma and when the patient was 6 years of age. The following complications were registered: pulp necrosis (PN), pulp canal obliteration (PCO), ankylosis with replacement root resorption (ARR), infection-related root resorption (IRR), premature tooth loss (PTL), and repair-related resorption (RRR). STATISTICS: The Kaplan-Meier and Aalen-Johansen estimators were employed. The level of significance was 5%. RESULTS: A total of 74 teeth were included. 42 teeth were extracted at the initial examination. Risks estimated after 3 years: PTL 45.9% [95% CI: 28.8-63.0], PCO 12.9% [95% CI: 2.3-23.4], PN 14.9% [95% CI: 3.9-25.9], RRR 2.6% [95% CI: 0.0-7.5]. No teeth showed ARR or IRR. All complications were diagnosed within the first year. Most common sequelae in the permanent dentition was demarcated opacities, with an estimated risk of 20% [95% CI: 8.2-41.3]. CONCLUSIONS: There is a low risk of healing complications following a root fracture in the primary dentition. Root fractures often result in early extraction of the coronal fragment. The remaining apical fragment will undergo a physiological resorption. Aside from opacities, there is a low risk of sequelae in the permanent dentition.

High opsonic phagocytosis activity and growth inhibition of merozoites are associated with RON4 antibody levels and protect against febrile malaria in Ghanaian children.

Background: Naturally acquired immunity to malaria may involve different immune mechanisms working in concert, however, their respective contributions and potential antigenic targets have not been clearly established. Here, we assessed the roles of opsonic phagocytosis and antibody-mediated merozoite growth inhibition in Plasmodium falciparum (P. falciparum) infection outcomes in Ghanaian children. Methods: The levels of merozoite opsonic phagocytosis, growth inhibition activities and six P. falciparum antigen-specific IgG of plasma samples from children (n=238, aged 0.5 to 13 years) were measured at baseline prior to the malaria seasons in southern Ghana. The children were then actively and passively followed up for febrile malaria and asymptomatic P. falciparum infection detection in a 50-week longitudinal cohort. P. falciparum infection outcome was modelled as a function of the measured immune parameters while accounting for important demographic factors. Results: High plasma activity of opsonic phagocytosis [adjusted odds ratio (aOR)= 0.16; 95%CI= 0.05 - 0.50, p = 0.002], and growth inhibition (aOR=0.15; 95% CI = 0.04-0.47; p = 0.001) were individually associated with protection against febrile malaria. There was no evidence of correlation (b= 0.13; 95% CI= -0.04-0.30; p=0.14) between the two assays. IgG antibodies against MSPDBL1 correlated with opsonic phagocytosis (OP) while IgG against PfRh2a correlated with growth inhibition. Notably, IgG antibodies against RON4 correlated with both assays. Conclusion: Opsonic phagocytosis and growth inhibition are protective immune mechanisms against malaria that may be acting independently to confer overall protection. Vaccines incorporating RON4 may benefit from both immune mechanisms.

All-cause mortality among Danish nursing home residents before and during the COVID-19 pandemic: a nationwide cohort study.

A substantial part of mortality during the COVID-19-pandemic occurred among nursing home residents which caused alarm in many countries. We investigate nursing home mortality in relation to the expected mortality prior to the pandemic. This nationwide register-based study included all 135,501 Danish nursing home residents between 2015 until October 6, 2021. All-cause mortality rates were calculated using a standardization method on sex and age distribution of 2020. Survival probability and lifetime lost for 180 days was calculated using Kaplan Meier estimates. Of 3,587 COVID-19 related deaths, 1137 (32%) occurred among nursing home residents. The yearly all-cause mortality rates per 100,000 person-years in 2015, 2016, and 2017 were 35,301 (95% CI: 34,671-35,943), 34,801 (95% CI: 34,180-35,432), and 35,708 (95% CI: 35,085-36,343), respectively. Slightly elevated mortality rates per 100,000 person-years were seen in 2018, 2019, 2020, and 2021 of 38,268 (95% CI: 37,620-38,929), 36,956 (95% CI: 36,323-37,600), 37,475 (95% CI: 36,838-38,122), and 38,536 (95% CI: 37,798-39,287), respectively. For SARS-CoV-2-infected nursing home residents, lifetime lost difference was 42 days (95% CI: 38-46) in 2020 versus non-infected in 2018. Among vaccinated in 2021, lifetime lost difference was 25 days (95% CI: 18-32) for SARS-CoV-2-infected versus non-infected. Even though a high proportion of COVID-19 fatalities took place in nursing homes and SARS-CoV-2-infection increased the risk of individual death, the annual mortality was only slightly elevated. For future epidemics or pandemics reporting numbers of fatal cases in relation to expected mortality is critical.

Colonoscopy performance monitoring: do we need to adjust for case mix?

INTRODUCTION: Overall caecum intubation rate(oCIR) and overall polyp detection rate(oPDR) have been proposed as performance indicators, but varying complexity in case mix among endoscopists may potentially affect validity. The study aims to explore the effect of adjusting for case mix on individual endoscopist performance by calculating case mix-adjusted performance estimates (cmCIR and cmPDR) and comparing them to overall performance estimates (oCIR and oPDR). The study also provides an R program for case mix analysis. METHODS: Logistic regression associated endoscopist, colonoscopy indication, patient age and patient gender with the binary outcomes of cecum intubation and polyp detection. Case mix-adjusted performance indicators were calculated for each endoscopist based on logistic regression and bootstraps. Endoscopists were ranked from best to worst by overall and case mix-adjusted performance estimates, and differences were evaluated using percentage points(pp) and rank changes. RESULTS: The dataset consisted of 7376 colonoscopies performed by 47 endoscopists. The maximum rank change for an endoscopist comparing oCIR and cmCIR was eight positions, interquartile range (IQR 1-3). The maximum change in CIR was 1.95 percentage point (pp) (IQR 0.27-0.86). The maximum rank change in the oPDR versus cmPDR analysis was 17 positions (IQR 1.5-8.5). The maximum change in PDR was 11.21 pp (IQR 2.05-6.70). Three endoscopists improved their performance from significantly inferior to within the 95% confidence interval (CI) range of performance targets using case mix-adjusted estimates. CONCLUSIONS: The majority of endoscopists were unaffected by adjustment for case mix, but a few unfortunate endoscopists had an unfavourable case mix that could invite incorrect suspicion of inferior performance.

Ranking of average treatment effects with generalized random forests for time-to-event outcomes.

Linkage between drug claims data and clinical outcome allows a data-driven experimental approach to drug repurposing. We develop an estimation procedure based on generalized random forests for estimation of time-point specific average treatment effects in a time-to-event setting with competing risks. To handle right-censoring, we propose a two-step procedure for estimation, applying inverse probability weighting to construct time-point specific weighted outcomes as input for the generalized random forest. The generalized random forests adaptively handle covariate effects on the treatment assignment by applying a splitting rule that targets a causal parameter. Using simulated data we demonstrate that the method is effective for a causal search through a list of treatments to be ranked according to the magnitude of their effect on clinical outcome. We illustrate the method using the Danish national health registries where it is of interest to discover drugs with an unexpected protective effect against relapse of severe depression.

Association between primary care electrocardiogram markers and Alzheimer's disease.

OBJECTIVE: The association between common electrocardiogram (ECG) markers and Alzheimer's disease has been scarcely investigated, and it is unknown if ECG markers can improve risk prediction. Thus, we aimed to examine the association between common ECG markers and Alzheimer's disease in a large population. METHODS: We studied the association between ECG markers and Alzheimer's disease using Cox models with adjustment for age, sex, and comorbidities using a large primary care population of patients aged 60 years or more. RESULTS: We followed 172,236 subjects for a median of 7.5 years. Increased PR interval (hazard ratio for PR > 188 ms: 0.76 [95% confidence interval: 0.69-0.83, p < 0.001) and increased QTc interval (hazard ratio for QTc = [426;439]: 0.90 [0.83-0.98], p = 0.02) were associated with a decreased rate of Alzheimer's disease. A positive Sokolow-Lyon index >35 mm (1.22 [1.13-1.33], p < 0.001) and increased T-wave amplitude >4.1 mm (1.15 [1.04-1.27]) were associated with an increased rate of Alzheimer's disease. Upon addition of ECG markers to a reference model, 10-year prediction area under the receiver-operator characteristics curve (AUC) improved by 0.39 [0.06-0.67] %-points. The 10-year absolute risk of Alzheimer's disease was 6.5% and 5.2% for an 82-year old female and a male, respectively, with a favorable ECG, and 12% and 9.2%, respectively, with an unfavorable ECG, almost twice as high. CONCLUSIONS: We identified several common ECG markers which were associated with Alzheimer's disease, and which improved risk prediction for Alzheimer's disease.

Marginal structural models with monotonicity constraints: A case study in out-of-hospital cardiac arrest patients.

This paper deals with estimating the probability of a binary counterfactual outcome as a function of a continuous covariate under monotonicity constraints. We are motivated by the study of out-of-hospital cardiac arrest patients which aims to estimate the counterfactual 30-day survival probability if either all patients had received, or if none of the patients had received bystander cardiopulmonary resuscitation (CPR), as a function of the ambulance response time. It is natural to assume that the counterfactual 30-day survival probability cannot increase with increasing ambulance response time. We model the monotone relationship with a marginal structural model and B-splines. We then derive an estimating equation for the parameters of interest which however further relies on an auxiliary regression model for the observed 30-day survival probabilities. The predictions of the observed 30-day survival probabilities are used as pseudo-values for the unobserved counterfactual 30-day survival status. The methods are illustrated and contrasted with an unconstrained modeling approach in large-scale Danish registry data.

Development and validation of prediction models for incident atrial fibrillation in heart failure.

OBJECTIVES: Accurate prediction of heart failure (HF) patients at high risk of atrial fibrillation (AF) represents a potentially valuable tool to inform shared decision making. No validated prediction model for AF in HF is currently available. The objective was to develop clinical prediction models for 1-year risk of AF. METHODS: Using the Danish Heart Failure Registry, we conducted a nationwide registry-based cohort study of all incident HF patients diagnosed from 2008 to 2018 and without history of AF. Administrative data sources provided the predictors. We used a cause-specific Cox regression model framework to predict 1-year risk of AF. Internal validity was examined using temporal validation. RESULTS: The population included 27 947 HF patients (mean age 69 years; 34% female). Clinical experts preselected sex, age at HF, NewYork Heart Association (NYHA) class, hypertension, diabetes mellitus, chronic kidney disease, obstructive sleep apnoea, chronic obstructive pulmonary disease and myocardial infarction. Among patients aged 70 years at HF, the predicted 1-year risk was 9.3% (95% CI 7.1% to 11.8%) for males and 6.4% (95% CI 4.9% to 8.3%) for females given all risk factors and NYHA III/IV, and 7.5% (95% CI 6.7% to 8.4%) and 5.1% (95% CI 4.5% to 5.8%), respectively, given absence of risk factors and NYHA class I. The area under the curve was 65.7% (95% CI 63.9% to 67.5%) and Brier score 7.0% (95% CI 5.2% to 8.9%). CONCLUSION: We developed a prediction model for the 1-year risk of AF. Application of the model in routine clinical settings is necessary to determine the possibility of predicting AF risk among patients with HF more accurately and if so, to quantify the clinical effects of implementing the model in practice.