Thrombolytic Treatment in Wake-Up Stroke: A Propensity Score-Matched Analysis of Treatment Effectiveness in the Norwegian Stroke Registry.

Background: Previous clinical trials found improved outcome of thrombolytic treatment in patients with ischemic wake-up stroke (WUS) selected by advanced imaging techniques. The authors assessed the effectiveness of thrombolytic treatment in patients with WUS in a nationwide stroke registry.

Methods And Results: Using propensity score matching, the authors assessed the effectiveness and safety of thrombolytic treatment versus no thrombolytic treatment in 726 patients (363 matched pairs) with WUS in the Norwegian Stroke Registry in 2014 to 2019.

Risk of myocardial infarction after invasive outpatient procedures.

Objective: To assess the short-term risk of acute myocardial infarction (AMI) associated with procedures performed at outpatient specialised hospital clinics.

Methods: In this case-crossover, population-based study, we identified first-time AMI cases aged ≥40 years via patient registries and linked them to their surgical intervention in Norway (2008-2016) and Sweden (2001-2014), respectively. The number of individuals with AMI who underwent procedures 0-7 days (hazard period) prior to the AMI diagnosis was compared with cases who were exposed 29-36 days (control period) before the AMI.

Wake-up stroke and unknown-onset stroke; occurrence and characteristics from the nationwide Norwegian Stroke Register.

Introduction: Population-based knowledge of the characteristics of wake-up stroke and unknown-onset stroke is limited. We compared occurrence and characteristics of ischaemic and haemorrhagic wake-up stroke, unknown-onset stroke and known-onset stroke in a nationwide register-based study.

Patients And Methods: We included patients registered in the Norwegian Stroke Register from 2012 through 2019.

Risk for Acute Myocardial Infarction After Ophthalmologic Procedures.

Background: Preoperative cardiovascular evaluations are frequently done before ambulatory ophthalmologic procedures. However, whether these procedures can trigger an acute myocardial infarction (AMI) is unknown.

Objective: To assess the short-term risk for AMI associated with ophthalmologic procedures.

Validating Acute Myocardial Infarction Diagnoses in National Health Registers for Use as Endpoint in Research: The Tromsø Study.

Purpose: To assess whether acute myocardial infarction (MI) diagnoses in national health registers are sufficiently correct and complete to replace manual collection of endpoint data for a population-based, epidemiological study.

Patients And Methods: Using the Tromsø Study Cardiovascular Disease Register for 2013-2014 as gold standard, we calculated correctness (defined as positive predictive value (PPV)) and completeness (defined as sensitivity) of MI cases in the Norwegian Myocardial Infarction Register and the Norwegian Patient Register separately and in combination. We calculated the sensitivity and PPV with 95% confidence intervals using the Clopper-Pearson Exact test.

Data from national health registers as endpoints for the Tromsø Study: Correctness and completeness of stroke diagnoses.

Aim: To assess whether stroke diagnoses in national health registers are sufficiently correct and complete to replace manual collection of endpoint data for the Tromsø Study, a population-based epidemiological study.

Method: Using the Tromsø Study Cardiovascular Disease Register for 2013-2014 as the gold standard, we calculated correctness (defined as positive predictive value, PPV) and completeness (defined as sensitivity) of stroke cases in four different data subsets derived from the Norwegian Patient Register and the Norwegian Stroke Register. We calculated the sensitivity and PPV with 95% confidence intervals (CIs) assuming a normal approximation of the binomial distribution.

Influenza vaccination and risk for cardiovascular events: a nationwide self-controlled case series study.

Background: US and European guidelines diverge on whether to vaccinate adults who are not at high risk for cardiovascular events against influenza. Here, we investigated the associations between influenza vaccination and risk for acute myocardial infarction, stroke and pulmonary embolism during the 2009 pandemic in Norway, when vaccination was recommended to all adults.

Methods: Using national registers, we studied all vaccinated Norwegian individuals who suffered AMI, stroke, or pulmonary embolism from May 1, 2009 through September 30, 2010.

[Stroke in Norway 2015–16 – treatment and outcomes].

Background: Treatment of stroke in Norway is decentralised; patients with stroke are treated at 50 different hospitals. We have surveyed the treatment of stroke in these hospitals and collated this with data from the Norwegian Stroke Registry. We wished to investigate whether there was any variation in treatment interventions and treatment outcomes between university hospitals and local hospitals.

Percutaneous Coronary Intervention as a Trigger for Stroke.

Percutaneous coronary intervention (PCI) is a plausible triggering factor for stroke, yet the magnitude of this excess risk remains unclear. This study aimed to quantify the transient change in risk of stroke for up to 12 weeks after PCI. We applied the case-crossover method, using data from the Norwegian Patient Register on all hospitalizations in Norway in the period of 2008 to 2014.

Comparison of the validity of stroke diagnoses in a medical quality register and an administrative health register.

Aims: Health registers are essential sources of data used in a wide range of stroke research, including epidemiological, clinical and healthcare studies. Regardless of the type of register, the data must be of high quality to be useful. In this study, we investigated and compared the correctness and completeness of the Norwegian Patient Register (an administrative health register) and the Norwegian Stroke Register (a medical quality register for acute stroke).

Inter-rater reliability of a national acute stroke register.

Background: Medical quality registers are useful sources of knowledge about diseases and the health services. However, there are challenges in obtaining valid and reliable data. This study aims to assess the reliability in a national medical quality register.