Smoking habits and detection rate of unruptured intracranial aneurysms and incidence rate of subarachnoid haemorrhage in Norway between 2008 and 2015

Objective The aim of this study was to investigate the detection rate of unruptured intracranial aneurysms (UIAs) and incidence of aneurysmal subarachnoid haemorrhage (SAH) in relation to the rapidly changing smoking rates in Norway between 2008 and 2015. Methods The registry-based study included all patients (≥ 16 years old) admitted to a hospital in Norway between 2008 and 2015 with a primary diagnosis of aneurysmal SAH or an outpatient diagnosis of UIAs. Age group–specific and total detection rate of UIAs and incidence rate of SAH over the years were calculated. Age group–specific data on smoking habits was retrieved from a national annual survey representative of the whole Norwegian population. Results The rate of daily smokers decreased by 48% between 2008 and 2015. The detection rate of UIAs decreased by 47% from 17.3 in 2008 to 9.3 per 100,000 persons in 2015, and the incidence of SAH decreased by 30% from 11.3 in 2008 to 7.9 per 100,000 persons in 2015. The average annual decline in prevalence of daily smoking, UIA detection rate, and SAH incidence was 6.9%, 6.7%, and 4.3% per year, respectively. Multinomial logistic regression analyses revealed that the correlation between the decline in estimated daily smoking rates and decline in detection rate of UIAs (hazard ratio 52.5 CI = (14.9,∞), p < 0.00001) and incidence of SAH (hazard ratio 11.8 CI=(5.6,32.5), p < 0.00001) are statistically significant. The association is particularly strong in young and middle-aged cohorts (< 66 years old). Conclusion It is likely that reducing cigarette smoking on a population-based level strongly reduces the rates of UIAs and SAH

What is the current clinico-radiological diagnostic accuracy for intracranial tumours?

Objective To determine the diagnostic accuracy of routine clinico-radiological workup for a population-based selection of intracranial tumours. Methods In this prospective cohort study, we included consecutive adult patients who underwent a primary surgical intervention for a suspected intracranial tumour between 2015 and 2019 at a single-neurosurgical centre. The treating team estimated the expected diagnosis prior to surgery using predefined groups. The expected diagnosis was compared to final histopathology and the accuracy of preoperative clinico-radiological diagnosis (sensitivity, specificity, positive and negative predictive values) was calculated. Results 392 patients were included in the data analysis, of whom 319 underwent a primary surgical resection and 73 were operated with a diagnostic biopsy only. The diagnostic accuracy varied between different tumour types. The overall sensitivity, specificity and diagnostic mismatch rate of clinico-radiological diagnosis was 85.8%, 97.7% and 4.0%, respectively. For gliomas (including differentiation between low-grade and high-grade gliomas), the same diagnostic accuracy measures were found to be 82.2%, 97.2% and 5.6%, respectively. The most common diagnostic mismatch was between low-grade gliomas, high-grade gliomas and metastases. Accuracy of 90.2% was achieved for differentiation between diffuse low-grade gliomas and high-grade gliomas. Conclusions The current accuracy of a preoperative clinico-radiological diagnosis of brain tumours is high. Future non-invasive diagnostic methods need to outperform our results in order to add much value in a routine clinical setting in unselected patients

Incidence and Case Fatality of Aneurysmal Subarachnoid Hemorrhage Admitted to Hospital Between 2008 and 2014 in Norway

Background To provide age- and sex-specific incidence and case fatality rates for non-traumatic aneurysmal subarachnoid hemorrhage (aSAH) in Norway. We also studied time trends in incidence and case fatality, as well as predictors of death following aSAH. Methods A nationwide study using discharge data for patients admitted with aSAH between 2008 and 2014. Results A total of 1732 patients with aSAH were included. The mean age was 60 years (SD 14) and 63% were females. Crude annual incidence was 5.7 per 100,000 person-years (95% CI 5.4–6.0) and was higher in females (6.3 per 100,000, 95% CI 5.9–6.7) compared with males (4.9 per 100,000, 95% CI 4.5–5.3). The annual decline in aSAH incidence was 3.2% per year (p = 0.007). The cumulative proportions of fatalities at days 30, 90, and 1 year were 22%, 25%, and 37%, respectively. The 30-day mortality rate did not change during the study period. Age (HR 0.7–2.2) and aneurysms in the posterior circulation (HR 1.7, 95% CI 1.3–2.3, p = 0.001) were associated with higher 30-day case fatality following aSAH, while aneurysm repair (HR 0.2, 95% CI 0.2–0.3, p < 0.001) was associated with lower risk. Conclusions The incidence of aSAH declined in Norway between 2008 and 2014. Case fatality following aSAH continues to be high, and the 30-day mortality during the study period was unchanged. Increasing age and aneurysms in the posterior circulation were associated with increased risk of death within 30 days following aSAH