Return to Work after Surgical Clipping versus Endovascular Treatment of Unruptured Intracranial Aneurysms: A Nationwide Registry-Based Study.

PURPOSE: To assess return to work following the treatment of unruptured intracranial aneurysms (UIAs). MATERIALS AND METHODS: This retrospective, nationwide registry-based study included all adult patients of working age treated for a UIA in Norway between 2008 and 2018 who had a record of sickness leave on the day of treatment. Data from The Norwegian Patient Registry and The Norwegian Labour and Welfare Administration were linked on an individual level. Daily sickness and recipiency of disability benefits, as an indirect measure of working status, from 1 year before treatment to 1 year after treatment were analyzed. Return to work after endovascular treatment and surgical clipping was compared. RESULTS: In total, 412 patients were included. Of patients who worked 1 year before treatment, 83% returned to work 1 year after treatment. The number of days from treatment to the first day back at work in a continuous 3-month working period was lower in patients who underwent endovascular treatment than in those treated with surgical clipping (median, 69 days; 95% confidence interval [CI], 51-87; vs 201 days, 95% CI, 163-239; P < .001). Return to work was more likely in patients who underwent endovascular treatment at 3 months after treatment (hazard ratio, 3.53; 95% CI, 2.54-4.93; P < .001). There was no difference in return to work at 6 and 12 months after treatment. CONCLUSIONS: The treatment of UIAs affects patients' postoperative working status. Patients treated endovascularly return to work earlier than those who undergo open surgery.

The Epidemiology of Moderate and Severe Traumatic Brain Injury in Central Norway.

INTRODUCTION: Few studies account for prehospital deaths when estimating incidence and mortality rates of moderate and severe traumatic brain injury (msTBI). In a population-based study, covering both urban and rural areas, including also prehospital deaths, the aim was to estimate incidence and mortality rates of msTBI. Further, we studied the 30-day and 6-month case-fatality proportion of severe TBI in relation to age. METHODS: All patients aged ≥17 years who sustained an msTBI in Central Norway were identified by three sources: (1) the regional trauma center, (2) the general hospitals, and (3) the Norwegian Cause of Death Registry. Incidence and mortality rates were standardized according to the World Health Organization's world standard population. Case-fatality proportions were calculated by the number of deaths from severe TBI at 30 days and 6 months, divided by all patients with severe TBI. RESULTS: The overall incidence rates of moderate and severe TBI were 4.9 and 6.7 per 100,000 person-years, respectively, increasing from age 70 years. The overall mortality rate was 3.4 per 100,000 person-years, also increasing from age 70 years. Incidence and mortality rates were highest in men. The case-fatality proportion in people with severe TBI was 49% in people aged 60-69 years and 81% in people aged 70-79 years. CONCLUSION: The overall incidence and mortality rates for msTBI in Central Norway were low but increased from age 70 years, and among those ≥80 years of age with severe TBI, nearly all died. Overall estimates are strongly influenced by high incidence and mortality rates in the elderly, and studies should therefore report age-specific estimates, for better comparison of incidence and mortality rates.

Return to work after surgical clipping versus endovascular treatment for ruptured intracranial aneurysms - A nationwide registry-based study.

OBJECTIVES: The aim of this study was to assess return to work following aneurysmal subarachnoid haemorrhage (SAH) and compare working status after open surgical clipping and endovascular treatment. METHODS: This nationwide registry-based study included all adult patients in working age treated for a ruptured intracranial aneurysm in Norway between 2008 and 2018 who had a record of sickness leave on the day of treatment. Data from The Norwegian Patient Registry and The Norwegian Labour and Welfare Administration were linked on an individual level. Daily sickness and disability benefits recipiency one year preoperatively to one year postoperatively was analysed. Return to work after endovascular treatment and surgical clipping was compared. RESULTS: 183 patients were included in the study. Among patients who worked at one year preoperatively, 57% had returned to work one year after treatment. Mean number of days from treatment to the first day back at work in a continuous 3-month working period was 298 (95% CI: 276-321) vs. 319 (95% CI: 299-339) for patients who underwent endovascular treatment compared to patients treated with clipping (p = 0.365). Older patients were less likely to return to work after treatment (hazard ratio 0.977 per year of age, 95% CI 0.956-1.000, p = 0.046). There was no significant association between return to work and patient sex or location of the aneurysm. CONCLUSIONS: Aneurysmal SAH profoundly affects patient working status. This study found no significant difference in time to return to work after treatment between patients treated with endovascular techniques compared to patients undergoing open surgery.

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.

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.

Risk Factors for Unruptured Intracranial Aneurysms and Subarachnoid Hemorrhage in a Prospective Population-Based Study.

Background and Purpose- We wanted to evaluate potential risk factors for unruptured intracranial aneurysms (UIAs) and aneurysmal subarachnoid hemorrhage (aSAH) in a large, prospective study of the general population with risk factors collected before the detection of UIA or aSAH. Methods- All residents ≥20 years were invited to the HUNT (The Nord-Trøndelag Health Study). In this study, 89 951 participants were included. The study included standardized measurements of blood pressure and self-administered questionnaires. Cases of UIA and aSAH from 1999 to 2014 were identified using hospital records and the Norwegian Cause of Death Register. Hazard ratios with CIs were estimated using Cox regression analysis. Results- The detection rate of UIA was 8.2 per 100 000 person-years (97 patients). Current smoking (hazard ratio, 4.1; 95% CI, 2.4-7.1) and female sex (hazard ratio, 2.8; 95% CI, 1.7-4.5) were associated with markedly increased risk of UIA, but we found no association with systolic blood pressure (P for trend 0.62). The incidence of aSAH was 9.9 per 100 000 person-years (117 patients). The most important risk factors for aSAH were current smoking, female sex and increasing blood pressure (P for trend 0.006 for systolic blood pressure). Conclusions- In contrast to previous studies on risk factors of UIA, we found no association with systolic blood pressure. However, there was a strong association between systolic blood pressure and aSAH in the same population. Current smoking and female sex were associated with both diseases.

Incidental Intracranial Findings and Their Clinical Impact; The HUNT MRI Study in a General Population of 1006 Participants between 50-66 Years.

OBJECTIVES: Evaluate types and prevalence of all, incidental, and clinically relevant incidental intracranial findings, i.e. those referred to primary physician or clinical specialist, in a cohort between 50 and 66 years from the Nord-Trøndelag Health (HUNT) study. Types of follow-up, outcome of repeated neuroimaging and neurosurgical treatment were assessed. MATERIAL AND METHODS: 1006 participants (530 women) underwent MRI of the head at 1.5T consisting of T1 weighted sagittal IR-FSPGR volume, axial T2 weighted, gradient echo T2* weighted and FLAIR sequences plus time of flight cerebral angiography covering the circle of Willis. The nature of a finding and if it was incidental were determined from previous radiological examinations, patient records, phone interview, and/or additional neuroimaging. Handling and outcome of the clinically relevant incidental findings were prospectively recorded. True and false positives were estimated from the repeated neuroimaging. RESULTS: Prevalence of any intracranial finding was 32.7%. Incidental intracranial findings were present in 27.1% and clinically relevant findings in 15.1% of the participants in the HUNT MRI cohort. 185 individuals (18.4%) were contacted by phone about their findings. 40 participants (6.2%) underwent ≥ 1 additional neuroimaging session to establish etiology. Most false positives were linked to an initial diagnosis of suspected glioma, and overall positive predictive value of initial MRI was 0.90 across different diagnoses. 90.8% of the clinically relevant incidental findings were developmental and acquired cerebrovascular pathologies, the remaining 9.2% were intracranial tumors, of which extra-axial tumors predominated. In total, 3.9% of the participants were referred to a clinical specialist, and 11.7% to their primary physician. 1.4% underwent neurosurgery/radiotherapy, and 1 (0.1%) experienced a procedure related postoperative deficit. CONCLUSIONS: In a general population between 50 and 66 years most intracranial findings on MRI were incidental, and >15% of the cohort was referred to clinical-follow up. Hence good routines for handling of findings need to be in place to ensure timely and appropriate handling.

Unruptured intracranial aneurysms in the Norwegian Nord-Trøndelag Health Study (HUNT): risk of rupture calculated from data in a population-based cohort study.

BACKGROUND: Rupture risk of unruptured intracranial aneurysms (UIAs) has been investigated in studies observing the natural history of this condition. Such studies have been prone to selection bias that may influence the results. OBJECTIVE: To calculate the overall rupture risk from data on the prevalence of UIA, which constitutes the population at risk, and the incidence of aneurysmal subarachnoid hemorrhage (aSAH) in the same population. METHODS: Data were collected from the Norwegian Nord-Trøndelag Health Study (HUNT), a large population-based cohort study. The prevalence of UIAs was estimated by performing magnetic resonance angiography in 1006 randomly selected volunteers 50 to 65 years of age from this population cohort. The incidence of aSAH was investigated by searching national and hospital registers with thorough case ascertainment to avoid inclusion of nonaneurysmal subarachnoid hemorrhage. RESULTS: The prevalence of UIAs was 1.9% and incidence of aSAH was 16.4 per 100,000 person-years. Based on these figures, the overall rupture risk in the 50- to 65-year age group in the HUNT population is 0.87% per year. CONCLUSION: This is the first study to estimate rupture risk of intracranial aneurysms from epidemiologic data in a large population-based cohort. This study design is less prone to selection bias and may provide an important supplement to the existing literature of studies of natural history of UIAs.