2.External Validation of the ELAPSS Score for Prediction of Unruptured Intracranial Aneurysm Growth Risk
Mayte Sánchez VAN KAMMEN ; Jacoba P GREVING ; Satoshi KURODA ; Daina KASHIWAZAKI ; Akio MORITA ; Yoshiaki SHIOKAWA ; Toshikazu KIMURA ; Christophe COGNARD ; Anne C JANUEL ; Antti LINDGREN ; Timo KOIVISTO ; Juha E JÄÄSKELÄINEN ; Antti RONKAINEN ; Liisa PYYSALO ; Juha ÖHMAN ; Melissa RAHI ; Johanna KUHMONEN ; Jaakko RINNE ; Eva L LEEMANS ; Charles B MAJOIE ; W Peter VANDERTOP ; Dagmar VERBAAN ; Yvo B W E M ROOS ; René VAN DEN BERG ; Hieronymus D BOOGAARTS ; Walid MOUDROUS ; Ido R VAN DEN WIJNGAARD ; Laura ten HOVE ; Mario TEO ; Edward J ST GEORGE ; Katharina A M HACKENBERG ; Amr ABDULAZIM ; Nima ETMINAN ; Gabriël J E RINKEL ; Mervyn D I VERGOUWEN
Journal of Stroke 2019;21(3):340-346
BACKGROUND AND PURPOSE: Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for prediction of the risk of unruptured intracranial aneurysm growth. METHODS: From 11 international cohorts of patients ≥18 years with ≥1 unruptured intracranial aneurysm and ≥6 months of radiological follow-up, we collected data on the predictors of the ELAPSS score, and calculated 3- and 5-year absolute growth risks according to the score. Model performance was assessed in terms of calibration (predicted versus observed risk) and discrimination (c-statistic). RESULTS: We included 1,072 patients with a total of 1,452 aneurysms. During 4,268 aneurysm-years of follow-up, 199 (14%) aneurysms enlarged. Calibration was comparable to that of the development cohort with the overall observed risks within the range of the expected risks. The c-statistic was 0.69 (95% confidence interval [CI], 0.64 to 0.73) at 3 years, compared to 0.72 (95% CI, 0.68 to 0.76) in the development cohort. At 5 years, the c-statistic was 0.68 (95% CI, 0.64 to 0.72), compared to 0.72 (95% CI, 0.68 to 0.75) in the development cohort. CONCLUSIONS: The ELAPSS score showed accurate calibration for 3- and 5-year risks of aneurysm growth and modest discrimination in our external validation cohort. This indicates that the score is externally valid and could assist patients and physicians in predicting growth of unruptured intracranial aneurysms and plan follow-up imaging accordingly.
Aneurysm
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Calibration
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Cohort Studies
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Discrimination (Psychology)
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Follow-Up Studies
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Humans
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Intracranial Aneurysm
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Risk Factors
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Subarachnoid Hemorrhage
3.Replacement of SARS-CoV-2 strains with variants carrying N501Y and L452R mutations in Japan: an epidemiological surveillance assessment
Yusuke Kobayashi ; Takeshi Arashiro ; Miyako Otsuka ; Yuuki Tsuchihashi ; Takuri Takahashi ; Yuzo Arima ; Yura K. Ko ; Kanako Otani ; Masato Yamauchi ; Taro Kamigaki ; Tomoko Morita-Ishihara ; Hiromizu Takahashi ; Sana Uchikoba ; Michitsugu Shimatani ; Nozomi Takeshita ; Motoi Suzuki ; Makoto Ohnishi
Western Pacific Surveillance and Response 2022;13(3):41-50
Objective:
Monitoring the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants is important due to concerns regarding infectivity, transmissibility, immune evasion and disease severity. We evaluated the temporal and regional replacement of previous SARS-CoV-2 variants by the emergent strains, Alpha and Delta.
Methods:
We obtained the results of polymerase chain reaction screening tests for variants conducted in multiple commercial laboratories. Assuming that all previous strains would be replaced by one variant, the new variant detection rate was estimated by fitting a logistic growth model. We estimated the transmission advantage of each new variant over the pre-existing virus strains.
Results:
The variant with the N501Y mutation was first identified in the Kinki region in early February 2021, and by early May, it had replaced more than 90% of the previous strains. The variant with the L452R mutation was first detected in the Kanto-Koshin region in mid-May, and by early August, it comprised more than 90% of the circulating strains. Compared with pre-existing strains, the variant with the N501Y mutation showed transmission advantages of 48.2% and 40.3% in the Kanto-Koshin and Kinki regions, respectively, while the variant with the L452R mutation showed transmission advantages of 60.1% and 71.9%, respectively.
Discussion
In Japan, Alpha and Delta variants displayed regional differences in the replacement timing and their relative transmission advantages. Our method is efficient in monitoring and estimating changes in the proportion of variant strains in a timely manner in each region.