TY - JOUR
T1 - Incidence and mortality of aneurysmal subarachnoid hemorrhage in two Norwegian cohorts, 1984-2007
AU - Sandvei, M. S.
AU - Mathiesen, E. B.
AU - Vatten, L. J.
AU - Müller, T. B.
AU - Lindekleiv, H.
AU - Ingebrigtsen, T.
AU - Njølstad, I.
AU - Wilsgaard, T.
AU - Løchen, M. L.
AU - Vik, A.
AU - Romundstad, P. R.
PY - 2011/11/15
Y1 - 2011/11/15
N2 - Objective: The incidence of aneurysmal subarachnoid hemorrhage (aSAH) ranges from 4 to 10 per 100,000 person-years in most countries, and 30-day case fatality is high. The aim of this study was to estimate the incidence and case fatality of aSAH and to assess preictal predictors of survival in 2 large Norwegian population-based cohort studies. Methods: A total of 94,976 adults (≥20 years) in the Nord-Trøndelag Health Study and 31,753 participants (aged ≥20 years) in the Tromsø Study were included. During follow-up, aSAHs were identified, incidence rates were estimated, and predictors of survival were assessed using Cox and Poisson regression analysis. Results: A total of 214 patients with aSAH were identified during 2,077,927 person-years of follow-up from 1984 to 2007. The incidence rate was 10.3 per 100,000 person-years: 13.3 for women and 7.1 for men. The incidence increased by 2% (95% confidence interval [CI] 0-4) per 5-year time period. Case fatality at 3, 7, and 30 days was 20%, 24%, and 36%. Thirty-day case fatality remained stable during follow-up (odds ratio 1.01, 95% CI 0.97-1.06 per year). Never smokers had poorer survival after aSAH than current and former smokers combined (hazard ratio 1.6, 95% CI 0.9-2.9). Conclusions: The slight increase in incidence of aSAH over time may be explained by differences in diagnostic procedures. Case fatality remained stable during 23 years of follow-up.
AB - Objective: The incidence of aneurysmal subarachnoid hemorrhage (aSAH) ranges from 4 to 10 per 100,000 person-years in most countries, and 30-day case fatality is high. The aim of this study was to estimate the incidence and case fatality of aSAH and to assess preictal predictors of survival in 2 large Norwegian population-based cohort studies. Methods: A total of 94,976 adults (≥20 years) in the Nord-Trøndelag Health Study and 31,753 participants (aged ≥20 years) in the Tromsø Study were included. During follow-up, aSAHs were identified, incidence rates were estimated, and predictors of survival were assessed using Cox and Poisson regression analysis. Results: A total of 214 patients with aSAH were identified during 2,077,927 person-years of follow-up from 1984 to 2007. The incidence rate was 10.3 per 100,000 person-years: 13.3 for women and 7.1 for men. The incidence increased by 2% (95% confidence interval [CI] 0-4) per 5-year time period. Case fatality at 3, 7, and 30 days was 20%, 24%, and 36%. Thirty-day case fatality remained stable during follow-up (odds ratio 1.01, 95% CI 0.97-1.06 per year). Never smokers had poorer survival after aSAH than current and former smokers combined (hazard ratio 1.6, 95% CI 0.9-2.9). Conclusions: The slight increase in incidence of aSAH over time may be explained by differences in diagnostic procedures. Case fatality remained stable during 23 years of follow-up.
UR - http://www.scopus.com/inward/record.url?scp=82955228938&partnerID=8YFLogxK
U2 - 10.1212/WNL.0b013e3182377de3
DO - 10.1212/WNL.0b013e3182377de3
M3 - Article
C2 - 22049205
AN - SCOPUS:82955228938
SN - 0028-3878
VL - 77
SP - 1833
EP - 1839
JO - Neurology
JF - Neurology
IS - 20
ER -