Lindekleiv HM, Njølstad I, Ingebrigtsen T, Mathiesen EB. Incidence of aneurysmal subarachnoid hemorrhage in Norway, 1999–2007.
Acta Neurol Scand: 2011: 123: 34–40.
© 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard.
Objective – To investigate changes and regional variations in annual incidence rates of aneurysmal subarachnoid hemorrhage (SAH) in Norway between 1999 and 2007.
Methods – The authors retrospectively reviewed data from the Norwegian Patient Register for the period 1999–2007.
Results – Crude incidence of aneurysmal SAH was 10.0/100,000 person years [95% CI (confidence interval): 9.7–10.3] and was higher in women (12.0/100,000 person years; 95% CI: 11.5–12.5) than men (8.1/100,000 person years; 95% CI: 7.7–8.4). Decreasing annual incidence rates were observed from 11.1/100,000 person years (95% CI: 10.5–11.6) in the period 1999–2001 to 8.9/100,000 person years (95% CI: 8.4–9.4) in the period 2005–2007 (P for trend <0.001). Regional variations were observed, from 8.4/100,000 person years (95% CI: 7.7–9.00) in the southern region, 10.4/100,000 person years (95% CI: 9.5–11.2) in the central region and 11.9/100,000 person years (95% CI: 10.8–12.9) in the northern region.
Conclusions – Incidence of aneurysmal SAH in Norway decreased from 1999 to 2007, with significant regional variations indicating an increasing gradient from south to north.