Table 4 Annual time trend of incidence of subarachnoid haemorrhage in the reference region*
No of studiesIncidence ratio† (95% CI)Incidence ratio† (95% CI) adjusted for gender and age
Reference region421.001 (0.997 to 1.004)0.994 (0.987 to 1.001)
Reference region after 1990240.973 (0.961 to 0.985)0.994 (0.967 to 1.022)

  • *All countries other than Japan, Finland and South and Central America.

  • †Incidence ratio represents coefficient for year-to-year annual change.