Table 1

 Characteristics of studies

Total (deep/lobar)
Study*Year of publicationStudy populationMethodological quality criteria fulfilled†Exclusions due to secondary causes% of patient excludedNumber of patients in analysesMean or median ageTime to scan
AVM, arteriovenous malformation; CVT, cerebral venous thrombosis; NR, not reported; SLE, systemic lupus erythematosus.
*Studies are ordered first according to whether they included mixed-age or younger populations, and then by year of publication.
†; BP-pre, definition of hypertension based on pre-stroke blood pressure (not post-stroke or combination of pre-stroke and post-stroke blood pressure); FES, first-ever stroke only; P, population based.
‡Percentage of all deep and lobar supratentorial haemorrhages excluded because of secondary causes (except for Rome, Cincinnati (b) and USA, where the percentage excluded is calculated with all haemorrhages, including those in the posterior fossa, as the denominator).
§A total of 3930 patients with haemorrhage were included in the analyses, 2196 of whom had a deep haemorrhage.
¶Mean or median (indicated by **) age of total population with intracerebral haemorrhage (including those with posterior fossa haemorrhage). In cases where age was reported as the number of patients within various age bands, mean age was derived by assigning the middle value of each age band to the number of patients included.
Studies of populations unselected for age
New Orleans, USA481979Consecutive admissions to the neurology departmentAVM, blood dyscrasia, coagulopathy or on anticoagulants9% (3%/41%)242 (222/20)NRWithin 8 days
Heidelberg, Germany341982Non-consecutive admissions to hospitalAVM, CVT, or on anticoagulants19% (2%/37%)71 (44/27)58 (NR)NR
Copenhagen, Denmark331984Non-consecutive admissions to neurology and neurosurgery departmentsAVM, on anticoagulants, alcohol misuse25% (0%/41%)36 (19/17)54** (NR)Median 2 days
Cincinnati (a), USA271986Retrospective review of admissions to 16 general hospitalsBP-preNone0%124 (51/73)NRNR
New York, USA381987Consecutive admissions to one hospital in the Bronx area of the cityBP-preBlood dyscrasia, vasculitis or AVM18% (11%/29%)92 (62/30)NRWithin 24 h of admission
Rome, Italy291988Admissions to one city-centre hospitalBP-preAVM or on anticoagulants6% (NR)87 (56/31)62 (NR)Mean 1.6 days
Florence, Italy361990Non-consecutive patients identified from the neuroradiology serviceBP-preBlood dyscrasia, on anticoagulants, or AVM31% (24%/48%)70 (54/16)63 (NR)NR
Giessen, Germany441990Admissions to neurology department of one hospitalAVM, haemorrhagic diathesis, or on warfarin13% (8%/15%)79 (57/22)66** (NR)NR
Linkoping, Sweden411991Consecutive admissions to neurology departmentNone0%182 (102/80)65 (NR)NR
Riyadh, Saudi Arabia501991Admissions to hospitalFES, BP-preNRNR13 (10/3)49 (51/43)NR
USA391991Admissions to hospitals (multicentre involving 4 different cities)AVM, coagulopathy, ventricular haemorrhage, multiple haemorrhages or on anticoagulants17% (NR)172 (107/65)62** (59/68)Mean 1 day
Cincinnati (b), USA261993Review of medical records from 20 acute-care hospitals and 5 coroner’s officesP, BP-preHaemorrhagic infarction, AVM, anticoagulants, thrombolytic treatment, cocaine use11% (NR)143 (77/66)NRNR
Oxford, UK251993Community-based (overlapping sources used to identify cases occurring in a defined area)P, FES, BP-preNone0%42 (18/24)71 (67/72)NR
Durham, USA301994Consecutive admissions to one hospitalBP-preThrombocytopenia, inherited coagulopathy, or AVMNR45 (29/16)61 (56/67)NR
Essen, Germany241994Admissions to hospitalNone0%300 (46/254)NRWithin 24 h of admission
Perth, Australia231994Community-based (overlapping sources used to identify cases occurring in a defined area)P, BP-preNone0%37 (18/19)68 (NR)Median 4 days
Massachusetts, USA321996Consecutive patients aged >50 years with lobar haemorrhage, and with non-lobar haemorrhage. Unclear if both groups were recruited from same place and during the same time periodAVM, vasculitis or coagulopathyNR63 (18/45)73 (69/75)NR
Cologne, Germany421997Retrospective review of admissions to two hospitalsHaemorrhagic infarcts, AVM, cavernoma, coagulation disorders, on thrombolytic or anticoagulation therapy23% (10%/33%)575 (278/297)57 (NR)NR
Victoria, Australia461998Consecutive admissions to all hospitals serving a defined population and regular inspection of coroner’s reportsP, FES, BP-preAVM, haemorrhagic transformation, bleeding diathesis or drug misuseNR264 (122/142)64 (NR)NR
Besançon, France452000Consecutive admissions to neurology, neurosurgery or intensive care units of the only hospital in the county to which patients with neurological diseases are referredP, FES, BP-preHaemorrhagic infarction, AVM, cavernoma or on thrombolytic treatment,NR295 (167/128)67 (NR)Mean 1 day
Sweden402000Community-based (12 hospitals and four pathology departments serving a defined population)PAVM, haemorrhagic infarctionNR297 (121/176)74** (72/75)1–2 days
Cincinnati (c), USA492002Non consecutive patients, identified by surveillance of emergency and radiology departments, and hospital discharge diagnosesBP-preHaemorrhagic infarction, AVM or cavernomaNR188 (121/67)65 (65/65)NR
Izumo, Japan352003Admissions to the four hospitals in the city, and review of general practitioner death certificatesPAVM, moyamoya disease haemorrhagic infarction or coagulation disorderNR274 (229/45)68 (68/71)NR
Studies in younger patient populations
Iowa, USA471987Patients aged 15–45 years admitted to hospitalAVM, haemorrhage as a result of drug or alcohol misuse, SLE, moyamoya, cryoglobulinaemia, or preeclampsia58% (41%/67%)22 (10/12)31 (NR)NR
Dijon, France311991Patients aged <45 years admitted to neurosurgery, neurology and rehabilitation departments of the city’s university hospitalAVM, cerebral vein thrombosis, SLE, endocarditis, leukaemia or on anticoagulants59% (27%/76%)12 (8/5)33 (NR)NR
Mexico City, Mexico431991Consecutive admission of patients aged <40 years to stroke unitAVM, cavernous angioma, CVT, drug use, toxaemia or other known causes75% (49%/85%)38 (22/16)27 (NR)NR
Tainan Taiwan (a)371997Patients aged 14–40 years admitted to hospitalAVM, drug misuse, blood dyscrasia, alcohol misuse, SLE, moyamoya or infective endocarditis35% (24%/50%)40 (26/14)34 (NR)NR
Kaohsiung, Taiwan (b)281999Patients aged 15–44 years admitted to hospitalAVM, blood dyscrasia and “other rare causes” (including alcohol and drug misuse, uraemia, etc). We could not exclude 4 patients with tumours.33% (12%/53%)126 (102/24)36 (NR)NR