Identification of stroke in the community: a comparison of three methods.
BACKGROUND
Evidence concerning secondary prevention of cerebrovascular disease is not optimally used in clinical practice. A necessary first step is to identify those eligible for treatment. In primary care, this equates to setting up a register of prevalent stroke.


OBJECTIVE
To compare three different methods for identifying prevalent cases of cerebrovascular disease in the community: general practice-based computer systems; population surveys; and hospital-based routine information systems.


METHODS
Comparison of results of each method applied to a defined population and then assessed against reference criteria for cerebrovascular disease.


METHODS
A total of 5801 people aged 65 years or over, resident in seven practices situated within the South Birmingham Primary Care Trust area.


METHODS
The sensitivity, specificity, and predictive value of each method of identification were calculated against reference criteria applied by two investigators independently of each other.


RESULTS
The prevalence of reference criteria-validated cerebrovascular disease in patients aged 65 years or over was 8.2%. Overall, general practice-based computer systems had a sensitivity of 81.0%, a specificity of 97.2% and a positive predictive value (PPV) of 71.8%, but there was a wide range of sensitivity (33% to 90%) and PPV (42% to 92%) between practices. Patient survey and hospital information systems were less sensitive (75.7% and 28.4%, respectively) but had higher PPVs (77.5% and 89.2%, respectively). Thirty-nine per cent of patients with a history of cerebrovascular disease had not been admitted to hospital.


CONCLUSIONS
General practice-based computer systems can produce reasonably accurate prevalent stroke registers. In areas where these are poorly developed, patient survey is an alternative.
Mant
J
J
Department of Primary Care and General Practice, University of Birmingham, Primary Care Clinical Sciences Building, Edgbaston, Birmingham B15 2TT. j.w.mant@bham.ac.uk
McManus
R J
RJ
Hare
R
R
Mayer
P
P
D000368:Aged; D002561:Cerebrovascular Disorders / Q000175:diagnosis / Q000453:epidemiology*; D018672:Community Health Planning / Q000592:standards; D005194:Family Practice / Q000706:statistics & numerical data; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D016347:Medical Records Systems, Computerized / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D012042:Registries / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity