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Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage
Published on: August 30, 2020
Positive Predictive Value of Primary Subarachnoid Hemorrhage Diagnoses on Death Certificates
Shane English1, Carl van Walraven Van Walraven2
1School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa Hospital Research Institute, Ottawa, ON Canada. email@email.com.
Purpose:
Epidemiological studies of primary subarachnoid hemorrhage (pSAH) frequently include population-based death registries for case finding. The positive predictive value of pSAH diagnoses in death registries is unknown.
Methods:
This cross-sectional study identified all people in Ontario, Canada with pSAH listed as a cause of death between 2013 and 2017. pSAH was classified as "very likely" if diagnosis of pSAH was confirmed by autopsy, there was a previous hospitalization where pSAH probability exceeded 85% or death was preceded within a week by an emergency room visit where pSAH probability exceeded 25%. pSAH was classified as "very unlikely" if previous cerebrovascular imaging had never been done. Remaining cases were classified as "pSAH status unknown".
Results:
1,613 deaths attributed to pSAH were identified (mean 322/year). pSAH classification frequencies were as follows: very likely 528 (32.7%); very unlikely 433 (26.8%); and status unknown 652 (40.4%).
Conclusion:
We found that a quarter of pSAH cases in our province's death registry were very unlikely to be true pSAH while 40% had unknown veracity. These data should be considered when using death registries for pSAH case finding.
