This study was an open prospective nationwide cohort study including all patients
admitted due to HS in the National Health Insurance Research Database (NHIRD)
between January 1, 2001 and December 31, 2013. The NHIRD prospectively records
the data submitted to the National Health Insurance (NHI) program, which covers
more than 99% of the population in Taiwan. Diagnoses are registered using
International Classification of Diseases, Ninth Revision, Clinical Modification
(ICD-9-CM) codes, and are routinely monitored by the NHI Bureau.14 (link) The patients of interest were first-ever primary HS survivors. In total,
114,219 hospitalized patients with a primary diagnosis of HS in the NHIRD
(ICD-9-CM code 431) were initially included for analysis. We excluded patients
with traumatic intracerebral hemorrhage (ICD-9-CM code 853) or with a previous
history of HS including intracerebral hemorrhage and subarachnoid hemorrhage. We
also excluded patients assumed to be associated with secondary HS if they also
had a concurrent diagnosis of venous sinus thrombosis, cerebral aneurysm or
arteriovenous fistula, non-aneurysmal subarachnoid hemorrhage, or non-traumatic
subdural hemorrhage. In order to validate the diagnostic accuracy of a
first-ever HS in NHIRD, we compared the data of patients with the primary
diagnosis of HS from both the NHIRD and the Stroke Registry in Chang Gung
Healthcare System (SRICHS) from 2009 to 2013.15 (link) The details are provided inSupplemental Figure 1 .
According to our previous study,1 (link) more than half of the mortality in HS patients occurred within the first
month after stroke onset. Drug switching or discontinuation occurs more commonly
within the first 180 days after the start of medication.16 (link) These factors may lead to misinterpretation of the correlations between
antihypertensive drugs and clinical outcomes. To study HS patients in the stable
phase, we excluded those patients who died during the index hospitalization and
those who developed HS or had composite cardiovascular outcomes within 180 days
after the index hospitalization. We also excluded those patients who had follow
up of fewer than 180 days and who did not receive any antihypertensive agents
within 180 days after the index hospitalization (Figure 1 ). The Ethics Institutional
Review Board of Chang Gung Memorial Hospital approved this study (approval
number: 201601164B0). Because the enrolled patients cannot be identified in this
claims database study, informed consent was waived by our Ethics Institutional
Review Board.
admitted due to HS in the National Health Insurance Research Database (NHIRD)
between January 1, 2001 and December 31, 2013. The NHIRD prospectively records
the data submitted to the National Health Insurance (NHI) program, which covers
more than 99% of the population in Taiwan. Diagnoses are registered using
International Classification of Diseases, Ninth Revision, Clinical Modification
(ICD-9-CM) codes, and are routinely monitored by the NHI Bureau.14 (link) The patients of interest were first-ever primary HS survivors. In total,
114,219 hospitalized patients with a primary diagnosis of HS in the NHIRD
(ICD-9-CM code 431) were initially included for analysis. We excluded patients
with traumatic intracerebral hemorrhage (ICD-9-CM code 853) or with a previous
history of HS including intracerebral hemorrhage and subarachnoid hemorrhage. We
also excluded patients assumed to be associated with secondary HS if they also
had a concurrent diagnosis of venous sinus thrombosis, cerebral aneurysm or
arteriovenous fistula, non-aneurysmal subarachnoid hemorrhage, or non-traumatic
subdural hemorrhage. In order to validate the diagnostic accuracy of a
first-ever HS in NHIRD, we compared the data of patients with the primary
diagnosis of HS from both the NHIRD and the Stroke Registry in Chang Gung
Healthcare System (SRICHS) from 2009 to 2013.15 (link) The details are provided in
According to our previous study,1 (link) more than half of the mortality in HS patients occurred within the first
month after stroke onset. Drug switching or discontinuation occurs more commonly
within the first 180 days after the start of medication.16 (link) These factors may lead to misinterpretation of the correlations between
antihypertensive drugs and clinical outcomes. To study HS patients in the stable
phase, we excluded those patients who died during the index hospitalization and
those who developed HS or had composite cardiovascular outcomes within 180 days
after the index hospitalization. We also excluded those patients who had follow
up of fewer than 180 days and who did not receive any antihypertensive agents
within 180 days after the index hospitalization (
Review Board of Chang Gung Memorial Hospital approved this study (approval
number: 201601164B0). Because the enrolled patients cannot be identified in this
claims database study, informed consent was waived by our Ethics Institutional
Review Board.
