External Validation of the Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale (ISAN) Score for Predicting Stroke-Associated Pneumonia in the Athens Stroke Registry.
OBJECTIVE
The Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale (ISAN) score was developed recently for predicting stroke-associated pneumonia (SAP), one of the most common complications after stroke. The aim of the present study was to externally validate the ISAN score.


METHODS
Data included in the Athens Stroke Registry between June 1992 and December 2011 were used for this analysis. Inclusion criteria were the availability of all ISAN score variables (prestroke independence, sex, age, National Institutes of Health Stroke Scale score). Receiver operating characteristic curves and linear regression analyses were used to determine the discriminatory power of the score and to assess the correlation between actual and predicted pneumonia in the study population. Separate analyses were performed for patients with acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH).


RESULTS
The analysis included 3204 patients (AIS: 2732, ICH: 472). The ISAN score demonstrated excellent discrimination in patients with AIS (area under the curve [AUC]: .83 [95% confidence interval {CI}: .81-.85]). In the ICH group, the score was less effective (AUC: .69 [95% CI: .63-.74]). Higher-risk groups of ISAN score were associated with an increased relative risk of SAP; risk increase was more prominent in the AIS population. Predicted pneumonia correlated very well with actual pneumonia (AIS group: R(2) = .885; β-coefficient = .941, P < .001; ICH group: R(2) = .880, β-coefficient = .938, P < .001).


CONCLUSIONS
In our external validation in the Athens Stroke Registry cohort, the ISAN score predicted SAP very accurately in AIS patients and demonstrated good discriminatory power in the ICH group. Further validation and assessment of clinical usefulness would strengthen the score's utility further.
Comprehensive Stroke Centre, Salford Royal NHS Foundation Trust, Manchester Academic Health Sciences Centre, Salford Royal Foundation Trust, Manchester M6 8HD, UK. Electronic address: Vasileios.Papavasileiou@srft.nhs.uk.
Vasileios
V
Papavasileiou
Department of Medicine, Ioannina University Hospital, School of Medicine, University of Ioannina, Ioannina, Greece.
Haralampos
H
Milionis
Comprehensive Stroke Centre, Salford Royal NHS Foundation Trust, Manchester Academic Health Sciences Centre, Salford Royal Foundation Trust, Manchester M6 8HD, UK; Stroke and Vascular Research Centre, Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK.
Craig J
CJ
Smith
Department of Medicine, Larissa University Hospital, School of Medicine, University of Thessaly, Larissa, Greece.
Konstantinos
K
Makaritsis
Division of Health and Social Care Research, King's College London, UK.
Benjamin D
BD
Bray
Neurology Service, CHUV, University of Lausanne, Lausanne, Switzerland.
Patrik
P
Michel
Department of Clinical Therapeutics, Medical School of Athens, Alexandra Hospital, Athens, Greece.
Efstathios
E
Manios
Department of Clinical Therapeutics, Medical School of Athens, Alexandra Hospital, Athens, Greece.
Konstantinos
K
Vemmos
Department of Medicine, Larissa University Hospital, School of Medicine, University of Thessaly, Larissa, Greece.
George
G
Ntaios
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000150:complications*; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000175:diagnosis* / Q000209:etiology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012042:Registries; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications*
ISAN score; intracerebral hemorrhage; outcome; pneumonia; prediction; stroke