Development and validation of a risk scoring tool to predict respiratory syncytial virus hospitalization in premature infants born at 33 through 35 completed weeks of gestation.
OBJECTIVE
The purpose of the study was to develop and validate a clinical instrument predicting the risk of respiratory syncytial virus (RSV)-associated hospitalization (RSV-H) in premature infants born at 33 through 35 completed weeks of gestation (33-35GA).


METHODS
An RSV risk scoring tool (RSV-RS) was developed by entering risk factors for RSV-H, determined in a Canadian prospective study, into a multiple logistic regression model. The scoring tool was then validated externally with data from a Spanish case-control study (FLIP). The Canadian cohort comprised 1758 RSV-positive infants born 33-35GA, of whom 66 (3.7%) had confirmed RSV-H. The FLIP data set comprised 186 (33.4%) RSV-H cases and 371 (66.7%) controls.


METHODS
The primary outcome measure was RSV-H. The RSV-RS score was the sum of the weighted probabilities for each included risk factor multiplied by 100 and ranged from 0 to 100. Receiver operator characteristic curve analyses determined cutoff points to predict subjects at low, moderate, or high RSV-H risk.


RESULTS
The RSV-RS included 7 risk factors and cutoff scores of 0-48, 49-64, and 65- 100 for low-, moderate-, and high-risk subjects, respectively. For the Canadian cohort, RSV-RS sensitivity in predicting RSV-H cases was 68.2%, with 71.9% specificity. With the FLIP data set, the RSV-RS had lower accuracy (61.3% sensitivity; 65.8% specificity) but showed significant positive association with increased risk for RSV-H.


CONCLUSIONS
The RSV-RS accurately identified 33-35GA infants at increased risk for RSV-H in a Canadian cohort. External validation with Spanish case-control study data further confirmed that the scoring tool is appropriate for the estimation of RSV-H risk.
Sampalis
John S
JS
Department of Surgery and Medicine, McGill University and JSS Medical Research Inc, Montreal, Quebec, Canada. jsampalis@jssresearch.com
Langley
Joanne
J
Carbonell-Estrany
Xavier
X
Paes
Bosco
B
O'Brien
Karel
K
Allen
Upton
U
Mitchell
Ian
I
Aloy
José Figueras
JF
Pedraz
Carmen
C
Michaliszyn
Andrea F
AF
D005260:Female; D005865:Gestational Age; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D015233:Models, Statistical; D012372:ROC Curve; D018357:Respiratory Syncytial Virus Infections / Q000628:therapy*; D018570:Risk Assessment