Chest radiograph scores as potential prognostic indicators in severe acute respiratory syndrome (SARS).
OBJECTIVE
We analyzed serial chest radiographic scores for lung opacification in patients with severe acute respiratory syndrome (SARS) for temporal changes and differences between fatal and discharged cases. We sought to establish the earliest radiographic scores sensitive as potential prognostic indicators of fatal outcomes.


METHODS
Chest radiographs that had been obtained from presentation until the death or discharge of 313 patients with SARS were scored on the basis of the percentage area and location of lung opacification. Profile analysis and univariable logistic regression were performed on these radiographic scores.


RESULTS
Despite the increased mortality risks of advanced age and male sex, no significant difference was seen in the percentage area of opacification (AO%) between the sexes in either the group of patients with fatal outcomes or the group of patients who were discharged. No difference existed between age groups (< 65 years vs >/= 65 years), except for the radiograph showing the peak lung opacification in the deceased group in which the lungs of older patients had less opacification than those of younger patients. The radiographic scores obtained by day 7 were the earliest ones with good performance in prognostic prediction. The model showed good discriminatory performance, indicated by high C-indexes for receiver operator characteristic curves (0.86 for AO% and 0.90 for the number of opacified zones). The predicted proportion of patients with fatal outcomes showed high agreement with percentage of patients who died (goodness-of-fit statistic p = 0.18 for AO%, 0.73 for the number of opacified zones). By day 7, crude odds ratio of death was 1.73 per 5% of AO% (p < 0.0001) or 2.93 per lung zone opacified (p < 0.0001).


CONCLUSIONS
Chest radiographic scores (percentage of lung or the number of zones opacified) by day 7 could be used as fatal prognostic indicators.
Antonio
Gregory E
GE
Department of Diagnostic Radiology and Organ Imaging, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China.
Wong
Ka T
KT
Tsui
Eva L H
EL
Chan
David P N
DP
Hui
David S C
DS
Ng
Alex W H
AW
Shing
Kwok K
KK
Yuen
Edmund H Y
EH
Chan
Jane C K
JC
Ahuja
Anil T
AT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011859:Radiography; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D045169:Severe Acute Respiratory Syndrome / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D013997:Time Factors