Prognostic analysis of orthostatic intolerance using survival model in children.
BACKGROUND
Orthostatic intolerance (OI) is a common disease at pediatric period which has a serious impact on physical and mental health of children. The purpose of this study was to investigate the effect of related factors on the prognosis of children with OI.


METHODS
The subjects were 170 children with OI, including 71 males (41.8%) and 99 females (58.2%) with age from 6 to 17 (12.0±2.6) years. The effect of related factors on the prognosis of children was studied by using univariate analysis. Then, the impact of children's age, symptom score, duration, disease subtype, and treatment on patient's prognosis was studied via analysis of COX proportional conversion model.


RESULTS
Among 170 cases, 48 were diagnosed with vasovagal syncope, including 28 cases of vasoinhibitory type, 16 cases of mixed type, and 4 cases of cardioinhibitory type; 115 cases were diagnosed with postural tachycardia syndrome and 7 cases with orthostatic hypotension. By using univariate analysis of Cox regression, the results showed that symptom score had a marked impact on the time of symptoms improvement of children after taking medication (P < 0.05), while other univariates had no impact (P > 0.05). Multivariate analysis using Cox proportional hazards regression model showed that the symptom score at diagnosis had a significant effect on holding time of symptoms improvement of children after taking medication (P < 0.05). Kaplan-Meier curve showed that symptom-free survival was higher in children with symptom score equal to 1 than children with symptom score equal to or greater than 2 during follow-up (P < 0.05).


CONCLUSIONS
Symptom score is an important factor affecting the time of symptom improvement after treatment for children with OI.
School of Economics and Management, Tsinghua University, Beijing 100084, China.
Yawen
Y
Li
Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
Hongxia
H
Li
School of Economics and Management, Tsinghua University, Beijing 100084, China.
Xueying
X
Li
South China Agriculture University, Guangzhou, Guangdong 510642, China.
Xiaoming
X
Li
Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
Hongfang
H
Jin
D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D008879:Midodrine / Q000627:therapeutic use; D054971:Orthostatic Intolerance / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D000068357:Saline Waters / Q000627:therapeutic use; D019462:Syncope, Vasovagal / Q000175:diagnosis / Q000188:drug therapy / Q000401:mortality / Q000473:pathology
D008879:Midodrine; D008790:Metoprolol