A Study On The Value Of The Chinese Version Of ODSS In Orthostatic Intolerance Syndrome

ObjectiveThe purpose of this study was to translate the Orthostatic discriminate and severity scale(ODSS)into Chinese and to evaluate the internal consistency of the Chinese version of ODSS,as well as its predictive value for the supine-to-standing test and Valsalva movement to explore whether it can be used as an initial screening tool for Orthostatic intolerance syndrome(OIS).MethodsPatients who reported orthostatic intolerance symptoms in outpatients or inpatients at the First Affiliated Hospital of University of South China between May2019 and December 2020 and normal controls were recruited,and general clinical information were collected.The Chinese version of ODSS,Orthostatic intolerance symptom score,and Orthostatic Grading Scale(OGS)were completed.The supineto-standing test were performed to continuously monitoring changes in mean cerebral blood flow velocity(m CBFV)in combination with Transcranial Doppler(TCD),and measuring blood pressure and heart rate.The Valsalva maneuver was performed and the curves of m CBFV and heart rate were recorded by TCD.ResultsA total of 105 study subjects were recruited,and were divided into OIS group(n=32),NOIS group(n=53),and control group(n=20).The overall Cronbach’s αcoefficient of the Chinese version of ODSS was 0.924.The Cronbach’s alpha coefficients of Orthostatic scores(OS)and Non-orthostatic scores(NS)were 0.905 and 0.852,respectively,suggesting good internal consistency of the Chinese version of ODSS.OS and NS were negatively correlated with blood pressure in standing position,as well as difference of systolic pressure in supine and upright position.OS and NS were positively correlated with orthostatic cerebral blood flow score,suggesting that the Chinese version of ODSS was correlated with the hemdynamic changes of the supine-to-standing test.OS and NS were strongly correlated with OGS and OIS symptom questionnaire.These results suggest that Chinese version of ODSS has good clinical relevance.Patients in the OIS group had a statistically significantly higher OS than the NOIS group(P=0.002).NS was also higher in the OIS group than in the NOIS group,but the difference was not statistically significant(P=0.225).Therefore,only OS was used to calculate the critical value,and the area under the Receiver operating curve(ROC)for OS was 0.754,which is between 0.7 and 0.9,with a 95% confidence interval of 0.650-0.808 and excluding 0.5,suggesting that OS has a moderate predictive value for the outcome of the supine-to standing test.With a threshold of OS = 18,the sensitivity of the Chinese version of ODSS was 87.5%(n = 28/32),and specific was 56.6%(n = 23/53),identifying OIS patients and non-OIS patients with60% accuracy.The analysis of the Chinese version of ODSS and related indicators in the Valsalva maneuver showed that there was a statistical difference between the OIS group and the other two groups,and these two indicators are correlated with OS,suggesting that Chinese ODSS is related to autonomic nervous dysfunction.OS was also negatively correlated with the VM1.And when measured by VM1= 0.90 or 0.85,patients with orthostatic symptoms were divided into two groups for comparison,and there was a statistically significant difference in OS scores(VM1=0.90: P=0.012,VM1=0.85: P=0.026).Combined with the area under the ROC curve and 95%confidence interval results,was found that OS have certain predictive value for both indicators.The overall prediction accuracy was 68.06% for both.ConclusionThe Chinese version of ODSS has good internal consistency,and has predictive value for the supine-to-standing standing test,as well as VM1 of Valsalva maneuver,can be used as an initial screening tool for diagnosis of OIS.