Study on the prediction of cardiovascular disease based on sleep heart rate variability analysis / 生物医学工程学杂志

The peak period of cardiovascular disease (CVD) is around the time of awakening in the morning, which may be related to the surge of sympathetic activity at the end of nocturnal sleep. This paper chose 140 participants as study object, 70 of which had occurred CVD events while the rest hadn't during a two-year follow-up period. A two-layer model was proposed to investigate whether hypnopompic heart rate variability (HRV) was informative to distinguish these two types of participants. In the proposed model, the extreme gradient boosting algorithm (XGBoost) was used to construct a classifier in the first layer. By evaluating the feature importance of the classifier, those features with larger importance were fed into the second layer to construct the final classifier. Three machine learning algorithms, i.e., XGBoost, random forest and support vector machine were employed and compared in the second layer to find out which one can achieve the highest performance. The results showed that, with the analysis of hypnopompic HRV, the XGBoost+XGBoost model achieved the best performance with an accuracy of 84.3%. Compared with conventional time-domain and frequency-domain features, those features derived from nonlinear dynamic analysis were more important to the model. Especially, modified permutation entropy at scale 1 and sample entropy at scale 3 were relatively important. This study might have significance for the prevention and diagnosis of CVD, as well as for the design of CVD-risk assessment system.

Impacts of the zero price margin for drugs on the revenue-expenditure structure of primary healthcare organizations / 中华医院管理杂志

ObjectiveTo probe into the influence of the zero price margin for drugs on the revenue-expenditure structure at primary healthcare organizations.MethodsOne of the pilot districts experimenting with this system in Ningbo city was earmarked as the research object.Within this district,the data of their revenue,expenditure and surplus were collected from 20 primary healthcare organizations prior to and after the zero price margin for drugs was in place for classification analysis.ResultsThe percentage of service revenue among the total revenue has dropped from 68.34％ before the system was in place to 65.44％ after,reducing 4.24％.The percentage of drug revenue has dropped from 71.68％ before to 63.57％ after,reducing 11.31％.The percentage of service surplus has dropped from 15.81％ before to - 23.07％ after,reducing 245.94％.The total standard workload has increased 61.77％.Average medical expense per outpatient and per inpatient has reduced 32.85％ and 57.18％,from 71.44yuan and 2642.08 yuan before to 48.33 yuan and 1131.28 yuan after respectively.ConclusionThe deficit rise and higher percentage of drug revenue at primary healthcare organizations deserve attention.A comprehensive reform is recommended to establish a regular government financial support mechanism,further adjust the revenue-expenditure structure,set up the system of rational drug use,and effectively reduce the medical expense of patients.