[Analysis of the effect of gene mutations on the efficacy of ruxolitinib in patients with myelofibrosis based on second-generation sequencing technology].

Objective: To assess the effect of gene mutations on the efficacy of ruxolitinib for treating myelofibrosis (MF) . Methods: We retrospectively analyzed the clinical data of 56 patients with MF treated with ruxolitinib from July 2017 to December 2020 and applied second-generation sequencing (NGS) technology to detect 127 hematologic tumor-related gene mutations. Additionally, we analyzed the relationship between mutated genes and the efficacy of ruxolitinib. Results: ①Among the 56 patients, there were 36 cases of primary bone marrow fibrosis (PMF) , 9 cases of bone marrow fibrosis (ppv-mf) after polycythemia vera, and 11 cases of bone marrow fibrosis (PET-MF) after primary thrombocytosis (ET) . ②Fifty-six patients with MF taking ruxolitinib underwent NGS, among whom, 50 (89.29%) carried driver mutations, 22 (39.29%) carried ≥3 mutations, and 29 (51.79%) carried high-risk mutations (HMR) . ③ For patients with MF carrying ≥ 3 mutations, ruxolitinib still had a better effect of improving somatic symptoms and shrinking the spleen (P=0.001, P<0.001) , but TTF and PFS were significantly shorter in patients carrying ≥ 3 mutations (P=0.007, P=0.042) . ④For patients carrying ≥ 2 HMR mutations, ruxolitinib was less effective in shrinking the spleen than in those who did not carry HMR (t= 10.471, P=0.034) , and the TTF and PFS were significantly shorter in patients carrying ≥2 HMR mutations (P<0.001, P=0.001) . ⑤Ruxolitinib had poorer effects on spleen reduction, symptom improvement, and stabilization of myelofibrosis in patients carrying additional mutations in ASXL1, EZH2, and SRSF2. Moreover, patients carrying ASXL1 and EZH2 mutations had significantly shorter TTF [ASXL1: 360 (55-1270) d vs 440 (55-1268) d, z=-3.115, P=0.002; EZH2: 327 (55-975) d vs 404 (50-1270) d, z=-3.219, P=0.001], and significantly shorter PFS compared to non-carriers [ASXL1: 457 (50-1331) d vs 574 (55-1437) d, z=-3.219, P=0.001) ; 428 (55-1331) d vs 505 (55-1437) d, z=-2.576, P=0.008]. Conclusion: The type and number of mutations carried by patients with myelofibrosis and HMR impact the efficacy of ruxolitinib.

[Association between endurance quality and blood pressure levels in Han students aged 13-18 years in China, 2014].

Objective: To analyze the association between the endurance quality and blood pressure levels in Han students aged 13-18 years in China. Methods: We used the data of Han students aged 13-18 years from 2014 Chinese National Survey on Students' Constitution and Health. Elevated blood pressure and its components, including isolated elevated SBP, isolated elevated DBP, and mix elevated blood pressure, were evaluated according to the reference of screening for elevated blood pressure among children and adolescents aged 7-18 years. The students' endurance quality was scored according to the National Standards for Students' Physical Health (2014 revision) and categorized based on their percentiles into four groups as follows: P(0)-, P(25)-, P(50)-, and P(75)-P(100). Trend χ(2) test was used to analyze the trend of the detection rates of elevated blood pressure and its components in different groups of endurance quality. Logistic regression model was used to estimate the odds ratio (OR) for elevated blood pressure and its components in different endurance quality groups and P(0)-group was set as reference group. Quantile regression model was used to analyze the association between different blood pressure levels and endurance quality. Results: The detection rate of elevated blood pressure in the students aged 13-18 years in China in 2014 was 9.2%. The detection rate of elevated blood pressure and its components decreased with the improvement of endurance quality (P<0.001). With the P(0)-endurance quality group as reference, the OR(95%CI) were 0.89(0.84-0.95), 0.81(0.76-0.86) and 0.79(0.74-0.84) respectively in P(25)-, P(50)- and P(75)-P(100) endurance quality groups respectively. The negative association existed between endurance quality and elevated blood pressure in overweight, obese and normal students, but not in malnourished students. The quantile regression analysis results showed that in overweight and obese students, the SBP levels at the P(10), P(25), P(50), P(75), P(9)0 and P(95) groups were negatively associated with the endurance quality, and the DBP levels at the P(25) and above group were negatively associated with the endurance quality. In malnourished and normal students, only some levels of DBP were negatively associated with the endurance quality. Conclusions: The negative association existed between endurance quality and elevated blood pressure in Han students aged 13-18 years in China. In overweight and obese students, the association between endurance quality and blood pressure level was stronger. Improving students' endurance quality may facilitate the prevention of elevated blood pressure.

[Analysis on the trend of prevalence of excellent and good physical fitness and health status among Chinese Han students aged 13 to 18 years and related influencing factors from 1985 to 2014].

Objective: Using the Chinese National Survey on Students' Constitution and Health data from 1985 to 2014 to analyze the trend of excellent and good physical fitness and health status among Chinese Han students aged 13 to 18 years and the related influencing factors. Methods: 738 523 students aged 13 to 18 years with completed data of gender, age, urban and rural, physical form, vital capacity and physical fitness were selected from the six Chinese National Surveys on Students' Constitution and Health. According to National Standards for Students' Physical Health (2014 revision), the comprehensive scores and the prevalence of excellent and good physical fitness and health status were calculated (90.0-120.0 was classified as excellent, and 80.0-89.9 was classified as good). The trend of prevalence of excellent and good physical fitness and health status in different years and the corresponding differences among students with different characteristics were analyzed and compared. The log-binomial regression model was used to analyze related factors of physical fitness and health status. Results: From 1985 to 2014, the overall prevalence of excellent and good physical fitness and health status increased from 27.6% in 1985 to 35.6% in 1995, and then declined to 13.9% in 2005. In the 2010 and 2014 cycles, the prevalence increased steadily, at 16.5% and 19.1% respectively. Except for 1995 and 2014, the prevalence of boys was higher than that of girls (P<0.001). The prevalence of students aged 13 to 15 was higher than that of students aged 16 to 18 (P<0.001). Log-binomial regression model analysis showed that girls ï¼»PR（95%CI）=1.03（1.00-1.05）, P=0.021ï¼½, rural area ï¼»PR（95%CI）=1.09（1.07-1.12）, P<0.001ï¼½, 13-15 years oldï¼»PR（95%CI）=1.89（1.84-1.94）, P<0.001ï¼½, eastern regionï¼»PR（95%CI）=1.94（1.88-2.00）, P<0.001ï¼½, middle regionï¼»PR（95%CI）=1.15（1.11-1.20）, P<0.001ï¼½, Exercise time ≥1 h/dï¼»PR（95%CI）=1.41（1.37-1.45）, P<0.001ï¼½, parents support participation in sports activities after schoolï¼»PR（95%CI）=1.10（1.06-1.15）, P<0.001ï¼½, TV time ≤1 h/dï¼»PR（95%CI）=1.26（1.21-1.30）, P<0.001ï¼½, playing video games, watching videos or e-books ≤1 h/dï¼»PR（95%CI）=1.05（1.02-1.09）, P<0.001ï¼½ were all related to the high prevalence of excellent and good physical fitness and health status. Conclusion: The prevalence of excellent and good physical fitness and health status among students aged 13 to 18 was changing between 1985 and 2014. Gender, age, area, physical exercise time, screen time for non-learning purposes, and parents' attitudes toward students' participation in physical activities were all related to the excellent and good physical fitness and health status of students.

[The application of the National Standards for Students' Physical Health (2014 revision) in SPSS].

The National Standards for Students' Physical Health (2014 revision)is a standard for providing primary guidance for the national school education work and applicable to the evaluation of the physical health of primary school, secondary school and university students in China. This standard sets indicators and assessment scores by gender and grade from three aspects, i.e. body shape, function and quality. Given the complexity of the application process and the large number of indicators, it could be inefficient and misused due to a large sample size. Therefore, this study aims to comprehensively introduce the application of the standard with examples, and compile the corresponding SPSS package for potential audience to quickly and accurately evaluate students' physical health.

[Subnational inequalities of early marriage and fertility among Chinese females from 1990 to 2010].

OBJECTIVE: To analyze the inequality of early marriage and adolescent fertility with respect to local economic development among Chinese females aged 15-19 years from 1990 to 2010. METHODS: Aggregated data were extracted from the Chinese National Census from 1990 to 2010. We calculated the ever-married rate and fertility rate of female adolescents aged 15-19 years. Using gross domestic product (GDP) per capita as an indicator for socio-economic status of a province, we calculated the slope index of inequality (SII) and the concentration index (CI) to analyze the subnational inequalities of early marriage and adolescent fertility. Weighted linear regression models were also established to assess the associations between GDP per capita and the ever-married rate/fertility rate. RESULTS: The ever-married rate for Chinese female adolescents aged 15-19 years decreased from 4.7% in 1990 to 1.2% in 2000, and rebounded to 2.1% in 2010. From 1990 to 2000, the fertility rate decreased from 22.0 per 1 000 to 6.0 per 1 000, and further decreased to 5.9 per 1 000 in 2010. In 1990, the socio-economic inequalities of the ever-married rate and fertility rate for female adolescents aged 15-19 years were not statistically significant (P for SII or CI>0.05). The values of SII revealed that, in 2000 and 2010, female adolescents with the lowest GDP per capita had an ever-married rate 2.4% (95%CI: 0.4-4.4) and 2.3% (95%CI: 0.3-4.2) higher than those with the highest GDP per capita, respectively. In the meantime, in 2000 and 2010, female adolescents with the lowest GDP per capita had a fertility rate 12.9 per 1 000 (95%CI: 5.4-20.5) and 9.3 per 1 000 (95%CI: 4.6-14.0) higher than those with the highest, respectively. In 2000 and 2010, the CIs for marriage were -0.32 (P=0.02) and -0.17 (P=0.03), respectively, and the CIs for childbirth were -0.37 (P<0.01) and -0.26 (P<0.01), respectively. In 2000, the ever-married rate and the fertility rate were estimated to increase by 1.4% (95%CI: 0.1-2.7) and 7.9 per 1 000 (95%CI: 2.9-12.8) with 100% increase in GDP per capita, respectively; in 2010, the numbers were 1.5% (95%CI: 0.1-2.9) and 6.7 per 1 000 (95%CI: 3.2-10.1), respectively. CONCLUSION: Subnational socio-economic inequality of early marriage and adolescent fertility existed in 2000 and 2010. Female adolescents residing in less-developed areas were more likely to engage in early marriage and childbirth. Reducing income inequality and increasing education investment for poverty-stricken areas seem to be effective measures to reduce this inequality.

[Comparison of status of physical activity time at school and influencing factors in students in China, 2010 and 2014].

Objective: To compare the probability of physical activity (PA) time ≥1 hour at school and influencing factors in students in China between 2010 and 2014. Methods: We used the data of 2010 and 2014 Chinese National Survey on Students' Constitution and Health (CNSSCH). The surveys covered the Han students aged 9-22 years and Tibetan students aged 9-18 years (Tibet). The participants were primary school students (9-12 years old), junior high school students (13-15 years old), senior high school students (16-18 years old) and college students (19-22 years old). The probability of PA time ≥1 hour at school was compared using χ(2) tests between 2010 and 2014 survey years. Log-binomial Regression was used to estimate the relative risk (RR) for the probability of PA time ≥1 hour at school in different age groups. Results: The overall probability of PA time ≥1 hour at school in students aged 9-22 years was 20.5% in 2010, and 23.8% in 2014. The difference between 2010 and 2014 was significant (P<0.001). On the whole, the probability of PA time ≥1 hour at school increased in the eastern, central and western areas in 2014 compared with 2010 (P<0.05), and the increase range was highest in eastern area, followed by western area and central area (P<0.05). The probability of PA time of 1 hour at school in all age groups increased in 2014 compared with 2010 (P<0.05). The increase in the probability of PA time ≥1 hour at school was larger in primary school students than that in high school students and college students (P<0.05). The probability of PA time ≥1 hour at school increased in all age groups in three areas, except in junior and senior high school students in the central area where the probability of PA time ≥1 hour at school decreased. The probability of PA time ≥1 hour at school in primary and junior/senior high school students in the eastern area had the greatest increase, but in college students it had the smallest increase in the three areas. From 2010 to 2014, the changes in the probability of PA time ≥1 hour at school in students in different provinces were quite different, especially in primary school students. The probability of PA time ≥1 hour at school in four age groups increased in only three provinces. With the probability of PA time ≥1 hour at school in primary school students as the reference, the RR in junior high students had no significant change between 2010 and 2014. The RR in senior high school increased from 0.34 (0.33-0.35) in 2010 to 0.36 (0.36-0.37) in 2014, and the RR in college students increased from 0.33 (0.32-0.34) in 2010 to 0.43 (0.42-0.44) in 2014. Conclusions: The probability of PA time ≥1 hour at school in all age groups increased in 2014 compared with 2010, but there were great differences among provinces. The findings of our study suggests that although the national policy played a certain role, the provinces should take specific measures to improve the probability of PA time ≥1 hour at school in students according to their own conditions. In addition, more attention should be paid to PA of older students.

[Trends of prevalence of excellent health status and physical fitness among Chinese Han students aged 13 to 18 years from 1985 to 2014].

OBJECTIVE: To analyze the trends of prevalence of excellent health status and physical fitness among Chinese Han students aged 13 to 18 years from 1985 to 2014. METHODS: In the study, 738 523 students aged 13 to 18 years were extracted from the 1985 to 2014 Chinese National Survey on Students' Constitution and Health. Height, weight, vital capacity and indicators of physical fitness were measured for each student. According to National Standards for Students' Physical Health (2014 Revision), students meeting an overall score ≥ 90.0 were considered to be of excellent health status and physical fitness. We used the Chi-square test to compare the differences in prevalence of excellent health status and physical fitness among different subgroups and draw maps of regional distribution of prevalence by using ArcGIS. RESULTS: From 1985 to 2014, the average height, weight, and BMI for Chinese Han students aged 13 to 18 years increased consistently, while the average vital capacity and indicators of physical fitness fluctuated largely. The overall prevalence of excellent health status and physical fitness increased from 2.7% in 1985 to 4.4% in 1995, dropped consistently to 1.1% in 2005, rebounded 0.6 percentage points in 2010, and increased to 2.2% in 2014. In each survey year, the prevalence for the boys was always higher than for the girls (P<0.001), the prevalence for middle school students aged 13 to 15 years was always higher than for high school students aged 16-18 years (P<0.001), and the prevalence for students in eastern region was higher than in western and central regions (P<0.001). In 1985 and 1995, the prevalence in certain provinces in eastern and central regions was <1%. In 2005, almost half provinces (14/30) had a prevalence <1%. In 2014, provinces in eastern coastal areas had relatively high prevalence of excellent health status and physical fitness in students aged 13 to 18 years, while provinces in central and western regions had relatively low prevalence. CONCLUSION: A fluctuating trend of the prevalence of excellent health status and physical fitness has been observed among Chinese Han students aged 13 to 18 years during the past three decades. There is great difference between the current prevalence of excellent health status and physical fitness and the goal of Outline of the Healthy China 2030 Plan, thus, the effective interventions and strategies for promoting students' physical activity and physical fitness are urgently needed in China.

[Secular trends and geographic disparities of all-cause mortality among Chinese adolescents aged 10-24 years, between 1953 and 2010].

Objective: To analyze the secular trends and geographic disparities of all-cause mortality among Chinese adolescents aged 10-24 years over the period of 1953-2010. Methods: Data were extracted from the Chinese National Census in 1953-2010. We calculated the all-cause mortality and annualized rates of the changes. Using the provincial gross domestic product (GDP) per capita as an indicator of regional socio-economic development level, we calculated the Wagstaff normal concentration indices for adolescent mortality. Results: Over the period of 1953-2010, the general patterns of Chinese adolescent mortality appeared higher in males than those in females, higher in the 20-24-year-old than those in the 15-19 year-old and in the 10-14 year-old groups, higher in adolescents from the western than those in the eastern regions. The mortality of adolescents decreased from 554.6/100 000 in 1953-1964 to 55.7/100 000 in 2010 in males and decreased from 488.4/100 000 to 26.7/100 000 in females, respectively. The percentage of decrease for females (94.5%) was higher than that for males (90.0%). In 1981-2010, the highest annualized rate of decline for males was seen in Beijing (4.4%), with the lowest seen in Qinghai (0.1%). For girls, Hubei showed the highest annualized rate of decline (6.4%) while Qinghai the lowest (0.8%). Provinces that with higher mortality tended to have lower annualized rate of decline. The concentration indices for boys were -0.07 (95%CI: -0.11- -0.03), -0.13 (95%CI: -0.18- -0.08), and -0.16 (95%CI: -0.22- -0.10) in 1990, 2000, and 2010, respectively, and were -0.07 (95%CI: -0.13- -0.02), -0.18 (95%CI: -0.24- -0.12), and -0.18 (95%CI: -0.26- -0.09) respectively in girls. The indices among 1990, 2000, and 2010 did not show statistically significantly differences, both for boys and girls (P>0.05). Conclusions: Over the half century, the mortality of Chinese adolescents showed dramatic decreasing trend. However, in terms of death rates, gender and geographic disparities were consistently seen in the adolescents.

[Analysis on the urban-rural disparity of childhood stunting and its association with economic growth among Chinese Han students aged 7-18 years old].

Objective: To analyze the urban-rural disparity of childhood stunting and its association with subnational economic growth among Chinese Han students aged 7-18 years. Methods: We used the data from 2014 Chinese National Survey on Students' Constitution and Health. 213 940 Chinese Han students aged 7-18 years with complete height records were included in this study. Stunting was defined according to the Screening Criteria of Malnutrition for School-age Children and Adolescents(2014 version, in Chinese). We divided students into two groups (economically developed and underdeveloped areas) according to the provincial GDP per capita. Spearman correlation coefficient was used to explore the association between the difference of urban-rural stunting prevalence and the provincial GDP per capita. Logistic regression models were established to assess the risk of stunting in rural children compared with urban children. Results: Among 213 940 students, 107 033 (50.0%) were from urban areas. The average height of 7-18 years old and 18 years old [(152.9±15.7) and (166.1±8.7) cm] of urban students were both higher than those of rural students [(150.7±16.0) and (165.1±8.6) cm] (P<0.001). The stunting prevalence of Chinese urban students (0.4%) was statistically significant lower than that of rural students (1.1%) (P<0.001), which was consistent in all age groups (P<0.05). The urban-rural disparity was found in 60% (18/30) of Chinese provinces. The difference of urban-rural stunting prevalence was negatively associated with provincial GDP per capita (r=-0.62, P<0.001). In economically underdeveloped areas, the risk of stunting for rural students aged 7-9 years was 4.69 (95%CI: 2.93-7.52) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.44 (95%CI: 2.02-2.96). In economically developed areas, the risk of stunting for rural students aged 7-9 years was 5.43 (95%CI: 3.67-8.03) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.15 (95%CI: 1.85-2.49). Conclusions: The urban-rural disparity of childhood stunting existed in most places in China. The difference of growth retardation between urban and rural areas was related to regional economic development.

[Comparative study on growth retardation prevalence in students aged 7-18 years from 26 minority ethnic groups in China].

Objective: To compare the prevalence of growth retardation in students aged 7-18 years from 26 minority ethnic groups in China and provides reference evidence to promote the growth and improve the health status of students in minority ethnic groups. Methods: The body height data of students aged 7-18 years in 26 minority ethnic groups in 2014 Chinese National Surveys on Students' Constitution and Health were used for the analysis and comparison. Growth retardation was defined according to the school-aged child and adolescent malnutrition screening standard (WS/T 456-2014). Results: In 2014, the average body heights of school boys and school girls aged 18 years in 26 ethnic minority groups were (168.3±6.8) cm and (156.2±5.9) cm respectively. The overall growth retardation prevalence rate of school boys and school girls in 26 ethnic groups were 5.4% and 5.1%, respectively. The growth retardation prevalence rate was highest in students of Shui ethnic group (24.5% for boys and 23.0% for girls), and lowest in students of Hui ethnic group (0.1% for boys and 0.3% for girls). The growth retardation prevalence rates in 9 ethnic minority groups were higher than the average level, in these 9 ethnic groups, the differences in prevalence rates of boys of Buyi ethnic group, girls of Lisu ethnic group and girls of Hani ethnic group had no significance among four age groups. Growth retardation in students of Sala ethnic group was mainly observed in age group 7-9 years, but in others ethnic group, for example, Wa ethnic, it was mainly observed in older age group. The students in minority ethnic groups in southwestern China had the highest growth retardation prevalence rate (8.1%), significantly higher than that in northern China (0.8%) (OR=10.6, 95%CI: 7.8-14.4). The overall growth retardation prevalence rate between 7 and 17 years old was negatively correlated with the body height of 18 years old (boys: r=-0.811, P<0.001; girls: r=-0.715, P<0.001). Conclusions: In 2014, the differences in body height among students aged 18 years in 26 minority ethnic groups in China were significant. In general, the first five minority ethnic groups with high detection rate of growth retardation in boys were Shui, Wa, Buyi, Yao and Yi, and the five minority ethnic groups with high detection rate of growth retardation in girls were Shui, Yao, Buyi, Wa and Miao. The detection rate of growth retardation was highest in students of minority ethnic groups in southwestern China. Nutritional interventions and healthy education should be carried out in minority ethnic groups and areas with high growth retardation prevalence rate to promote the growth of the students.

[Analysis of characteristics and influencing factors of fine particulate matters and submicron particulate matters in printing shop].

Objective: To analyze the physical characteristics of fine particulate matters (PM(2.5)) and submicron particulate matters (PM(1)), and investigate the factors influencing the emission peak of printer particles. Methods: A 12-hour particle concentration monitoring for PM(2.5) and PM(1) was conducted in a printing shop on January 5(th), 2018. PM(2.5) in the air was analyzed after the monitoring process to figure out morphological characteristics and element composition of printer particles. Besides, experiments were carried out in an enclosed space to detect the number concentration peaks of PM(1) during every printing process. Influencing factors investigated in this study were printer types, toner coverages and interval time between different printing processes. Results: The 12-hour particles concentration monitoring showed that the number concentration of PM(1) and the mass concentration of PM(2.5) were 7.510×10(4) pt/cm(3) and 96.85 µg/m(3). The diameter of most PM(2.5) was less than 100 nm, with a fractal dimension of 2.591. Most PM(2.5) appeared as regular spheres with typical agglomeration phenomenon, while some were in rhabditiform or irregular shapes. Element analysis showed that PM(2.5) was mainly composed of C, O, Si, Ca, with less metallic element. The PM(1) emission peak values of three printers were 3.60×10(4), 3.43×10(4), 0.31×10(4) pt/cm(3), respectively and the difference was not statistically significant (χ(2)=5.42, P>0.05). When the page coverage rate was 0%, 2.5%, 5%, 10%, 20% and 50%, the PM(1) emission peak value of printer A was 6.74×10(4), 4.62×10(4), 3.82×10(4), 2.82×10(4), 1.00×10(4) and 1.08×10(4) pt/cm(3), and the difference was also not statistically significant (χ(2)=7.01, P>0.05). The natural logarithm of PM(1) emission peak value in printing work was associated with the resting time before printing and the change value of heating roller temperature (r value was 0.83 and 0.89, respectively, all P values<0.05). Conclusion: PM(2.5) and PM(1) in the printing shop stayed at a high level. Particles appeared as various shapes and element compositions were complex. The temperature change of heating roller was one of most important factors that lead to the increased number concentration peak of PM(1).

[Analysis on the current situation of insufficient sleep and its association with physical exercise among Chinese Han students aged 9-18 years, in 2014].

Objective: To describe the situation of insufficient sleep and the association between insufficient sleep and physical exercise, among Chinese Han students aged 9-18 years. Methods: We selected 172 197 Chinese Han students aged 9-18 years from the project 2014 Chinese National Survey on Students Constitution and Health. The average sleep duration per day of less than 9 h for children aged 9-12 years and of less than 8 h for adolescents aged 13-18 years, were defined as insufficient sleep. We described the distribution of sleep duration and the prevalence rates of insufficient sleep for each subgroup. Logistic regression models were established to assess the association between insufficient sleep and physical exercise. Results: In 2014, 6.6%, 30.8%, 26.3%, 20.8%, 13.8% and 1.8% of the Chinese Han students self-reported sleep duration were <6, 6-, 7-, 8- and ≥10 h, respectively. The overall prevalence rate of insufficient sleep was 77.2%, with 75.8% for boys and 78.6% for girls. No gender disparity was found at each 9-11 age groups. However, in the 12-18 age groups, the prevalence rates for girls were significantly higher than that for boys. The prevalence rates of insufficient sleep for primary school, middle school and high school students were66.6%, 74.1% and 93.8%, respectively. Rates were increasing with age for children aged 9-12 years and adolescents aged 13-18 years respectively. The three provinces with the lowest prevalence rates of insufficient sleep were Zhejiang (68.8%), Jiangsu (66.7%) and Shaanxi (65.2%). Data from the logistic regression models revealed that, when comparing to those students with only exercise of <0.5 h per day, the exercise hours of 0.5-1 h (OR=0.72, 95%CI: 0.69-0.74) or ≥1 h (OR=0.46, 95%CI: 0.44-0.47) per day seemed as protective factors for insufficient sleep. When compared with physical exercise frequency <2 times per week, the 2 times (OR=0.82, 95%CI: 0.78-0.86) or >2 times (OR=0.65, 95%CI: 0.62-0.68) frequencies also appeared as protective. Conclusions: The prevalence rate of insufficient sleep prevailing among students aged 9-18 years was high, in China. Our data called for setting up effective measures to deal with this situation.

[The change in mortality and major causes of death among Chinese adolescents from 1990 to 2016].

Objective: To analyze the change in mortality and major causes of death among Chinese adolescents aged 10-19 years from 1990 to 2016. Methods: Data of death for Chinese adolescents aged 10-19 years were extracted from the Global Burden of Disease Study 2016 (GBD 2016). The data was used to describe the change in mortality of Chinese adolescents from 1990 to 2016.Top 15 causes of death were compared between 1990 and 2016. Results: From 1990 to 2016, the all-cause mortality of Chinese adolescents aged 10-19 years old dropped from 102.5/100 000 to 41.2/100 000, reaching about a half of the global average (78.6/100 000) but still almost twice as high as the average of high-income countries (24.3/100 000) by 2016; the reduction in mortality was higher among females than that among males (decreased 68.7% vs. 54.7%), and among adolescents aged 10-14 years than that among those aged 15-19 years (decreased 62.1% vs. 57.1%). During the 26-year period, the cause-specific mortality of all top 15 causes saw sharp decreases. Among them, communicable, maternal, and nutritional diseases saw the most significant decrease (78.1%), and its proportion in all adolescent deaths fell from 11.1% to 6.1%. Meanwhile, non-communicable diseases and injuries saw relatively small decreases (58.2% and 57.3% respectively), and their proportions rose from 33.4% and 55.6% to 34.8% and 59.1%, respectively. The top 5 causes of death changed from drowning (17.39/100 000 in mortality, 17.0% in proportion), road injuries (14.77/100 000, 14.4%), self-harm (11.44/100 000, 11.2%), leukemia (5.48/100 000, 5.4%) and interpersonal violence (3.12/100 000, 3.0%) in1990 into road injuries (9.27/100 000, 22.5%), drowning (6.83/100 000, 16.6%), leukemia(2.73/100 000, 6.6%), self-harm (2.53/100 000, 6.2%) and congenital birth defects (1.76/100 000, 4.3%) in 2016, and tuberculosis, poisonings and rheumatic heart disease had dropped out of the top 15 in 2016. Conclusion: The mortality of Chinese adolescents aged 10-19 years has decreased significantly, but still higher than developed countries. Since 1990, injuries,especially for road injuries and drowning, have always been the leading causes of death among Chinese adolescents aged 10-19 years, followed by non-communicable diseases.

[A cross-sectional study of seroepidemiology of viral hepatitis among Uighurs in Shufu of Xinjiang].

Objective: To explore the status of seroepidemiology on hepatitis A, B and C among students and residents aged equal or greater than 18 years in south Xinjiang, and to provide scientific evidence for prevention and control of viral hepatitis. Methods: Uyghur students in four towns and villages were selected by cluster random sampling from Feb to May, 2015, and Uyghur residents aged 18 to 69 years were selected by stratified cluster sampling from May to September, 2016. 4 507 middle and primary Uygur students and 4 833 Uyghur resides equal or greater than 18 years attended this survey. Self-designed questionnaire was used to collect the demographic information. And Elisa test was adopted to detect HAV-IgG, HBsAg, HBsAb and HCV-IgG. Chi-square test was used to calculate the difference on antibody positive rate of three types of hepatitis among the participants. Results: The overall HAV-IgG positive rate was 99.45% (9 289/9 340). The positive rates were 99.70% (4 006/4 018) in male and 99.27% (5 283/5 322) in female (χ(2)=7.95, P=0.005). The HAV-IgG positive rate among people aged 10 to 14 years was the highest (99.91%, 2 233/2 235), and the difference between the age specific HAV-IgG positive rates was statistical significant (χ(2)=38.21, P<0.001). The overall HBsAg positive rate was 4.11% (384 cases), with 4.55% (183 cases) for male and 3.78% (201 cases) for female. The HBsAg positive rate among participants 19 to 24 years old was the highest (9.46%, 21/222) and the differences between the age specific HBsAg was statistically significant (χ(2)=116.22, P<0.001). The HBsAb positive rate was 35.03% (3 272 cases), with 35.59% (1 430 cases) for male and 34.61% (1 842 cases) for female, and the HBsAb positive rate among participants aged 15 to 18 years was the highest, which was 69.12% (696/1 007). The differences between the age specific HBsAb rates appeared statistically significant (χ(2)=671.80, P<0.001). The overall HCV-IgG positive rate was 0.65%(61 cases). The HCV-IgG positive rate in female was 0.86% (46 cases) and 0.37% (15 cases) in male (χ(2)=8.51, P=0.004).The HCV-IgG positive rate among participants aged over 70 years was the highest (3.78%,9/238) , and the difference between the age specific HCV-IgG positive rates had statistic significance (χ(2)=70.30, P<0.001). The HAV-IgG positive rate in hepatitis A vaccinees (100%, 876/876) was higher than that among the non-vaccinees (99.40%, 8 413/8 464) (χ(2)=4.26, P=0.039). The HBsAb positive rate in hepatitis B vaccinees was 39.32% (1 816/4 619) which was higher than that among the non-vaccinees (30.84%, 1 456/4 721) (χ(2)=73.68, P<0.001). Conclusion: The positive rate of overall HAV-IgG was high, male and participants aged between 10 to 14 had higher probability to be infected. But the infection rates of hepatitis B and C were low, with the low vaccination rate and the poor protective effectiveness of hepatitis B.

[Knowledge, attitude and practice to chronic diseases and associated influencing factors in Uygur population in Kashgar area of Xinjiang Uygur Autonomous Region].

Objective: To investigate the knowledge, attitude and practice (KAP) to chronic diseases and associated influencing factors in Uygur adults in Kashgar of southern Xinjiang, and provide basic information for developing ethnic specific prevention and control strategies for chronic diseases. Methods: With stratified cluster random sampling, investigations, including questionnaire survey, physical examination and laboratory tests were performed among local residents who were aged ≥18 years and selected in Shufu county in southern Xinjiang. KAP scores were calculated and unconditional logistic regression models were used to analyze influencing factors. Results: A total of 4 772 Uygur adults were surveyed. The awareness rate of chronic disease related knowledge ranged from 4.32% to 56.04%, while the awareness rate of preventive measures were from 1.76% to 85.18% and the participation rate of prevention program varied from 4.00% to 97.99%. The average KAP score was 15.90±4.20 and the rate of total KAP was 47.86%. Multi-factor analysis suggested the pass rate of total KAP score increased with educational level. Other factors positively associated with 'KAP score pass rate' were commercial insurance investment, hypertension, family history of common chronic diseases, female and abdominal obesity, while overweight was negatively associated with the KAP score pass rate. Conclusions: The KAP level on chronic diseases was low in Uygur adults in Kashgar. It is necessary to continuously implement ethnic targeted health education and health promotion campaigns, especially in low education level, low income level, overweight and male groups.

[Prevalence of hypertension and risk factors in Uygur population in Kashgar area of Xinjiang Uygur Autonomous Region].

Objective: To investigate the prevalence of hypertension and risk factors in Uygur adults in Kashgar of Xinjiang. Methods: A total of 4 748 Uygur adults aged ≥18 years selected through cluster random sampling in Shufu county of Kashgar prefecture were surveyed by means of questionnaire survey, physical examination and laboratory test. The prevalence, awareness, treatment and control rate of hypertension of different groups were calculated and risk factors of hypertension was analyzed by using non-conditional logistic regression model. Results: The overall prevalence of hypertension was 15.73% (age-adjusted prevalence was 13.75%). The prevalence rates of hypertension in men and women were 16.36% (age-adjusted prevalence was 12.96%), 15.39% (age-adjusted prevalence was 14.34%), respectively. The rates of awareness, treatment and control of hypertension were 59.57%, 52.74%, 21.29%, respectively. The prevalence of hypertension increased with age. Compared with age group 18-34 years, the age groups 55-64, ≥65 years had higher risk of hypertension and the OR values were 10.53, 20.96 for men and 16.27, 33.20 for women. The overweight (OR=1.47 for men, OR=1.82 for women, P<0.05) and obesity (OR=1.88 for men, OR=2.66 for women, P<0.05) also increased the risk of hypertension. The groups with family history of hypertension (OR=3.85 for men, OR=2.34 for women, P<0.05) also had higher risk of hypertension. Hypertriglyceridemia was positively correlated with the prevalence of hypertension in men (OR=1.62, 95%CI: 1.09-2.41). Conclusions: The prevalence of hypertension in Uygur adults in Kashgar area of Xinjiang was at relatively low level. The related risk factors were age, overweight, obesity, family history and hypertriglyceridemia in men and the risk factors were similar in women except hypertriglyceridemia.

Effects of decreasing the frequency of ventilator circuit changes to every 7 days on the rate of ventilator-associated pneumonia in a Beijing hospital.

INTRODUCTION: We investigated whether decreasing ventilator circuit changes from every 2 days to every 7 days would impact ventilator-associated pneumonia rates at our institution. METHODS: All mechanically ventilated patients at Peking Union Medical College Hospital were studied over a 21 month period. From March 1998 to February 1999, ventilator circuits were changed every 2 days, and from June through December 1999, ventilator circuits were changed every 7 days. Nosocomial pneumonia was identified using the criteria of the Centers for Disease Control. RESULTS: In the 2-day-change group, there were 2,277 ventilator-patient days and 38 patients developed pneumonia, resulting in a pneumonia rate of 16.7 cases per 1,000 ventilator days. The 7-day-change group accumulated 972 ventilator days and 8 patients contracted pneumonia, resulting in a pneumonia rate of 8.2 cases per 1,000 ventilator days. The pneumonia rate was significantly lower in the 7-day-change group (p = 0.007). To standardize for seasonal variability, we compared results from the same seasonal time frames (June to December 1998 for the 2-day-change group, and June to December 1999 for the 7-day-change group), and obtained similar findings: during those periods, pneumonia rates were 24.2 cases per 1,000 ventilator days for the 2-day-change group and 8.9 cases per 1,000 ventilator days for the 7-day-change group (p = 0.001). CONCLUSIONS: A circuit change interval of 7 days had a lower risk of ventilator-associated pneumonia than a 2-day change interval. Therefore, ventilator circuits can be safely changed every 7 days in our setting.