Development,validation,and transportability of several machine-learned,non-exercise-based VO_(2max)prediction models for older adults

Background:There exist few maximal oxygen uptake(VO_(2max))non-exercise-based prediction equations,fewer using machine learning(ML),and none specifically for older adults.Since direct measurement of VO_(2max)is infeasible in large epidemiologic cohort studies,we sought to develop,validate,compare,and assess the transportability of several ML VO_(2max)prediction algorithms.Methods:The Baltimore Longitudinal Study of Aging(BLSA)participants with valid VO2_(max)tests were included(n=1080).Least absolute shrinkage and selection operator,linear-and tree-boosted extreme gradient boosting,random forest,and support vector machine(SVM)algorithms were trained to predict VO_(2max)values.We developed these algorithms for:(a)the overall BLSA,(b)by sex,(c)using all BLSA variables,and(d)variables common in aging cohorts.Finally,we quantified the associations between measured and predicted VO_(2max)and mortality.Results:The age was 69.0±10.4 years(mean±SD)and the measured VO_(2max)was 21.6±5.9 mL/kg/min.Least absolute shrinkage and selection operator,linear-and tree-boosted extreme gradient boosting,random forest,and support vector machine yielded root mean squared errors of 3.4 mL/kg/min,3.6 mL/kg/min,3.4 mL/kg/min,3.6 mL/kg/min,and 3.5 mL/kg/min,respectively.Incremental quartiles of measured VO_(2max)showed an inverse gradient in mortality risk.Predicted VO_(2max)variables yielded similar effect estimates but were not robust to adjustment.Conclusion:Measured VO_(2max)is a strong predictor of mortality.Using ML can improve the accuracy of prediction as compared to simpler approaches but estimates of association with mortality remain sensitive to adjustment.Future studies should seek to reproduce these results so that VO_(2max),an important vital sign,can be more broadly studied as a modifiable target for promoting functional resiliency and healthy aging.

Breastfeeding and genetic factors in the etiology of inflammatory bowel disease in children

Inflammatory bowel disease is a chronic,debilitating disorder of the gastrointestinal tract.The etiology of inflammatory bowel disease has not been elucidated,but is thought to be multifactorial with both environmental and genetic influences.A large body of research has been conducted to elucidate the etiology of inflammatory bowel disease.This article reviews this literature,emphasizing the studies of breastfeeding and the studies of genetic factors,particularly NOD2 polymorphisms.

Prevalence and Correlates of Elevated Blood Pressure in Chinese Children Aged 6-13 Years: a Nationwide School-Based Survey

Objective To estimate the prevalence of elevated blood pressure（EBP） in Chinese children and identify individual and family factors associated with EBP. Methods A nationwide cross-sectional study was conducted in 2010 using stratified cluster sampling. Participants＇ blood pressure was measured, and their parents completed a questionnaire on personal and family characteristics. Prevalence and correlates of EBP were assessed. Results Among a total of 24,333 participants, 20.2% of boys and 16.3% of girls had EBP. The prevalence of EBP increased with the ascending trend of waist circumference, Waist-to-height ratio, and body mass index. The adjusted prevalence ratios（aP Rs） for obese boys and girls were 2.50 and 2.97, respectively. Fewer urban boys（16.2%） had EBP than rural boys（21.7%）. Boys with a family history of hypertension were 12% more likely to have EBP. Children whose mothers received a college education tended to have lower likelihood of EBP; with an aP R was 0.85 among boys and 0.78 among girls. Conclusion EBP is common among obese students and those who have a family history of hypertension. A negative association between mothers＇ education levels and EBP risk in children was found.

Systematic overview of hepatitis C infection in the Middle East and North Africa

AIM To assess the quality of and to critically synthesize the available data on hepatitis C infections in the Middle East and North Africa(MENA) region to map evidence gaps.METHODS We conducted an overview of systematic reviews(SRs) following an a priori developed protocol(CRD42017076736). Our overview followed the preferred reporting items for systematic reviews and metaanalyses guidelines for reporting SRs and abstracts and did not receive any funding. Two independent reviewers systematically searched MEDLINE and conducted a multistage screening of the identified articles. Out of 5758 identified articles, 37 SRs of hepatitis C virus(HCV) infection in populations living in 20 countries in the MENA region published between 2008 and 2016 were included in our overview. The nine primary outcomes of interest were HCV antibody(anti-) prevalences and incidences in different at-risk populations; the HCV viremic(RNA positive) rate in HCV-positive individuals; HCV viremic prevalence in the general population(GP); the prevalence of HCV co-infection with the hepatitis B virus, human immunodeficiency virus, or schistosomiasis; the HCV genotype/subtype distribution; and the risk factors for HCV transmission. The conflicts of interest declared by the authors of the SRs were also extracted. Good quality outcomes reported by the SRs were defined as having the population, outcome, study time and setting defined as recommended by the PICOTS framework and a sample size > 100.RESULTS We included SRs reporting HCV outcomes with different levels of quality and precision. A substantial proportion of them synthesized data from mixed populations at differing levels of risk for acquiring HCV or at different HCV infection stages(recent and prior HCV transmissions). They also synthesized the data over long periods of time(e.g., two decades). Anti-HCV prevalence in the GP varied widely in the MENA region from 0.1%(study dates not reported) in the United Arab Emirates to 2.1%-13.5%(2003-2006) in Pakistan and 14.7%(2008) in Egypt. Data were not identified for Bahrain, Jordan, or Palestine. Good quality estimates of anti-HCV prevalence in the GP were reported for Algeria, Djibouti, Egypt, Iraq, Morocco, Pakistan, Syria, Sudan, Tunisia, and Yemen. Anti-HCV incidence estimates in the GP were reported only for Egypt(0.8-6.8 per 1000 person-year, 1997-2003). In Egypt, Morocco, and the United Arab Emirates, viremic rates in anti-HCV-positive individuals from the GP were approximately 70%. In the GP, the viremic prevalence varied from 0.7%(2011) in Saudi Arabia to 5.8%(2007-2008) in Pakistan and 10.0%(2008) in Egypt. Anti-HCV prevalence was lower in blood donors than in the GP, ranging from 0.2%(1992-1993) in Algeria to 1.7%(2005) in Yemen. The reporting quality of the outcomes in blood donors was good in the MENA countries, except in Qatar where no time framework was reported for the outcome. Some countries had anti-HCV prevalence estimates for children, transfused patients, contacts of HCV-infected patients, prisoners, sex workers, and men who have sex with men.CONCLUSION A substantial proportion of the reported outcomes may not help policymakers to develop micro-elimination strategies with precise HCV infection prevention and treatment programs in the region, as nowcasting HCV epidemiology using these data is potentially difficult. In addition to providing accurate information on HCV epidemiology, outcomes should also demonstrate practical and clinical significance and relevance. Based on the available data, most countries in the region have low to moderate anti-HCV prevalence. To achieve HCV elimination by 2030, up-to-date, good quality data on HCV epidemiology are required for the GP and key populations such as people who inject drugs and men who have sex with men.

The importance of household composition in epidemiological analyses of sleep: Evidence from the Understanding Society longitudinal panel survey

Aims: To establish the relationship between household composition and sleep, we: 1) used latent class analysis (LCA) to classify households;2) examined the reliability and stability of household composition classes over time;3) conducted multinomial logistic regression analyses to determine the relationship between household class and the self-reported sleep duration and quality of adults. Methods: Data were sourced from Waves 1 and 2 of the United Kingdom “Understanding Society” (USoc) longitudinal panel survey. LCA was used to classify household composition as a categorical latent construct using data on the number and ages of household occupants and the number of rooms used for sleeping. The Bayesian Information Criterion assessed model fit and identified the optimum number of latent classes. Multi-nomial logistic regression was used to investigate cross-sectional relationships between the household classes and self-reported sleep duration and quality amongst adults, after adjustment for confounders. Results: Household composition was best defined by 7 latent classes in data from Wave 1 of USoc. This finding was confirmed in Wave 2. Compared to the reference class (households with no children and no overcrowding), there was a higher risk of short sleep (≤5 hours) versus 7-8 hours sleep for latent household composition classes that included children (RR: 1.56;95% CI: 1.29-1.89) and for those with both children and overcrowding (RR: 1.57;95% CI: 1.31-1.88). Similarly the risk of “very bad” versus “fairly good” quality sleep was significantly higher in those household classes with overcrowding, particularly those with extended (RR: 1.75;95% CI: 1.34-2.29) and large (RR: 1.51;95% CI: 1.21-1.87) households. Conclusion: These analyses of a recent, nationally representative cohort from the UK, demonstrated that latent household composition classes are reliable over time;and that these latent household composition classes are important correlates of self-reported sleep amongst adult occupants. We showed that household composition is an important contextual variable to consider in most epidemiological studies of sleep.

Risk stratification for ST segment elevation myocardial infarction in the era of primary percutaneous coronary intervention

Acute coronary syndromes presenting with ST elevation are usually treated with emergency reperfusion/revascularisation therapy. In contrast current evidence and national guidelines recommend risk stratification for non ST segment elevation myocardial infarction(NSTEMI) with the decision on revascularisation dependent on perceived clinical risk. Risk stratification for STEMI has no recommendation. Statistical risk scoring techniques in NSTEMI have been demonstrated to improve outcomes however their uptake has been poor perhaps due to questions over their discrimination and concern for application to individuals who may not have been adequately represented in clinical trials. STEMI is perceived to carry sufficient risk to warrant emergency coronary intervention [by primary percutaneous coronary intervention(PPCI)] even if this results in a delay to reperfusion with immediate thrombolysis. Immediate thrombolysis may be as effective in patients presenting early, or at low risk, but physicians are poor at assessing clinical and procedural risks and currently are not required to consider this. Inadequate data on risk stratification in STEMI inhibits the option of immediate fibrinolysis, which may be cost-effective. Currently the mode of reperfusion for STEMI defaults to emergency angiography and percutaneous coronary intervention ignoring alternative strategies. This review article examines the current risk scores and evidence base for risk stratification for STEMI patients. The requirements for an ideal STEMI risk score are discussed.

Favorable lifestyle before diagnosis associated with lower risk of screen-detected advanced colorectal neoplasia

AIM: To investigate the association between adherence to health recommendations and detection of advanced colorectal neoplasia(ACN) in colorectal cancer(CRC) screening.METHODS: A total of 14832 women and men were invited to CRC screening, 6959 in the fecal immunochemical test arm and 7873 in the flexible sigmoidoscopy arm. These were also sent a self-reported lifestyle questionnaire to be completed prior to their first CRC screening. A lifestyle score was created to reflect current adherence to healthy behaviors in regard to smoking, body mass index, physical activity, alcohol consumption and food consumption, and ranged from zero(poorest) to six(best). Odds ratios(ORs) and 95%CIs were calculated using multivariable logistic regression to evaluate the association between the single lifestyle variables and the lifestyle score and the probability of detecting ACN.RESULTS: In all 6315 women and men completed the lifestyle questionnaire, 3323(53%) in the FIT arm and 2992(47%) in the FS arm. This was 89% of those who participated in screening. ACN was diagnosed in 311(5%) participants of which 25(8%) were diagnosed with CRC. For individuals with a lifestyle score of two, three, four, and five-six, the ORs(95%CI) for the probability of ACN detection were 0.82(0.45-1.16), 0.43(0.28-0.73), 0.41(0.23-0.64), and 0.41(0.22-0.73), respectively compared to individuals with a lifestyle score of zero-one. Of the single lifestyle factors, adherence to non-smoking and moderate alcohol intake were associated with a decreased probability of ACN detection compared to being a smoker or having a high alcohol intake 0.53(0.42-0.68) and 0.63(0.43-0.93) respectively.CONCLUSION: Adopted healthy behaviors were inversely associated with the probability of ACN detection. Lifestyle assessment might be useful for risk stratification in CRC screening.

Fast Track Extubation Post Coronary Artery Bypass Graft: A Retrospective Review of Predictors of Clinical Outcomes

Introduction: Fast track (FT) cardiac surgery and early extubation (EE) are aimed at safe and effective rapid post-operative progression to discharge, and have been practiced for more than two decades. Their goal is to optimize patient care perioperatively in order to decrease costs without negatively affecting morbidity and mortality. However, the factors that predict successful EE are poorly understood, and patients with significant co-morbidities are frequently excluded from protocols. We hypothesize that independent of disease severity, early extubation leads to shorter hospital stays and can be performed safely without negatively affecting outcomes. Materials and Methods: We performed a retrospective review of 919 patients who underwent coronary artery bypass grafting (CABG) at the Southern Arizona Veteran’s Affairs Health Care System medical center over 7 years. We collected pre-operative data regarding patients’ NYHA classification, presence and severity of cerebral vascular disease, peripheral vascular disease, pulmonary disease, diabetes and hypertension. Intra-operative variables were also recorded including ASA scores, ischemic times, and time to extubation. Finally, post-operative variables such as rates of reintubation and tracheotomy, and both length of ICU and total hospital stay were also compared. Results: Prolonged periods of ischemia were found to predict a delayed extubation (HR = 0.992;CI = 0.988 - 0.997, p = 0.0015) while small body surface area (HR = 1.57;CI = 1.13, 2.17, p = 0.007) and higher pre-operative functional status of the patient, such as independent versus dependent status (HR =1.68;CI = 1.30 - 2.16, p = 1.33;CI = 1.03 - 1.70, p = 0.03) were found to be associated with earlier extubation. The early extubation (EE) group (those extubated in less than the median 7.3 hours) had an average hospital stay of 5.1 ± 4.0 days, versus 7.8 ± 8.1 days in the delayed group (>4 hours), p Conclusions: In our study population, pre-operative functional class and total body surface area predicted those patients able to tolerate early extubation after cardiac surgery. Prolonged ischemia resulted in delayed extubation. Patients that were extubated in less than 4 hours had shorter ICU and hospitalization stays, while there was no significant difference between the two groups in rate of reintubation or tracheotomy.

Comparison of the Performance of Three Commonly Used Electrocardiographic Indexes for the Diagnosis of Left Ventricular Hypertrophy in Black Hypertensive Patients with Reduced Kidney Function Managed at a Tertiary Healthcare Hospital: A Post-Hoc Analysis

Background: Reduced kidney function in blacks is associated with an increased frequency of left ventricular hypertrophy. Given the unavailability of echocardiography in most developing countries, the diagnostic performance of current ECG indexes needs to be evaluated. Objective: To compare the diagnostic performance of 3 commonly used ECG indexes (Sokolow-Lyon, Cornell voltage and Cornell product) in black hypertensive patients. Methods: Electrocardiography and echocardiography estimated left ventricular mass of 155 consecutive hypertensive patients who participated from January 2012 to January 2013 to an echocardiographic cross-sectional study of left ventricular structure was analyzed to compare Cornell voltage and Cornell product indexes with Sokolow-Lyon voltage index as a reference. Reduced kidney function was defined as eGFR 2. ROC curves in relation to LVH diagnosis were used to estimate the sensitivities and specificities of each index. P Results: The sensitivity and specificity were 43% and 85%, 23% and 77% and 26% and 77% for Sokolow-Lyon, Cornell voltage and Cornell product indexes, respectively. However, Sokolow-Lyon index (AUC;95% CI: 0.64;0.50 - 0.78) showed better performance than Cornell voltage (0.42;0.25 - 0.59) and Cornell product (0.43;0.28 - 0.59). Sokolow-Lyon index cut-point ≥ 37 mm corresponded to the highest Youden index (39.4% of sensitivity and 92.3% of specificity). Conclusion: Although the overall performance of the 3 ECG indexes versus echocardiography was low, Sokolow-Lyon index performed better than the two other indexes in diagnosing LVH.

Estimating geographic variation of infection fatality ratios during epidemics

Objectives We aim to estimate geographic variability in total numbers of infections and infection fatality ratios(IFR;the number of deaths caused by an infection per 1,000 infected people)when the availability and quality of data on disease burden are limited during an epidemic.Methods We develop a noncentral hypergeometric framework that accounts for differential probabilities of positive tests and reflects the fact that symptomatic people are more likely to seek testing.We demonstrate the robustness,accuracy,and precision of this framework,and apply it to the United States(U.S.)COVID-19 pandemic to estimate county-level SARS-CoV-2 IFRs.Results The estimators for the numbers of infections and IFRs showed high accuracy and precision;for instance,when applied to simulated validation data sets,across counties,Pearson correlation coefficients between estimator means and true values were 0.996 and 0.928,respectively,and they showed strong robustness to model misspecification.Applying the county-level estimators to the real,unsimulated COVID-19 data spanning April 1,2020 to September 30,2020 from across the U.S.,we found that IFRs varied from 0 to 44.69,with a standard deviation of 3.55 and a median of 2.14.Conclusions The proposed estimation framework can be used to identify geographic variation in IFRs across settings.

Curative effect of acupuncture on quality of life in patient with depression： a clinical randomized single-blind placebo-controlled study

OBJECTIVE:To evaluate the effect of acupuncture on the quality of life in patients with depression by clinical randomized single-blind placebo-controlled study.METHODS:one hundred and sixty-three cases of depression according with the inclusion criteria were randomly divided into a group of acupuncture dredging liver and regulating flow of theosophy(group 1),a group of acupoint shallow stab(group 2)and a group of non-acupoint shallow stab(group 3)at 1∶1∶1 ratio,and treated with acu-puncture,moxibustion,and intradermal embedding of needle,twice a week,for a total of 12 weeks.Scale of Quality of Life(SF-36)was used to measure the scores at four different time points and evaluate the effect of acupuncture on the quality of life of the patients with depression.RESULTS:At each time point after treatment,in scores of the 8 items,physical function,physical role,bodily pain,general physical condition,energy,social function,emotional function and mental health there were statistically significant differences among the 3 groups(P<0.0125).CONCLUSION:Acupuncture can effectively improve the quality of life of patients with depression.

Zinc deficiency in patients with chronic pancreatitis

BACKGROUND Zinc is a key element in numerous proteins and plays an important role in essential cell functions such as defense against free radicals and DNA damage repair. Chronic pancreatitis(CP) is a chronic inflammation with progressive fibrosis of pancreas ultimately resulting in pancreatic exocrine insufficiency(PEI),which is associated with malnutrition. Studies analyzing zinc levels in patients with CP are sparse and lead to conflicting results.AIM To investigate serum zinc levels in patients with CP of various etiologies.METHODS Between October 2015 and March 2018, patients with a diagnosis of CP were identified and recruited from the Pancreatic Outpatient Clinic at the Karolinska University Hospital in Stockholm, Sweden. Demographic, clinical and laboratory data were analyzed. Etiology of CP was determined according to the MANNHEIM classification system into the following etiological subcategories:alcohol consumption, nicotine consumption, hereditary factors, efferent pancreatic duct factors and immunological factors. Pancreatic exocrine function was defined as normal(fecal elastase 1 > 200 μg/g), mildly reduced(100-200μg/g) and severely reduced(fecal elastase 1 < 100 μg/g).RESULTS A total of 150 patients were included in the analysis. Zinc deficiency(< 11μmol/L) was present in 39(26.0%) of patients: 22 females and 17 males. In the group of patients with zinc deficiency, 76.7% of patients had an exocrine pancreatic insufficiency(FE-1 < 200 μg/g). Older age was significantly associated with low zinc levels. Following a univariate analysis, patients aged 60-69 and patients ≥ 70 years of age had a significantly higher prevalence of zinc deficiencies compared to patients < 40 years of age [OR: 3.8, 95%CI(1.08-13.4); P= 0.04]; [OR 6.26, 95%CI(1.94-20.2), P > 0.002]. Smoking and number of packyears were additionally associated with low zinc levels. The risk of zinc deficiency in current smokers and smokers with ≥ 20 pack-years was approximately three times higher compared to those who had never smoked.Gender, body mass index, etiology of CP, presence of diabetes mellitus, levels of glycated hemoglobin(HbA1 c), bone mineral density, alcohol intake and presence of PEI were not associated with low zinc levels.CONCLUSION Zinc deficiency is common in patients with CP and is significantly associated with age ≥ 60, smoking and the number of pack-years, but not with PEI.

Assessing 10-year coronary heart disease risk in people with Type 2 diabetes mellitus: Framingham versus United Kingdom Prospective Diabetes Study

Aims: Previous studies have suggested that the Framingham coronary heart disease risk prediction equation underestimates risk among people with Type 2 diabetes. We compared the 10-year absolute risks of coronary heart disease (CHD) using a Framingham equation and a United Kingdom Prospective Diabetes Study (UKPDS) equation in adults with Type 2 diabetes. Methods: Participants were from a cross-sectional survey of a randomly selected population. There were 461 people with newly (n = 132) or previously diagnosed (n = 329) diabetes aged 35 to 74 years with no past history of cardiovascular disease or nephropathy. We examined predicted 10-year CHD risk by age, gender, and newly or previously diagnosed diabetes. Results: Overall the mean 10-year CHD risks predicted by the two equations were similar. Among men, the UKPDS and Framingham scores were almost identical below 60 years of age but at older ages, the UKPDS score was 4% - 11% higher than Framingham. For women, the Framingham score was higher than the UKPDS score between ages 40 and 65 years, but the UKPDS score was about 4% - 5% higher for women aged 70 years and over. The UKPDS equation tended to give higher risk estimates in people with a predicted 10-year Framingham CHD risk above 15%. Conclusion: Framingham CHD risk scores tended to be lower than UKPDS scores primarily in people above standard thresholds for drug treatment, so the clinical impact of underestimating risk is likely to be limited. Moreover, the UKPDS equation predicted lower risks than Framingham for women and newly diagnosed diabetes at otherwise low to moderate CHD risk, which could result in later initiation of therapy in these groups if the UKPDS score was used instead of the Framingham score.

Association between polymorphisms of prokineticin receptor(PKR1 rs4627609 and PKR2 rs6053283) and recurrent pregnancy loss

Recurrent pregnancy loss （RPL） is a condition with complex etiologies, to which both genetic and envi- ronmental factors may contribute. During the last decade, studies indicated that the expression patterns of the pro- kineticin receptor （PKR1 and PKR2） are closely related to early pregnancy. However, there are few studies on the role of PKR1 and PKR2 in RPL. In this study, we purpose to investigate the association between polymorphisms of the prokineticin receptor （PKR1 rs4627609 and PKR2 rs6053283） and RPL on a group of 93 RPL cases and 169 healthy controls. Genotyping of the single nucleotide polymorphisms （SNPs） was performed using a Sequenom MassARRAY iPLEX system. The results revealed a significant association between PKR2 rs6053283 polymorphism and RPL （P=0.003）, whereas no association was observed between PKR1 rs4627609 polymorphism and RPL （P=-0.929） in the Chinese Han population.

Association of homocysteine and smoking with cerebral microemboli in patients with mechanical heart valves:a transcranial Doppler study

Objectives Microembolic signals(MES)on transcranial Doppler(TCD)predict stroke and cognitive decline.Plasma levels of total homocysteine(tHcy),a prothrombotic factor,are higher in patients with microemboli in carotid stenosis and in patients with paradoxical embolism.In this study we assessed the association between the level of tHcy and the number of MES in patients with mechanical heart valves(MHVs).Methods TCD monitoring was performed to detect MES before and after breathing 100% oxygen and repeated every 2-4 weeks up to six times.results Twenty-five patients with MHVs(mean age:63.60±10.15 years)participated in this study;15 were men(66.47±7.25 years)and 10 were women(59.30±12.60 years).In total,there were 126 study visits.In multiple regression,higher tHcy was associated with more MES in both preoxygenation(OR 1.34(95%CI 1.07 to 1.68,P=0.009))and postoxygenation(OR 1.40(95% CI 1.07 to 1.83,P=0.01))phases.Current smoking and the length of time between the operation and monitoring also correlated with a higher number of MES before and after breathing oxygen,particularly in women.conclusions Higher tHcy and smoking were associated with a higher MES count in both preoxygenation and postoxygenation phases.Because smoking can be stopped and hyperhomocysteinaemia is treatable,these are clinically important findings.

Characteristics of and Risk Factors Associated with Self-Reported Sexual Repression among Internal Migrants in China: A Large-Scale Cross-Sectional Study

Objective:This large-scale cross-sectional study aims to identify the characteristics of and risk factors associated with sexual repression among internal migrants in China.Methods:Between August 2013 and August 2015,a total of 8,669 internal migrants from four major cities in China(Beijing,Shanghai,Chengdu,and Chongqing)voluntarily participated in our study.They were interviewed,and the data on their demographic information,occupation,and sexual activities were collected.The Chi-square test and multiple logistic regressions were conducted to identify significant associations.A stepwise method was adopted for the selection of variables.Results:There were 3,597(41.49%)males and 5,072(58.51%)females in total.A higher percentage of males reported that they felt sexual repression compared to females(14.43%vs.9.21%).After adjusting for other covariates,the consequence was showed that male migrants working for more than 5 days were more likely to report sexual repression(odds ratio[OR]=1.40,P<0.05).Living in a collective dormitory with others was also a risk factor for male migrants.The longer males spent with their partners,the less sexual repression occurred(OR=0.94,P<0.05).Similarly,agricultural household registration status and working for more than 5 days increased the risk for sexual repression among female migrants(OR=1.41 and OR=1.46,respectively,P<0.05).Frequent and constructive communication also protected females against sexual repression(P<0.05).Well-educated females experienced relatively less sexual repression when compared to their counterparts with less education(P<0.05).Conclusions:Sexual repression was significantly associated with a few demographic,occupational,and sexual risk factors.Meaningful differences have been identified between male and female migrants.More effective intervention programs such as safeguard measures and welfare policies should be designed and implemented for a majority of female migrants and for those with agricultural household registration status.

Choosing a Method to Reduce Selection Bias: A Tool for Researchers

Selection bias is well known to affect surveys and epidemiological studies. There have been numerous methods proposed to reduce its effects, so many that researchers may be unclear which method is most suitable for their study;the wide choice may even deter some researchers, for fear of choosing a sub-optimal approach. We propose a straightforward tool to inform researchers of the most promising methods available to reduce selection bias and to assist the search for an appropriate method given their study design and details. We demonstrate the tool using three examples where selection bias may occur;the tool quickly eliminates inappropriate methods and guides the researcher towards those to consider implementing. If more studies consider selection bias and adopt methods to reduce it, valuable time and resources will be saved, and should lead to more focused research towards disease prevention or cure.

治疗后甲状腺功能亢进患者的甲状腺功能及死亡率

背景：据报道甲状腺功能亢进可提高全因死亡率和循环系统疾病死亡率。正如还不清楚这种情况是否受轻度持续性甲状腺功能不全和治疗引起的甲状腺功能减退的影响一样，这种情况是否能被逆转亦属未知。 目的：确定放射性碘治疗是否与死亡率增加有关；明确轻度甲状腺功能不全以及发生明显甲状腺功能减低时，甲状腺素（T4）治疗的影响。 设计、地点及参试者：于2 668例≥40岁患者中进行以人群为基础的研究。所有患者均于1984～2002年在英格兰West Midland地区因明显甲状腺功能亢进而接受放射性碘治疗。 主要观测指标：与英格兰和威尔土地区相关年龄别和时期别死亡率参照比较的死亡原因，对T4治疗放射性碘治疗所致甲状腺功能减退和亚临床甲状腺功能不全对死亡率的影响进行评估。 结果：在15 968人年随访中，实际死亡554人，预期死亡487人（标准化死亡率比[standardized mortality ratio，SMR]，1．14；95％可信区间[confidence interval，CI]，1．04～1．24，P=0．002）。在随访无需T4治疗或T4治疗之前，与相应年龄别和时期别死亡率相比，病人全因死亡和循环系统疾病死亡危险增加。T4治疗者随访期间未见死亡危险增加（接受T4治疗前循环系统疾病SMR，1．33；95％CI，1．14～1．53而T4治疗期间SMR 0．91；95％CI，0．70～1．17）。接受T4治疗的病人其死亡危险较不需T4治疗或T4治疗之前降低（全因病死风险比[harzard ratio，HR]，0．65；95％CI，0．54～0．79；循环系统疾病死亡HR，0．65；95％CI，0．48～0．87）。与背景人群相比，接受T4治疗之前随访全因死亡率的增加与血清甲状腺球蛋白水平降低、正常和升高相关。按照甲状腺球蛋白水平的不同进行分析发现，缺血性心脏疾病的SMR轻度升高，高血清甲状腺球蛋白者SMR最高（低血清甲状腺球蛋白者SMR，1．06；95％CI，0．75～1．45；血清甲状腺球蛋白水平正常者SMR，1．17；95％CI，0．76～1．71；高血清甲状腺球蛋白者SMR，1．48；95％CI，0．86～2．37）。队列内比较显示，与甲状腺生化检查正常者比较，T4治疗前轻度甲状腺功能不全与缺血性心脏疾病的死亡危险增加相关（HR，2．08；95％CI，1．04～4．19）。 结论：与英格兰和威尔土地区相应年龄别和时期别的死亡率比较，因甲状腺功能亢进症而接受放射性碘治疗的病人死亡率升高，而接受T4治疗者则不再明显。此结果支持甲状腺功能亢进应用放射性碘治疗足以导致明显甲状腺功能减退的结论。在缺血性心脏疾病死亡队列内，这种与亚临床甲状腺功能减退的相关性提示，放射性碘治疗后若发生牛化异常时，应该考虑T4替代治疗。

International chicken trade and increased risk for introducing or reintroducing highly pathogenic avian influenza A (H5N1) to uninfected countries

Every year billions of chickens are shipped thousands of miles around the globe in order to meet the ever increasing demands for this cheap and nutritious protein source.Unfortunately,transporting chickens internationally can also increase the chance for introducing zoonotic viruses,such as highly pathogenic avian influenza A(H5N1)to new countries.Our study used a retrospective analysis of poultry trading data from 2003 through 2011 to assess the risk of H5N1 poultry infection in an importing country.We found that the risk of infection in an importing country increased by a factor of 1.3(95%CI:1.1e1.5)for every 10-fold increase in live chickens imported from countries experiencing at least one H5N1 poultry case during that year.These results suggest that the risk in a particular country can be significantly reduced if imports from countries experiencing an outbreak are decreased during the year of infection or if biosecurity measures such as screening,vaccination,and infection control practices are increased.These findings show that limiting trade of live chickens or increasing infection control practices during contagious periods may be an important step in reducing the spread of H5N1 and other emerging avian influenza viruses.

Reinfection of urogenital schistosomiasis in pre-school children in a highly endemic district in Northern Zimbabwe:a 12 months compliance study

Background:In light of the shift to aiming for schistosomiasis elimination,the following are needed:data on reinfection patterns,participation,and sample submission adherence of all high-risk age groups to intervention strategies.This study was conducted to assess prevalence,reinfections along with consecutive participation,sample submission adherence,and effect of treatment on schistosomiasis prevalence in children aged five years and below in an endemic district in Zimbabwe,over one year.Methods:The study was conducted from February 2016-February 2017 in Madziwa area,Shamva district.Following community mobilisation,mothers brought their children aged 5 years and below for recruitment at baseline and also urine sample collection at baseline,3,6,9 and 12 months follow up surveys.At each time point,urine was tested for urogenital schistosomiasis by urine filtration and children found positive received treatment.Schistosoma haematobium prevalence,reinfections as well as children participation,and urine sample submission at each visit were assessed at each time point for one year.Results:Of the 535 children recruited from the five communities,169(31.6%)participated consecutively at all survey points.The highest mean number of samples submitted was 2.9 among communities and survey points.S.haematobium prevalence significantly reduced from 13.3%at baseline to 2.8%at 12 months for all participants and from 24.9%at baseline to 1.8%at 12 months(P<0.001)for participants coming at all-time points.Among the communities,the highest baseline prevalence was found in Chihuri for both the participants coming consecutively(38.5%,10/26)and all participants(20.4%,21/103).Reinfections were significantly high at 9 months follow up survey(P=0.021)and in Mupfure(P=0.003).New infections significantly decreased over time(P<0.001).Logistic regression analysis showed that the risk of acquiring schistosomiasis was high in some communities(P<0.05).Conclusions:S.haematobium infections and reinfections are seasonal and depend on micro-geographical settings.The risk of being infected with schistosomes in pre-school aged children increases with increasing age.Sustained treatment of infected individuals in a community reduces prevalence overtime.Participation compliance at consecutive visits and sample submission adherence are important for effective operational control interventions.