Association between coronary artery stenosis and myocardial injury in patients with acute pulmonary embolism:A case-control study

Background:The potential impact of pre-existing coronary artery stenosis(CAS)on acute pulmonary embolism(PE)episodes remains underexplored.This study aimed to investigate the association between pre-existing CAS and the elevation of high-sensitivity cardiac troponin I(hs-cTnI)levels in patients with PE.Methods:In this multicenter,prospective case-control study,88 cases and 163 controls matched for age,sex,and study center were enrolled.Cases were patients with PE with elevated hs-cTnI.Controls were patients with PE with normal hs-cTnI.Coronary artery assessment utilized coronary computed tomographic angiography or invasive coronary angiography.CAS was defined as≥50%stenosis of the lumen diameter in any coronary vessel>2.0 mm in diameter.Conditional logistic regression was used to evaluate the association between CAS and hs-cTnI elevation.Results:The percentage of CAS was higher in the case group compared to the control group(44.3%[39/88]vs.30.1%[49/163];P=0.024).In multivariable conditional logistic regression model 1,CAS(adjusted odds ratio[OR],2.680;95%confidence interval[CI],1.243-5.779),heart rate>75 beats/min(OR,2.306;95%CI,1.056-5.036)and N-terminal pro-B type natriuretic peptide(NT-proBNP)>420 pg/mL(OR,12.169;95%CI,4.792-30.900)were independently associated with elevated hs-cTnI.In model 2,right CAS(OR,3.615;95%CI,1.467-8.909)and NT-proBNP>420 pg/mL(OR,13.890;95%CI,5.288-36.484)were independently associated with elevated hs-cTnI.Conclusions:CAS was independently associated with myocardial injury in patients with PE.Vigilance towards CAS is warranted in patients with PE with elevated cardiac troponin levels.

A Nested Case-Control Study to Explore the Association between Immunoglobulin G N-glycans and Ischemic Stroke

Objective This study prospectively investigates the association between immunoglobulin G(IgG)N-glycan traits and ischemic stroke(IS) risk.Methods A nested case-control study was conducted in the China suboptimal health cohort study,which recruited 4,313 individuals in 2013–2014. Cases were identified as patients diagnosed with IS, and controls were 1:1 matched by age and sex with cases. Ig G N-glycans in baseline plasma samples were analyzed.Results A total of 99 IS cases and 99 controls were included, and 24 directly measured glycan peaks(GPs) were separated from Ig G N-glycans. In directly measured GPs, GP4, GP9, GP21, GP22, GP23, and GP24 were associated with the risk of IS in men after adjusting for age, waist and hip circumference,obesity, diabetes, hypertension, and dyslipidemia. Derived glycan traits representing decreased galactosylation and sialylation were associated with IS in men(FBG2S2/(FBG2 + FBG2S1 + FBG2S2): odds ratio(OR) = 0.92, 95% confidence interval(CI): 0.87–0.97;G1n: OR = 0.74, 95% CI: 0.63–0.87;G0n: OR =1.12, 95% CI: 1.03–1.22). However, these associations were not found among women.Conclusion This study validated that altered Ig G N-glycan traits were associated with incident IS in men, suggesting that sex discrepancies might exist in these associations.

Having a Partner and Having Children:Comparisons of Adults with Congenital Heart Disease and the General Population:A 15-Year Case-Control Study

Objectives:To examine whether patients with congenital heart disease(CHD)are less likely to have a partner or children than individuals from the general population.Methods:Longitudinal study with two assessments of the same patients(n=244)from a hospital population and controls(n=238)from the German Socio-Economic Panel(GSOEP)using parental education,patients age,and sex as matching criteria.The first patient study was conducted between 5/2003 and 6/2004,the second one between 5/2017 and 4/2019.Controls were drawn from GSOEP-surveys 2004 and 2018.CHD-severity was classified according to type of surgery:curative,reparative,or palliative.Living single was used as outcome measure,for offspring the outcome was having children or not.Results:Among women with CHD the rate of those living single was higher than among controls with the differences depending on disease complexity(curative:OR=5.5;reparative:OR=1.9;palliative:OR=2.7).No statistically significant differences between patients and controls emerged in the male study population.With respect to children a marked difference emerged between women with CHD and controls.Among patients the odds of having children were lower than among controls(curative:OR=0.3;reparative:OR=0.3;palliative:OR=0.2).The rate of patients with children with CHD(women:5.6%;men:4.9%)was higher than expected(1%)if compared with the general population.Conclusions:Using partnership and children as outcome criteria,patients with CHD are disadvantaged if compared to subjects from the general population.In female patients the social consequences of the disease turned out as more pervasive than in women.

Reduced risk of dementia in patients with type 2 diabetes mellitus using Chinese herbal medicine:A nested case-control study

BACKGROUND Dementia is a prevalent condition in type 2 diabetes mellitus(T2DM)patients.While Chinese herbal medicine(CHM)is often employed as complementary therapy for glycemic control,its effect in controlling likelihood of dementia has not yet been fully elucidated.AIM To compare the risk of dementia between T2DM patients with and without CHM treatment.METHODS We undertook a nested case-control study and obtained data on patients 20-70 years of age who received medical care for T2DM between 2001 and 2010 from the National Health Insurance Research database in Taiwan.Cases,defined as those with dementia that occurred at least one year after the diagnosis of T2DM,were randomly matched to controls without dementia from the study cohort at a 1:1 ratio.We applied conditional logistic regression to explore the associations between CHM treatment and dementia.RESULTS A total of 11699 dementia cases were matched to 11699 non-dementia controls.We found that adding CHM to conventional care was related to a lower risk of dementia[adjusted odds ratio(OR)=0.51],and high-intensity CHM treatment was associated with an adjusted OR of 0.22.CONCLUSION This study shows that the cumulative CHM exposure was inversely associated with dementia risk in an exposureresponse manner,implying that CHM treatment may be embraced as a disease management approach for diabetic patients to prevent dementia.

Rural implementation of the perioperative surgical home:A case-control study

BACKGROUND Perioperative surgical home(PSH)is a novel patient-centric surgical system developed by American Society of Anesthesiologist to improve outcomes and patient satisfaction.PSH has proven success in large urban health centers by reducing surgery cancellation,operating room time,length of stay(LOS),and readmission rates.Yet,only limited studies have assessed the impact of PSH on surgical outcomes in rural areas.AIM To evaluate the newly implemented PSH system at a community hospital by comparing the surgical outcomes using a longitudinal case-control study.METHODS The research study was conducted at an 83-bed,licensed level-III trauma rural community hospital.A total of 3096 TJR procedures were collected retrospectively between January 2016 and December 2021 and were categorized as PSH and non-PSH cohorts(n=2305).To evaluate the importance of PSH in the rural surgical system,a case-control study was performed to compare TJR surgical outcomes(LOS,discharge disposition,and 90-d readmission)of the PSH cohort against two control cohorts[Control-1 PSH(C1-PSH)(n=1413)and Control-2 PSH(C2-PSH)(n=892)].Statistical tests including Chi-square test or Fischer’s exact test were performed for categorical variables and Mann-Whitney test or Student’s t-test were performed for continuous variables.The general linear models(Poisson regression and binomial logistic regression)were performed to fit adjusted models.RESULTS The LOS was significantly shorter in PSH cohort compared to two control cohorts(median PSH=34 h,C1-PSH=53 h,C2-PSH=35 h)(P value<0.05).Similarly,the PSH cohort had lower percentages of discharges to other facilities(PSH=3.5%,C1-PSH=15.5%,C2-PSH=6.7%)(P value<0.05).There was no statistical difference observed in 90-d readmission between control and PSH cohorts.However,the PSH implementation reduced the 90-d readmission percentage(PSH=4.7%,C1-PSH=6.1%,C2-PSH=3.6%)lower than the national average 30-d readmission percentage which is 5.5%.The PSH system was effectively established at the rural community hospital with the help of team-based coordinated multi-disciplinary clinicians or physician comanagement.The elements of PSH including preoperative assessment,patient education and optimization,and longitudinal digital engagement were vital for improving the TJR surgical outcomes at the community hospital.CONCLUSION Implementation of the PSH system in a rural community hospital reduced LOS,increased directto-home discharge,and reduced 90-d readmission percentages.

基于case-control法分析鸡脂肪性状QTL区域SNP与性状的关系

以华南农业大学杏花鸡×隐性白羽洛克鸡全同胞家系为群体,选取腹脂重性状两尾样本共96个个体,在已报道家禽腹脂重性状QTL区域相关基因中选取14个SNP,采取PCR-RFLP法进行基因定型、case-control法进行关联分析,经100000次重排检验后,发现rs16480367、rs15687533、rs16481126、rs15685408均达到显著水平,P值分别为0.0202、0.0215、0.0257、0.0319。说明这4个SNP位点与脂肪性状有一定的相关性,可为家禽的标记辅助选择提供理论参考。

Multicenter case-control study of the risk factors for ulcerative colitis in China

AIM:To evaluate potential risk factors in the development of ulcerative colitis(UC) in China.METHODS:A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China.The UC cases were collected from 17 hospitals in China from April 2007 to April 2010.Uniform questionnaires were designed to investigate risk factors including smoking,appendectomy,stress,socio-economic conditions,nonsteroidal antiinflammatory drugs(NSAIDs),oral contraceptives,diet,breastfeeding,infections and family sanitary conditions.Group comparisons by each factor were done using simple logistic regression analysis.Conditional logistic regression was used for multivariate analysis.RESULTS:By univariate analysis,the variables predictive of UC included feeling stress,light and heavy alcoholic drinking,spicy food,sugar consumption and infectious diarrhea,while heavy tea intake and tap water consumption were protective against UC.On multivariate analysis,the protective factor for UC was tap water consumption [odds ratios(OR) = 0.424,95%CI:0.302-0.594,P < 0.001];while the potential risk factors for UC were heavy sugar consumption(OR = 1.632,95%CI:1.156-2.305,P < 0.001),spicy food(light intake:OR = 3.329,95%CI:2.282-4.857,P < 0.001;heavy intake:OR = 3.979,95%CI:2.700-5.863,P < 0.001),and often feeling stress(OR = 1.981,95%CI:1.447-2.711,P < 0.001).Other factors,such as smoking habit,appendectomy,breastfeeding,a history of measles,rural or urban residence,education,oral contraceptives,and NSAID use have not been found to have a significant association with the development of UC in the present study.CONCLUSION:Our study showed tap water consumption was a protective factor for UC,while spicy food,heavy sugar consumption and often feeling stress were risk factors for UC in this Chinese population.

Glutathione S-transferases M1,T1 genotypes and the risk of gastric cancer:A case-control study

AIM: Glutathione S-transferases (GSTs) are involved in the detoxification of many potential carcinogens and appear to play a critical role in the protection from the effects of carcinogens. The contribution of glutathione S-transferases M1 and T1 genotypes to susceptibility to the risk of gastric cancer and their interaction with cigarette smoking are still unclear. The aim of this study was to determine whether there was any relationship between genetic polymorphisms of GSTT1 and GSTT1 and gastric cancer. METHODS: A population based case-control study was carried out in a high-risk area, Changle County, Fujian Province, China. The epidemiological data were collected by a standard questionnaire and blood samples were obtained from 95 incidence gastric cancer cases and 94 healthy controls. A polymerase chain reaction method was used to detect the presence or absence of the GSTT1 and GSTT1 genes in genomic DNA. Logistic regression model was employed in the data analysis. RESULTS: An increase in risk for gastric cancer was found among carriers of GSTT1 null genotype. The adjusted odds ratio (OR) was 2.63 95% Confidence Interval (95% CI) 1.17-5.88, after controlling for age, gender, cigarette smoking, alcohol drinking, and fish sauce intake. The frequency of GSTT1 null genotype in cancer cases (43.16%) was not significantly different from that in controls (50.00%). However, the risk for gastric cancer in those with GSTT1 null and GSTT1 non-null genotype was significantly higher than in those with both GSTT1 and GSTT1 non-null genotype (OR = 2.77, 95% CI 1.15-6.77). Compared with those subjects who never smoked and had normal GSTT1 genotype, ORs were 1.60 (95% CI:0.62-4.19) for never smokers with GSTT1 null type, 2.33 (95% CI 0.88-6.28) for smokers with normal GSTT1, and 8.06 (95% CI 2.83-23.67) for smokers with GSTT1 null type. CONCLUSIONS: GSTT1 gene polymorphisms may be associated with genetic susceptibility of stomach cancer and may modulate tobacco-related carcinogenesis of gastric cancer.

Risk factors for alcohol-related liver injury in the island population of China: A population-based case-control study

AIM:To investigate the association of alcohol dose, duration of drinking and obesity with abnormal alcohol-related liver injury indicators, the prevalence of alcohol-related liver injury in the island population of China.METHODS:Randomized multistage stratified cluster sampling from the island population of China was used in the population-based case-control study. Then interview, physical examination, laboratory assessments and ultrasonography were done. RESULTS:Daily alcohol intake ≥ 20 g, duration of drinking ≥ 5 years and obesity were closely related to alcohol-related liver injury (P < 0.05). The odds-ratio (OR) (95% CI) was 1.965 (1.122-3.442), 3.412 (1.789-6.507) and 1.887 (1.261-2.824), respectively. The prevalence rate of alcohol-related liver injury in ≥ 20 g daily alcohol intake group and < 20 g daily alcohol intake group was 37.14% and 12.06%, respectively. The prevalence rate of alcohol-related liver injury in ≥ 5 years drinking group and < 5 years drinking group was 34.44% and 8.53%, respectively. No significant dose-response relation was found between daily alcohol intake and abnormal alcohol-related liver injury indicators as well as between duration of drinking and abnormal alcohol-related liver injury indicators. There was no significant difference in the prevalence of alcohol-related liver injury between beer drinking group and yellow rice wine drinking group, hard liquor drinking group, multiple drinking group.CONCLUSION:The risk threshold of daily alcohol intake is 20 g and duration of drinking inducing alcohol-related liver injury 5 years in the island population of China. Liver injury induced by obesity should be concerned.

Association between PPARG genetic polymorphisms and ischemic stroke risk in a northern Chinese Han population: a case-control study

Two common polymorphisms of the peroxisome proliferator-activated receptor gamma(PPARG) gene, rs1801282 and rs3856806, may be important candidate gene loci affecting the susceptibility to ischemic stroke. This case-control study sought to identify the relationship between these two single-nucleotide polymorphisms and ischemic stroke risk in a northern Chinese Han population. A total of 910 ischemic stroke participants were recruited from the First Hospital of China Medical University, Shenyang, China as a case group, of whom 895 completed the study. The 883 healthy controls were recruited from the Health Check Center of the First Hospital of China Medical University, Shenyang, China. All participants or family members provided informed consent. The study protocol was approved by the Ethics Committee of the First Hospital of China Medical University, China on February 20, 2012(approval No. 2012-38-1). The protocol was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR-COC-17013559). Plasma genomic DNA was extracted from all participants and analyzed for rs1801282 and rs3856806 single nucleotide polymorphisms using a SNaPshot Multiplex sequencing assay. Odds ratios(ORs) and 95% confidence intervals(CIs) were calculated using unconditional logistic regression to estimate the association between ischemic stroke and a particular genotype. Results demonstrated that the G allele frequency of the PPARG gene rs1801282 locus was significantly higher in the case group than in the control group(P < 0.001). Individuals carrying the G allele had a 1.844 fold increased risk of ischemic stroke(OR = 1.844, 95% CI: 1.286–2.645, P < 0.001). Individuals carrying the rs3856806 T allele had a 1.366 fold increased risk of ischemic stroke(OR = 1.366, 95% CI: 1.077–1.733, P = 0.010). The distribution frequencies of the PPARG gene haplotypes rs1801282-rs3856806 in the control and case groups were determined. The frequency of distribution in the G-T haplotype case group was significantly higher than that in the control group. The risk of ischemic stroke increased to 2.953 times in individuals carrying the G-T haplotype(OR = 2.953, 95% CI: 2.082–4.190, P < 0.001). The rs1801282 G allele and rs3856806 T allele had a multiplicative interaction(OR = 3.404, 95% CI: 1.631–7.102, P < 0.001) and additive interaction(RERI = 41.705, 95% CI: 14.586–68.824, AP = 0.860;95% CI: 0.779–0.940;S = 8.170, 95% CI: 3.772–17.697) on ischemic stroke risk, showing a synergistic effect. Of all ischemic stroke cases, 86% were attributed to the interaction of the G allele of rs1801282 and the T allele of rs3856806. The effect of the PPARG rs1801282 G allele on ischemic stroke risk was enhanced in the presence of the rs3856806 T allele(OR = 8.001 vs. 1.844). The effect of the rs3856806 T allele on ischemic stroke risk was also enhanced in the presence of the rs1801282 G allele(OR = 2.546 vs. 1.366). Our results confirmed that the G allele of the PPARG gene rs1801282 locus and the T allele of the rs3856806 locus may be independent risk factors for ischemic stroke in the Han population of northern China, with a synergistic effect between the two alleles.

Risk factors of intrahepatic cholangiocarcinoma in patients with hepatolithiasis:a case-control study

BACKGROUND:Why 3.3% to 10% of all patients with hepatolithiasis develop intrahepatic cholangiocarcinoma (ICC) remains unknown.We carried out a hospital-based case-control study to identify risk factors for the development of ICC in patients with hepatolithiasis in China.METHODS:Eighty-seven patients with pathologically diagnosed hepatolithiasis associated with ICC and 228 with hepatolithiasis alone matched by sex,age (±2 years),hospital admittance and place of residence were interviewed during the period of 2000-2008.Odds ratios (OR) and 95% confidence intervals (CI) were calculated for each risk factor.RESULTS:Among the patients with hepatolithiasis associated with ICC,the mean age was 57.7 years and 61.0% were female Univariate analysis showed that the significant risk factors for ICC development in hepatolithiasis were smoking,family history of cancer,appendectomy during childhood (under age 20),and duration of symptoms >10 years.In multivariate stepwise logistic regression analysis,smoking (OR=1.931,95% CI:1.000-3.731),family history of cancer (OR=5.175,95% CI:1.216-22.022),and duration of symptoms >10 years (OR=2.348 95% CI:1.394-3.952) were independent factors.CONCLUSION:Smoking,family history of cancer and duration of symptoms >10 years may be risk factors for ICC in patients with hepatolithiasis.

TNF-α and IL-1RA Polymorphisms and Silicosis Susceptibility in Chinese Workers Exposed to Silica Particles:A Case-Control Study

Abstract Objective To assess the association of TNF-α and IL-1RA SNPs with the risk of silicosis in Chinese workers exposed to silica particles. Methods Case-control study design was used to enroll 68 silicotic patients induced by silica particles and 68 healthy workers matched for length of silica particle exposure as controls. Both cases and controls were from the same company in southwest China, and each of them was requested to complete a questionnaire. Blood samples were drawn for genomic DNA extraction from each participant. The genotyping of TNF-α （-238 and -308） and IL-1RA （＋2018） was performed using polymerase chain reaction-based restriction fragment length polymorphism （PCR-RFLP） and SYBR green-based quantitative polymerase chain reaction {qPCR）, respectively. Unconditional logistic regression model was used to estimate odds ratios （ORs） and their 95% confidential intervals （Cl） for SNPs. Results No significant differences were found between cases and controls in particles exposure length, body mass index （BMI）, and status of smoking and alcohol consumption except for age （P=O.O01） and blood type （P=0.042）. The frequencies of TNF-c（（-238） and IL-1RA （＋2018） genotypes in cases were significantly different from those in controls, （P=O.O01 and P=0.O02, respectively）, while a borderline significant difference was found in the frequencies of TNF-α（-308） between cases and controls （P=0.063）. The variants of three SNPs increased the risk of silicosis in the Chinese workers exposed to silica particles. The adjusted ORs of TNFα（-308）, TNF-α（-238） and IL-1RA （＋2018） were 2.8 （95% Ch 2.1-7.5）, 20.9 （95% Ch 2.8-236.4） and 4.0 （95% CI： 2.6-10.2）, respectively. Conclusion It is suggested that cytokine polymorphisms of TNF-ct （-238, -308） and IL-1RA （＋2018） are associated with the risk of silicosis in the Chinese workers exposed to silica particles. Further independent studies on the interaction between SNPs and exposure to silica particles with a larger sample size are therefore warranted.

Risk of colorectal polyps in patients with sporadic gastric polyps:A case-control study

AIM:To assess the risk of colonic polyps,adenomas and advanced neoplastic lesions(ANL) in patients with sporadic gastric polyps,especially those with fundic gland polyps(FGP).METHODS:Clinical records of patients who had performed an upper and a lower digestive endoscopy between September 2007 and August 2008 were retrospectively analyzed.A case-control study was carried out,calling patients with gastric polyps as 'cases' and patients without gastric polyps as 'controls'.The risk of colonic polyps,adenomas and ANL(villous component ≥ 25%,size ≥ 10 mm,or high grade dysplasia) was assessed [odds ratio(OR) and its corresponding 95%CI].RESULTS:Two hundred and forty seven patients were analyzed:78 with gastric polyps(cases) and 169 without gastric polyps(controls).Among the cases,the majority of gastric polyps were FGP(80%,CI:69-88) and hyperplastic(20%,CI:12-31);25% had colonic polyps(25% hyperplastic and 68% adenomas,from which 45% were ANL).Among the controls,20% had colonic polyps(31% hyperplastic and 63% adenomas,from which 41% were ANL).The patients with sporadic FGP had an OR of 1.56(CI:0.80-3.04) for colonic polyps,an OR of 1.78(CI:0.82-3.84) for colonic adenomas,and an OR of 0.80(CI:0.21-2.98) for ANL.Similar results were found in patients with gastric polyps in general.CONCLUSION:The results of this study did not show more risk of colorectal adenomas or ANL neither in patients with sporadic gastric polyps nor in those with FGP.

Barriers to colorectal cancer screening:A case-control study

AIM:To investigate barriers to colorectal cancer(CRC) screening in a community population.METHODS:We conducted a community-based case-control study in an urban Chinese population by questionnaire.Cases were selected from those completing both a fecal occult blood test(FOBT) case and colonoscopy in a CRC screening program in 2004.Control groups were matched by gender, age group and community.Control 1 included those having a positive FOBT but refusing a colonoscopy.Control 2 included those who refused both an FOBT and colonoscopy.RESULTS:The impact of occupation on willingness to attend a colorectal screening program differed by gender.P for heterogeneity was 0.009 for case vs control group 1, 0.01 for case versus control group 2, and 0.80 for control group 1 vs 2.Poor awareness of CRC and its screening program, characteristics of screening tests, and lack of time affected the screening rate.Financial support, fear of pain and bowel preparation were barriers to a colonoscopy as a screening test.Eighty-two percent of control group 1 and 87.1% of control group 2 were willing attend if the colonoscopy was free, but only 56.3% and 53.1%, respectively, if it was self-paid.Multivariate odds ratios for case vs control group 1 were 0.10 among those unwilling to attend a free colonoscopy and 0.50 among those unwilling to attend a self-paid colonoscopy.CONCLUSION:Raising the public awareness of CRC and its screening, integrating CRC screening into the health care system, and using a painless colonoscopy would increase its screening rate.

A nested case-control study of maternal-neonatal transmission of hepatitis B virus in a Chinese population

AIM:To examine the determinants of maternal-neonatal transmission of hepatitis B virus(HBV) METHODS:A nested case-control study was conducted in Changsha,Hunan,People's Republic of China from January 1,2005 to September 31,2006 To avoid potential maternal blood contamination,we collected vein blood of newborns immediately after birth and before initial hepatitis B vaccination to determine the HBV infection status of the newborn For each HBsAg-positive infant,one HBsAg-negative infant born to an HBsAg-positive mother was matched by hospital at birth(same),gender(same),and date of birth(within 1 mo) A faceto-face interview was conducted to collect clinical and epidemiological data Conditional logistic regression analysis was used to estimate the independent effects of various determinants on maternal-neonatal transmission of HBV RESULTS:A total of 141 HBsAg-positive infants and 141 individually matched HBsAg-negative infants were included in the final analysis Maternal first-degree family history of HBV infection,intrahepatic cholestasis,and premature rupture of membranes were risk factors for perinatal transmission of HBV,whereas systematic treatment and HBV immunoglobulin injections for mothers with HBV infection were protective factors for maternal-neonatal transmission of HBV,after adjustment for potential confounding factors CONCLUSION:For HBsAg-positive mothers,systematic treatment,HBV immunoglobulin administration,and controlling intrahepatic cholestasis and pregnancy complications may reduce the incidence of perinatal transmission of HBV.

Risk Factors of Low Back Pain among the Chinese Occupational Population:A Case-control Study

Objective To explore the risk factors of low back pain among the Chinese occupational population in several major industries. Methods A total of 7200 subjects （3600 cases and 3600 controls） were randomly sampled from a cross-sectional study, and they were investigated for individual and occupational factors of low back pain. The potential risk factors were first selected by using chi-square tests. Secondly, collinearity diagnosis proceeded by using the Kendall＇s rank correlation. Finally, binary logistic regression model was used for multi-factor analysis. Results Collinearity diagnosis showed that there was a severe collinearity problem among the potential risk factors of low back pain. Logistic regression model included 20 variables with statistical significance. Bending neck forward or holding neck in a forward posturefor long periods （0R=1.408） was the most important risk factor inducing low back pain in this study, followed by bending heavily with the trunk （0R=1.402）, carrying out identical work almost for the whole day （0R=1.340）. Additionally, suHicient normal break was a protective factor of low back pain. Conclusion Low back pain among the Chinese occupational population was associated with body height, occupation, work organization, physical work, working posture, and others. All these risk factors could be regarded as the indicators of low back pain, and some relevant preventive measures should be taken to reduce low back pain risk.

Risk of Active Pulmonary Tuberculosis among Patients with Coal Workers'Pneumoconiosis:A Case-control Study in China

The aim of this study was to estimate the association between occupational, environmental, behavioral risk factors, and active pulmonary tuberculosis（PTB） among coal workers＇ pneumoconiosis（CWP） patients. A matched case-control study was conducted in 86 CWP patients with active PTB and 86 CWP controls without TB. A standardized questionnaire was used for risk factors assessment. Conditioned logistic regression analysis was used to identify associations between the risk factors and active PTB among CWP patients. The results showed that the stage of CWP, poor workplace ventilation, family history of TB, and exposure to TB were independent risk factors for active PTB in patients with CWP with which recommendations for improving work environments, and for case finding activities in patients with CWP could be made.

Nested case-control study on risk factors for opportunistic infections in patients with inflammatory bowel disease

BACKGROUND When opportunistic infections occur, patients with inflammatory bowel disease(IBD) commonly display a significantly increased rate of morbidity and mortality.With increasing use of immunosuppressive agents and biological agents,opportunistic infections are becoming a hot topic in the perspective of drug safety in IBD patients. Despite the well-established role of opportunistic infections in the prognosis of IBD patients, there are few epidemiological data investigating the incidence of opportunis-tic infections in IBD patients in China. Besides, the risk factors for opportunistic infection in Chinese IBD patients remain unclear.AIM To predict the incidence of opportunistic infections related to IBD in China, and explore the risk factors for opportunistic infections.METHODS A single-center, prospective study of IBD patients was conducted. The patients were followed for up to 12 mo to calculate the incidence of infections. For each infected IBD patient, two non-infected IBD patients were selected as controls. A conditional logistic regression analysis was used to assess associations between putative risk factors and opportunistic infections, which are represented as odds ratios(OR) and 95% confidence intervals(CIs).RESULTS Seventy(28.11%) out of 249 IBD patients developed opportunistic infections.Clostridium difficile infections and respiratory syncytial virus infections were found in 24 and 16 patients, respectively. In a univariate analysis, factors such as the severity of IBD, use of an immunosuppressant or immunosuppressants, high levels of fecal calprotectin, and C-reactive protein or erythrocyte sedimentation rate were individually related to a significantly increased risk of opportunistic infection. Multivariate analysis indicated that the use of any immunosuppressant yielded an OR of 3.247(95%CI: 1.128-9.341), whereas the use of any two immunosuppressants yielded an OR of 6.457(95%CI: 1.726-24.152) for opportunistic infection. Interestingly, when immunosuppressants were used in combination with infliximab(IFX) or 5-aminosalicylic acid, a significantly increased risk of opportunistic infection was also observed. The relative risk of opportunistic infection was greatest in IBD patients with severe disease activity(OR = 9.090; 95%CI: 1.532-53.941, relative to the remission stage). However, the use of IFX alone did not increase the risk of opportunistic infection.CONCLUSION Factors such as severe IBD, elevated levels of fecal calprotectin, and the use of immunosuppressive medications, especially when used in combination, are major risk factors for opportunistic infections in IBD patients. The use of IFX alone does not increase the risk of opportunistic infection.

Environmental and Psycho-social Factors Related to Prostate Cancer Risk in the Chinese Population:a Case-control Study

Objective To study the risk environmental and psycho-social factors associated to prostate cancer （PCa） in Chinese population. Methods 250 PCa patients and 500 controls were enrolled in this case-control study. Information was collected and logistic regression analysis was used to estimate the odds ratios （OR） and 95% confidence intervals （95% CI） for relationship between lifestyle, eating habits and psycho-social factors with PCa risk. Results Green vegetables and green tea were associated with a decreased risk of PCa （0R=0.39, 95% CI： 0.28-0.53; 0R=0.59, 95% Cl： 0.40-0.87, respectively）. Family history of PCa （0R=7.16, 95% CI： 2.01-25.49）, history of prostate diseases （0R=2.28, 95% Cl： 1.53-3.41）, alcohol consumption （0R=1.97, 95% CI： 1.33-2.90）, red meat consumption （0R=1.74, 95% CI： 1.20-2.52）, barbecued （0R=2.29, 95% CI： 1.11-4.73） or fried （0R=2.35, 95% CI： 1.24-4.43） foods were related with increased PCa risk. Negative psycho-social factors including occupational setbacks （0R=1.61, 95% CI： 2.00-2.59）, marital separation （0R=1.94, 95% CI： 1.29-2.91）, self-contained suffering {0R=2.37, 95% CI： 1.58-3.55）, and high sensitivity to the personal comments （0R=1.73, 95% CI： 1.18-2.54） were related to PCa. Conclusion Regular consumption of green vegetables and green tea may suggest protective effects on PCa. Alcohol consumption, red meat consumption and barbecued or fried foods were associated with PCa. Negative psycho-social factors may also play a role in the incidence of PCa in Chinese population.

case-control方法在企业集群研究中的运用

case-control方法①是广泛运用于病因学的一种回顾性研究方法,在发病后来研究探讨可能发病的原因。在集群研究中受广泛关注的Porter的企业集群概念中,包含着企业的经济联系和地理集聚两方面的含义,那么是否企业之间广泛深入的经济联系会成为导致企业在地理上趋于集中的重要因素呢?借用case-control方法,将企业划分为有经济联系的产业群和没有经济联系的产业群,综合企业间购入——售出关系信息来检验有经济联系的企业是否趋于空间上的集聚。