Endoscopic or laparoscopic resection for small gastrointestinal stromal tumors: a cumulative meta-analysis / 中华医学杂志(英文版)

BACKGROUND@#Despite the recent large number of studies comparing endoscopic and laparoscopic resection for small gastrointestinal stromal tumors (GISTs) (diameter ≤ 5 cm), the results remain conflicting. The objective of this work was to perform a cumulative meta-analysis to assess the advantages and disadvantages of endoscopic resection vs. laparoscopic resection.@*METHODS@#The meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched medical databases up to January 2020. Meta-analytical random or fixed effects models were used in pooled analyses. Meta-regression, cumulative meta-analyses, and subgroup analyses were performed to improve the accuracy of the conclusion. Sensitivity analyses were applied to assess the robustness of the results.@*RESULTS@#A total of 12 cohort studies with 1383 participants comparing endoscopic resection and laparoscopic resection were identified, while three cohort studies with 167 participants comparing endoscopic resection and laparoscopic and endoscopic cooperative surgery were found. We found that endoscopic resection had shorter operation times (weighted mean difference [WMD] = -27.1 min, 95% confidence interval [CI]: -40.8 min to -13.4 min) and lengths of hospital stay (WMD = -1.43 d, 95% CI: -2.31 d to -0.56 d) than did laparoscopic resection. The results were stable and reliable. There were no significant differences in terms of blood loss, hospitalization costs, incidence of complications or recurrence rates. For tumor sizes 2 - 5 cm, endoscopic resection increased the risk of positive margins (relative risk [RR] = 5.78, 95% CI: 1.31 - 25.46). Although operation times for endoscopic resection were shorter than those of laparoscopic and endoscopic cooperative surgery (WMD = -41.03 min, 95% CI: -59.53 min to -22.54 min), there was a higher incidence of complications (RR = 4.03, 95% CI: 1.57 - 10.34).@*CONCLUSIONS@#In general, endoscopic resection is an alternative method for gastric GISTs ≤ 5 cm. Laparoscopic and endoscopic cooperative surgery may work well in combination. Further randomized controlled trials are recommended to validate or update these results.

Effects of boiling duration in processing of White Paeony Root on its overall quality evaluated by ultra-high performance liquid chromatography quadrupole/time-of-flight mass spectrometry based metabolomics analysis and high performance liquid chromatography quantification / 中国天然药物

Boiling processing is commonly used in post-harvest handling of White Paeony Root (WPR), in order to whiten the herbal materials and preserve the bright color, since such WPR is empirically considered to possess a higher quality. The present study was designed to investigate whether and how the boiling processing affects overall quality of WPR. First, an ultra-high performance liquid chromatography quadrupole/time-of-flight mass spectrometry-based metabolomics approach coupled with multivariate statistical analysis was developed to compare the holistic quality of boiled and un-boiled WPR samples. Second, ten major components in WPR samples boiled for different durations were quantitatively determined using high performance liquid chromatography to further explore the effects of boiling time on the holistic quality of WPR, meanwhile the appearance of the processed herbal materials was observed. The results suggested that the boiling processing conspicuously affected the holistic quality of WPR by simultaneously and inconsistently altering the chemical compositions and that short-time boiling processing between 2 and 10 min could both make the WPR bright-colored and improve the contents of major bioactive components, which were not achieved either without boiling or with prolonged boiling. In conclusion, short-term boiling (2-10 min) is recommended for post-harvest handling of WPR.

UPLC/ESI-QTOF-MS-based metabolomics survey on the toxicity of triptolide and detoxication of licorice / 中国天然药物

Triptolide (TP) from Tripterygium wilfordii has been demonstrated to possess anti-inflammatory, immunosuppressive, and anticancer activities. TP is specially used for the treatment of awkward rheumatoid arthritis, but its clinical application is confined by intense side effects. It is reported that licorice can obviously reduce the toxicity of TP, but the detailed mechanisms involved have not been comprehensively investigated. The current study aimed to explore metabolomics characteristics of the toxic reaction induced by TP and the intervention effect of licorice water extraction (LWE) against such toxicity. Obtained urine samples from control, TP and TP + LWE treated rats were analyzed by UPLC/ESI-QTOF-MS. The metabolic profiles of the control and the TP group were well differentiated by the principal component analysis and orthogonal partial least squares-discriminant analysis. The toxicity of TP was demonstrated to be evolving along with the exposure time of TP. Eight potential biomarkers related to TP toxicity were successfully identified in urine samples. Furthermore, LWE treatment could attenuate the change in six of the eight identified biomarkers. Functional pathway analysis revealed that the alterations in these metabolites were associated with tryptophan, pantothenic acid, and porphyrin metabolism. Therefore, it was concluded that LWE demonstrated interventional effects on TP toxicity through regulation of tryptophan, pantothenic acid, and porphyrin metabolism pathways, which provided novel insights into the possible mechanisms of TP toxicity as well as the potential therapeutic effects of LWE against such toxicity.

Sulfur-containing derivatives as characteristic chemical markers in control of sulfur-fumigated Moutan Cortex / 药学学报

The amount of sulfur dioxide residue is currently employed by Chinese Pharmacopoeia (CP) as an index to screen sulfur-fumigated herbs, but it is unclear if this index can objectively reflect the quality of sulfur-fumigated herbs. In the present study, sulfur-containing derivatives were confirmed in sulfur-fumigated Moutan Cortex (MC) by UPLC-QTOF-MS/MS analysis, and the contents of sulfur-containing derivatives and sulfur dioxide residues were statistically analyzed both in self-made and commercially available sulfur-fumigated and non-fumigated MC as well as the samples thereof before and after eight-month storage. The amount of sulfur dioxide was significantly decreased, but that of the newly-generated sulfur-containing markers was not, after eight-month storage of the sulfur-fumigated MC samples, indicating that the amount of sulfur dioxide residue may not be positively correlated with the quality of sulfur-fumigated MC. Therefore, sulfur dioxide residue index alone may not objectively reflect the sulfur-fumigation extent (quality change extent) of MC, more specific method using characteristic sulfur-containing derivatives as chemical markers should be developed to supplement the sulfur dioxide residue determination in the quality control of sulfur-fumigated MC.

A time series analysis on under 5 mortality rate in Zhejiang Province / 预防医学

Objective To study the temporal distribution regular pattern of under 5 mortality rate(U5MR)from 1 998 to 201 4 in Zhejiang Province,and to predict the under 5 mortality rate in 201 5.Methods A time series ARIMA (p,d,q) forecasting model for U5MR was conducted using IBM SPSS Statistics 20.0 statistical analysis software.Results The UMAR showed downward trend.The ARIMA(2,1 ,2)model of U5MR from 1 998 to 201 4 in Zhejiang Province is yt =-0.696 +0.636yt -1 +0.024yt -2 +0.340yt -3 +αt -0.003αt -1 +0.997αt -2 ,and the model fitting was good.Each of the actual mortality was consistent with the trend of model prediction,and was within the 95% confidence interval.The predicted value of U5MR was 4.08‰ (95% CI:1 .52‰ -6.64‰)in 201 5.Conclusion Time series analysis is an effective way to analyze the temporal distribution regular pattern of U5MR,which could be used for short -term prediction.

An investigation on status of health literacy and its influencing factors among residents in Qiandao Lake town / 预防医学

Objective To understand the status of health literacy of residents in Qiandao Lake town in order to complete the surveillance system.Methods A total of 484 residents aged 15 to 69 years old from 9 communities were selected using cluster random sampling method.Then the household interview was conducted.Results The overall level of health literacy of residents was 26.03%.As for the 4 health literacy related aspects including basic health knowledge,health lifestyle and behaviors,health related skill and health beliefs,the rates were 32.54% ,4.77% ,60.30% and 92.62%,respectively. The multivariate logistic regression analysis showed that the level of health literacy of residents was related to age and education.Conclusion The health education in Qiandao Lake town has got some achievements.

Reliability of sulfur dioxide determination method documented in Chinese pharmacopoeia for evaluating Paeoniae Radix Alba / 中国中药杂志

The content of SO2 in Paeoniae Radix Alba (RPA) was determined by the method documented in Chinese Pharmacopoeia (CP) 2010 edition to validate the repeatability of the method for evaluating RPA, and the contents of paeoniflorin sulfonate in both the residual material and distilled solution of RPA were determined by HPLC to study the transformation of paeoniflorin sulfonate to SO2 by HCl. It was found that the repeatability of the method in CP for evaluating RPA is unacceptable, and paeoniflorin sulfonate was detectable in both the residual material and distilled solution of RPA even at "the end point" of SO2 determination, merely about 50% of paeoniflorin sulfonate was transformed to SO2 by HCl, indicating that the current SO2 determination method in CP is not able to accurately quantify SO2 in RPA. It is recommended that more special method for determining SO2 content in RPA should be developed regarding the chemical characteristics of sulfur-fumigated RPA.

Association between air particulate matter and stroke attack or mortality: a Meta-analysis / 中华流行病学杂志

Objective To analyze the associations between particulate air pollution (PM10,PM25) and stroke daily attack or mortality. Methods Meta-analysis method was used to polysynthetically analyze 16 quantitative studies about the associations between particulate air pollution and stroke daily attack or mortality. The relative odds ratio(OR) of stroke attack or mortality associated with per 10 μg/m3 increase of particulate matter concentration was used as effective value,taking a sensitivity analysis for the results. Results A 10 μg/m3 increase in PM10was associated with a 1.09% (95%CI: 0.10%-2.08% ) increase in stroke daily attack (OR=1.011,95%CI: 1.001-1.021)and 0.70% (95%CI: 0.60%-0.80% ) increase in stroke daily mortality (OR= 1.007, 95%CI: 1.006-1.008). The results of sensitivity analysis supported above results. As for PM2.5 OR appeared to be 1.001 (95%CI: 0.992-1.010) with a 10 μg/m3 increase in stroke daily attack and 1.052 (95%CI:0.958-1.154) for daily mortality. Conclusion There are positive associations between PM10 and stroke daily attack and mortality, increase of PM25 was not associated with stroke attack and mortality.

A case-crossover study on the relationship between air pollution and acute onset of cerebral hemorrhage in Hangzhou city / 中华流行病学杂志

Objective To explore the relationship bet-ween air pollution and acute onset of cerebral hemorrhage in Hangzhou.Methods Time-stratified case-crossover study was used to analyze the effect of aerosol optical depth(AOD),PM10,SO2 and NO2 on the acute onset of cerebral hemorrhage.Conditional logistic regression was used to estimate the odds ratios(Ors) and their 95% confidence intervals(Cis) in relation to an increase of one unit of AOD and 10 μg/m3 of air pollutants.Results After adjusted temperature and relative humidity,the Ors of acute onset of cerebral hemorrhage by a unit increase in AOD at a 2 day-lag were 1.727(95%CI:1.103-2.703)in first half year and 2.412 (95%CI:1.230-4.733) at a 2 day-lag in spring.For a 10 μg/m3 increase in SO2,the Ors were 1.119(95% CI:1.019-1.229),1.230(95%CI:1.092-1.386),1.254(95%CI:1.076-1.460) in the whole year(2 day-lag),in first half year(2 day-lag) and in spring(2 day-lag),respectively.NO2 exposure in first half year(2 day-lag) was associated with cerebral hemorrhage,with OR as 0.841(95% CI:0.734-0.964).However,there were no statistical significances for AOD,SO2,NO2 in the rest time-periods(P>0.05).Additionally,no association was found between PM10 and the acute onset of cerebral hemorrhage in any time-periods(P>0.05).Conclusion Our data showed that there was association between air pollution and the acute onset of cerebral hemorrhage,especially in spring and in the first half of the year.

Bayesian statistics in spatial epidemiology / 浙江大学学报·医学版

Through the multi-stage hierarchical Bayesian model and Markov Chain Monte Carlo methods, Bayesian statistics can be used in dependent spatial data analysis, including disease mapping in small areas, disease clustering, and geographical correlation studies. Recently, Bayesian spatial models have been developed with many types, which have made considerable progress in data analysis. This paper introduces several approaches that have been fully developed and applied, such as BYM model,joint model, semi-parameter model, moving average model and so on. Recently,many studies focused on the comparison work through Deviance Information criterion. Those results show that BYM model and MIX model of semi-parameter model could obtain better results. As more research going on, Bayesian statistics will have more space in applications of spatial epidemiology.

Cohort studies on cancer mortality of digestive system among workers exposed to asbestos: a meta-analysis / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To determine if there are excessive risks of malignant tumors or not among workers exposed to asbestos by applying a meta-analysis technique.</p><p><b>METHODS</b>All data meeting the criteria of cohort studies on cancer mortality of digestive system among workers exposed to asbestos would be incorporated into the meta-analysis. The pooled standardized mortality ratios (SMR) and their corresponding 95% confidence intervals (CIs) for main cancer sites of digestive system were calculated by using two approaches of un-weighted ratio and random effects model. The heterogeneity and its sources of the results were examined with a Q-statistic and Z-score test.</p><p><b>RESULTS</b>69 asbestos-exposed cohorts were summarized. The significantly elevated meta-SMR for all deaths (1.16), all cancers (1.42), cancer of digestive system (1.15) and cancer of stomach (1.20) among workers exposed to chrysotile alone or mixed asbestos were observed (P < 0.01). The stomach cancer SMR was significantly increased in the asbestos cement workers, the screening mine workers and the insulators, (1.27, 1.21 and 2.13 respectively) (P < 0.05). meta-SMR for cancers at other sites of digestive system including esophagus, colon, rectum and liver were not significant.</p><p><b>CONCLUSION</b>There are likely excessive risks of cancer of stomach among workers exposed to asbestos. However, there is likely no convincing indication of an etiological association between asbestos exposure and cancers at other sites of digestive system.</p>

Scan statistic theory and its application in spatial epidemiology / 中华流行病学杂志

To introduce the basic concept of scan statistic, its computation method and application in the area of spatial epidemiology. Retrospective space-time permutation statistics for evaluating the clustering of disease monitoring program is illustrated, using data on recent acute onset of cardiovascular disease in Hangzhou, China. Calculations were performed with SaTScan Version 7.0.3. With 999 Monte Carlo replications, the program took 5 seconds to run on a 100-MHz Pentium PC. The geographical surveillance program on acute onset clusters of cardiovascular disease, data which showed statistical significance, would include: a) from January 1, 1997 to February 28, 2007 in Qiantan township, Jiande county (P = 0.001); b) highly significant between January 1, 1997 and February 28, 1999 for Lushan street, Lingqiao township in Fuyang county (P = 0.003); c) between March 1, 2001 and February 29, 2004 for Dayuan town, Xinyi town, Shouxiang town in Fuyang (P = 0.004); d) between March 1, 2004 and Feb 28, 2006 for Chengzhan street, Ziyang street, Hubin street, Qinbo street, Xiaoying street, Wangjiang street, Chaoming street, Changqing street, Wulin street, Tianshui street, Wenhui street and Shiqiao street in Hangzhou (P = 0.005), respectively. The retrospective space-time permutation statistics seems useful as a screening tool for identifying the cluster of disease. Scan statistics are practical and effective method for deciding which cluster alarms would merit further investigation and which clusters are probably chance occurrences in the study of spatial epidemiology.

A case-crossover study on air pollutants and the mortality of stroke / 中华流行病学杂志

Objective To investigate the short-term effect of particulate matter in air on the mortality of stroke. Methods Using time-stratified case-crossover study design,an association was examined between stroke mortality and particulate matter with aerodynamic diameter of ＜10μm(PM10) of 2002- 2004 in Hangzhou city.Meanwhile,the acute health effect of other gaseous pollutants (sulfur dioxide,SO2 and nitrogen dioxide,NO2) was also analyzed.Results A total of 9906 deaths of stroke were included.The crude stroke mortality was 83.54 per 100 000.After being adjusted for meteorological factors,when an increase of 10 μg/m3 in PM10,SO2 and NO2 in three days was noticed,it appeared that the increases of mortality of stroke were 0.56%(95%CI:0.14%-0.99%),1.62%(95%CI:0.26%-3.01%) and 2.07%( 95%CI:0.54%-3.62%) respectively.There was no distinct association in multipollutant models.In sensitivity analysis,the associations were found in all single-pollutant models but not statistically significant in multi-pollutant models after replacing the missing values.Conclusion It is suggested that the short-term elevation in PM10 as well as SO2 and NO2 daily concentrations were related to the increase of stroke mortality in Hangzhou city.

Association between social psychological factors and depressive symptoms among healthcare workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the association between the effort-reward imbalance at work and depressive symptoms among healthcare workers.</p><p><b>METHODS</b>The effort-reward imbalance at work was conceptualized in terms of the Chinese version of the effort-reward imbalance (ERI) model. Depressive symptoms were assessed by the Chinese version of the Center of Epidemiology Survey Depression (CES-D) scale. The data came from the cross-sectional survey of 1 179 healthcare workers aged between 18 and 73 employed in 6 affiliated hospitals of Zhejiang University. The questionnaire comprised questions on the effort-reward at work, over-commitment, the full CES-D scale of depression and a range of other characteristics. Univariate analyses were used with Spearman's correlation, Mann-Whitney test, Pearson chi(2) test and likelihood chi(2) test. Multivariate logistic regression analyses was used to discover factors associated with depressive symptoms.</p><p><b>RESULTS</b>The prevalence of depressive symptoms among healthcare workers was 48.12% (95% CI: 45.08% to 51.16%). The prevalence of depressive symptoms among nurses was 52.40% (95% CI: 47.87% to 56.93%) higher than doctors' 44.70% (95% CI: 10.64% to 48.77%) with the significant difference (chi(2) = 6.077, P = 0.014). Positive associations were found between the high effort-low reward, level of work-related over commitment and depressive symptoms (OR = 1.859, 95% CI: 1.337 to 2.585; OR = 2.207, 95% CI: 1.656 to 2.942) among healthcare workers, respectively.</p><p><b>CONCLUSION</b>The high effort-low reward and the work-related over-commitment have a negative impact on healthcare workers' health.</p>

Comment on "the reliability and validity of the effort-reward imbalance - the Chinese version" / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate reliability and validity of the effort-reward imbalance (ERI) in the Chinese version.</p><p><b>METHODS</b>A cross-sectional survey was conducted comprising a large sample of 4782 subjects in China, using ERI in the Chinese version. This scale contained 23 scaled items while the questionnaire including questions on the effort and reward at work, over-commitment, the full CES-D scale of depression and a range of other characteristics. Reliability analysis was applied to evaluate reliability of the ERI scale in the Chinese version and factor analysis was applied to analyze validity of the scale.</p><p><b>RESULTS</b>Theoretical hypothesis on the ERI model was supported by the data derived in this study. Reliability and validity of the effort sub-scale, the reward sub-scale of the ERI scale in the Chinese version seemed to be better, but reliability and validity of the over-commitment sub-scale were not perfect.</p><p><b>CONCLUSION</b>The results of the study showed that the effort sub-scale, the reward sub-scale of the ERI in the Chinese version was applicable to the Chinese population but the scaled items of the over-commitment sub-scale should be further modified.</p>

A connection number-based principal factor analysis forecast method to forecast the encephalitis B epidemics / 中华流行病学杂志

<p><b>OBJECTIVE</b>To detect the relations between incidence rate of the epidemical encephalitis B and related factors, to provide a simple, valid and practical new method for forecasting encephalitis B eipdemics.</p><p><b>METHODS</b>Connection number between the incidence rate of encephalitis B and the historical forecast factors was computed, before ranking the first, second and the third principal factor, to remove the factor with the smallest value in the light of the connection number before comparing the newest value of forecast factors with the same kind of history while the most nearly value becoming the forecasting factor value and to establish a forecasting equation according to the factor value and the consistent degree of the incidence rate of encephalitis B at that time. Finally, to put into the new factor value to get this forecast value under this equation. Assuming that there are n' (n' >or= 2) forecast factors, this time forecast value can then be directly obtained from the average of these estimate values.</p><p><b>RESULTS</b>Using above forecast method to forecast the incidence rate of encephalitis B at certain place and year, the predicting value is very much close to the actual incidence rate. Difference between the predicting value forecasted by the above-mentioned method and the actual incidence rate is only 0.0264/100 000 with an accurate rate of 97.94%.</p><p><b>CONCLUSION</b>This principal factor analysis forecast method based on connection number in forecasting the incidence rate of encephalitis B prevention is acceptable.</p>

Cohort studies on cancer mortality among workers exposed only to chrysotile asbestos: a meta-analysis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine whether there was excessive risk of cancer among workers exposed to chrysotile fiber alone by applying a meta-analysis technique.</p><p><b>METHODS</b>All data meeting the criteria of cohort studies on cancer mortality among workers exposed only to chrysotile were incorporated into meta-analysis. Pooled standardized mortality ratios (SMRs) and their corresponding 95% confidence intervals (CIs) for main cancer sites were calculated using two approaches of unweighted ratio and random effect model. The heterogeneity and its sources of the results were examined with a Q-statistic and Z-score test. The dose-response effect as reflected in the percentage of all deaths due to mesothelioma served as a proxy measure of chrysotile exposure.</p><p><b>RESULTS</b>A cohort of twenty six workers exposed to chrysotile alone was summarized. The significantly elevated meta-SMRs for all deaths (1.27), all cancers (1.28), cancers of respiratory organs (2.51), cancers of lung (2.35) and cancers of stomach (1.24) were observed. The significantly elevated meta-SMRs for lung cancer within occupational strata were observed among textile workers (3.55), asbestos product manufacturers (3.30), miners and millers (2.24), cement product workers (1.22), and for stomach cancer among asbestos product manufacturers (1.49). Meta-SMRs for cancers at other sites were not significant. Meta-SMR for lung cancer showed an increasing trend with an elevated percentage of all deaths from mesothelioma, but no such trend for stomach cancer.</p><p><b>CONCLUSION</b>There are excessive risks of lung cancer and mesothelioma among workers exposed to chrysotile fiber alone, and likely no convincing indication of an etiological association between chrysotile exposure and cancers at other sites.</p>

A meta-analysis of cohort studies on cancer mortality among workers exposure to chrysotile fiber alone / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine there was excessive risk of malignant tumors or not among workers exposure to chrysotile fiber alone by applying a meta-analysis technique.</p><p><b>METHODS</b>All data meeting the criteria of cohort studies on cancer mortality among workers exposed only to chrysotile would incorporate into the meta-analysis. The pooled standardized mortality ratios (SMR) and their corresponding 95% confidence intervals (95% CI) for main cancer sites were calculated using two approaches of unweighted ratio and random effects model. The heterogeneity and its sources of the results were examined with a Q-statistic and Z-score test.</p><p><b>RESULTS</b>26 chrysotile-exposed alone cohorts were summarized. The significantly elevated meta-SMRs for all deaths (1.28), all cancers (1.26), cancers of respiratory organs (2.24), cancer of lung (2.29) and cancer of stomach (1.27) were observed. The significantly elevated meta-SMRs for lung cancer within occupational strata were observed among textile workers (3.64), asbestos products manufacturers (3.07), miners and millers (2.24), cement products workers (1.22), and for stomach cancer among asbestos products manufacturers (1.48). Meta-SMRs for cancers at other sites were not significant.</p><p><b>CONCLUSION</b>There were excessive risks of lung cancer and mesothelioma among workers exposure to chrysotile fiber alone, and likely no convincing indication of an etiological association between chrysotile exposure and cancers at other sites.</p>

The morbidity of chronic diabetic complication with logistic regression analysis of related potential risk factors / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the morbidity and potential risk factors of chronic diabetic complication in Zhejiang province.</p><p><b>METHODS</b>In the paper the morbidity of diabetic chronic complication was illustrated, using descriptive statistics. The potential risk factors of diabetic chronic complication were studied with logistic regression modeling, using data from a large retrospective study involving 1083 patients from two hospitals in Zhejiang province.</p><p><b>RESULTS</b>Principal chronic diabetic complications were found to be cardiovascular diseases, ophthalmic diseases, nephropathy, esthetic diseases, plant nerve diseases, cerebral blood vessel diseases, limbsblood vessel diseases and athletic nerve diseases. The principal potential risk factors would include the courses of diabetes and hypertension, age, age being diagnosed, blood pressure, baseline blood glucose, two hour blood glucose after dietary, HBAIC, nitroglycerine, cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol.</p><p><b>CONCLUSION</b>The analytic method used in the paper was fit for the study of morbidity and potential risk factors of other chronic diseases complication and the discriminant function could be built for clinical diagnosis.</p>

Quantitative study by grey system on the latent period of lung cancer induced by air pollutants / 中华流行病学杂志

<p><b>OBJECTIVE</b>To calculate the latent period of lung cancer induced by air pollution.</p><p><b>METHODS</b>The degree of grey incidence (DGI) between the concentrations of TSP or SO(2) and the mortality of lung cancer were assessed through a grey system model. According to the maximum values of DGI, the total latent period of lung cancer was calculated. Data was collected in H city.</p><p><b>RESULTS</b>The maximum DGI value of TSP was 0.886 while the relationship between the comparison sequence from 1985 to 1989 and the reference sequence from 1994 to 1998 was greatly correlated. The maximum DGI value of SO(2) was 0.919 while the relationship between the comparison sequence from 1986 to 1990 and the reference sequence from 1994 to 1998 was most correlated.</p><p><b>CONCLUSIONS</b>The latent periods of lung cancer induced by TSP and SO(2) were 7 and 8 years respectively in H city. The model of grey system was less affected by the confounding factors, and the calculation process was relatively simple. A feasible and useful new way was provided by the model of grey system for quantitative analysis of the latent period of lung cancer induced by air pollutants.</p>