ABSTRACT
This study examined whether exposure to nitrate in drinking water is associated with increased risk for bladder cancer by conducting a comprehensive literature research. A meta-analysis was performed with and without adjustment for confounding factors. Three groups (reference, intermediate and high groups) were established in terms of different nitrate concentrations in each included study. Separate relative risk measures were calculated for intermediate and high groups. Heterogeneity was assessed by using the Q statistics. Publication bias was evaluated by Egger's and Begg's test. Quality assessment for studies was performed by using the Newcastle-Ottawa scale. Two cohorts, two case-controls, and one ecological study were included in this study. The adjusted data showed that the combined risk ratios (RRs) were 1.13 (95% CI: 0.81 to 1.57) and 1.27 (95% CI: 0.75 to 2.15) for intermediate and high groups respectively. For unadjusted data, the corresponding RRs were 1.18 (95% CI: 0.89 to 1.57) and 1.29 (95% CI: 0.81 to 2.07). Sensitivity test indicated that results were significantly underestimated when Ward's study was included. No significant publication bias was found. There was heterogeneity among studies. The results suggested that there was no sufficient evidence that nitrate in drinking water is associated with increased risks for bladder cancer.
Subject(s)
Humans , Drinking Water , Nitrates , Risk Factors , Urinary Bladder NeoplasmsABSTRACT
This study examined whether exposure to nitrate in drinking water is associated with increased risk for bladder cancer by conducting a comprehensive literature research. A meta-analysis was performed with and without adjustment for confounding factors. Three groups (reference, intermediate and high groups) were established in terms of different nitrate concentrations in each included study. Separate relative risk measures were calculated for intermediate and high groups. Heterogeneity was assessed by using the Q statistics. Publication bias was evaluated by Egger's and Begg's test. Quality assessment for studies was performed by using the Newcastle-Ottawa scale. Two cohorts, two case-controls, and one ecological study were included in this study. The adjusted data showed that the combined risk ratios (RRs) were 1.13 (95% CI: 0.81 to 1.57) and 1.27 (95% CI: 0.75 to 2.15) for intermediate and high groups respectively. For unadjusted data, the corresponding RRs were 1.18 (95% CI: 0.89 to 1.57) and 1.29 (95% CI: 0.81 to 2.07). Sensitivity test indicated that results were significantly underestimated when Ward's study was included. No significant publication bias was found. There was heterogeneity among studies. The results suggested that there was no sufficient evidence that nitrate in drinking water is associated with increased risks for bladder cancer.
ABSTRACT
ObjectiveTo assess the quality of applications for the state funds for natural sciences and the research capabilities of researchers in medicine and other relevant fields in China so as to provide the State Fund Committee for Natural Sciences with scientific basis for systematically planning research funds for the medical field and improving the system of supervising funds for life sciences. MethodsAnalysis was conducted on project applications that were submitted to the Life Sciences Department from 1984 through 2001 and underwent quantitative peer review to explore trends of changes in project applications, the scores and the rate of fund-winning projects. ResultsBoth the quantity and quality of project applications in medicine and other relevant fields showed the trend of going up year by year whereas the rate of fund-winning projects presented an opposite trend. ConclusionThe State Fund Committee for Natural Sciences ought to broaden the scope of subsidization for medicine and other relevant fields and readjust existing funds for life sciences so as to shunt and alleviate the application pressure in medicine and other relevant fields.