The results of clinical studies are usually described with statistical data. When we conduct systematic reviews of clinical studies it is important that the statistical methods used in the original research are evaluated. By doing so, we can assess the validity and reliability of the evidence.
Objective To evaluate the right usage of statistical methods in medical articles. Methods 544 theses from eight medical journalspublished during1998 and 2005 were analyzed. Results 136 theses had obvious statistical errors,accounting for 25.00%. The main types of the errors were: the wrong methods of data analyzing for 61.76%, diagram error for 14.71%, nonstatistical dealing for8.82%, the mixture of rate and ratio for 8.82%, and the other error for 5.88%. Conclusion The statistical methods should be highly valued. Despite handing themanuscript to the specialist in the same field, the statistician checking system should be built through the process of manuscript dealing.
ObjectiveTo investigate the relation between histology type and prognosis of gastric cancer.MethodsThe clinical database of 311 patients who underwent surgical resection for gastric cancer in our hospital, between 2000 and 2004, was retrospectively reviewed and analyzed with SPSS 13.0. ResultsLymph node metastasis, tumor invasion depth, and Borrman type of gastric cancer were related with histology type （χ2 test, Plt;0.05）. KaplanMeier survival analysis was used to compare the survival rate and showed that there was a significant difference between highly/moderately differentiated cancers and the poorly differentiated (Plt;0.05), while there was no statistical difference between those patients with same invasion depth （Pgt;0.05）. ConclusionThe prognosis of gastric cancers with same invasion depth is same regardless of their histology types.
Objective To analyze the status of applying diagnostic test in imaging scientific study internationally and domestically, and to compare the application of the image diagnostic studies of our country with that of abroad. Method We hand-searched the diagnosis tests published in the "Chinese Journal of Radiology", the most influential in China, and in "Radiology’’, the most influential abroad, from 1998 to 1999 respectively. Then we evaluated each of the diagnosis tests according to the international standards. Results We searched 408 original articles in "Chinese Journal of Radiology" in which the diagnostic test articles were 12%, and 796 original articles in "Radiology" with the diagnostic test articles 23% from 1998 to 1999 respectively. In these diagnosis tests, by comparing the "Chinese journal of radiology" with the "Radiology", it was found that 19% applied blind comparison with Gold Standard, 28% calculated sensitivity, specificity and accuracy, 9% both calculated negative predictive value and positive predictive value and none calculated likelihood ratios in the former versus 64%, 57%, 33% and 26% and 3% respectivdy in the latter. Conclusions Compared with the international level, both the quality and the quantity of the diagnosis tests applied in the specialty of imaging scientific study in China are much lower and far from meeting the clinical requirement. Improving the methods of scientific study and carrying on more diagnosis tests with high qualities are of important significance in improving the diagnostic level of imaging.
Some risks affecting the quality of published systematic reviews and in our teaching practice were listed and compared with the correct concept. The current problems include misunderstanding of the relationship of meta-analysis and systematic review, applying meta-analysis and assessing heterogeneity, randomization, allocate concealment, and how to make inclusion and exclusion criteria, etc. This paper aims to help Chinese reviewers improve the quality of their systematic reviews.
Objective To evaluate the quality of clinical studies on dentistry from the Chinese Journals. Methods Clinical studies in Chinese Journal of Conservative Dentistry of 2002 were searched. The quality of the clinical studies on assessment of treatments’ efficacy was evaluated. Results Among 204 related studies from 12 issues, there were 93 (45.58%) restrospective intervention studies, 6 randomized controlled blinded trials (2.94%), 42 randomized trials without blindness (20.58%), 20 controlled trials without randomization (9.80%) and 25 clinical observational studies (12.25%). The statistical analysis showed that 20 studies were with inappropriate methods. Conclusions It is necessary to improve the design and statistical analysis of clinical studies on stomatology in China to produce high-quality research evidence.
Objective To investigate how many hospitals can perform vitrectomy and its relationship to economic development in China.Methods Bibliometric data of retina-vitreous literatures were searched from the China National Knowledge Infrastructure (CNKI) academic databases. We used pars plana vitrectomy (PPV) as a keyword and defined address as mainland China, limited years to 1993 -2009. From those data we analyzed which hospital performed PPV. We also communicated with some hospitals by phone, email to confirm if they were performing PPV. Gross domestic product (GDP), population data and economic development ranking were extracted from the China Statistical Yearbook 2009 (National Bureau of Statistics of China). PPV carry-out rate, PPV-hospital shares and their relationships with the GDP in each regional municipality were analyzed.Results All together this study retrieved 4632 articles meet our requirements. There were 340 hospitals carrying out PPV in mainland China, located in 22 provinces, five autonomous regions and four metropolitan municipalities. The top five provinces with higher PPV carryout rate were Shandong (93,75%), Zhejiang (90,00%), Hebei province (90.00%), Jiangsu (83.33%) and Guangdong (75.00%). There was significant difference in per capita share of PPVhospitals between different cities (chi;2=181,153，P=0,000) and in the PPV carry-out rate between different cities (chi;2=749.217，P=0.000). There were 210 private eye hospitals in China,62 hospitals (18.23%) of them could perform PPV included 39 hospitals located in regionallevel cities. The coefficient correlation between PPV and GDP of different provinces was 0.842 (P=0.000). Conclusions Vitrectomy is widely performed in mainland China, but geographical distribution of PPV-performing hospitals is uneven. PPV performance is closely related with regional economic development,and private hospitals play certain roles in promoting the application of vitrectomy.
Objective To clarify the most important factors affecting the survival of patient with gastric carcinoma. Methods 428 cases of resected gastric carcinoma were studied by using univariate analyses and multivariate regression analyses. Results The most significant factors influencing survival of these patients were peritoneal dissemination, Borrmann classification, type of operation, hepatic metastasis, size of tumor, location, lymph node metastasis and age. Conclusion The factors influencing survival in patient with gastric carcinoma after resection can be correctly analyzed by cox’s proportional hazard model.