Introduction on 'assessing the risk of bias of individual studies' in systematic review of health-care intervention programs revised by the Agency for Healthcare Research and Quality / 中华流行病学杂志

This paper summarizes the Risk of Bias of Individual Studies in Systematic Reviews of Health Care Interventions revised by the Agency for Healthcare Research and Quality (AHRQ) and introduces how to use Revman software make risk of bias graph or risk of bias summary. AHRQ tool can be used to evaluate following study designs: RCTs, cohort study, case-control study (including nested case-control), case series study and cross-sectional study. The tool evaluates the risk of bias of individual studies from selection bias, performance bias, attrition bias, detection bias and reporting bias. Each of the bias domains contains different items, and each item is available for the assessment of one or more study designs. It is worth noting that the appropriate items should be selected for evaluation different study designs instead of using all items to directly assess the risk of bias. AHRQ tool can be used to evaluate risk of bias individual studies when systematic reviews of health care interventions is including different study designs. Moreover, the tool items are relatively easy to understand and the assessment process is not complicated. AHRQ recommends the use of high, medium and low risk classification methods to assess the overall risk of bias of individual studies. However, AHRQ gives no recommendations on how to determine the overall bias grade. It is expected that future research will give corresponding recommendations.

Series of risk of bias assessment (5): Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) / 中华流行病学杂志

This paper summaries the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I), a tool for evaluating risk of bias about Non-randomized Studies-of Interventions (NRSI), and introduces the application of ROBINS-I in a published NRSI. According to the characteristics of NRSI, evaluation field and signaling question were designed in ROBINS-I to provide essential information about risk of bias for NRSI included in systematic reviews. ROBINS-I is the tool in assessment of risk of bias in observational studies and quasi-randomised studies. Although the tool has been used in practice to some extent, but it still needs further improvement. Attention should be paid to its update and progress.

Risk on bias assessment: (6) A Revised Tool for the Quality Assessment on Diagnostic Accuracy Studies (QUADAS-2) / 中华流行病学杂志

This paper introduced the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2), including the development and comparison with the original QUADAS, and illustrated the application of QUADAS-2 in a published paper related to the study on diagnostic accuracy which was included in systematic review and Meta-analysis. QUADAS-2 presented considerable improvement over the original tool. Confused items that included in QUADAS had disappeared and the quality assessment of the original study replaced by the rating of risk on bias and applicability. This was implemented through the description on the four main domains with minimal overlapping and answering the signal questions in each domain. The risk of bias and applicability with 'high','low' or 'unclear' was in line with the risk of bias assessment of intervention studies in Cochrane, so to replace the total score of quality assessment in QUADAS. Meanwhile, QUADAS-2 was also applicable to assess the diagnostic accuracy studies in which follow-up without prognosis was involved in golden standard. It was useful to assess the overall methodological quality of the study despite more time consuming than the original QUADAS. However, QUADAS-2 needs to be modified to apply in comparative studies on diagnostic accuracy and we hope the users would follow the updates and give their feedbacks on line.

Risk of bias assessment: (7) Assessing Bias in Studies of Prognostic Factors / 中华流行病学杂志

This paper introduces the tools related to Quality In Prognosis Studies (QUIPS) to assess the risk of bias in studies of prognostic factors and the relevant points of assessment and to illustrate the application of QUIPS in published prognostic research. The QUIPS tool identified 6 important areas to consider when evaluating validity and bias in studies of prognostic factors including participation, attrition, measurement on prognostic factors, outcomes, confounding factors, statistical analysis and reporting. It also provided a new method for evaluation on bias in the areas of prognostic research.

Characteristics on spatial and temporal distribution as well as the driving effect of meteorological factors on brucellosis in Datong city, Shanxi province, 2005-2015 / 中华流行病学杂志

Objective: To explore the spatio-temporal epidemic trends and related driving effects of meteorological factors on brucellosis in Datong city, Shanxi province, from 2005 to 2015. Methods: We collected the surveillance data on brucellosis and related meteorological data in Datong city from 2005 to 2015, to describe the epidemic characteristics of the disease. Quasi-Poisson distribution lag non-liner model (DLNM) was built to explore the driving effect of monthly meteorological data on the disease. Results: From 2005 to 2015, Datong city reported a total of 17 311 cases of brucellosis including one death, with the annual average incidence as 47.43 per 100 000 persons. A rising trend was seen during the study period. The monthly incidence of Brucellosis presented an obvious curve with a major peak from March to June, accounted for 48.40% of the total cases. The high incidence areas in the city gradually expanded from the northeast and southeast to the western areas. Results from the DLNM studies suggested that seasonality of brucellosis in Datong was significantly affected by metrological factors such as evaporation, rainfall and temperature. The peak of delayed effect appeared the highest when the monthly cumulative evaporation capacity was 140-260 mm and the monthly cumulative rainfall was 20-60 mm with lag less than 1 month or the monthly temperature was -13 ℃ with lag of 4-5 months. Conclusions: The incidence of human brucellosis in Datong city increased significantly from 2005 to 2015. Meteorological factors such as evaporation, rainfall, temperature all showed significant driving effects on the disease.

Risk of bias assessment: (9) Application of the risk of bias assessment results / 中华流行病学杂志

In this last paper of the series about risk of bias assessment, we introduce the application of risk of bias assessment results. Risk of bias assessment is one of the key steps in the assessment of quality of evidence. The risk of bias assessment results could be the "diagnosis" of individual studies, which helps decision making related to the inclusion and exclusion of individual studies, as well as the data analysis in the systematic review process. This paper focuses on how to incorporate risk of bias assessment results in the GRADE assessment for quality of evidence, including the principles and the tips for the application.