Assessment of the risk of bias is an essential component of any systematic review. This is true for both nonrandomized studies and randomized trials, which are the main study designs of systematic reviews. The Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS) was developed in 2013 and has gained wide usage as a risk-of-bias assessment tool for nonrandomized studies. Four risk-of-bias assessment experts revised it by reviewing existing assessment tools and user surveys. The main modifications included additional domains of selection and detection bias susceptible to nonrandomized studies of interventions, a more detailed consideration of the comparability of participants, and more reliable and valid outcome measurements. A psychometric assessment of the revised RoBANS (RoBANS 2) revealed acceptable inter-rater reliability (weighted kappa, 0.25 to 0.49) and construct validity in which intervention effects of studies with an unclear or high risk of bias were overestimated. The RoBANS 2 has acceptable feasibility, fair-to-moderate reliability, and construct validity. It provides a comprehensive framework for allowing authors to assess and understand the plausible risk of bias in nonrandomized studies of interventions.

Seo HJ, et al. Yonsei Med J. 2016 Sep;57(5):1165-1177. https://doi.org/10.3349/ymj.2016.57.5.1165

A systematic review is used to investigate the best available evidence of clinical safety and effectiveness of healthcare intervention. This requires methodological rigor in order to minimize bias and random error. The purpose of this study is to assess the quality of systematic reviews or meta-analyses for nursing interventions conducted by Korean researchers.

The aim of this study was to evaluate the mediating role of psychological capital (PCP) in the relationship between occupational stress and turnover intention in nurses. Data were collected from a sample of 447 nurses working at four Veterans Administration Hospitals throughout South Korea from July 1 to July 31, 2014. We collected data from the nurses using the following surveys: the Short Form Korean-Occupational Stress Scale, the Korean version of the Turnover Intention Scale, and the Korean version of the Psychological Capital Questionnaire. Multiple linear regression analysis was performed to examine the mediating role of PCP. The level of occupational stress was 1.81 ± 0.23, the level of turnover intention was 3.29 ± 0.86, and the PCP level was 3.95 ± 0.52. There were significant correlations among the three variables (occupational stress, turnover intention, and PCP). PCP played a partial mediating role (β=-0.22, p=.008) in the relationship between occupational stress and turnover intention (p<.001) among nurses working at the Veterans Administration Hospitals. Based on the findings of this study, we recommend that South Korean hospitals offer occupational stress management programs that incorporate relevant programs in efforts to strengthen the overall components of PCP among nurses to reduce turnover intentions. Further studies are required to determine the most effective intervention programs for hospital settings.