An increasing number of health system researchers use systematic review to synthesize research evidence to inform the development of health policies at global and national levels. However, there are methodological challenges facing the health system research in undertaking systematic reviews of health policy literatures. This paper explored the constraints and promise of systematic review as a tool for evidence-based health system research in developing countries. It introduced the systematic review method and its evolution in health research over the past decades. The paper then discussed the definition of health system research, as system science, and contrasted its features/characteristics to those of medical research. It discussed and analyzed if the systematic review could be an effective tool for evidence-based health system research, particularly in developing countries. The paper concludes that the systematic review may be a very useful tool that can be used for evidence-based health system research to address specific policy issues; however, research on some health system/policy issues may not be appropriate to use the systematic review at all.
ObjectivesTo systematically review the association between serum high sensitivity C-reactive protein (HS-CRP) and nonalcoholic fatty liver disease (NAFLD).MethodsPubMed, EMbase, The Cochrane Library, CNKI, SinoMed and WanFang Data databases were electronically searched to collect case-control studies on the association between HS-CRP and NAFLD from inception to October, 2019. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies. Meta-analysis was then performed using RevMan 5.3 software.ResultsA total of 22 case-control studies involving 5 825 subjects were included. The results of meta-analysis showed that HS-CRP levels in NAFLD group were higher than non-NAFLD group (SMD=1.25, 95%CI 0.81 to 1.68, P<0.000 01). The results of subgroup analysis showed that, HS-CRP levels in NAFLD group were higher in Asian region (SMD=1.32, 95%CI 0.82 to 1.83, P<0.000 01), however not in American region (SMD=0.48, 95%CI −0.02 to 0.98, P=0.06). HS-CRP levels in NAFLD group were higher in BMI≥30 kg/m2 group (SMD=0.37, 95%CI 0.19 to 0.54, P<0.000 1), however not in BMI<30 kg/m2 group (SMD=1.19, 95%CI −0.28 to 2.66, P=0.11). Additionally, HS-CRP levels in NAFLD group were higher with or without diabetes (SMD=0.86, 95%CI 0.49 to 1.24, P<0.000 01; SMD=1.47, 95%CI 0.84 to 2.10, P<0.000 01).ConclusionsCurrent evidence shows that NAFLD patients have higher levels of HS-CRP than non-NAFLD patients, and are affected by high levels of BMI and geographical regions. Therefore, HS-CRP may play important roles in the non-invasive field of NAFLD detection. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.