Reference no: EM133147933

Article: Chen, B., Chen, R., Feng, B., Gao, J., Huang, S., Jin, H., Shi, Y., & Xiang, H. (2017). Efficacy of sublingual immunotherapy for house dust mite-induced allergic rhinitis: A meta-analysis of randomized controlled trials. Allergy, Asthma & Immunology Research, 9(3), 220-228. https://doi.org/10.4168/aair.2017.9.3.220

Can you please identify the dependent and independent variable to the mixed method and randomized control trial and meta-analysis research article and provide the level of choice for this article? 

The levels I am to choose from are:

Level I: 

• Evidence from a systematic or narrative review (literature review) of all relevant randomized controlled trials (RCTs) or at least three RCTs that have similar results
• A meta-analysis study
• An evidence-based clinical practice guideline based on systematic reviews (literature reviews) of RCTs 

Level II: 

• Evidence obtained from at least one well-designed Randomized Controlled Trial (RCT) 

Level III: 

• Evidence obtained from well-designed controlled trials without randomization
• A quasi-experimental design: Not true experiment designs. Descriptive research involves collecting data to test hypotheses or answer questions concerning the current status of the subjects of the study. Describes the variables. Lacks the element of random assignment. Usually assigned to 2 groups without randomization or using a comparison group instead of a control group. Quasi-experimental research involves the manipulation of an independent variable without the random assignment of participants to conditions or orders of conditions. Among the important types are nonequivalent groups designs, pretest-posttest, and interrupted time-series designs. 

Level IV: 

• Evidence from well-designed cross-sectional study 
• A case-control study (not the same as a case study) or retrospective studies in which people who have a specific condition or outcome are compared with people who do not. Researchers are retrospectively relying on patient recall or medical records for their data collection.
• A cohort study, an observational study type that prospectively follows a large group of patients with a specific exposure or treatment and then compares outcomes with an unaffected group. Cohort studies are observational. Longitudinal designs fall here, too.

Level V: 

• Evidence from systematic or narrative reviews (literature review) of descriptive studies and/or qualitative studies 
• A meta-synthesis study 
• Meta-aggregation is an approach that is increasing in popularity as a method of qualitative synthesis designed to model the Cochrane process of systematic reviews summarizing results of quantitative studies while being sensitive to the nature of qualitative research and its traditions 

Level VI: 

• Evidence from a single descriptive study (also single case study)
• Evidence from a single qualitative study: Like interviews without intervention or focus groups. They provide a rich data on the views or experiences of one person or more. Can provide insights in unexplored contexts.

Level VII: 

• Evidence from the opinion of authorities and/or reports of expert committees