Question

1. Identify the research design of this article and explain why.

2. Determine the level of evidence of this article using the hierarchy of evidence for intervention studies table in Melnyk's article " Evidence-based Practice, step by step 5 appraisal.

Article

Cai, Y., Xu, K., Hou, W., Yang, Z., & Xu, P. (2017). Preoperative chlorhexidine reduces the incidence of surgical site infections in total knee and hip arthroplasty: A systematic review and meta-analysis. International Journal of Surgery, 39, 221-228. doi:10.1016/j.ijsu.2017.02.004

Abstract

OBJECTIVE: This meta-analysis aims to assess the incidences of surgical site infection of patients who applied preadmission chlorhexidine skin preparation, versus those who applied the traditional skin preparation before undergoing total knee and hip arthroplasty.

METHODS: A systematic search is carried out through Medline (1966–2016.11), PubMed (1966–2016.11), Embase (1980–2016.11), ScienceDirect (1985–2016.11) and the Cochrane Library. Only high quality studies are identified. Meta-analysis is conducted with the use of Stata 11.0 software.

RESULTS: One RCT and five retrospective studies, published between 2010 and 2016, are included in the present meta-analysis. The present meta-analysis indicates that there are significant differences in surgical site infection rate (RD = −0.02, 95% CI: −0.02 to −0.01, P < 0.00001), revision surgery rate (RD = −0.01, 95% CI: −0.01 to −0.01, P < 0.00001) and length of stay (MD = −0.29, 95% CI: −0.48 to −0.11, P = 0.002) between groups.

CONCLUSION: Preoperative chlorhexidine skin preparation appears to reduce the risk of infection, the incidence of revision surgery, and the length of stay for patients undergoing total knee and hip arthroplasty. No adverse effects, such as DVT or PE, appear to be related to chlorhexidine preparation. Due to the limited quality of the evidence currently available, high quality RCTs with better study designs, larger sample sizes and longer follow-ups are needed.

Answer 1

Research design of this article is :- randomized experimental design

• The reason that studies are placed into a hierarchy is that those at the top are considered the “best evidence".
• This is the case of therapeutic trials so this is the randomized controlled trial (RCT) and meta-analyses of RCTs.
• the nature of randomization, an ability to help control bias.
• Randomization is able to achieve this by not only controlling for known prognostic variables but also and more importantly controlling for the unknown prognostic variables within a sample population.
• This bias-controlling measure helps attain a more accurate estimation of the truth.

The level of evidence of this article according to the hierarchy of evidence is :- Level II (Randomized controlled trial) which is an experiment in which subjects are randomized to a treatment group or control group.