Conduct a critical appraisal of a primary research paper. Follow the format of an academic essay and use well structured headings: introduction, research problem and it’s significance, research design and the methods, findings and their relevance to contemporary nursing policy and practice, conclusion. Research article is Relationship between nurse staffing level and adult nursing-sensitive outcomes in tertiary hospitals of Korea: retrospective observational study by Chul-Gyu an Kyun-Seop Bae