Gerene S. Bauldoff, PhD, RN, FAAN Professor of Clinical Nursing EBP Mentor CRITICAL APPRAISAL OF DESCRIPTIVE STUDIES 1
Objectives Discuss the key elements of critical appraisal of descriptive studies Critically appraise a descriptive study Clinical Inquiry Formulate a Searchable, Answerable Question (PICOT) Search for the Best Evidence Rapid Critical Appraisal, Evaluation, and Synthesis of Evidence Integrate the Evidence with Clinical Expertise and Patient Preference(s) Generate Evidence Internal: QI External: Research Evaluate Outcomes based on Evidence Melnyk, Fineout Overholt 2010 Disseminate the Outcome(s) 2
Systematic review or meta analysis Evidence obtained from at least one well designed RCT Evidence obtained from well designed controlled trials without randomization and from well designed case control and cohort studies Level of Evidence; Use the hierarchy as your tool Evidence from systematic reviews of descriptive and qualitative studies Evidence from a single descriptive or qualitative study Evidence from the opinion of authorities and/or reports of expert committees Descriptive Studies Describe Observe Explain Document Predict a phenomenon Serve as a foundation for developing hypotheses or testing theories. There is NO manipulation of variables. There is NO attempt to establish causality. Used when it undesirable or unethical to manipulate the IV (treatment). 3
Types of Descriptive Study Designs 1. Survey Studies Descriptive, Exploratory, Comparative 2. Correlational Studies Descriptive, Predictive or Model Testing 1. Survey Studies Descriptive/Exploratory/Comparative Survey Studies Description of current conditions, practices in order to make plans for improving health care practices. Variables of interest: opinions, attitudes, or facts. Data collection: interviews or questionnaires Attempt to relate one variable to another NOT causality. 4
2. Correlational Design Descriptive Correlational Designs Describe a phenomena as it occurs between: 2 or more groups or 2 or more variables Explain the degree and characteristics of relationships that exist among the variables or groups. 2. Correlational Design Predictive Correlational Designs Used when there is an interest in whether one variable that occurs earlier in time predicts another variable. Researcher hypothesizes which variables are predictors and which are outcomes. Considered stronger than descriptive study design (re: causal inference) because of the time sequence. 5
What is critical appraisal? Process of examining, appraising, determining the worth or value of research evidence (findings) to evaluate its validity, reliability of the results, and relevance for clinical decisionmaking Appraisal is not the same as critique! EBP is all about appraisal! The strength of a study is determined by Level of evidence of the study + Quality of the study = Strength of the study 6
Preliminary Questions of Critical Appraisal 1. Why was the study done? Was there a clear explanation of the purpose of the study and, if so, what was it? 2. What study design was used? Was it appropriate for the purpose of the study? 3. What was the sample size? Were there enough people in the study to establish that the findings did not occur by chance? 3. Were the instruments of the major variables valid and reliable? Were the instruments designed to measure a valid concept? (Did they measure what the researchers said they measured)? Were they reliable? (Did they measure the concept the same way every time they were used)? Adapted with permission from Melnyk BM, Fineout Overholt E, editors. Evidence based practice in nursing and healthcare: a guide to best practice [2010]. 2 nd ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams and Wilkins. Preliminary Questions of Critical Appraisal 4. How were the data analyzed? What statistics were used to determine if the purpose of the study was achieved? Were they appropriate? 5. Were there any untoward events during the study? For example Did people leave the study and, if so, was there something special about them? 6. How did the results fit with previous research in the area? Did the researchers base their work on a thorough literature review? 7. What does this research mean for clinical practice? Was the study purpose an important clinical issue? Adapted with permission from Melnyk BM, Fineout Overholt E, editors. Evidence based practice in nursing and healthcare: a guide to best practice [2010]. 2 nd ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams and Wilkins. 7
Descriptive Studies RCA Tool (page 1) Descriptive Studies RCA Tool (page2) 8
Descriptive Studies RCA Tool (page3) Descriptive Studies Group Appraisal & Decision Example Study 9
Descriptive Studies Discussion Example Study Moving to the next step After the strength of the individual studies is determined, then the strength of the BODY of EVIDENCE can be determined. This requires evaluation and synthesis of all of the studies. 10
References Melnyk, B., & Fineout Overholt, E. (2011). Evidence Based Practice in Nursing and Health Care. A Guide to Best Practice. (2 nd Edition). Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins. Fineout Overholt, E., Melnyk, B.M., Stillwell, S.B., & Williamson, K.M. (2010). Evidence based practice, step by step: Critical appraisal of the evidence: part II: Digging deeperexamining the keeper studies. American Journal of Nursing, 110 (9), 41 48. Slide Copyright 2012, Center for Transdisciplinary Evidence Based Practice 11