Research Design

Research is based on Scientific Method Propose a hypothesis that is testable Objective observations are collected Results are analyzed in an unbiased manner Conclusions proposed are based on the results of the study and previous knowledge

Identifying the problem

Perform a Literature Review

Formulate the Purpose

Design Procedures

Review of Study When using human subjects, protecting them is of up most importance. In the research world, this is accomplished by independent review of the research proposal and methods by an IRB (Institutional Review Board). Those conducting research outside of institutions should refer to administration or independent reviews for this process and use the Nuremburg Code, a version of the Declaration of Helsinki to govern choices. Once approved, if design changes or methods are altered, the design must be resubmitted.

Collect Data

What Are Statistics? The means by which quantitative data are organized, analyzed and interpreted. Only through statistical application may scientific data be treated and made meaningful The means by which quantitative data are organized, analyzed and interpreted. Only through statistical application may scientific data be treated and made meaningful

Interpret Findings and Form Conclusions

Publish Your Answer

Evaluating a Study There are many reasons many professionals choose not to perform research. But being able to evaluate publications is of paramount importance.

Evaluating a study Literature Review Literature Review Design Design Assignment Assignment Assessment Assessment Analysis Analysis Interpretation Interpretation Extrapolation Extrapolation

Lit Review Separated subjective opinions and untested theories form research finding Separated subjective opinions and untested theories form research finding Was investigator objective in listing results form studies that refuted as well as stated his/her hypothesis Was investigator objective in listing results form studies that refuted as well as stated his/her hypothesis Were previous studies reported correctly Were previous studies reported correctly References are current References are current Varity of journal, sources, and related professions consulted Varity of journal, sources, and related professions consulted

Proper Design.. Purpose of study defined Purpose of study defined Hypothesis correctly stated Hypothesis correctly stated Was study type appropriate to the question being answered Was study type appropriate to the question being answered

Does the assignment of experimental and control groups demonstrate integrity? Researches try to make both groups identical except for characteristics under question Researches try to make both groups identical except for characteristics under question Selection Bias occurs when an investigator unintentionally introduces factors into the selection of the study that can predetermine the outcome. Selection Bias occurs when an investigator unintentionally introduces factors into the selection of the study that can predetermine the outcome.

Assessing Results of a Study Research must define the outcome that is to be measured and that outcome must meet these criteria Research must define the outcome that is to be measured and that outcome must meet these criteria –Use a measure of outcome that is appropriate the the question to be answered –Measurements of the outcome must be precise –Measurement of the outcome must be complete –The outcome of the study must not be influenced by the process of observation

Analysis Researcher compares result of control and experimental groups. Researcher compares result of control and experimental groups. Researcher identifies and adjusted for (confounding variables) factors other than those being studied Researcher identifies and adjusted for (confounding variables) factors other than those being studied After adjustments, statistical tests are performed After adjustments, statistical tests are performed Research reports the size of the differences and the degree of overlap in differences presented Research reports the size of the differences and the degree of overlap in differences presented

Interpretation Deciding the clinical usefulness of the results obtained or determining whether a cause and effect relationship has been established Deciding the clinical usefulness of the results obtained or determining whether a cause and effect relationship has been established

Extrapolation (Inference) involves obtaining the meaningful study for the larger, outside population. (Inference) involves obtaining the meaningful study for the larger, outside population. Four types of extrapolation errors when extrapolating to larger population Four types of extrapolation errors when extrapolating to larger population –Beyond data range (longer duration of experiment will produce same effects in subjects) –Inferring conclusions about individuals from population data –Error resulting from unappreciated factor in new population –Errors in going from study population to general population

19 Questions to ask 1. Was the purpose of the study sufficiently designed? 2. Were the study hypothesis clearly stated? 3. Was an appropriate question being asked 4. What was the study population? Was it adequate composition and size to answer the study questions? 5. Was the assignment of patients to study and control groups proper? Could selection bias have occurred? 6. Were the study and control groups comparable with respect to the characteristic other that the study factors(s).

7. Was the measure of outcome appropriate to the study aims? 8. Was the measure of outcomes precise? 9. Was the measure of outcomes complete? 10. Did the process of observation affect the outcome? 11. Were the results adjusted to take into account the effect of the possible confounding variables? 12. Was a significant test properly performed to assess the probability that the difference was due to chance?

13. Was the proper measure of the size of the difference presented? 14. Was a proper Measure of the degree of overlap of the difference presented? 15. Did the investigators properly reject or fail the null hypothesis? 16. Interpreting the meaning of any relationship, was the clinical concept of cause and effect properly applied? 17. Did the investigators stay within the limits of the data hen extrapolating the results? 18. If the investigators extrapolated from population data to individual data, did they committee an ecological fallacy? 19. Did researchers take into consideration differences between study population and the population to which they extrapolated their data