Research Design. Research is based on Scientific Method Propose a hypothesis that is testable...

Research DesignResearch Design

Research is based on Scientific MethodResearch is based on Scientific Method

Propose a hypothesis that is testablePropose a hypothesis that is testable

Objective observations are collectedObjective observations are collected

Results are analyzed in an unbiased mannerResults are analyzed in an unbiased manner

Conclusions proposed are based on the results Conclusions proposed are based on the results of the study and previous knowledgeof the study and previous knowledge

Identifying the problemIdentifying the problem

Perform a Literature ReviewPerform a Literature Review

Formulate the PurposeFormulate the Purpose

Design ProceduresDesign Procedures

Review of StudyReview of Study

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

Once approved, if design changes or methods are Once approved, if design changes or methods are altered, the design must be resubmitted.altered, the design must be resubmitted.

Collect DataCollect Data

What Are Statistics?What Are Statistics?

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

Interpret Findings and Form Interpret Findings and Form ConclusionsConclusions

Publish Your AnswerPublish Your Answer

Evaluating a StudyEvaluating a Study

There are many reasons many There are many reasons many professionals choose not to perform professionals choose not to perform research. But being able to evaluate research. But being able to evaluate

publications is of paramount publications is of paramount importance.importance.

Evaluating a studyEvaluating a study

Literature ReviewLiterature Review DesignDesign AssignmentAssignment AssessmentAssessment AnalysisAnalysis InterpretationInterpretation ExtrapolationExtrapolation

Lit ReviewLit Review

Separated subjective opinions and untested Separated subjective opinions and untested theories form research findingtheories form research finding

Was investigator objective in listing results Was investigator objective in listing results form studies that refuted as well as stated form studies that refuted as well as stated his/her hypothesishis/her hypothesis

Were previous studies reported correctlyWere previous studies reported correctly References are currentReferences are current Varity of journal, sources, and related Varity of journal, sources, and related

professions consultedprofessions consulted

Proper Design..Proper Design..

Purpose of study definedPurpose of study defined Hypothesis correctly statedHypothesis correctly stated Was study type appropriate to the question Was study type appropriate to the question

being answeredbeing answered

Does the assignment of experimental and Does the assignment of experimental and control groups demonstrate integrity?control groups demonstrate integrity?

Researches try to make both groups Researches try to make both groups identical except for characteristics under identical except for characteristics under questionquestion

Selection Bias occurs when an investigator Selection Bias occurs when an investigator unintentionally introduces factors into the unintentionally introduces factors into the selection of the study that can predetermine selection of the study that can predetermine the outcome.the outcome.

Assessing Results of a StudyAssessing Results of a Study

Research must define the outcome that is to Research must define the outcome that is to be measured and that outcome must meet be measured and that outcome must meet these criteriathese criteria– Use a measure of outcome that is appropriate Use a measure of outcome that is appropriate

the the question to be answeredthe the question to be answered– Measurements of the outcome must be preciseMeasurements of the outcome must be precise– Measurement of the outcome must be completeMeasurement of the outcome must be complete– The outcome of the study must not be The outcome of the study must not be

influenced by the process of observationinfluenced by the process of observation

AnalysisAnalysis

Researcher compares result of control and Researcher compares result of control and experimental groups.experimental groups.

Researcher identifies and adjusted for Researcher identifies and adjusted for (confounding variables) factors other than those (confounding variables) factors other than those being studiedbeing studied

After adjustments, statistical tests are performedAfter adjustments, statistical tests are performed Research reports the size of the differences and the Research reports the size of the differences and the

degree of overlap in differences presenteddegree of overlap in differences presented

InterpretationInterpretation

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

ExtrapolationExtrapolation

(Inference) involves obtaining the meaningful study (Inference) involves obtaining the meaningful study for the larger, outside population. for the larger, outside population.

Four types of extrapolation errors when Four types of extrapolation errors when extrapolating to larger populationextrapolating to larger population– Beyond data range (longer duration of experiment will Beyond data range (longer duration of experiment will

produce same effects in subjects)produce same effects in subjects)– Inferring conclusions about individuals from population Inferring conclusions about individuals from population

data data – Error resulting from unappreciated factor in new Error resulting from unappreciated factor in new

populationpopulation– Errors in going from study population to general Errors in going from study population to general

populationpopulation

19 Questions to ask19 Questions to ask1.1. Was the purpose of the study sufficiently designed?Was the purpose of the study sufficiently designed?2.2. Were the study hypothesis clearly stated?Were the study hypothesis clearly stated?3.3. Was an appropriate question being askedWas an appropriate question being asked4.4. What was the study population? Was it adequate What was the study population? Was it adequate

composition and size to answer the study questions?composition and size to answer the study questions?5.5. Was the assignment of patients to study and control Was the assignment of patients to study and control

groups proper? Could selection bias have occurred?groups proper? Could selection bias have occurred?6.6. Were the study and control groups comparable with Were the study and control groups comparable with

respect to the characteristic other that the study respect to the characteristic other that the study factors(s).factors(s).

7.7. Was the measure of outcome appropriate to the Was the measure of outcome appropriate to the study aims?study aims?

8.8. Was the measure of outcomes precise?Was the measure of outcomes precise?

9.9. Was the measure of outcomes complete?Was the measure of outcomes complete?

10.10. Did the process of observation affect the Did the process of observation affect the outcome?outcome?

11.11. Were the results adjusted to take into account Were the results adjusted to take into account the effect of the possible confounding variables?the effect of the possible confounding variables?

12.12. Was a significant test properly performed to Was a significant test properly performed to assess the probability that the difference was due assess the probability that the difference was due to chance?to chance?

13.13. Was the proper measure of the size of the difference Was the proper measure of the size of the difference presented?presented?

14.14. Was a proper Measure of the degree of overlap of the Was a proper Measure of the degree of overlap of the difference presented?difference presented?

15.15. Did the investigators properly reject or fail the null Did the investigators properly reject or fail the null hypothesis?hypothesis?

16.16. Interpreting the meaning of any relationship, was the Interpreting the meaning of any relationship, was the clinical concept of cause and effect properly applied?clinical concept of cause and effect properly applied?

17.17. Did the investigators stay within the limits of the data Did the investigators stay within the limits of the data hen extrapolating the results?hen extrapolating the results?

18.18. If the investigators extrapolated from population data to If the investigators extrapolated from population data to individual data, did they committee an ecological individual data, did they committee an ecological fallacy?fallacy?

19.19. Did researchers take into consideration differences Did researchers take into consideration differences between study population and the population to which between study population and the population to which they extrapolated their datathey extrapolated their data