Research Design

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Research Design
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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

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Identifying the problem
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Perform a Literature Review
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Formulate the Purpose
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Design Procedures
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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.

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Collect Data
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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

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Interpret Findings and Form Conclusions
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Publish Your Answer
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Evaluating a Study

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

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Evaluating a study

• Literature Review
• Design
• Assignment
• Assessment
• Analysis
• Interpretation
• Extrapolation

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Lit Review

• 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
• Were previous studies reported correctly
• References are current
• Varity of journal, sources, and related
  professions consulted

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Proper Design..

• Purpose of study defined
• Hypothesis correctly stated
• Was study type appropriate to the question being
  answered

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Does the assignment of experimental and control
groups demonstrate integrity?

• 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.

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Assessing Results of a Study

• 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

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Analysis

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

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Interpretation

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

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Extrapolation

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

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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).

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1. Was the measure of outcome appropriate to the
   study aims?
2. Was the measure of outcomes precise?
3. Was the measure of outcomes complete?
4. Did the process of observation affect the
   outcome?
5. Were the results adjusted to take into account
   the effect of the possible confounding variables?
6. Was a significant test properly performed to
   assess the probability that the difference was
   due to chance?

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