Purpose: to interpret your results and justify your interpretation

1
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
2
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
3
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion

4
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion.
5
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result.
6
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion.
7
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion.
8
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study.
9
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature.
10
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics.
11
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics. - Emphasize strengths of study and what is new/useful.
12
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics. - Emphasize strengths of study and what is new/useful. State limitations/caveats (frankly, without apology).
13
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics. - Emphasize strengths of study and what is new/useful. State limitations/caveats (frankly, without apology). Make recommendations.
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The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics. - Emphasize strengths of study and what is new/useful. State limitations/caveats (frankly, without apology). Make recommendations. - changes in practice/policy - future studies
15
The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics. - Emphasize strengths of study and what is new/useful. State limitations/caveats (frankly, without apology). Make recommendations. - changes in practice/policy - future studies include some specifics (methods/population/setting)
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The DISCUSSION
Purpose to interpret your results and justify
your interpretation
Guidelines for Constructing the Discussion
Focus on the main results and conclusion. - Restate the key result. - State the main conclusion. Be clear about why results support this conclusion. Maintain connection with purpose of the study. Interpret in context of literature. - Present/compare with results of and methods used in other studies on same/similar topics. - Emphasize strengths of study and what is new/useful. State limitations/caveats (frankly, without apology). Make recommendations. - changes in practice/policy - future studies - include some specifics (methods/population/setting)
can often be accomplished in four or five
paragraphs
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The analysis of alcohol-related crash
rates clearly demonstrates a rise in both
alcohol-related crashes and alcohol-related crash
fatalities occurring between noon on Sunday and
noon on Monday, after the ban on Sunday packaged
alcohol sales was lifted. The 29 increase in
Sunday alcohol-related crash rates resulted in an
estimated excess of 543.1 alcohol-related motor
vehicle crashes between July 1, 1995, and June
30, 2000, over what would have been observed had
the ban not been repealed. There was a 42 pre-
to postrepeal increase in the Sunday
alcohol-related crash fatality rate, resulting in
an excess of 41.6 fatalities attributable to
repealing the ban on Sunday packaged alcohol
sales (95 CI 6.6, 76.6). No other day of the
week showed any statistically significant change
in alcohol-related crashes or alcohol-related
crash fatalities. Furthermore, the analysis of
nonalcohol-related crash rates indicates that
relative crash rates on Sundays cannot be
attributed to background trends in crash risks.

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Some limitations are apparent. The
reporting police officer classified nonfatal
crashes as alcohol involved or not alcohol
involved. There has been some debate about the
accuracy of such reporting because the
designation often relies on the subjective
judgment of the reporting police officer. Some
researchers have suggested that investigators use
single-vehicle nighttime crashes as a proxy
measure of alcohol-related crashes and
alcohol-related crash fatalities. This tactic,
however, did not allow us to estimate the true
impact of repealing the ban on the number of
alcohol-related crashes and alcohol-related crash
fatalities (Table 2), which is of primary concern
to state legislators. The issue is of less
concern, however, because it has been shown that
police-reported rates of alcohol involvement and
rates of single-vehicle nighttime crashes tend to
be highly correlated. Furthermore, a recent study
using the New Mexico crash data to investigate
drive-up liquor window closure on crash rates in
New Mexico found no difference in any results
whether one considered single-vehicle nighttime
or all alcohol-related crashes. Analyses of
driving-while-impaired citation data would help
corroborate our findings. Moreover, there is no
reason to believe that an error in police officer
reporting would be biased only on Sundays and
only after the ban on Sunday packaged alcohol
sales was lifted. Even so, this limitation does
not apply to fatal crash results for which
alcohol involvement was determined by blood
alcohol concentration.
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Our results strongly suggest that
increasing alcohol availability on Sunday was
associated with increases in alcohol-related
motor vehicle crashes and fatalities. Legalizing
Sunday packaged alcohol sales may increase state
tax revenues, but at the same time it exacts a
significant price that is paid by crash victims
and their loved ones, health care providers,
insurers, and law enforcement and judicial
systems. State legislators should consider these
consequences when deciding on policy that is
intended to serve the public well-being.
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Excess or Reduction (95 Confidence Interval) Excess or Reduction (95 Confidence Interval)
Alcohol-Related Crash Alcohol-Related Crash Fatality
Sunday 543.1 (158.9, 927.4) 41.6 (6.6, 76.6)
Monday -5.8 (-392.1, 380.5) 3.1 (-29.7, 35.9)
Tuesday 184.5 (-199.2, 568.2) 13.9 (-15.6, 43.3)
Wednesday -67.1 (-514.2, 380.0) 4.5 (-28.2, 37.2)
Thursday 121.7 (-355.7, 599.1) 9.9 (-26.4, 46.1)
Friday -117.9 (-1003.2, 767.3) 8.0 (-46.6, 62.6)
Saturday 89.9 (-764.6, 944.5) 17.2 (-41.4, 75.8)

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Excess or Reduction (95 Confidence Interval) Excess or Reduction (95 Confidence Interval)
Alcohol-Related Crash Alcohol-Related Crash Fatality
Sunday 543 (159, 927) 42 (7, 77)
Monday -6 (-392, 380) 3 (-30, 36)
Tuesday 185 (-199, 568) 14 (-16, 43)
Wednesday -67 (-514, 380) 5 (-28, 37)
Thursday 121 (-356, 599) 10 (-26, 46)
Friday -118 (-1003, 767) 8 (-47, 63)
Saturday 90 (-765, 945) 17 (-41, 76)

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Study Purpose

• smokers among pregnant women
• smokers among non-pregnant women
• compare to 50

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• C1
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• .
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• R2
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• C2

R1 R2 ? C1 C2
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R1 R2 ? C1
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Structured Discussion BMJ
Suggested structure for discussion of scientific papers Statement of principal findings Strengths and weaknesses of the study Strengths and weaknesses in relation to other studies, discussing particularly any differences in results Meaning of the study possible mechanisms and implications for clinicians or policymakers Unanswered questions and future research
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Other resources to help you write better papers

• Observational studies STROBE
• Clinical trials CONSORT
• Diagnostic studies STARD
• Meta-analysis QUOROM

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STROBE Statement
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• The true number of examinations for oral cancer
  is probably far below the national objective of
  40. An unknown number of clinicians may not
  conduct oral examinations routinely or when
  patient behaviors indicate one.

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• The true number of examinations for oral cancer
  is probably far below the national objective of
  40. An unknown number of clinicians may not
  conduct oral examinations routinely or when
  patient behaviors indicate one.

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Author conjecture
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Author conjecture
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• The true number of examinations for oral cancer
  is probably far below the national objective of
  40. An unknown number of clinicians may not
  conduct oral examinations routinely or when
  patient behaviors indicate one.

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'When I use a word,' Humpty Dumpty said, it
means just what I choose it to mean -- neither
more nor less.' 'The question is,' said Alice,
'whether you can make words mean so many
different things.' 'The question is,' said
Humpty Dumpty, 'which is to be master -- that's
all.' Alice was too much puzzled to say
anything.