The Pharmaceutical Promotional Literature

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The Pharmaceutical Promotional Literature

• A Users Guide

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CaseIt is a busy day in your practice and
you are sitting at your desk, legs up, leafing
through a recent issue of Diversion, The Magazine
for Physicians at Leisure. You come across an ad
for Plavix,TM which states that this medication
reduces the risk of cardiovascular events by 9
compared to aspirin. You wonder if you should be
switching all your patients to Plavix. TM
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Promotional spending on prescription drugs,
l996-2003
Source IMS Health
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Promotional spending on prescription drugs, 2003
Total spending 24.9 billion
Source IMS Health
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But isnt all this advertising and promotion a
good thing? Isnt it an important way for doctors
to learn about new products?
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Scientific versus commercial sources of influence

• Telephone questionnaire of 85 randomly selected
  internists in Boston area
• Questioned about two classes of drugs
• Propoxyphene analgesics
• Cerebral and peripheral vasodilators.

Am J Med 19822734
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Scientific versus Commercial Sources of Influence
Am J Med 19822734
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Scientific versus Commercial Sources of Influence
Am J Med 19822734
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Pharmaceutical Advertisements in Leading Medical
Journals Experts Assessments

• Peer review of all ads from 10 journals during
  January, 1990.
• 109 advertisements were analyzed by 113
  experienced physician peer reviewers and 54
  clinical pharmacists.
• 71 of reviewers had received money from the drug
  industry within the past 2 years 53 had
  received more than 5000.

Ann Int Med 1992116912
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Pharmaceutical Advertisements in Leading Medical
Journals Experts Assessments

• FDA regulations specify that ads are false,
  lacking in fair balance, or otherwise misleading
  if
• They make claims about relative safety and
  efficacy or about the populations in which the
  drug is useful that are not supported by the
  current literature.
• Use literature or references inappropriately to
  support claims in the advertisement.
• Use statistics erroneously.
• Use headlines, sub-headlines, or pictorial or
  other graphic material in way that is misleading.

Ann Int Med 1992116912
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Pharmaceutical Advertisements in Leading Medical
Journals Experts Assessments
Ann Int Med 1992116912
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The Quantity and Quality of Scientific Graphs in
Pharmaceutical Advertisements

• Review of all pharmaceutical ads in from 10
  leading American journals in 1999.
• 498 unique advertisements (3,185 total).
• 74 unique graphs

JGIM 200318294-297
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The Quantity and Quality of Scientific Graphs in
Pharmaceutical Advertisements

• 36 of graphs contained numeric distortion.
• 66 of graphs contained chart junk.
• 54 reported intermediate outcomes.

JGIM 200318294-297
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Are the risk reductions relative or absolute?
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Risk (Rx) 8/100 8Risk (Pl) 12/100 12
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Relative Risk(RR) Risk (Rx)/ Risk (Pl)
.08/.12 .67 Relative Risk Reduction (RRR) 1
- RR 1- .67 .33 or 33
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Absolute Risk Reduction (ARR) Risk (Pl) - Risk
(Rx) .12 - .08 .04 or 4
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Number Needed to Treat (NNT) NNT 1/ARR

• Number of patients needed to treat to prevent one
  outcome

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NNT 1/ARR

• ARR 4NNT 1/.04 25

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Completeness of reporting trial results effect
on physicians willingness to prescribe

• Questionnaire concerning Helsinki Heart Study.
• 148 Italian physicians completed questionnaire.
• Results of HHS
• Cardiac events in treatment group 2.73
• Cardiac events in placebo group 4.14

Lancet 1994. 343 1209
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Completeness of reporting trial results effect
on physicians willingness to prescribe

• ARR 1.41
• RRR 34
• NNT 71
• Difference in event free rates (97.3 vs 95.9)
• RR of cardiac events - RI deaths 6

Lancet 1994. 343 1209
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Completeness of reporting trial results effect
on physicians willingness to prescribe

• You are in doubt whether to start drug treatment
  to reduce serum cholesterol of one of your
  patients. We will gave you 5 statements derived
  from 5 different randomized trials recently
  published in leading medical journals. On the
  basis of each statement you should indicate how
  likely you are to prescribe each drug for your
  patient. Assume that the dosage is the same for
  each treatment.

Lancet 1994. 343 1209
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Completeness of reporting trial results effect
on physicians willingness to prescribe

• Likelihood of prescribing
• Drug A (RRR) 77
• Drug B (ARR) 24
• Drug C ( event free) 37
• Drug D (NNT) 34
• Drug E (complete) 28

P lt 0.001 for RRR vs other measures
Lancet 1994. 343 1209
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• Are the results statistically significant?
• Are they clinically significant?

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Are the graphs telling the truth?
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Are the graphs telling the truth?

• Does the size of the effect shown equal the size
  of the effect in the data?

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Tuftes Lie Factor

• Size of effect shown in graphic
• Size of effect in data

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Are the graphs telling the truth?

• Does the size of the effect shown equal the size
  of the effect in the data?
• Is only a small percentage of the possible event
  rate displayed?

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Are the graphs telling the truth?

• Does the size of the effect shown equal the size
  of the effect in the data?
• Is only a small percentage of the possible event
  rate displayed?
• Does the y-axis start at zero?

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Are the graphs telling the truth?

• Does the size of the effect shown equal the size
  of the effect in the data?
• Is only a small percentage of the possible event
  rate displayed?
• Does the y-axis start at zero?
• Is the survival curve longer than the study?

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Are the references real?
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Is Cal Ripken in the ad?(Appeal to celebrity)
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Logical Fallacies in Pharmaceutical Promotion

• Argumentum ad populum
• Appeal to popularity

J Gen Intern Med 19949563-7
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Logical Fallacies in Pharmaceutical Promotion

• Argumentum ad verecundiam
• Appeal to authority

J Gen Intern Med 19949563-7
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Logical Fallacies in Pharmaceutical Promotion

• Argumentum ad celebritam
• Appeal to celebrity

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Logical Fallacies in Pharmaceutical Promotion

• Fallacy of ignoratio elenchi
• (or fallacy of irrelevant conclusions,
• or fallacy of ignoring the issue
• or the non-sequitur)

J Gen Intern Med 19949563-7
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Logical Fallacies in Pharmaceutical Promotion

• Appeal to emotion

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Check-list

• Are the risks relative or absolute?

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Check-list

• Are the risks relative or absolute?
• Relative.
• Absolute 0.9

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant?

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Check-list

• Are the risks relative or absolute?
• Is the result statistically significant?
• Yes, marginally.
• P .045 95 CI (0.3 to 16.5)

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant?

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant?
• No
• NNT 1/ARR 1/.009 111 95CI (57 - 2500)

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant? No
• Does the size of the effect shown equal the size
  of the effect in the data?

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant? No
• Does the size of the effect shown equal the size
  of the effect in the data? No

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant? No
• Does the size of the effect shown equal the size
  of the effect in the data? No
• Are the references "real?

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant? No
• Does the size of the effect shown equal the size
  of the effect in the data? No
• Are the references "real?
• Yes, the CAPRIE study, The Lancet, Vol. 348,
  November 16,1996.

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant? No
• Does the size of the effect shown equal the size
  of the effect in the data? No
• Are the references "real? Yes
• Is Cal Ripken in the ad?

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Check-list

• Are the risks relative or absolute? Relative
• Is the result statistically significant? Yes
• Is the result clinically significant? No
• Does the size of the effect shown equal the size
  of the effect in the data? No
• Are the references "real? Yes
• Is Cal Ripken in the ad? No, thankfully.

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Conclusions

• Pharmaceutical ads are often inaccurate, biased,
  and misleading.
• They misuse statistics and graphics, over-state
  results, and employ fallacious reasoning.
• They should not be used to guide clinical
  decisions.
• Keep your patients on aspirin!

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A few sources of prescribing information

• Medical Letter (http//www.medicalletter.com)
• Prescribers Letter (http//www.prescribersletter.
  com)
• Therapeutics Initiative (http//www.ti.ubc.ca)
• Drug and Therapeutics Bulletin (UK)
• (http//www.dtb.org.uk/idtb)