Research Design

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Research Design Analysis 2 Class 16

• Announcements Faculty job interviews
• Ex-Post-Facto designs (continued)
• Breast cancer relative risks
• A comparison of Prospective Retrospective data
• Review for Midterm

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Colloquium Series Job Candidate

• Margo Watt
• St. Francis Xavier
• Learning History Origins of Anxiety Sensitivity
• Monday, March 13, 2000, 330 p.m.
• HSH 202

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Lifetime Risks of Developing Breast Cancer (US
study published in Science 93)
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Top 10 Womens Cancers
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Incidence of Breast Cancer by Stage
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Incident Mortality Rate Trends
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penny
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Relative Risk Ratios for Breast Cancer
relative risk gt4 relative risk of 2-
4 relative risk of 1.1-1.9
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Putting risk of Breast Cancer in Perspective

• One woman in 9 in whom breast cancer will
  develop, has a 50 chance of receiving the
  diagnosis after age 65 and a 60 chance of
  surviving that cancer and dying of other causes
• Risk of breast cancer in any given decade never
  exceeds 1 in 34 (at 30 is 1 in 250)
• Based on editorial in NEJM

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Cyclic Moods?

• How many believe their moods vary with
• Days of the week?
• Lunar cycle?
• Menstrual cycle?
• How would you study this?

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• Raging female hormones in the courts
• Macleans, June 15, 1981
• Treatment for PMS ordered as stabber put on
  probation
• Globe and Mail, Feb 10, 1987
• Womens violence blamed on period
• Toronto Star, August 25th 1978
• Womans syndrome brings leniency
• Vancouver Sun, February 10th, 1987

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Politics of PMS

• 1929 term premenstrual tension Dr. Robert Frank
• Since 1970s Dr. Katherine Dalton - supports
  progesterone therapy
• estimates of prevalence 6-95
• 150 somatic and psychological symptoms associated
  with PMS
• According to some, PMS is a social and political
  construct

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Hormonal Changes Over Menstrual Cycle
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Premenstrual Dysphoric Disorder Criteria

• A At least five of the following, present during
  last week of luteal phase, remit within days of
  follicular phase onset and absent week postmenses
• (1) markedly depressed mood, feelings of
  hopelessness. or self deprecating thoughts
• (2) marked anxiety, tension, feelings of being
  "keyed up.' or "on edge"
• (3) marked affective lability, (e.g.. feeling
  suddenly sad or tearful or increased sensitivity
  to rejection)
• (4) persistent and marked anger or irritability
  or increased interpersonal conflicts
• (5) decreased interest in usual activities (e.g.,
  work, school, friends, hobbies)
• from DSM IV

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Premenstrual Dysphoric Disorder Criteria

• Continued
• (6) subjective sense of difficulty in
  concentrating
• (7) lethargy, easy fatigability or marked lack of
  energy
• (8)marked change in appetite, overeating, or
  specific food cravings
• (9) hypersomnia or insomnia
• (10) a subjective sense of being overwhelmed or
  out of control
• (11) other physical symptoms, such as breast
  tenderness or swelling, headaches, joint or
  muscle pain, a sensation of "bloating," Weight
  gain
• from DSM IV

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Premenstrual Dysphoric Disorder Criteria
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Comparing Retrospective and Prospective
DataMood FluctuationsWomen versus men and
menstrual versus other cyclesJessica McFarland,
et. al.
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McFarland et.al.

• Methodological problems with existing literature
• demand characteristics (expectations of
  participants, bias, volunteers)
• Measured negative moods (truncated range)
• Retrospective reports
• No control groups
• No assessment of normal range of moods

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McFarland et.al.

• Data suggest menstrual cycle related mood effects
  are not an issue, yet the belief is there
• Why?
• The methodological flaws mentioned
• Women believe they have menstrual mood
  fluctuations when they do not.
• Two questions of interest
• Do women have classic cyclic mood fluctuation?
• Are womens moods more labile than mens

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McFarland et.al.

• Methods
• Studies both prospectively and retrospectively
• Participants blind to purpose
• Recorded moods for 70n days (at least 2 cycles)
• 3 groups 1) normally cycling women, 2) women on
  O.C.s and 3) men

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Mood grid
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Mood Pleasantness
Women NC
Women OC
Men
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Arousal Levelswomen only concurrent vs.
retrospective reports
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Mood Pleasantnesswomen only concurrent vs.
retrospective reports
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Mood Pleasantness Ratings by days of the Week
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Data on Prevalence of PMS Symptoms

• In surveys, most women report being more
  emotional premenstrually
• With prospective studies, most women do not show
  any relationship between mood and time of month
• Of those who report PMS symptoms, only 50
  actually have these mood fluctuations
• Significant positive correlation between a
  womans belief in PMS prevalence and the extent
  of her retrospective bias.

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Midterm Review

• Factorial Experiments Advantages
• Factorial designs terminology
• levels IV1 x levels IV2 x etc.
• Interpreting data from factorial experiments and
  experiments with three or more levels of one
  (ANOVA outputs from data)
• Ex-post-facto designs prospective and
  retrospective designs - advantages disadvantages
• Problems Partial solutions

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Midterm Review

• DVs used in Ex-post-facto studies
• Time-series designs, small-n designs
• A-B studies (e.g., homicides after prize fights,
  JFKs assassination etc.)
• multiple baseline designs
• non-equivalent control group
• replication within- and between-subjects
• reliability and generalizability
• Assessing external and ecological validity
• Volunteers