behavioral sci

Question 1

1. cross-sectional study
2. case-control study
3. cohort study

Answer 1

1. “what is happening?”
   
   • measures disease prevalance- simultaneously measures exposure + outcome
   • “snapshot” study- uses surveys
2. “what happened?”
   
   • compares group of ppl w/ disease (case) to group w/o (control)
   • measures OR
3. “who developed the disease (exposed vs. non-exposed)?”
   
   • meaures RR
   • compares a group with a given exposure or risk factor to group w/o

Question 2

clinical trial

1. phase 1
2. phase 2
3. phase 3
4. phase 4

Answer 2

1. is it safe? – assess safety, toxicity, pharmacokinetcs
2. does it work? – assess efficacy, optimal dosing, adverse effects
3. is it as good as or better than? – compares to std of care/gold std
4. what are the long-term adverse effects?

Question 3

• sensitivity
• specficity
• PPV
• NPV

Answer 3

• a/a+c (down arrow)
  
  • true-positive rate
  • SN-N-OUT– with a highly SeNsitive test when (-) rule it OUT
  • used for screening
• d/b+d (up arrow)
  
  • true negative rate
  • SP-P-IN: high SPecific test, when (+) rule it IN
• a/a+b (right arrow)
  
  • varies directly with prevalance of pretest probablity
  • high pre-test prob –> high PPV
• d/c+d (left arrow)
  
  • varies indirectly with prevalance or pretest prob
  • high pretest prob –> low NPV

Question 4

1. odds ratio
2. Relative risk
3. relative risk reduction

Answer 4

1. odds that the group with the disease (case) was exposed to the risk factors/ odds that the group w/o the disease(control) was exposed
2. EER/CER
   
   • risk of developing the outcome with the invervention/risk factor
   • RR<1 – less risk
3. RRR= 1 - RR
   
   • how much are you reducing the risk from the baseline?

Question 5

1. attributable risk
2. absolute risk reduction
3. NNT
4. NNH

Answer 5

1. diff in risk between exposed and unexposed groups
   
   • ie: if risk of lung cancer in smokers = 21% and risk in non-smokers = 1% then AR = 21-1 = 20%
2. ARR= CER-EER
3. NNT = 1/ARR
4. NNH = 1/AR

Question 6

precision vs accuracy

Answer 6

• precision = reliability (constitency + reproduciblity of a test)
• accuracy = validity (the trueness of test measurment)

Question 7

1. selection bias
2. recall bias
3. procedure bias

Answer 7

1. non-random assignment to participate in study group
   
   • ex: loss to follow up- losses don’t happen equally between both groups –> skews results
   • ex: study pops are healther than general pop
2. awareness of disorder alters recall by subjects (retrospective studies)
3. subjects in diff groups are not treated the same

Question 8

1. observer bias
2. confounding bias
3. lead-time bias

Answer 8

1. researcher’s belief in efficacy of tx changes outcome of that tx
2. ie: pulmonary disease is more common in coal workers, but coal workers are more likely to smoke
3. early detection is confused with increased survival

Question 9

1. normal distribution
2. bimodal distribution
3. positive skew
4. negative skew

Answer 9

1. Gaussian/bell-shaped
   
   1. 68% lie w/i 1 SD, 95% w/i 2 SD
2. suggest 2 diff populations
3. asymmetry with longer tail on R
4. asymmetry with longer tail on L

Question 10

1. null hypothesis
2. type I error
3. type II error
4. statistical power

Answer 10

1. hypothesis of no difference (if p<0.05 reject the H₀ – ie: the observed results did not occur by chance alone)
2. alpha: you saw a difference that didn’t exist
   
   • null hypothesis incorrectly rejected
3. beta: you were blind to a difference that did exist
   
   • null hypothesis is not rejected when it should have been
4. statistical power = 1 - beta
   
   • increase power by decreasing beta
   • increased sample size = increased power

Question 11

1. if 95% CI for a mean difference between 2 variables includes 0
2. if 95% CI for OR or RR includes 1
3. t-test
4. ANOVA
5. chi-square

Answer 11

1. there is no significant difference – you can’t reject null hypothesis
2. can’t reject null hypothesis
3. tests for diff of mean between 2 groups
   
   • “tea is for 2”
4. tests for diff of mean between 3+ groups
5. checks diff between categorical outcomes (no means values)
   
   • “chi-tegorical”

Question 12

disease prevention

Answer 12

• primary = prevent (ie: HPV vaccination)
• secondary = screen (ie: pap smear)
• tertiary= treat (ie: chemotherapy)

Question 13

early developmental milestones

1. infant (0-12 mo)
2. toddler (1-3 years)
3. preschool (3-5 years)

Answer 13

1. Parents Start Observing
   
   1. Primitive reflexes disappear, Posture (walks) Picks (pincer grasp, passes toys hand to hand), Points to object
   2. Social Smile (by 2 mo), Stranger anxiety (by 6 mo), Sep anxiety (by 9 mo)
   3. Orients (1st to voice then by name), Object permanence (by 9 mo), Oratory (“mama + dada” by 10 mo)
2. Child Rearing Working
   
   1. Climbs stairs, Cubes stacked, Cultured (feeds oneself)
   2. Recreation (parallel play), Rapprochement, Realization (gender identity)
   3. Words (200 by age 2)
3. Don’t Forget, they’re still Learning!
   
   1. Drive tricycle, drawings, dexterity (hops on 1 foot, uses buttons)
   2. Freedom (spends part of day away from mom), Friends (coop play)
   3. Language (1000 words by age 3), Legends (can tell stories)