Statistics and Screening Flashcards
What is the formula for +LR and -LR?
LR+= sens/(1-spec)
LR-=(1-sens)/spec
remember specificity always goes in the denominator
How are +LRs>1 interpreted?
LRs of 2, 5, and 10 increase disease probability by 15%, 30%, and 45%
How are +LRs interpreted?
LRs of 0.5, 0.2, and 0.1 decrease disease probability by 15%, 30%, and 45%
Convert odds to probability
probability=odds/(odds+1)
ex: 2:1 odds means 2/3=66% probability
Convert probability to odds
odds=prob/(1-prob)
ex: 66% probability means .66/.33= 2:1 odds
Overdiagnosis is a form of what kind of bias?
length-time bias. Because indolent things are picked up, which never would have harmed the patient. So of course it looks like screening has a better outcome.
What 6 things does the USPTF recommend AGAINST for screening?
- coronary artery stenosis (I guess stress test?)
- CAD in lowe risk patients
- testicular cancer
- ovarian cancer
- pancreatic cancer
- bladder cancer
who should be screened for depression?
anyone with access to appropriate follow-up
who should be screened for diabetes?
Some say: Only patients with HTN or DLD
Other say: All age>45 yrs every 3 yrs
USPSTF: adults aged 40 to 70 years who are overweight or obese
who should be screened for colon cancer?
everyone age 50-75 yrs
who should be screened for DLD?
Book says…..
if risk factors: >20 yrs old
Online says…
if man with no RF: >35 yrs old
if woman with RF: >45 yrs old
who should get a mammogram?
age>40 yrs old every 2 yrs
who should get a pap smear?
women age 21-65 every 3 yrs
who should get screened for chlamydia?
sexually active women age 24 years and younger and in older women who are at increased risk for infection
who should get screened for HIV?
1x screening for all aged 15 to 65 years
who should get a DEXA scan?
women>65 yrs old
men>70
adult with fracture
women >60 yrs old with RF
who should get AAA screening?
1x ultrasound screen for men age 65-75 yrs with a smoking history
when do you give Td booster?
No wound: every 10 years
Presenting with a wound:
Clean wound: Last had it >10 yrs ago
Big wound: Last had it >5 yrs ago
Which adults get Tdap?
1x dose for those 19-64 years old
who should NOT get the MMR?
pregnant women, immunocompromised patients, or those born before 1957 (have immunity to measles and mumps)
who should get HPV vaccine?
females 9-26 yrs old. Males can get it too, but not as strong a recommendation
is hep B vaccine safe for pregnant women?
yes. But the MMR and the varicella are not.
what age adult should get the zoster vaccine?
> 60 yrs old, regardless if have had shingles outbreak or not
who should get meningococcal vaccine?
young adults, or those without a spleen, or those traveling to endemic area
What is the timeline for grief vs. depression after a loved one dies?
Symptoms of depression for >2 weeks at >2 months out = depression
OR
Symptoms of anger, intense longing, thinking about the person, etc at >6 months out = complicated giref
Difference between length time bias and lead time bias
Lead-time: Same person dies at same age, but “death from diagnosis” is longer because you picked it up earlier
Length time: Pick up more indolent cases in your group, so outcomes seem to improve
Which patients need TWO pneumococcal vaccines after age 65? (the second after 5 years)
- Asplenia
- CKD
- Cancer
- Immunocompromised
