epi final exam

diseased, Signs, diagnose, asymtomatic

diseased, Signs, diagnose, asymtomatic

purpose of screening: identify individuals who exhibit signs of 

• Being _____ (HIV);

• Early ____ of disease (Cancer);

• Known risk factors for disease (ie cholesterol, hypertension);

• Generally not intended to _____; distinguish btwn those who have the disease/risk factor from those who don’t

• usually _______ persons

• Early detection: basis for any screening program: in the natural history disease, should be detectable between initiation and clinical symptoms

add examples from homework

observed, inferred, checklist

Associations are _____; causation is _______; evidence must be considered & criteria weighted against each other to infer causal relationship; NOT a ______

history, compare, discomfort

Ideally screening tests 

• Are acceptable to people;

• Is natural ______ of disease understood;

• Are the costs acceptable —> Should be inexpensive

• Have an acceptable level of ______;

• Must have reasonable gold standard with which to ______ (mammography and subsequent tissue biopsy; cardiac stress test and subsequent angiogram)

invasive

mammograms

• detection prevents treatment (mastectomy & death from cancer);

• Incidence rises w/ age & family history (define target pop) 

  • Sensitivity & specificity; minor discomfort & non _____

blind, burden, listen

Evaluation of screening tests 

•  Independent _____ comparison w/ gold standard;

• sample population must include an appropriate spectrum of patients to who are applied in clinical practice; will your patients be better off? Will pop be better off? 

•  What is the _____ of suffering associated w/ the screening protocol? Effectiveness of treatment ?

•  Labeling effects; psychological effect of test results or diagnoses on patients can help or hurt 

• U.S. Preventive Services Task Force → When do insurance begin to cover X (they ____ to guidelines)

prioritization

foodborne illness

______: limited resources; high priority are life threatening; high risk; large # ppl, on-going, new cases, political pressure, intentionality;

local PH agency leads outbreaks when exposure and or majority of ill resided within jurisdiction; state PH lead multistate & multi county;

lead, selection, length, slower

screening biases

• Prolong life or reducing invasiveness

• ___ time: perception that the screen-detected case has a longer survival;

• ______: people who seek screening are different than people who do not;

• ______ time: proportion of slow growing lesions diagnosed during screening programs is greater than the proportion of those diagnosed during usual medical care;

• ____-growing tumors makes screening seem to improve survival;  usually related to cancer

traceback

• ______ investigation: how many were sick? Contact info? Specimen? Treatment? Contacted PHD? Local PH gather info & shared w state HD and FDA/USDA; different industries different agencies 

control

• _____ measures: asap when outbeak; prvenent more disease & protect credibility; do not wait for lab

  • Education, disinfection, exclusion, avoidance, close, recall 

pitfalls

• ________: “too long ago”, incomplete questionnaires, no casedefinition, not interviewing well ppl, no specimen, communication 

consistency, strength

relative risk of breast cancer for alcohol drinkers as compared to persons who did notdrink alcohol were 2.5, 3.4, 5.2, 2.6, 4.2, and 3.2 in the six cohort studies. __________ & _________

consistency

review of literature identified 6 cohort studies that had investigated the associationbetween alcohol use and breast cancer. All found a positive association between alcohol consumption and increased risk of breast cancer.

______

done response

in the study by Smith-Warner, 1998, the findings indicated that as alcohol consumption increased, the relative risk of having breast cancer also increased. ______ ________

plausibility, coherence

Alcohol may increase the risk of breast cancer by its effect on estrogen levels. Simplyput, it is known that estrogen is a cancer promoting hormone in high levels; and alcohol tends to increase the availability of estrogen in the body.

_______, ________

dose response

The rate of second heart attacks (MI) decreases progressively with higher dosage formulations _______ ________

plausibility

Studies have shown that lipitor decreases the formation of blood clots, which precede MI’s

____________

strength

In the 1990’s, it was established that lipitor reduced the risk of 2nd MI by 5-7 times _______

consistency

Nearly all studies show a positive association between lipitor use and reduced rate of recurrent MI. _______

temporality

The risk of MI decreases soon after lipitor use has begun

false +, specificity

If the diagnostic (confirmatory) test is expensive orinvasive, or anxiety provoking Minimize _____ ______ & use _______ cutpoint

length time bias

lead time bias

lead time bias

opposite

screening measured in 2 ways

true + / total positives or _____

necessary

types of cause: Causal pies

________ cause ≡ found in all cases

contributing

_______ cause≡ needed in some cases

sufficient

_______ cause ≡the constellation of necessary &contributing causes that make disease inevitable in an individual

susceptibility

Causal complement = the set of factors that completes a sufficient causal mechanism

ex. in tb the bacteria is the necessary agent but the causal component is

proof

causal webs (hierarchy)

____ is impossible but causal statements can be made strong

point source outbreak

propagated outbreak

continuous common source