82 terms

ashleyhintherPLUS

Cross-Sectional Study

Collects data from a group of people to assess frequency of disease at a particular point and time.

DOES NOT establish causality.

What is happening now??

DOES NOT establish causality.

What is happening now??

Case-Control Study

Compares a group of people with disease to a group without the disease.

OR-Odds Ratio

What happened in the past??

OR-Odds Ratio

What happened in the past??

Cohort Study

Compares a group with a given exposure or risk factor to a group without such exposure.

Likelihood of disease

RR-Relative Risk

Does exposure increase disease?

Likelihood of disease

RR-Relative Risk

Does exposure increase disease?

Twin Concordance Study

Compares the frequency with which both monozygotic twins or both dizygotic twins develop the same disease.

Measures heritability and the influence of environmental factors.

Measures heritability and the influence of environmental factors.

Adoption Study

Compares siblings raised by biological vs. adoptive parents.

Measures heritability and the influence of environmental factors.

Measures heritability and the influence of environmental factors.

Clinical Trial

Experimental study involving humans. Compares therapeutic benefits of two or more treatments, or of treatment and placebo.

Study quality improves: randomized, controlled or double blinded.

Study quality improves: randomized, controlled or double blinded.

Sensitivity (True Positive Rate)

Proportion of all people with disease who test positive, or the probability that when the disease is present, the test is positive.

=TP/(TP +FN)

SN-N-OUT=highly Sensitive test, when Negative, rules OUT disease.

=TP/(TP +FN)

SN-N-OUT=highly Sensitive test, when Negative, rules OUT disease.

Specificity (True Negative Rate)

Proportion of all people without disease who test negative, or the probability that when the disease is absent, the test is negative.

=TN/(TN +FP)

SP-P-IN=highly SPecific test, when Positive rules IN disease.

=TN/(TN +FP)

SP-P-IN=highly SPecific test, when Positive rules IN disease.

Positive Predictive Value

Proportion of positive test results that are true positive. Probability that a person who has a positive test result actually has the disease.

PPV=TP/(TP +FP)

PPV=TP/(TP +FP)

Negative Predictive Value

Proportion of negative test results that are true negative. Probability that a person with a negative test result actually does not have the disease.

NPV=TN/(TN+FN)

NPV=TN/(TN+FN)

Incidence Rate

Number of New Cases/Number of People at Risk.

Looks at new cases (incidents).

Looks at new cases (incidents).

Prevalence

Number of Exiting Cases/Total Number of People in a Population

Prevalence looks at all current causes.

Prevalence looks at all current causes.

Odds Ration

Typically used in Case-Control studies. Odds that the group with the disease (cases) are exposed to a risk factor divided by the odds that the group without the disease (controls) was exposed.

OR=ad/bc

OR=ad/bc

Relative Risk

Typically used in cohort studies. Risk of developing disease in the exposed group divided by the risk in the unexposed group.

Attributable Risk

The difference in risk between exposed and unexposed groups, or the proportion of disease occurrences that are attributable to the exposure.

Relative Risk Reduction

The proportion of risk reduction attributable to the intervention as compared to a control.

Absolute Risk Reduction

The difference in risk (not the proportion) attributable to the intervention as compared to a control.

Number Needed to Treat

Number of patients who need to be treated for one patient to benefit.

Number Needed to Harm

Number of patients who need to be exposed to a risk factor for one patient to be harmed.

Precision

The consistency and reproducibility of a test (reliability).

The absence of random variation.

High precision = low random error

The absence of random variation.

High precision = low random error

Accuracy

The trueness of test measurements (validity). The absence of systemic error or bias in the test.

high accuracy=low systemic error

high accuracy=low systemic error

Selection Bias

Error in assigning subjects to a study group resulting in an unrepresentative sample. Most commonly a sampling bias.

Recall Bias

Awareness of disorder alters recall by subjects; common in retrospective studies.

Measurement Bias

Information that is gathered in a systemically distorted manner.

Procedure Bias

Subjects in different groups are not treated the same.

Observer-Expectancy Bias

Researcher's belief in the efficacy of a treatment changes the outcome of that treatment.

Confounding Bias

When a factor is related to both the exposure and outcome, but not on the casual pathway-factor distorts or confuses effect of exposure on an outcome.

Lead-Time Bias

Early detection is confused with increased survival.

Measures of Central Tendency

Mean=(Sum of values)/(Total number of values)

Median=Middle value of a list of data sorted from least to greatest.

Mode=Most common value.

Median=Middle value of a list of data sorted from least to greatest.

Mode=Most common value.

Measures of Dispersion

Standard Deviation=how much variability exits form the mean in a set of values.

Standard Error the Mean= an estimate of how much variability exists between the sample mean and the true population.

SEM=SD/sqrt (n)

Standard Error the Mean= an estimate of how much variability exists between the sample mean and the true population.

SEM=SD/sqrt (n)

Percentages for gaussian distribution-standard deviations

1: 68%

2: 95%

3: 99.7%

2: 95%

3: 99.7%

Bimodal

Suggests two different populations.

Positive Skew

Typically, mean is greater than the median which is greater than the mode. Asymmetry with longer tail on the right.

Negative Skew

Typically the mean is less than the median which is less than the mode. Asymmetry with longer tail on the left.

Null Hypothesis

Hypothesis of no difference or relationship.

Alternative Hypothesis

Hypothesis of some difference or relationship.

Type I Error (Alpha)

Stating that there is an effect or difference when none exists. Also known as false-positive error. Measure of p value

Type II Error (Beta)

Stating that here is not an effect or difference when one exists. also known as false-negative error.

Beta-you were Blinded by the truth.

Beta-you were Blinded by the truth.

How can you reduce a Type II error?

increase sample size

increase expected effect size

increase precision of measurement

increase expected effect size

increase precision of measurement

What are factors that can increase the power of a study?

increase sample size

decrease standard deviation

increase p value (type I error)

increase difference between groups

decrease standard deviation

increase p value (type I error)

increase difference between groups

Confidence Interval

Range of values within which the true mean of a population is expected to fall, with a specified probability.

T-Test

Checks differences between the means of two groups.

Tea is meant for two.

Tea is meant for two.

ANOVA

Checks differences between means of three or more groups.

Chi-Square

Checks differences between two or more percentages or proportions of categorical outcomes (not mean values).

Autonomy

Obligation to respect patients as individuals (truth-telling, confidentiality), to create conditions necessary for autonomous choice (informed consent), and to honor their preference in accepting or not accepting medical care.

Beneficence

Physicians that have special ethical duty to act in the patients best interest. May conflict with autonomy or what is best for society.

Nonmaleficence

"Do no harm." Must be balanced against beneficence; if the benefits outweigh the risks, a patient may make an informed decision to proceed.

Justice

To treat persons fairly and equitably. This does not always imply to equally.

Advance Directives

Instructions given by a patient in anticipation o the need for a medical decision. Details vary per state law.

Oral Advance Directive

Incapacitated patient's prior oral statements commonly used as a guide. Variance in interpretations.

What is the priority of surrogate decision makers?

1. Spouse

2. Children

3. Parent

4. Sibling

4 parts of informed consent

1. Disclosure

2. understanding

3. capacity

4. Voluntary

Exceptions:

1. lack decision-making capacity

2. implied consent in emergencies

3. therapeutic privilege

4. waiver

2. understanding

3. capacity

4. Voluntary

Exceptions:

1. lack decision-making capacity

2. implied consent in emergencies

3. therapeutic privilege

4. waiver

When is parental consent not required?

Sex: STI, contraception, pregnancy

Drugs: substance abuse

Rock-Roll: emergency/trauma

Drugs: substance abuse

Rock-Roll: emergency/trauma

Exceptions to confidentiality

Developmental Milestones Infant 0-12 Months of Age(**P**arents **S**tart **O**bserving)

Infant 0-12mos: Motor reflexes

1. Moro--3mos

2. rooting--4 mos

3. Palmar--6mos

4. Babinski (up)--12mos

1. lifts head--1mos

2. rolls/sits--6mos

3. stands--10mos

4. walks--12-18mos

1. by 12mos

Infant 0-12mos: Social

Infant 0-12mos: Verbal/Cognitive

1. to Voice--4mos

2. to name/gestures--9mos.

1. by 9mos

1. says mama/dada--10mos.

Developmental Milestones Toddler 12-36 Months of Age (Child Rearing Working)

C: Cruises, climbs stairs, cubes stacked, cultured, kicks ball.

R: Recreation (parallel play), reapproachemnt (moves away form and then returns to mother), realization (core gender identity formed).

W: Words (200 words by age 2).

R: Recreation (parallel play), reapproachemnt (moves away form and then returns to mother), realization (core gender identity formed).

W: Words (200 words by age 2).

Toddler 12-36 mos: Motor

Toddler 12-36mos: Social

Toddler 12-36mos: Verbal/Cognitive

1. 200 by age 2

2. 2 word sentences

Developmental Milestones Preschool 3-5 Years of Age (Don't forget, they're still Learning)

D: drive (tricycle), drawing, dexterity (hops on one foot, using zippers).

F: Freedom (spending the day away from mother), friends.

L: Language (1,000 words by age 3), legends (tell detailed stories).

F: Freedom (spending the day away from mother), friends.

L: Language (1,000 words by age 3), legends (tell detailed stories).

Preschool 3-5yr: Motor

1. tricycle-3 years

1. copies line/circle-4 yr.

1. hops on 1 foot--4 yrs

2. buttons/zippers--5 yrs

Preschool 3-5yr: Social

1. spends part of day away--3yr

1. cooperative play--4yr

Preschool 3-5yr: Verbal/Cognitive

1. 1000 words by 3

2. complete sentences/prepositions--4yrs

1. tells detailed stories--4yrs

Children should be rear-facing till age_______ and in car seats with harness until age________

2; 4

Older children should use a booster until age______

8

Children under age ______ should not ride in a seat with a front facing airbag

12

What are the 4 parts of Medicare?

*A*: hospital **A****A**: hospital *A*dmission

*B*: *B*asic medical**B****B**: *B*asic medical **B**ills

*C*:**C**omb**C**: *C*ombo of A+B

*D*:**D****D**: *D*rugs

*B*: *B*asic medical

*C*:

*D*:

#1 cause of death in young adults?

Unintentional injury

#1 cause of death in infants?

congenital malformations

#1 cause of death in elderly?

Heart disease

Primary Disease Prevention

Prevent disease before it occurs (HPV Vaccination).

Secondary Disease Prevention

Screen early for and manage existing but asymptomatic disease (Pap smear for cervical cancer).

Tertiary Disease Prevention

Treatment to reduce complications form disease that is ongoing or has long-term effects (Chemotherapy).

PDSA Cycle

Process improvement model to test changes in real clinical setting.

Plan-define problem and solution

Do-test new processes

Study-measure and analyze data

Act-to integrate new process into regular workflow.

Plan-define problem and solution

Do-test new processes

Study-measure and analyze data

Act-to integrate new process into regular workflow.

Active Error

Occurs at level of frontline operatory (wrong IV pump dose programmed).

Latent Error

Occurs in processes indirect from operator but impacts patient care (different types of IV pumps used within same hospital).

Root Cause Analysis

Use records and participant interviews to identify all the underlying problems that led to an error. Categories of causes include process, people (providers or patients), environment, equipment, materials, and management.

Retrospective

Retrospective

Failure Mode and Effects Analysis

Use inductive reasoning to identify all the ways a process might fail and prioritize these by their probability of occurrence and impact on patients.

Prospective

Prospective

Metyrapone stimuation test

Blocks cortisol synthesis by inhibiting 11-beat-hydroxylase (converts 11-deoxycortisol to cortisol) in the zone fasciculata

Decreases cortisol

Increases in pituitary ACTH secretion

Leads to increased 11-deoxycortisol and further metabolized to hydroxycorticosteroids that accumulate in the urine (if both these metabolites increase than that means an intact HPA axis)

Decreases cortisol

Increases in pituitary ACTH secretion

Leads to increased 11-deoxycortisol and further metabolized to hydroxycorticosteroids that accumulate in the urine (if both these metabolites increase than that means an intact HPA axis)