Law Exam 2 Material

Pharmaccepidemology

The study of the use and the effects of drugs in large numbers of people

Core function of Public Health

To study what is affecting the population

Epidemiology

Study of the distribution and determinants of disease frequency in human populations and the application of this study to control health problems

What are the basic principles of epidemiology

1. Assumes disease does NOT occur at random

2. If causes can be identified, disease may be prevented

Epidemiology is describes disease in what 3 terms

1. Time

2. Place

3. Person

What is a Fixed population

Membership is permanent and defined by an event

What is a Dynamic Population

Membership is transient (temporary) and defined by being in or out of membership (an individual is either part of the group or not)

Life expectancy

the average number of years that a person can expect to live at a given age, usually birth, based on current death rates

Life expectancy is related to _____

Infant Mortality

Infant mortality is related to _____

Life expectancy

A high infant mortality will….

result in LOW life expectancy from birth

Compared to females, men have a higher or lower life expectancy

Lower

The leading causes of death in the US are:

1. Heart Disease

2. Cancer

3. Accidents (unintentional diseases)

The states report deaths to

The National Vital Statistics System

Measures of disease frequency should take into account

1. Number of individuals affected with the disease

2. Size of source population

3. Length of time the population was followed

Why do we use mathematical parameters

To relate the number of cases of

• Disease

• The size of population

• Time

Need to specify if measures represents event or people

Ratio

division of one number by another number. THEY DO NOT HAVE TO BE RELATED

Proportion

Numerator is subset of denominator, expressed as a percentage

Rate

Time is an intrinsic part of denominator

Prevalence

measures the number of cases of a disease already present in a population

Point Prevalence

number of ppl who have the disease of interest at a single point in time divided by the number of people in the population at that specific time

Period Prevalence (textbook)

the number of persons who have the disease at any point during a period of time divided by the number of persons in the population during that period of time

Period Prevalence includes

both existing cases at the start and new cases that develop during the period. (this was from chat)

Incidence

Quantifies number of NEW cases of disease that develop in population at risk during a specified time period

What are the three key concepts of incidence?

1⃣ New disease events (first occurrence of disease)
2⃣ Population at risk (must be able to develop the disease) and can’t already have the disease
3⃣ Time must pass for someone to move from healthy to diseased

What does cumulative incidence measure

The proportion of a population at risk that develops a disease over a specified time period.

How do you calculate cumulative incidence?

# of new cases divided by number of persons at risk in population

What are the key characteristics of cumulative incidence?

1⃣ Measures new cases in a population at risk

2⃣ Reported as a proportion (no units)

3⃣ Requires a specified time period

4. all individuals are followed for the same length of time

What are the key assumptions of cumulative incidence?

1⃣ The entire population is followed for the entire follow-up period.

2⃣ Everyone at risk is monitored until disease occurs or the study ends.

3⃣ No one is lost to follow-up.

Incidence rates do not _______ of complete follow up

make assumption

Incidence rates account for varying follow-up times in a study population by using person-time

What does incidence rate measure

The rate at which new cases occur in a population at risk, accounting for person-time of observation

How do you calculate incidence rate?

# of new cases divided by person-time of observation among those at risk

Prevalence and Incidence: The Sink Analogy

Incidence = The flow of water from the faucet (new cases of disease entering the population).

Prevalence = The amount of water in the sink (total number of cases at a given time).

Draining water = Recovery or death, which removes cases from prevalence.

What factors increase prevalence rates?

Increased incidence (more new cases)

Lower mortality (fewer deaths due to disease)

New treatments that prolong life but do not cure the disease

What Decreases Prevalence?

Lower incidence (fewer new cases)

Higher cure rates (more people recovering from the disease)

How do chronic and acute diseases affect prevalence?

• Chronic diseases (e.g., diabetes) → Higher prevalence because people live with them longer

• Acute diseases (e.g., flu) → Lower prevalence because they resolve quickly

Why does Ebola typically have a low prevalence despite outbreaks?

High mortality rate (infected individuals die quickly)

Short disease duration (patients recover or die within weeks)

Rapid containment efforts reduce the number of active cases

What is the mortality rate?

The total number of deaths from all causes in a population, usually expressed per 1,000, 10,000, or 100,000 people per year.

Variants of mortality rate

✔ Cause-specific (e.g., cancer mortality rate)
✔ Age-specific (e.g., child mortality rate)
✔ Race-specific

How is the infant mortality rate calculated?

total number of deaths of infants less than 1 year of age, calculated per 1,000 live births

Infant mortality rate is typically expressed for a ____________

1-year period

What does disease rate measure?

The number of existing or new cases of a disease in a population.

Can be expressed as incidence or prevalence

Varies based on time period and population size

What is attack rate and when is it used?

• cumulative incidence

• Measures new cases in a defined, short period among a healthy population at risk

What is survival rate?

The number of living cases per number of cases of disease after a given time.

1. What is the relationship between disease incidence and prevalence? Give two examples of uses of incidence and prevalence measures in pharmacoepidemiology.

Incidence represents new cases of a disease within a population over a specific time, while prevalence reflects the total number of existing cases at a given point in time.

• Prevalence helps estimate the burden of chronic diseases and the need for healthcare resources (e.g., cancer treatment centers).

• Incidence is used to study the effectiveness of prevention programs, such as diabetes management education​

2. What is the best measure to estimate the rapidity with which new cases of H1N1 influenza occur among students on a college campus?

The incidence rate (number of new cases per person-time) is the best measure, as it captures the speed of transmission within a population​

What is the best mortality measure to estimate the likelihood of death for patients diagnosed with breast cancer?

Survival Rate (percentage of patients surviving five years post-diagnosis)

Briefly describe the main similarities and differences between each of the following:

1. Incidence and prevalence

2. Cumulative incidence and incidence rate

• Incidence vs. Prevalence: Incidence tracks new cases, while prevalence measures total cases at a given time.

• Cumulative Incidence vs. Incidence Rate: Cumulative incidence assumes a closed population, while incidence rate accounts for varying follow-up times.

Clinical Trials

A research study that investigates medical, surgical, or behavioral interventions in human participants

Goal of clinical trials

to evaluate the safety, efficacy, and outcomes of treatments, medications, or procedures

Purpose of clinical trials

1. Develop new treatments for diseases

2. Determine the safety and side effects of new interventions

3. Compare a new treatment against standard care or a placebo

4. Identify the best dosage for effectiveness with minimal side effects

Primary Prevention Goal

Decrease new cases of disease (before exposure)

Why use primary prevention (rationale)

Decrease exposure rates can decrease new cases

Primary Prevention Approach

Remove or decrease risk source, pre-exposure prophylaxis

Primary Prevention Population

Those without diagnosed disease

Primary Prevention Examples

Vaccinations

Health education programs

Environmental sanitation

Use of insecticide-treated bed nets to prevent malaria

PREP for HIV

Contraceptives (not a disease)

Secondary Prevention Goal

Decrease new cases of disease (after exposure), decrease disease severity

Usually asymptomatic

Secondary Prevention Rationale

Decrease progression to severe disease, decrease morbidity and mortality

Secondary Prevention Approach

Screening, post-exposure prophylaxis, treatment to decrease impact/reverse disease course

Secondary Prevention Population

Those with diagnosed disease

Secondary Prevention Examples

• Mammograms to detect breast cancer early

• Daily low-dose aspirin to prevent further heart attacks

• Screening for high blood pressure

• Post-exposure prophylaxis for HIV

• Regular blood sugar monitoring for diabetes

Tertiary Prevention Goal

Decrease complications, deaths

Tertiary Prevention Rationale

Decrease disease severity and increase recovery, decrease deaths/complications

Tertiary Prevention Approach

Treatment tailored to patient, therapeutic intervention

Tertiary Prevention Population

Those with diagnosed disease

Tertiary Prevention Examples

Cardiac or stroke rehabilitation programs

Chronic disease management programs (e.g., for diabetes, arthritis, depression)

Support groups for chronic conditions

Vocational rehabilitation programs

Physical therapy for injury recovery

Parallel Group Design

• randomized controlled trial where participants are divided into different groups, each receiving a different treatment

What does Randomized mean

• participants are randomly assigned to treatment or control groups

What are fixed treatment groups

participants stay in their designed group for the entire study

What happens at the end of a Parallel Group Design study

Comparison: at the end of the study, outcomes are compared between groups to determine efficacy and safety

How was the parallel group design used in COVID-19 vaccine trials?

Participants were randomly assigned to either receive the vaccine or a placebo, and infection rates were compared between groups

What did the Placebo Group receive in the COVID-19 parallel group study?

A saline injection

What was the objective of the ALLHAT trial?

To compare the efficacy of different blood pressure medications in preventing heart attacks and strokes

How were participants assigned in the ALLHAT trial?

They were randomly assigned to one of four treatment groups.

What medication did Group 4 receive in the ALLHAT trial, and what happened to it?

Doxazosin (alpha-blocker); this group was stopped early due to poor results.

What was the key finding of the ALLHAT trial?

Diuretics (chlorthalidone) were the most effective at preventing heart attacks and strokes

Crossover Design

• a crossover trial is a type of clinical trial where participants receive multiple treatments in a sequential order, rather than being assigned to only one treatment group

How does a crossover design reduce variability?

Each participant serves as their own control, minimizing differences between groups.

How do you minimize bias in a cross over design

Treatment order is randomized

What is required before treatments to prevent carryover effects

washout period

Who needs more participants, Crossover Design or parallel-group trials

Crossover design and it makes it more efficient

Why was the migraine treatment trial a crossover design?

Each participant received both sumatriptan and a placebo during different migraine attacks, allowing them to serve as their own control and reducing variability.

How were participants assigned to treatments?

Patients were randomly assigned to receive sumatriptan (6 mg or 8 mg) or placebo during a migraine attack, with treatment order randomized.

Why is a washout period important in a crossover trial?

It prevents carryover effects from the first treatment before the second treatment is administered

What is a factorial design in clinical trials?

study design that evaluates the effects of multiple interventions simultaneously by testing different combinations within a single trial.

Why is factorial design efficient?

It allows researchers to assess multiple treatments and their interactions without conducting separate trials.

What are the key features of factorial design?

1. Multiple Interventions: Tests two or more treatments at the same time.

2. Combination Testing: Evaluates treatments alone and in combination.

3. Interaction Analysis: Detects if combined treatments have different effects than expected.

How are participants assigned in a 2x2 factorial design?

Participants are randomly assigned to one of four groups:

• Group 1: Treatment A only

• Group 2: Treatment B only

• Group 3: Both Treatments A and B

• Group 4: Control (Neither treatment)

What does a 2x2 factorial design allow researchers to analyze?

• The effect of Treatment A alone

• The effect of Treatment B alone

• The effect of both treatments combined

• Whether the treatments interact in unexpected ways

What was the objective of the ISIS-2 trial?

To assess the effects of aspirin and streptokinase on mortality in patients with suspected acute myocardial infarction

What type of study design was used in the ISIS-2 trial?

A 2×2 factorial design clinical trial

How were participants randomized in the ISIS-2 trial?

Patients were randomly assigned to one of four groups:

1. Aspirin only

2. Streptokinase only

3. Both aspirin and streptokinase

4. Neither (control group)

What were the key benefits of using a factorial design in the ISIS-2 trial?

• Allowed evaluation of two treatments simultaneously

• Assessed the individual effects of aspirin and streptokinase

• Determined whether the combination had an additive effect on reducing mortality

What is the definition of clinical trial conduct?

Clinical trials follow a structured process to ensure

1. scientific validity

2. participant safety

3. regulatory compliance

What is the first step in conducting a clinical trial?

Protocol Development – Defines

1. objectives

2. methodology

3. outcomes

What regulatory approvals are required before a clinical trial begins?

Approval from the

1. FDA (Food and Drug Administration)

2. IRB (Institutional Review Board).

Why is site selection and investigator recruitment important?

It ensures that the trial is conducted at

1. appropriate locations

2. qualified researchers.

What happens during participant recruitment and screening?

Eligible participants are identified and enrolled based on inclusion and exclusion criteria.

What occurs during trial execution and data collection?

Participants follow the intervention plan

Researchers collect data on efficacy and safety.

Why is monitoring and safety reporting essential in clinical trials?

To ensure participant safety, track adverse events, and maintain compliance with protocols.