[3]Descriptive occurance biostatistics

What is Descriptive Epidemiology

Describes disease occurrence in terms of person, place, and time to allocate resources and plan prevention.

2️⃣ What are the key elements of Time in epidemiology

Time of exposure, onset, special events, and epidemic curves.

3️⃣ What is an Epidemic Curve

A histogram showing cases against time of onset; helps visualize outbreaks.

4️⃣ What are the three types of disease occurrence by time

Sporadic (irregular cases),Secular trends (long-term patterns),Cyclic(seasonal outbreaks)

5️⃣ What is an endemic disease

A disease with a consistent presence in a population, but at a stable level.

6️⃣ Difference between epidemic and pandemic

An epidemic is excess cases above expected levels, while a pandemic spreads across multiple countries.

7️⃣ What is a Point Source Epidemic

A brief exposure causing a rapid rise and fall in cases.

8️⃣ What is a Propagated Epidemic

Disease spread person-to-person over time, causing multiple peaks in cases.

9️⃣ How is secular trend analysis useful

Tracks long-term disease patterns, helps identify key events affecting epidemiology.

🔟 Factors influencing secular trends

Changes in diagnostic techniques, age distribution, treatment, and actual disease incidence.

1️⃣1️⃣ What is the difference between Incidence and Prevalence

Incidence = new cases over time Prevalence = total existing cases (new + old)

1️⃣2️⃣ Formula for Incidence Rate

New cases ÷ Population at risk × 10ⁿ

1️⃣3️⃣ Formula for Prevalence Rate

All new & pre-existing cases ÷ Total population × 10ⁿ

1️⃣4️⃣ What are mortality measures

Quantifies deaths using crude death rate and specific death rates.

1️⃣5️⃣ Crude death rate vs. Specific death rate

Crude rate: total deaths per population Specific rate: deaths in a specific subgroup (age, sex, etc.)

1️⃣6️⃣ What is a ratio in epidemiology

Compares two groups, e.g., male-to-female cases of malaria.

1️⃣7️⃣ What is a proportion

A type of ratio where the numerator is included in the denominator, often expressed as percentages.

1️⃣8️⃣ What is a rate in epidemiology

Measures cases per unit of population per unit of time.

1️⃣9️⃣ What is morbidity

Refers to disease occurrence in a population.

2️⃣0️⃣ What is mortality

Refers to deaths in a population.

2️⃣1️⃣ What are exposure vs. outcome variables

Exposure: factors causing disease Outcome: measured disease occurrence

2️⃣2️⃣ How do health officials analyze disease trends over time

Compare weekly, monthly, and long-term trends using graphs/tables.

2️⃣3️⃣ What is hyperendemic vs. hypoendemic

Hyperendemic: persistently high disease level Hypoendemic: persistently low disease level

2️⃣4️⃣ What is a pandemic

An epidemic that affects multiple countries or continents.

2️⃣5️⃣ What is an outbreak threshold

Expected disease average over 3-5 years to determine excess cases.

2️⃣6️⃣ Why is analyzing data by date of onset important

Prevents misleading trends from delayed case reporting.

2️⃣7️⃣ How can periodic (cyclic) patterns help prevention

Anticipates outbreaks, allowing prevention measures like vaccines.

2️⃣8️⃣ What is an epidemic

Excess cases above normal frequency in a population.

2️⃣9️⃣ What is a continuous common source epidemic

Exposure occurs over time, leading to a prolonged plateau in cases.

3️⃣0️⃣ Why use graphs in epidemiology

Graphs visualize trends, compare data, and help predict outbreaks