Disease Incidence and Prevalence

Introduction

• Non-infectious diseases: Diseases not caused by pathogens but resulting from genetic factors, lifestyle choices, environmental influences, or nutritional issues. They are typically chronic and require extended management. Examples include cancer, heart disease, and diabetes.

  

• Incidence: Refers to the count of new disease cases in a population during a specific timeframe.

• Prevalence: Indicates the total number of both new and existing cases at a given moment.

Key Metrics and Public Health

• These metrics guide policy decisions and preventive strategies aimed at minimising the impact of diseases, including cardiovascular diseases and diabetes.
• They are essential for healthcare resource distribution; a high prevalence requires more healthcare facilities and personnel.

Categories of Non-Infectious Diseases

• Genetic disorders: Result from genetic anomalies (e.g., cystic fibrosis, sickle cell anaemia).

• Lifestyle diseases: Develop from behavioural choices (e.g., cardiovascular diseases, type 2 diabetes).

• Environmental diseases: Caused by exposure to pollutants (e.g., respiratory diseases, lead poisoning).

• Nutritional diseases: Stem from dietary deficiencies (e.g., scurvy, obesity).

  

Public Health Relevance

• Emphasises cardiovascular diseases and diabetes due to their widespread occurrence.

  

• Efficient healthcare systems can alleviate effects, minimising severity and improving health outcomes.

Data Collection in Non-Infectious Diseases

Methods

• Surveys: Gather information by selecting a representative sample from the population.

  

• Medical Records: Track disease trends using patient data.

• Databases: Compilations from organisations like WHO and CDC provide global insights.

Data Reliability

• Verification: Use trusted resources such as peer-reviewed journals.

  

Incidence vs. Prevalence Calculations

• Incidence Rate: $\text{Incidence Rate} = \frac{\text{Number of new cases}}{\text{Population at risk during the time period}}$

• Prevalence Rate: $\text{Prevalence Rate} = \frac{\text{Total number of cases}}{\text{Total population at that time}}$

  

Geographic and Demographic Trends

• Geographic Analysis: Shows varying prevalence between urban and rural areas.

• Demographics: Factors like age, gender, and socio-economic status influence incidence and prevalence.

  

Challenges in Mortality Rates

• Calculation: $\text{Mortality Rate} = \frac{\text{Number of deaths during a specific period}}{\text{Population at risk during the same period}} \times 100,000$

• Mortality rates are impacted by factors such as age, gender, and socio-economic conditions.

  

Nutrition and Environmental Factors

• Nutritional Diseases: A proper diet can either lower or increase disease risk.

• Environmental Diseases: Stem from challenges like air and chemical pollution.

  

By understanding these components, students can identify patterns and effectively apply them to public health strategies.