Epidemiology of Non-Communicable Diseases

Epidemiology of Non-Communicable Diseases

• NCDs, or chronic diseases, are long-lasting and result from a combination of genetic, physiological, environmental, and behavioral factors.
• The main types of NCDs are cardiovascular diseases, cancers, chronic respiratory diseases, and diabetes.

Scope of Prevention

• The decline in death rates in high-income countries during the nineteenth century was mainly due to a decrease in deaths from infectious diseases, as shown in the rate of tuberculosis deaths in England and Wales from 1840-1968

Chronic Disease Epidemiology: The Basis of Prevention

• NCDs are the major cause of death globally, accounting for 36 million deaths each year.
• This accounts for 61% of the world's deaths and 48% of the global burden of disease.
• 20% of NCD deaths occur in high-income countries, while 80% occur in low- and middle-income countries.
• The leading causes of chronic diseases are cardiovascular disease (17.5 million deaths), cancer (7.5 million deaths), chronic respiratory disease (4 million deaths), and diabetes (1.1 million deaths).

Levels of Prevention

• The four levels of prevention are primordial, primary, secondary, and tertiary, corresponding to different phases in disease development.
• Each level targets factors or conditions that have an established role in causing disease.
• Preventive actions may still be taken even with incomplete evidence of a risk, labelled as "precautionary prevention" because ignoring the risk has too great a threat to public health.
• The "precautionary principle" is commonly used in the environmental field to avoid public health risks from processes or products.

Primordial Prevention

• Actions that inhibit the emergence of risk factors related to environmental, economic, social, behavioral conditions, and cultural patterns of living.
• It prevents the development of risk factors in countries or population groups where they haven't appeared yet.
• Adult health problems like obesity and hypertension often have their origins in childhood lifestyles.
• Efforts are directed towards discouraging children from adopting harmful lifestyles.
• The main intervention is through individual and mass education.

Primary Prevention

• Actions are taken prior to the onset of disease, eliminating the possibility of the disease ever occurring.
• It is an intervention in the pre-pathogenesis phase of a disease or health problem.
• Accomplished by measures of "health promotion" and "specific protection."
• Includes the concept of "positive health," encouraging the achievement and maintenance of "an acceptable level of health".
• can be achieved by promoting general health and well-being or by specific protective measures.

Primary Prevention can be achieved by

• Health education
• Environmental modifications
• Nutritional interventions
• Lifestyle and behavioral changes

Specific Protection

• Immunization and seroprophylaxis
• Chemoprophylaxis
• Use of specific nutrients or supplementations
• Protection against occupational hazards
• Safety of drugs and foods
• Control of environmental hazards

Secondary Prevention

• Action that halts the progress of a disease at its start and prevents complications.
• The specific interventions are early diagnosis (e.g. screening tests and case finding programs) and adequate treatment.
• Attempts to arrest the disease process, restore health, and reverse communicability of infectious diseases.

Tertiary Prevention

• Used when the disease process has advanced beyond its early stages.
• Reduce or limit impairments and disabilities, and to promote the patients' adjustment to irremediable conditions.
• Intervention that should be accomplished in the stage of tertiary prevention are disability limitation, and rehabilitation.

Definition of Chronic Illness

• Chronic Disease” as "comprising all impairments or deviations from normal, which have one or more of the following characteristics:
• Are permanent
• Leave residual disability
• Are caused by non-reversible pathological alteration
• Require special training of the patient for rehabilitation
• May be expected to require a long period of supervision, observation or care

Gaps in Natural History

• More research is needed to understand the cause of chronic disease, making diagnosis and specific prevention difficult.

Multifunctional Causation

• Most chronic diseases are the result of multiple causes, rather than a simple one-to-one cause-effect relationship.

Long Latent Period

• Insight of the natural history of chronic disease involves the long latent period between initial exposure and the onset of disease.

Indefinite Onset

• Most chronic diseases have a slow onset and development, making it difficult to distinguish between diseased and non-diseased states.

Predisposing Factors to Cardiovascular Disease

Non-modifiable

• Age: between 50-60 years of age.
• Sex: More common among men.
• Family history: seen to run in families
• Genetic factors

Modifiable

• Cigarettes smoking
• Hypertension
• Serum cholesterol
• Serum homocysteine
• Diabetes mellitus
• Obesity
• Exercise
• Hormone
• Type A personality
• Alcohol
• Soft water
• Noise
• Drugs

Coronary Heart Disease (CAD) and Ischemic Heart Diseases

• Impairment of heart function due to inadequate blood flow to the myocardium, resulting from obstruction in the coronary circulation.
• Caused by plaques in the lumen of the coronary artery (Atherosclerosis)

CAD is manifested as

• Angina pectoris
• Myocardial infraction
• Irregularities of the heart
• Cardiac failure
• Cardiac arrest

Prevention of CAD

• Primordial
• Primary
• Secondary

Primordial Prevention

• Discouraging harmful lifestyles such as smoking, poor eating habits, lack of physical exercise, and alcoholism.
• The main intervention is through mass education.

Primary Prevention

• Elimination or modification of the risk factors of disease, following population and high-risk strategies.

Population Strategy

• Dietary changes: Consumption of saturated fats should be less than 10% of total energy intake
• Smoking changes
• Blood pressure
• Physical activity

High Risk Strategy

• Identifying at-risk individuals for CAD and providing preventive care.

Strategies for particular conditions

• Individuals with hypertension:Treatment.
• Smokers: to give up smoking
• Hyperlipidaemia: are treated

Secondary Prevention

• Preventing the reoccurrence of CAD by stopping smoking and taking tablets regularly.

Congenital Heart Disease (CHD)

• Defect in the structure and function of the heart, developed during fetal growth, present at birth, often detected later in life.
• The occurrence of CHD can be 5-9 in every 1000 children below the age of 10.

CHD is grouped in:

• Acyanotic and Cyanotic heart disease

Acyanotic Heart Disease (Left to right shunt)

• Atrial septal defect (ASD)
• Ventricular septal defect (VSD)
• Patent ductus arteriosus (PDA)
• Persistent trunkus arteriosus

Acyanotic Heart Disease Without a Shunt

• Congenital aortic stenosis
• Coarctation of aorta
• Congenital aortic incompetence; mitral incompetence

Cyanotic Heart Disease (Right to Left Shunt)

• Tetralogy of Fallot
• Complete transposition of great arteries
• Tricuspid atresia
• Coarctation of aorta
• VSD with reversed shunt
• PDA with reversed shunt
• ASD with reversed shunt

Signs and Symptoms of CHD

• A child with CHD is suspected if there is a history of Apnea, growth failure and repeated attacks of respiratory infections.
• Are physically retarded and often cyanotic.
• Cardiac murmurs are common

Causes of CHD

• Intrinsic agents chroromosomal aberration, defects of T lymphocytes, systemic lupus erythematous
• Altitude at birth
• External agents
• Prematurity
• Maternal age
• Sex of the child

Prevention of CHD

• avoid consanguineous marriages, 1st pregnancy not beyond 30 and Pregnant women should advised to avoid infections, alcohol, smoking, X-ray, drugs and chemicals.
• genetic counselling and antenatal care

Rheumatic Heart Disease (RHD)

• Ultimate sequelae and crippling stage of rheumatic fever; result of streptococcal pharyngitis.
• Rheumatic fever is an acute febrile disease

Agent Factors of Rheumatic Fever

• Agents: Group A, beta hemolytic streptococci.
• Reservior of infection: All the cases and carriers
• Age Incidence: Age 5-15
• Sex: it's equal in both the sexes.
• Immunity: It causes immunological process and repeated exposure to illness

Predisposing Factors

• Social factors
• Pathogenesis

Clinical Features

• Fever
• Polyarthritis
• Carditis

Prevention

• Health promotion
• Specific protection

Secondary Prevention: Early Diagnosis And Treatment

• Intensive treatment for joint pain and carditis
• Rehabilitation social, vacational and psychological measures

Hypertension

• Systolic <120 mmHg and diastolic <80 mmHg readings at each of two or more visits after an initial screening are considered hypertension.

Types of High Blood Pressure

• Primary

Risk Factors of Hypertension

• Above 45 years (men) and 65 years(female)
• Race
• Family History
• Too much salt (sodium) in your diet
• Too little potassium in your diet
• Being overweight or obese
• Using tobacco
• Too little vitamin D in your diet.
• Drinking too much alcohol
• Stress

Signs and Symptoms of Hypertension

• Asymptomatic
• Dizziness
• Flushed face
• Headache
• Fatigue
• Epistaxis and nervousness

Diagnosis of Hypertension

• Multiple measurements
• Urinalysis
• Blood tests
• Renal ultrasonography
• Evaluate for aldosteronism if potassium decreased
• ECG

Treatment of Hypertension

• Weight loss and exercise
• Smoking cessation
• Limiting alcohol

Obesity

• Characterized by the abnormal growth of the adipose tissue
• Corpulence index
• Body Mass Index

Risk Factors

• Age
• Sex
• Genetic factors

Modifiable Risk Factors

• Physical activity
• Socioeconomic status
• Literacy level

Prevention and Control

• Maintain BMI between 18 to 25 throughout adulthood.
• Dietary changes

Health Education

• Hazards of obesity and it's prevention by healthy diet and lifestyle

Cancer

• most fearful disease with abnormal and uncontrolled growth of the cells, it also has the presence of aberrations in the nucleus