1. 4
CHAPTER

2. Theoretical and Conceptual Models
Set of relatively abstract and general concepts
Addresses phenomena of interest to a discipline
Directs attention to relevant client situations, interventions

3. Theoretical and Conceptual Models (continued)
Systematic approach to
Assessing health status of a population
Planning nursing interventions
Implementing interventions
Evaluating effectiveness of nursing care

4. Two Useful Types of Models:
Epidemiologic models
Examine factors that influence health and illness
Nursing models
Suggest interventions to protect, improve, or restore health

5. Epidemiology
Study of distribution of health and illness within a population
Factors that determine population’s health
Use knowledge generated to control development of health problems

6. Epidemiologic Perspectives:
Causality
Risk
Rates of occurrence

7. Causality
Link between contributing factors and states of health and illness
One event is the result of another event
Evolution of concepts of causation
Will of God
Natural causes
Specific causes
Multifactorial causes

8. Risk Estimated likelihood a particular condition will occur
Probability that a given individual will develop a specific condition
Populations at risk
Groups with greatest potential to develop a particular health problem
Result of presence or absence of specific factors
Become target groups for interventions

9. Rates of Occurrence Statistical measures
Indicate extent of health problems in a group
Allow comparison between groups of different sizes
Several rates have wide use in epidemiology, those most important are the prevalence rate, and the incidence rate.

10. Prevalence Rate
Refers to all of the people with a particular health condition existing in a given population at a given point in time.
Eg. If a nurse discovers 50 cases of measles in an elementary school that has 500 students the prevalence of measles on that day would be 10 %.

11. Prevalence Rate Conti
Prevalence Rate= Number of persons with a characteristic × 100%
Total number in population
Prevalence
Total number of people affected by a particular condition
Specified point in time

12. Incidence Rate
Refers to all new cases of a disease or health condition appearing during a given time.
Incidence rate= Number of persons developing a disease × 100%
Total number at risk per unit of time
Incidence
Number of new cases of a particular condition
Specified time period

13. Morbidity and Mortality
Used to assess health status
Develop interventions
Evaluate long term outcomes
Morbidity is ratio of number of cases to number in population

14. Morbidity and Mortality (continued)
Morbidity rate: is the relative incidence of disease in a population, the ratio of the number of sick individuals to the total population

15. Morbidity and Mortality (continued)
Mortality is ratio of number of deaths of a particular category to number in population, or the sum of deaths in a given population at a given time.

16. Epidemiologic Statistics
Case fatality rates
Percentage of persons with a condition who die of that condition
Survival rates
Proportion of people with a condition remaining alive after a specified period
Survival time
Average length of time from diagnosis to death

17. Epidemiologic Models Provide direction for community health nurses
Strategies for interventions
Collection and interpretation of data
Control health-related conditions

18. Three Types of Models: Epidemiologic triad Web of causation
Determinants of health models

19. Epidemiologic Triad Model
Agent
Host
Environment

20. Elements of the Epidemiologic Triad Model
FIGURE Elements of the Epidemiologic Triad Model.

21. Host
is a susceptible human or animal who harbors and nourishes a disease-causing agent
Many physical (i.e.. Age), psychological (i.e.. Stress response), and life style factors (i.e.. Diet) influence the host’s susceptibility and response to an agent.

22. Agent Is a factor that causes or contributes to a health problem
Biologic: bacteria, HIV virus
Chemical: dusts, solid gases
Nutrient agent: excess vitamin A can be toxic
Physical: earthquake
Psychological: events that produce stress leading to health problems.

23. Environment
Refers to all the external factors surrounding the host that might influence vulnerability or resistance.
Physical environment: climate
Psychosocial environment: social, cultural.

24. Web of Causation Emphasizes interconnectedness of causal components
Multiple factors influence health
Direct causes
Proximal to health event
Indirect causes
Distal from health event

25. Web of Causation for Adolescent Tobacco Use
FIGURE The Web of Causation for Adolescent Tobacco Use, Indicating the Interplay Between Multiple Direct and Indirect Causative Factors.

26. Determinants of Health
Various factors affect health and illness
Social
Environmental
Biological
Psychological
Behavioral/lifestyle

27. Determinants of Health (continued)
Various factors affect health and illness
Health care/health systems
Genetics

28. A Composite Determinants of Health Model
FIGURE A Composite Determinants-of-Health Model.
Prosperity: ازدهار
Sustainability: استدامة

29. Community Health Nursing Models
Developed as result of professional practice
Utilize systematic, scientific inquiry

30. Types of Models Applied to Community Health Setting
Serve as a conceptual model for nurses to understand the interrelationships that exist among the specific concepts

31. Neuman’s Health System Model
Client system striving to prevent penetration or disruption of the system by a variety of stressors

33. The Interventions Wheel Model
Consists of 17 identified community health nursing interventions that cross over three levels of population-based practice
Individual-focused
Community-focused
System-focused practice

35. The Los Angeles County Public Health Nursing Practice Model
Links public health nursing with principles of public health practice.
Community health nursing is a multidisciplinary endeavor; clients must be active participants in the endeavor.
Community health nursing practice is population-based.
Community health nursing practice is based on the core functions and essential services of public health.
Community health nurses engage in the interventions described in the intervention wheel model.
Endeavor: مسعى محاولة

36. The Community-as-Partner Model
Incorporates Neuman’s health systems model and the nursing process

37. Resources
Nursing Theorist page Briefly describes and categorizes all the nursing theories with web links to individual theorists.
The Madeleine Leininger web site includes original works and writings by Dr. Madeleine Leininger, the founder of the worldwide Transcultural Nursing movement.