Theories give the community health nurse a lens for assessing the client (individual, family, group, or community), deciding what the problem is, choosing interventions, and evaluating results. In community practice the most tested frameworks are:

General systems theory

• Open system — continuously exchanges resources, information, and energy with its environment
• Input — resources entering the system: people, health needs, budget, staff, supplies, information
• Throughput (process / transformation) — activities that turn inputs into results: planning and carrying out health programs
• Output — results: improved health indicators (e.g., better glycemic control among participants), services delivered
• Feedback — information about output that returns to adjust inputs and processes, keeping the system stable
• Boundary — separates the system from its environment; its permeability controls exchange; healthy communities have boundaries that are open enough to receive resources
• Subsystems and suprasystem — the community has subsystems (health, education, welfare, economy) that are interdependent; it is part of a larger suprasystem (province, nation)
• Entropy — tendency toward disorder when new energy is not received; negentropy — order maintained through input
• Equifinality — the same end state can be reached by different paths

Homans' social exchange propositions

• Success — rewarded behavior tends to be repeated
• Stimulus — if a situation was linked to reward before, similar situations trigger the same behavior
• Value — the more valuable the reward, the more likely the behavior
• Deprivation–satiation — the more often a person has recently received a reward, the less valuable each additional unit becomes
• Aggression–approval — an expected reward not received, or an unexpected punishment, leads to anger; an unexpected reward, or an expected punishment that does not come, leads to approval
• Rationality — people choose the action with the greatest expected value (value of the result × probability of getting it)
• Costs include time, money, effort, side effects, and rewards given up
• Limitation — emphasizes external rewards and may underplay internal motivation, values, and responsibility

Neuman systems model

• Client system (individual, family, group, or community) with a basic structure (core survival factors) and five interacting variables: physiological, psychological, sociocultural, developmental, and spiritual
• Flexible line of defense — outermost, changes quickly, buffers temporary stressors
• Normal line of defense — the client's usual level of wellness
• Lines of resistance — internal factors activated when a stressor penetrates the normal line of defense
• Stressors — intrapersonal, interpersonal, extrapersonal
• Environment — internal, external, and created environment
• Reconstitution — return to stability after reaction, possibly at a higher or lower level of wellness than before
• Prevention as intervention:
  • Primary — before reaction: identify risk and strengthen the flexible line of defense
  • Secondary — after symptoms appear: early detection and treatment, strengthen lines of resistance
  • Tertiary — after treatment: support reconstitution, rehabilitation, prevent recurrence

Orem self-care deficit theory

• Self-care requisites:
  • Universal — shared by all people: air, water, food, elimination, activity and rest, solitude and social interaction, safety from hazards, normalcy
  • Developmental — linked to stages of the life cycle and to events that affect development (pregnancy, adolescence, aging, loss)
  • Health-deviation — arise from illness, injury, disability, and medical diagnosis and treatment (e.g., learning insulin injection after a diabetes diagnosis, taking medicines)
• Self-care deficit — when therapeutic self-care demand exceeds self-care agency → nursing is needed
• Dependent-care agent — a person (often a family member) who provides care for someone who cannot meet their own needs
• Nursing systems:
  • Wholly compensatory — the nurse does everything (unconscious client)
  • Partly compensatory — nurse and client share care (client with arthritis needs help dressing)
  • Supportive-educative — client can do the care but needs teaching, guidance, and support (newly diagnosed client learning lifestyle changes)
• Goal: develop, maintain, or restore the client's capacity for self-care

Roy adaptation model

• Stimuli:
  • Focal — the stimulus most immediately confronting the person
  • Contextual — all other stimuli present that contribute to the effect
  • Residual — factors whose effects are unclear (beliefs, past experiences)
• Coping mechanisms — regulator (physiologic) and cognator (cognitive-emotional)
• Four adaptive modes: physiologic, self-concept, role function, interdependence (giving and receiving love, respect, value)
• Responses — adaptive (promote integrity) or ineffective
• Nursing process: assessment of behavior → assessment of stimuli → nursing diagnosis → goal setting → intervention (manage stimuli) → evaluation

• Select a framework that fits the client and question; state it in plans and reports
• Use the framework consistently through assessment, diagnosis, planning, implementation, and evaluation
• Combine theory with community participation: the community helps define problems and solutions
• Evaluate whether theory-based interventions produced the intended outputs and outcomes
• Explain frameworks to midwives, BHWs, and students in simple terms

• Theories guide judgment but do not replace legal standards: care must stay within the nurse's scope under the Philippine Nursing Act of 2002 (RA 9173) and DOH program guidelines.
• Exchange-based incentives must be ethical: rewards should not coerce, deceive, or exploit poverty, and participation must remain voluntary with informed consent.
• Applying Orem's dependent-care concept requires respecting the client's autonomy and the caregiver's capacity; the nurse assesses caregiver burden.
• Family and community data gathered for assessment are protected under the Data Privacy Act (RA 10173).
• Justice: theory-driven priorities should reach the most vulnerable, not just those easiest to serve.

Case 1 — Classifying a program (Neuman). A PHN offers free blood pressure measurements to adults in the barangay to find undiagnosed hypertension.

• Answer: secondary prevention.
• Why: early detection after the stressor may have produced a reaction; it strengthens lines of resistance.

Case 2 — Choosing a nursing system (Orem). A client with a new hyperlipidemia diagnosis can cook and exercise but lacks knowledge.

• Answer: supportive-educative system.
• Why: the client can perform self-care with teaching and support.

Case 3 — Systems thinking. An immunization program's coverage drops after a vaccine storage problem.

• Answer: the storage problem is an input/process disruption; coverage data returning to planners is feedback used to correct the system.
• Why: systems theory links inputs, processes, outputs, and feedback.

Case 4 — Social exchange. Residents stop attending weekly exercise sessions once free snacks become routine.

• Answer: deprivation–satiation — repeated rewards lose value.
• Why: vary rewards and emphasize intrinsic benefits.

• Saying Neuman's primary prevention strengthens the lines of resistance — it strengthens the flexible line of defense; lines of resistance belong to secondary prevention.
• Calling a new diagnosis a developmental requisite — needs arising from illness and its treatment are health-deviation requisites.
• Confusing focal (immediate) and contextual (contributing) stimuli in Roy's model.
• Mixing systems output (results) with input (resources) — improved health indicators are outputs.
• Assuming a community is a closed system; communities are open systems.
• Treating Homans' theory as explaining intrinsic motivation; its focus is external reward and cost.

• Systems: input → throughput → output, with feedback; communities are open systems with permeable boundaries.
• Entropy = drift toward disorder without new input; subsystems are interdependent.
• Homans: success, stimulus, value, deprivation–satiation, aggression–approval, rationality; cost includes side effects and time.
• Neuman: flexible line (outer buffer) → normal line (usual wellness) → lines of resistance → basic structure.
• Neuman prevention: primary strengthens flexible line; secondary strengthens lines of resistance; tertiary supports reconstitution.
• Orem: universal, developmental, health-deviation requisites; wholly compensatory, partly compensatory, supportive-educative systems.
• Dependent-care agent = family member or other caregiver acting for a dependent person.
• Roy: focal, contextual, residual stimuli; physiologic, self-concept, role function, interdependence modes.
• Roy diagnosis links the ineffective response to its stimulus; nursing manages stimuli.
• Community-as-partner: core plus eight subsystems for community assessment.