ORIGINS OF LIFE COURSE:
- Life course perspective: proposed by Michael Lu and Neal Halfon in 2003 as a new approach to examining racial and ethnic disparities in birth outcomes.
- Synthesis of two longitudinal biomedical models: an early programming model and cumulative pathway model.
- Offers a broader way of looking at health, over a life span rather than disconnected stages (infancy, adolescence, child bearing years, old age) integrating biological, behavioral, psychological, social and environmental factors which contribute to health outcomes across the course of a person’s life.
KEY LIFE COURSE CONCEPTS:
- Timeline: today’s experiences and exposures determine tomorrow’s health
- Timing: health trajectories are particularly affected during critical or sensitive periods
- Environment: our social, physical and biological environments strongly affect our capacity to be healthy
- Equity: inequities are health determinants
Specific risk and protective factors can be mediated during critical periods.
EVIDENCE AND THEORIES:
- Critical periods: perinatal and peripubertal periods are sensitive times in human development. Disruptive events that occur during these times can have lasting effects on health.
- Early Programming:
- Early programming: early experiences can program an individual’s future health and development, either directly in diseases/conditions or through vulnerabilities to disease in the future.
- Developmental/Fetal origins of disease (Barker): susceptibility to cardiovascular disease, diabetes, cancer, obesity, and high blood pressure are programmed in utero as a response to fetal undernutrition.
- Cumulative Pathways:
- Weathering (A. Geronimus)/Cumulative effect: stressors can accumulate over time and have a profound direct impact on health and development through allostatic loads.
- Adverse childhood experiences (ACE study): children exposed to adverse experiences have a graded increased risk for multiple chronic health conditions.
- Epigenetics: our physical environment (including food, toxins, etc) can activate heritable changes in gene expression.
LINKING IT ALL TOGETHER:
- Life course, social determinants, and health equity are all complementary, synergistic, and integral to health
- Life course helps explain and illustrate how social determinants influence health
- Life course helps explain and illustrate how health inequities develop
- Life course incorporates human development into our understanding of health
TRANSLATION TO PRACTICE:
- There are multiple critical windows of time for intervening for health
- We can act on health through interventions, policy and systems in expanded settings
- Policies can have differential effects on families, which is why life course supports comprehensive approaches to health that include the family as the focus of intervention