A lifecourse trajectory is, in the simplest terms, the path a person takes from birth until the end of life. A trajectory is a route travelled from start to finish. For instance, when a ball is thrown, the force used to propel it, the direction in which it is thrown, and any obstacles it encounters along the way will dictate when and where it lands. The path the ball follows through the air on its way to landing is its trajectory.
Health trajectories are the pathways that individuals follow from a health perspective. These pathways evolve over time, and the directions taken are dependent on and shaped by individual actions, as well as by the circumstances and conditions that individuals experience throughout life.5
In reference to health, the path or trajectory followed can change during any life stage (childhood, adolescence, adulthood) and can vary from person to person depending on the factors interacting to influence health (biological, behavioural, physical, social). Both positive and negative factors evolve and interact within and across life stages, ultimately resulting in the positive and negative health outcomes that each individual experiences in his or her lifetime. Canadian researchers cite three models that explain the relationships between these influencing factors and health outcomes.5 The latency model shows the relationship between an exposure at one point in the lifecourse and the probability of a health outcome later (regardless of intervening or mitigating experience).5 For example, childhood exposure to high levels of ultraviolet rays from sunlight can eventually emerge as skin cancer in adulthood and adequate nutrition both in the prenatal period and the first year of life can reduce the risk of developing heart disease later in life.6–11
The cumulative model shows the health impact of multiple or recurring exposures over the lifecourse.5 For example, growing up in a low-income environment and being repeatedly exposed to conditions of poverty can adversely impact adult health outcomes such as high blood pressure, circulatory diseases and weakened immunity. Alternatively, children who grow up in a household where the father works in a higher-income occupation and who themselves work in higher-income occupations as adults have been shown to have decreased rates of ischemic heart disease in adulthood.12, 13
The pathway model shows a dependent sequence of exposures, where an exposure that occurs at one stage of a life influences the probability of other exposures later in the lifecourse and — potentially — across generations.5 For example, children living in a family experiencing financial worries or marital discord may be at greater risk of cognitive and behavioural difficulties.14, 15 A lack of readiness to learn and poor behaviour at school can reduce educational performance.16 In turn, in adolescence, this can lead to the adoption of health-damaging behaviours such as smoking and illicit drug use, having an unplanned pregnancy or dropping out of school.15 Consequently, this may limit employment options and financial success and impact health in adulthood.5, 15 Conversely, activities such as reading, spelling of words or singing to a child can promote language development leading to a lasting impact on the child's literacy and lifelong learning.17, 18 Being developmentally ready for school can influence school success and social competency among peers, which can lead to better decisions around risk behaviours and eventually better adult health outcomes.19, 20
The value of the lifecourse trajectory model to public health is that it helps us to understand the links and timing between exposure to a factor or combination of factors (at one point in time or over time) and the later health effects tied to those factors.5, 21–24 This knowledge can then be applied to identifying and understanding trends in the health of populations and links between life stages, and to proactively developing appropriate policies and interventions that address those trends and links.5, 22 In this way, public policy that incorporates the lifecourse approach can be considered “prevention policy”, identifying opportunities for creating ideal conditions for health and wellness at critical points across the lifecourse.5, 22
Events that affect health are important throughout life, but childhood is a critical period in which to establish a foothold on the road to good health.22 Children experience a phase of accelerated growth in the early years of their lives — including physical growth, brain development, and mental and emotional growth and development. The education, care and attention they receive during this period can have a crucial impact on their future health and well-being. In particular, the prenatal period to age six (and especially the first three years) is the time during which the foundation for developing competence and coping skills is formed, affecting learning, behaviour and health throughout life.25 It is also the stage during which nutrition, care and nurturing directly affect pathways of the brain that, among other things, affect risk for disease later in life.25
Although opportunities to maintain or return to good health exist along the lifecourse, establishing initial good health and developing resilience can make it easier to maintain a positive health trajectory in the face of later challenges.26 Evidence suggests that the greatest return on investment, in terms of lifelong health and quality of life, can be realized through interventions made during the earliest stages of the lifecourse (prenatal and childhood).25, 27–29
Canada has made substantial progress creating healthy starts, as noted in the following chronicle of actions taken over the last 150 years. These highlights illustrate how public health and other influencing factors have evolved in their approach to children's health and wellbeing. Looking to the past provides a sense of where we stand today on children's health and the foundation from which future actions in this important area can also be taken (for a more detailed history of public health in Canada, see The Chief Public Health Officer's Report on the State of Public Health in Canada, 2008).30
Before the 20th century, the health and safety of children in Canada was not a specific area of focus for government policy and community interventions. Most pregnancies were unmonitored and birth complications presented potential risks to mothers and children primarily due to the limited effectiveness of health care at that time, as well as limitations in access to health care.31 In the early 1890s, Canada's infant mortality rate (IMR) was approximately 145 deaths for every 1,000 live births.32, 33
During this period, many children were expected to help support the family — at home, on the farm, with family businesses or activities that generated income, or through participation in the paid labour force. For those abandoned or orphaned, early provisions made for them through legislation included the Orphan's Act of 1799 and Apprentices and Minors Act of 1851. Both provided legal recognition of these children but only in exchange for their labour by binding them into apprenticeship.34–36 For all children, working conditions were often difficult and dangerous, resulting in high rates of injury and death.37, 38
In the second half of the 19th century, the recognition of poor living and working conditions (particularly in industrial areas and among the poor and working classes), and the relationship of these conditions to health and safety, brought about initiatives for improvement. For example, policies such as Ontario's Factory Act of 1884 set minimum wages, imposed limits on hours worked and banned employment where injury was likely for women and children.39, 40 Similar legislation followed across Canada during the early 1900s.39
The care of abandoned or orphaned children also evolved during this period. Charitable organizations were given the legal authority to intervene in the maltreatment of apprenticed children. These organizations were also involved with the emergence of adoption, fostering and institutional care as alternatives to apprenticeships. Ontario's 1888 Act for Protection and Reformation of Neglected Children (also known as the Children's Protection Act) took child protection measures one step further: it allowed courts to make any neglected child — not just those orphaned or abandoned — a ward of institutions and charitable organizations.41, 42
During this period, school attendance was on the rise and by the end of the century compulsory attendance legislation had been passed in British Columbia, Ontario, Prince Edward Island and Nova Scotia. Most other provinces followed suit within the next decade.43
For Aboriginal children, health and safety issues are not well documented for this period. It can be assumed that their health paralleled that of adult Aboriginals. The arrival of European explorers and settlers had a detrimental impact on Aboriginal health — from the introduction of various diseases and non-traditional foods to a reduction of resources due to their confinement to specific areas of land.44–46 The health and well-being of First Nations and Inuit children experienced another setback with the introduction of the residential schools system in 1849. The system was based on the premise that if First Nations and Inuit learned English, adopted European customs and Christianity, they would be culturally assimilated into European-Canadian culture.47 As a result, children were removed from their homes and isolated from their family. In addition, many children suffered from verbal, emotional, physical or sexual abuse, harsh discipline, neglect and the loss of cultural identity. This had an impact not only on residential school attendees, but also on their children and grandchildren.47–51
By the early 20th century, community programs targeting parents and young children (e.g. well-baby clinics, immunization, dental health promotion, in-school medical inspections and greater health care access) were being put in place to fight high rates of infant mortality and contagious diseases.37 A vaccine against diphtheria was introduced in 1926, while widespread smallpox inoculations led to the disease's eradication from Canada by 1946.52, 53
Municipal water fluoridation programs were also introduced and recognized as beneficial in tooth decay prevention.54 Other improvements to water supplies reduced illness and deaths associated with water-borne diseases.30, 55 Infants’ diets were supplemented with vitamin D during the 1920s, which contributed to the decrease in the incidence of rickets in children over time.56 Additionally, foodborne illnesses were addressed to some extent with the requirement that saleable milk be pasteurized.57, 58
Some women, particularly middle- and high-income women living in urban areas, began receiving prenatal care and often delivered their babies in a hospital setting.31 Health services specifically aimed at the care of infants and children emerged during this time with, for example, paediatrics being recognized by the Royal College of Physicians and Surgeons of Canada as a separate freestanding medical specialty in 1937.59
This period was also marked by the introduction of broad social initiatives. In Manitoba and Ontario, for example, a Mother's Allowance was established in response to the poverty faced by families that were left fatherless after World War I.60 At the federal level, the Government of Canada initiated income support to families with children through the Child Tax Exemption of 1918.61
School attendance continued to grow, with more children attending school for longer periods of time. Compulsory school attendance was in force in all provinces of Canada except Quebec and Newfoundland.43 This had an important influence on child health because school was often a child's only link to health care.43, 62 In-school health inspections and examinations were common, as was inclusion of health promotion in curricula.62 Through these inspections, the need for childhood dental care and tooth decay prevention became apparent. Some provinces initiated travelling dental clinics to service remote areas (e.g. Newfoundland, Northern Ontario, Alberta and British Columbia).63–65
A very different school system was being experienced by First Nations and Inuit children at residential schools, where conditions were often neglectful and detrimental to the children's health. In 1907, the Chief Medical Inspector reported numerous deficiencies in the schools to the Department of Indian Affairs, including elevated tuberculosis rates and inadequate nutrition, health standards and staff training.44, 46, 66, 67 By 1920, it had become mandatory for every First Nations and Inuit child between the ages of 6 and 15 years to attend school, and by 1931, the residential schools system was at its peak with about 80 schools operating in Canada.66, 68
A decrease in infant and maternal mortality rates occurred during this time, although gaps in these rates were notable between upper- and lower-income families.69, 70 By the end of this period (1936–1940), Canada's IMR had fallen to an average of 71 deaths per 1,000 live births.71
Advances in children's health continued as Canada built upon the broad prevention initiatives and social and infrastructural change that had been initiated in the pre-World War II period. The success of immunization programs resulted in the eradication or near-eradication of many vaccine-preventable diseases that typically strike during childhood. The inactivated polio vaccine, introduced in 1955, combined with the initiation of in-school vaccination programs, resulted in Canada's certification as polio-free by 1994.52, 72 Similarly, widespread vaccination for diphtheria, pertussis and measles contributed to making these diseases rare by the end of the century.52
The Medical Care Act was passed in 1966, affording access to insured medical services for all Canadians. By the 1970s, all provinces had joined the universal health program.62, 73The Canada Health Act, passed in 1984, served to clarify health care funding conditions and identified the five principles — public administration, comprehensiveness, universality, portability and accessibility — of health care in Canada.74, 75
Children's safety also improved during this period with the introduction of legislation, standards and regulations to prevent childhood injury related to toys, equipment, furniture, sleepwear and transportation. These measures led to a decline in non-fatal childhood injuries by the end of the century.76–80 Additionally, provincial/territorial motor-vehicle restraint legislation and reduced speed limits contributed to a decrease in deaths from motor vehicle crashes during this same period.76, 78, 81–83
While there is little information on the nutritional practices of pregnant women, Canada's decision to fortify select grain products with folic acid (which became mandatory in November 1998), and to recommend the use of folic acid supplements by all women who could become pregnant, helped to greatly decrease the number of open neural tube defects such as anencephaly and spina bifida. A seven-province study showed a 46% reduction in the overall rate of neural tube defects (see Figure 2.1).84–86
In terms of broad social investments, a number of programs and policies to support families were introduced during this period, including:
In 1991, Canada ratified the United Nations Convention on the Rights of the Child and in doing so agreed that children have the right to the “highest attainable standard of health.”94, 95 The following year, Canada launched Brighter Futures: Canada's Action Plan for Children to prevent and reduce conditions of risk among children through targeted programs such as the Community Action Program for Children (CAPC) and the Canada Prenatal Nutrition Program (CPNP).93,96 Similarly, Canada's Aboriginal Head Start in Urban and Northern Communities (1995) and Aboriginal Head Start On Reserve (1998) programs were established to address the unique challenges facing First Nations, Inuit and Métis children and their families.97, 98 In 1997, the federal, provincial and territorial governments agreed to develop a National Children's Agenda, to co-ordinate and advance actions to ensure that all Canada's children have the best possible opportunity to develop to their full potential.99
By the mid- to late-1950s, First Nations children began entry into mainstream public schools.100, 101 In 1972, the National Indian Brotherhood, (which later became the Assembly of First Nations) called for “Indian control of Indian education” which was endorsed by the federal government in 1973.102–104 However, the last of the residential schools did not close until 1996, the same year that the Royal Commission on Aboriginal Peoples released its final report recommending a public inquiry to investigate and document the abuses faced by children who attended these schools.105, 106 According to results from the First Nations Regional Longitudinal Health Survey (RHS) 2002/03, the four most common negative experiences affecting the overall health and well-being of survivors of residential schools were isolation from family, verbal or emotional abuse, harsh discipline and loss of cultural identity.50
By the end of the 20th century, Canada's IMR had declined from an average rate of 45 deaths per 1,000 live births during the five-year period after World War II to 5.6 deaths per 1,000 live births for the period 1995–99.70, 107Figure 2.1 Prevalence of neural tube defects in seven Canadian provinces, 1993 to 200285
The seven Canadian provinces include Newfoundland and Labrador, Nova Scotia, Prince Edward Island, Quebec, Manitoba, Alberta and British Columbia.
Diagnostic categories include ICD-9 655.0 and 740.0 to 742.0 and ICD-10 Q00, Q01, Q05 and O35.0.
This decrease takes into consideration not only live births with these conditions, but also stillbirths and induced abortions.
Source: De Wals, P., Tairou, F., Van Allen, M. I., Uh, S.-H., Lowry, R. B., Sibbald, B. et al. (2007).
Canada continues to focus on building positive childhood experiences and strong families through initiatives and strategies centred on improving children's physical and mental health and safety. The federal-provincial-territorial Early Childhood Development Agreement (2003) was introduced to promote health, strengthen early childhood development, and support families and communities through employment, training and better access to early childhood care.93, 108 Social interventions to support families with children, including extended maternity and parental benefits (from six months to one year) were provided under amendments to the Employment Insurance Act in 2001.87, 93 And many of the programs established under the Brighter Futures initiative (e.g. Aboriginal Head Start, CAPC and CPNP) continue to contribute to reducing conditions of risk for children.96, 109, 110 In the area of child safety, the legislation, standards and regulations to prevent childhood injury that were established in the second half of the last century, along with new measures like Canada's 2004 ban on baby walkers, have resulted in a continuing decline in rates of injuries.78, 111
More recent measures have also been introduced that are tackling issues relevant to children's health and well-being. Canada's Universal Child Care Benefit (2006) provides financial assistance to all parents of children under six years of age with child care costs.112 As well, Canada's Fitness Tax Credit (2007) is one approach to support children's participation in fitness while promoting active living and tackling risk factors for childhood obesity. It is too early, however, to evaluate the effectiveness of these newer programs.113, 114
In terms of Aboriginal children, Prime Minister Stephen Harper apologized in June 2008 on behalf of all Canadians for the Indian Residential Schools System.115 The Truth and Reconciliation Commission will prepare a historical account of residential schools and their impacts on the lives of First Nations and Inuit people and will provide recommendations on how public policy can assist in moving forward.116
Over the past several decades (see Figure 2.2) Canada's IMR has fallen to 5 deaths per 1,000 live births, a vast improvement over the 145 deaths for every 1,000 live births experienced just over a century ago.32, 33, 117 Although international comparisons should be interpreted with caution due to differences in methods, it appears that Canada may not be keeping pace with some countries that have continued to make progress in this area.70, 117–127 As seen in the enlarged portion of Figure 2.2, Sweden, Finland and Japan's IMRs have continued to decline while Canada's has flattened over the last 10 years.
The United Nations Convention on the Rights of the Child outlines the responsibilities governments have to ensure a child's right to survival, healthy development, protection and participation in all matters that affect them. The four general principles of the Convention are: non-discrimination; the best interests of the child; the right to life, survival and development; and respect for the views of the child.90
There are two optional protocols to the Convention that provide additional protection in two specific areas. Canada ratified the Optional Protocol to the Convention on the Rights of the Child on the Involvement of Children in Armed Conflict in 2000 and the Optional Protocol to the Convention on the Rights of the Child on the Sale of Children, Child Prostitution and Child Pornography in 2005.91, 92 Canada has taken a range of actions that promote the guiding principles of the Convention and its optional protocols, implementing policies, legislation and programs that yield positive outcomes for children. Central to this is the National Plan of Action for children, A Canada Fit for Children, which was launched in 2004.93
As a state party to the Convention, Canada is required to report periodically on measures it is taking to ensure continued compliance with the Convention and its optional protocols and has regularly done so since its first report in 1994. Canada will report on progress on specific commitments this year.
* Excluding Quebec for 1925; Newfoundland for 1925 to 1926; and the Yukon Territory and the Northwest Territories for 1925 to 1949.
† Infant deaths are based on the live births occurring in the year, except in the years 1931–1956 when they were based on related live births.
‡ Infant mortality rate exclusive of stillbirths for 1925 to 1940.
Source: Australian Bureau of Statistics; Office for National Statistics; Grove, R. D. & Hetzel, A. M. (1968); Linder, F. E., Grove, R. D., & Dunn, H. L. (1947); Statistics Canada; Statistics Sweden; Ministry of Health, Labour and Welfare; Human Mortality Database; and Public Health Agency of Canada.
As seen in this brief historical overview, Canada's approach to creating the conditions for health and development in infancy and childhood has broadened over time, from reacting to disease outbreaks to proactively protecting and promoting the health and well-being of Canadians. There has also been a fundamental shift from viewing children's health as simply part of overall population health, to recognizing childhood as a unique stage in life that influences future health outcomes. Going beyond ensuring survival through the early years, Canada now strives to provide all children with the conditions and opportunities needed to grow up healthy and to live longer, healthier and more productive lives. These efforts include better prenatal and post-natal care, immunization, safety and social supports/programs, and legislation that have proven to be effective in preventing disease and injury both in childhood and across the lifecourse. Overall, the measures taken in Canada to improve children's health over the last 150 years have brought about a substantially lower infant mortality rate and a life expectancy that is now among the highest in the world. There are signs, however, that in some areas we are not keeping pace with the progress of others. Chapter 3 will explore the current health status of Canadian children under the age of 12, including the leading causes of death and patterns of ill health and disability within this age group.