The Ontario Child Health Study (OCHS) is a prospective study to evaluate the impact of early childhood experiences and development on later adult health, quality of life and functioning.

In 1983, Statistics Canada and McMaster University in Hamilton, Ontario, collected information on 3,294 Ontario children aged to 4 and 16 years living in 1869 families.

The main purpose of this original survey was to look at the overall health of children in Ontario, to see how their health needs were being met and to identify factors which help or hinder their development.

A follow-up study with these same children was conducted in 1987. The study provided important information on the extent to which the health of these children had changed over four years, and which factors seemed to influence these changes.

A second follow-up was completed in 2001 when the original group of children were young adults between 21 and 33 years of age. These assessments will make it possible to examine the possible influences of early experiences on important life transitions, such as joining the workforce, entering into a relationship with someone or becoming a parent. The information collected over this 17-year period will be unique in Canada because it will allow health to be studied over the long-term. In analyzing data from the three cycles of collection, researchers will be able to address a wide variety of questions on child development, such as:

• Which childhood emotional problems and difficulties disappear as a child matures and grows up and which tend to persist and need attention?

• Does childhood health, early family life or the neighbourhood in which you grew up exert an influence, on adult health, employment, lifestyle and satisfaction?

What impact have the earlier rounds of this study had on the lives of children?

Information from the first two cycles of OCHS have played a vital role in changing social, health and educational policy in Ontario. The information was key in:

• raising the profile of children and what they need to grow up healthy;

• adding motivation for government initiatives directed towards child health;

• triggering changes in service delivery and fostering more co-operation and collaboration between those organizations aimed at helping children and their families.

The principal investigators for this study are Drs. Michael Boyle, Cameron Mustard and the late Dan Offord. Dr. Boyle is a core member and Dr. Offord was first Director of the Offord Centre for Child Studies which is co-sponsored by McMaster University and Hamilton Health Sciences. Dr. Mustard is President & Senior Scientist at the Institute for Work & Health. The study was funded by the Canadian Institutes for Health Research.