The CHILD Study is characterised by numerous assessments of families and children over a prolonged period, by a broad spectrum of topics of study represented by many disciplines, and by geographical and ethnic diversity of the study population.
CHILD has 3,346 active participants (both Vanguard and General cohorts) in the study. The withdrawal rate for the General cohort across the 4 recruitment sites is 5.7% in the General cohort with approximately half of these being unavoidable (e.g., subjects no longer meet inclusion criteria such as twins, miscarriages, preterm births), bringing the true attrition rate to approximately 3%.
The last baby was born into the CHILD Study on October 20, 2012 and the earliest recruits into the General cohort of the study are now turning 3 years of age and clinic visits are scheduled for November. A total of 168 families continue to participate in the CHILD Vanguard cohort and nearly all of these have completed the 4 year questionnaires.
Site staff are busy coordinating and conducting the remaining 3-month home visits, 1-year and 3-year clinic visits. The 1-year clinic visits include:
- Questionnaires (home environment, residential moves, stress, psychosocial, SES, health, nutrition, medications, vitamins/supplements, sleep)
- Performing skin prick tests (mother, child)
- Spirometry (mother)
- Child clinical assessment by physician/nurse
- Collection of venous blood (mother, child)
- Collection of biological samples from child (stool, urine, nasal secretions)
The 3-year clinic visits include similar questionnaires, skin prick tests for child and collection of child urine.
A total of 3,313 3-month home visits and over 2,000 1-year clinic visits have been completed.
Collection of questionnaire data through electronic completion is continuing with similar success to paper based questionnaires. Electronic data requires the same amount of review, query-generation and data correction as paper based data entry, but cuts down on the amount of time required to manually enter the data into HealthDiary.
Investigators are actively analysing available study data as 38 data requests have been completed. Of note, CHILD has released:
- 1,597 3-month urine samples;
- 187 cord blood serum samples for cotinine analysis;
- 2,534 3-month and 1-year urine samples for phthalate analysis;
- 628 3-month dust samples for hopanes/PAHs/β-glucan/endotoxin analyses; and
- 738 birth/3-month/1-year fecal samples for microbiome analyses.
Anticipated Sample Collection Chart