The CHIME Study, now complete, was a multicenter cooperative study of home monitoring that aimed to determine whether home monitors are effective in identifying episodes that are dangerous to the infant's health. Other objectives were to correlate physiological markers, health status, and behavior with the propensity for life-threatening events; and provide important information on the maturation of heart and respiratory function in sleeping infants. The Pregnancy and Perinatology Branch (PPB) supported the CHIME Study.
The Study included nearly 1,200 infants in the following groups:
- Healthy term infants
- Preterm infants weighing less than 1,750 grams at birth
- Siblings of babies who died from SIDS
- Infants who experienced an idiopathic apparent life-threatening event
The CHIME Study is now complete. But the dataset from the CHIME Study, and from another completed study called the National Infant Sleep Position (NISP) Study, are available to the scientific community to ensure that these important data are used to their fullest extent.
When the CHIME Study was initiated, PPB staff, CHIME researchers, and industry members collaborated to develop new monitoring technology and to evaluate the technology for its potential to detect and record life-threatening cardiorespiratory episodes. The technology incorporated advanced computer capabilities, inductance plethysmography, electrocardiogram (ECG), pulse oximetry, and an accelerometer to detect motion and infant position. The technology conducted event recording, which captured physiology for a period before, during, and after an event, and also stored continuous RR intervals (heart rate) from the ECG, continuous breath-breath intervals, and normative three-minute epochs at hourly intervals.
Findings from CHIME showed that although cardiorespiratory events (such as apnea, bradycardia, etc.) meeting conventional alarm thresholds were quite common, even in healthy term infants. More severe events were common only in preterm infants, and their timing suggested that they were not likely immediate precursors to SIDS. ( JAMA, 2001; 285, 2199-2207). Based on this and other research, the American Academy of Pediatrics does not recommend using home monitors to predict or prevent SIDS ( Pediatrics, 2005, 116(5), 1245-1255).
The CHIME database contains raw and analyzed physiologic waveforms from overnight recordings and the home monitor recordings. In addition, data collected by CHIME also include sociodemographic and medical information on the mother and infant (collected at entry and from scheduled medical follow-up visits through one year of age), weekly phone calls, monitor knowledge and satisfaction scales, periodic assessments using standard scales such as the Parenting Stress Index, and hospitalizations for infants in the study.
Researchers who are interested in using data for their own analyses should visit http://slone-web2.bu.edu/ChimeNisp/Chime_Data.asp.