Methods
This study was approved by the Ramsey (now Regions) Hospital institutional review board. Mothers who gave birth at Regions Hospital in St. Paul, Minn., participated in the study. Mothers on the postpartum ward were invited to participate, but were excluded if they were not proficient in reading English, did not have a telephone, or lived more than 10 miles from the hospital. Infants were excluded if they were in the intensive care nursery, were not discharged on the same day as the mother, or if they received phototherapy. Mothers were advised to follow their health care providers’ instructions about timing for the first follow-up visit, and any provider instructions regarding jaundice.
After obtaining consent, the author or a study assistant showed the mothers how to examine their infants for jaundice by 2 methods. Each mother was instructed to examine her baby in a well-lighted room. First, the mother was shown how to look for jaundice by digitally blanching the skin on the cheek. The mother then documented whether she saw any underlying yellow color on her baby. Next, the mother was shown how to determine the caudal progression of the jaundice and to draw a horizontal line on an illustration of a baby corresponding to where the jaundice ended. The distance from the top of the infant’s head to the line drawn by the mother was used to determine the caudal progression. The mother was then shown how to use the Ingram icterometer and obtain a reading from the baby’s nose. Each mother was given an icterometer and a study booklet to document her examination for a total of 7 days, beginning the day after discharge from the hospital. The study booklet also contained some demographic questions, and questions about the mother’s comfort level with both methods of jaundice assessment. The mother was instructed to return the booklet and icterometer by mail when completed. The mother was sent a $25 gift certificate when the study materials were returned.
Within 7 days of discharge, a home health nurse visited each mother and infant in the home. The nurses were trained in the same methods of clinically assessing jaundice, and they assessed each infant by visually determining the caudal progression and by use of the icterometer. The nurse did not share the results of her examination with the mother. The nurse obtained bilirubin levels from all infants and notified the infants’ health care providers of any bilirubin levels higher than 14 mg/dL.
Standard descriptive statistics were calculated for all variables. Categorical relationships were assessed using kappa and chi-square statistics, as appropriate. All analyses were performed using Statistical Package for Social Sciences for Windows, version 10.0.5.
Results
A total 113 of 177 mothers returned their study packets. Home health nurses visited 96 of the 113 mothers; the other 17 mothers were not visited because they declined the visits or could not be located. Although all babies were to have serum bilirubin levels determined whether or not they appeared jaundiced, only 90 of the 96 infants had the blood test. For the other 6 infants, either insufficient blood was drawn or the mother refused the test. On the day of the nurse’s visits, mothers documented in their study booklets the caudal progression of jaundice (for 56 infants) and icterometer readings (for 55 infants).
The educational levels of the mothers were as follows: 15% completed grade school or less; 40% completed high school; and 45% completed college. The mothers reported being from the following racial and ethnic groups: white, 59%; Hispanic, 16%; black, 14%; Asian, 8%; and other, 3%. A total of 53% of the women were primiparous, 84% completed examination forms for their babies for all 7 days, and 53% assessed their infants as being jaundiced during the study.
On the day of the nurse’s visit, there was moderate agreement between the nurses and the mothers about the presence of jaundice in the infants (= 0.50; P < .001). For those infants with jaundice, there was little agreement on the extent of caudal progression between the nurses and the mothers (correlation = 0.36; P > 0.1), but there was moderate agreement between their icterometer readings (correlation = 0.58; P < .05).
The total serum bilirubin results ranged from 0.8 mg/dL to 18.8 mg/dL, with a mean of 7.4 mg/dL. The mean bilirubin level of infants thought to be jaundiced by their mothers was 11.3 mg/dL, while the mean bilirubin of infants not thought to be jaundiced was 4.8 mg/dL (P < .001).
The mothers’ icterometer readings and determinations of jaundice to the nipple line or below it are compared with bilirubin levels in (Table 1). (Table 2) summarizes the diagnostic accuracy of jaundice extending to the nipple line or below it, and for icterometer readings of 2.5, in identifying bilirubin levels of 12 mg/dL and 17 mg/dL. A bilirubin level of 12 mg/dL is the level at which the AAP guideline suggests considering phototherapy for infants aged 24 to 47 hours, and 17 mg/dL is the level at which phototherapy should be considered for infants older than 72 hours.3