This is a single blind randomized and controlled clinical trial study, carried out in Tabriz Al-Zahra teaching hospital during 6 months from September 2013 up to February 2014. The study population consists of healthy term newborns weighting 2500-4000 gr, delivered in Tabriz Al-Zahra hospital.
Study inclusion criteria includes: first day skin bilirubin level less than 5mg/dl, breastfed, unprohibited to massage (for example: edema, tissue damages, skin infections and skin rashes). Infants receiving bilirubin reducers and which required phototherapy for their increased levels of bilirubin, were excluded. To determine the sample size, initial data including mean and standard deviation of the main variable of the study (skin bilirubin level) was gathered based on a pilot study and five infants at each different groups measured at different times.
Consequently, and by considering the confidence level of 95%, power test at 80%, the minimum sample size was evaluated as 10, using Gpower software package (test Repeated Measure between factors, ANOVA, statistical test, Family=f test). Also by considering a 40% sample attrition, minimum sample size was raised to 14 infants per group, and sampling further continued until reaching 26 sample for intervention group and 28 samples for control group (taking into account the probability of starting phototherapy), to ensure achieving results.
Right after delivery, the newborns were transferred to caesarean and midwifery department of Tabriz Al-Zahra teaching hospital, and by successfully passing an initial eligibility, were selected through convenience sampling. As a following step, subjects were allocated to either of control and intervention groups, using size-2 random blocks and based on a 1:1 allocation ratio. Corresponding random numbers were generated using “Random Software Allocation” software.