This two-group, blinded, nonrandomized, clinical trial was conducted from May to December 2014. The study population consisted of mothers of premature infants, admitted to Omolbanin Hospital of Mashhad, Iran. The inclusion criteria for the mothers were age ≥ 18 years, literacy, and no experience of premature birth. The inclusion criteria for the infants were as follows: 1) gestational age < 37 weeks; 2) birth weight < 2500 g or > 1000 g; 3) lack of critical conditions, such as intraventricular hemorrhage or intracerebral hemorrhage (grades III and IV); 4) singleton pregnancy; 5) length of hospital stay > 1 week or < 1 month; 6) five-minute Apgar score > 7; and 7) lack of evidence on asphyxia. The exclusion criteria were infant’s discharge before the end of the program and infant’s death.
The data collection tool was a questionnaire, consisting of the demographic and background variables, such as cause of preterm delivery, mode of delivery, infant’s gender, and infant’s weight. To collect information related to stress coping strategies, the brief COPE questionnaire, designed by Carver in 1997, was used to determine the coping styles (problem-focused, emotion-focused, and insufficient) at times of stress.
The brief COPE is a self-report tool, consisting of 28 questions, rated on a 4-point Likert scale, ranging from never (
1) to always (
4). It assesses 3 main styles of coping, including problem-focused, emotion-focused, and insufficient coping; each group of 2 questions is a subset of a subscale. This tool includes a total of 14 subscales. The problem-focused style consists of 6 questions and 3 subscales (counter coping, planned coping, and instrumental support), with scores ranging from 6 to 24. The emotion-focused style consists of 10 questions and 5 subscales (acceptance, psychological support, humor, positive reassessment, and religious effort), with scores ranging from 10 to 40, and the avoidance style consists of 12 questions and 6 subscales (withdrawal behaviors, emotional withdrawal, self-blame, expression of emotions, drug abuse, and denial), with scores ranging from 12 to 48 (
12).
The dominant style of each individual was determined by collecting the scores. Those who obtained the same scores in 2 styles used a combination of both strategies. The content validity was measured to determine the validity of the coping questionnaire. The questionnaire was presented to the members of the Faculty of Nursing and Midwifery; after reviews, the required changes were applied. The internal consistency was also measured to assess the reliability of the questionnaire. The questionnaire was presented to 15 mothers, and then, Cronbach’s alpha coefficient was measured (r, 0.80 for the total coping strategy questionnaire).
The sample size was calculated in a pilot study, and the mean comparison formula (95% confidence level; test power, 80%; S1, 6.5; S2, 7.85; M1, 22.23; M2, 17.24) was used:

The sample size for each group was calculated to be 32. Considering an attrition rate of 10% per group, 3 more cases were added to each group, and the total sample size was measured to be 35 per group (70 in total). Sampling was carried out at the hospital after obtaining permission from the Ethics Committee of Mashhad University of Medical Sciences, as well as the officials of Omolbanin Hospital. After attending the ward, in order to collect data, the infants who met the inclusion criteria were first determined, and then, the medical records of their mothers were evaluated. If the mother also met the inclusion criteria, the research method was described to her. If she consented to participate in the study, the demographic questionnaire was completed by the researcher through an interview.
To prevent data interaction between the intervention and control groups, the researcher first performed sampling in the control group. Sampling was terminated for 3 weeks, and mothers from the control group were discharged from the hospital. Then, sampling was performed in the intervention group. The information required from the parents was provided in the written format. Also, at each stage, the mothers listened to an audio file (MP3) related to the corresponding stage in the absence of the researcher for about 15 minutes; the information was provided as a booklet for mothers if they wished to use it.
This study was performed in 4 stages: first stage, 1 - 2 days after the infant’s hospitalization; second stage, 2 - 4 days after the first stage; third stage, 1 - 4 days before the infant’s discharge; and fourth stage, 1 week after the infant’s discharge. To assess the stress coping strategies, the mothers completed the questionnaires once 2 - 4 days after the infant’s admission and once before discharge. On the other hand, routine support was applied for the control group, while assessment of coping strategies was similar to the intervention group. The research assistant, who was blind to the objectives and methodology of the study, interacted with the mothers. Data analysis was performed using SPSS version 16. P-value < 0.05 was considered as the significance level.