A quasi-experimental clinical trial was performed in 72 women undergoing cesarean section in 2017 at one of the medical centers of Sarpol-e Zahab. The statistical population of the study included all nulliparous and multiparous women with a history of the last cesarean section in the last two years and those who were referred to the hospital in 37 weeks of pregnancy, meeting the inclusion criteria. Random allocation in clinical trial studies refers to the process of dividing participants into different groups at random. Randomization gives each participant an equal chance of being in each of the groups. Successful randomization requires that researchers and study participants be able to predict the type. Sampling was based on inclusion criteria: 18 to 35 years of age, pregnancy age later than 37 weeks, ability to read and write, ability to see and hear and understand the Persian language, BMI < 30, not taking psychiatric drugs and vitamins, and not having psychological illness and chronic diseases according to medical records. The exclusion criteria were unwillingness to continue the study and refusal to attend the training session.
Based on the inclusion criteria, the subjects were randomly assigned to control or intervention groups. Written informed consent was obtained from all participants. The sample size was determined at a confidence level of 95% and a test power of 90%, and given that the effect size of the self-care training program on surgical site healing compared to the control group had to be at least d-1 (degrees of freedom) to consider the effect of the educational program as statistically significant, the calculated sample size in each group was 35 subjects. In addition, due to the possibility of sample drop-out, a 10% was added to the above sample size. Finally, the sample size in each group was determined to be 38 people (
4).
The instruments of this research included a questionnaire on demographic characteristics, which contained items on personal characteristics (age, education level, economic status, and mother's job), four questions on midwifery factors (body mass index, cesarean section length, gestational age, and reason for cesarean section), and three questions on factors after cesarean delivery (time to starting daily activities). This questionnaire was completed by interviewing mothers at the time of enrollment, 24 hours after the cesarean section, and nine days after the cesarean section. The second instrument was the REEDA cesarean scale, which was used to measure redness, edema, bruising, discharge from the wound, and edge adhesion. The mother was asked to lie down; then, a paper strip was placed vertically on the site of the cesarean section in a way that the midpoint of the tape was logically cut on the cesarean section site. Finally, a score from zero to three was given to each of the five criteria: Redness: no redness score 0 and a redness 0.5 cm from each side of surgery site score 3; Edema: no edema sore 0, edema less than 1 cm from the site score 1, edema 1 - 2 cm from the site score 2, and edema more than 2 cm from the site score 3; Ecchymosis: no edema sore 0, ecchymosis 0.25 cm from both sides or 0.5 to 2 cm from one side score 1, ecchymosis 1 cm from both sides or 0.5 to 2 cm from one side score 2, and ecchymosis more than 1 cm from both sides or more than 2 cm from one side score 3, Secretions: no discharge score 0, serous secretion score 1, hydro rhea and bloody secretion score 2, and bloody and purulent secretion score 3; Continuity: two edges of the scar are closed score 0, the distance between two edges of skin is less than or equal to 3 mm score 1, the skin and under-skin of both edges are separated score 2, and the fascia layer is separated score 3.
Scores obtained from all five criteria were summed; score 0 represented complete healing, and score 15 represented low healing. The REEDA index is a tool introduced in 1974 by Davidson to investigate the scar by assessing the redness, edema, ecchymosis, discharge, and continuity (
19). Malekpor et al. confirmed the validity of the scale for investigating episiotomy healing (
20). Amani et al. (2015) also investigated its reliability, which was 0.85 (
21).
In this research, the content validity method was used to determine the validity of data gathering tools. Therefore, the researcher prepared the tool considering the research goal and by studying books, related theses, and valid papers. After the tutors confirmed it, the statistics consultant developed the questionnaire, and then the prepared tool was investigated by 10 professors of the Iran School of Nursing and Midwifery. Next, the tool was modified using the comments and suggestions, and to obtain the final approval, it was sent to the research committee to assess and confirm the content of the questionnaire. The final modification was done using the research experts’ opinions.
The observation method (by the researcher and his/her trained fellow) was used to investigate the reliability of the research tool that 0.87 Pearson correlation coefficient (For the reliability of Reeda instrument, the observation method (by the researcher and the trained companion) was used, the coefficient of which was obtained based on Pearson correlation.) was obtained. After approval of the research plan by the Ethics Committee of Iran University of Medical Sciences, the researcher referred to the research setting and after explaining the research goal and methods to the authorities and receiving permission, presented at the Gynecology Department and invited nulliparous and multiparous women who were candidates for cesarean section and had the inclusion criteria to participate in the study. First, the research method was completely explained to the patients, and they signed informed consent forms. A continuous sampling method was used, and the subjects were randomly assigned to control or intervention groups via a coin. A pretest was done, and then a training booklet was taught by the researcher during a 45 - 60 min training session using the face-to-face method. The booklet was about surgical scar care, including nutrition, health observance, how to change wound dressing, movement, and activity. A posttest was also done to assess the learning process. The reason for doing the pretest and posttest was to insure the patient learning. At the end of the session, the booklet was given to the patients, and both intervention and control groups received routine care services. The assessment of surgery site healing was done after 24 hours and nine days of cesarean section in the surgery ward of the clinic by the researcher using the REEDA tool. Data were analyzed by IBM SPSS software version 20. The statistical indices (frequency, percentage, standard deviation, and mean) and tests (independent t-test, Fisher's exact test, Wilcoxon, and Friedman tests) were used to investigate the significance. The normality of data was evaluated using the Kolmogorov-Smirnov test. The significance level of the study was set at P < 0.05.