This study is an experimental randomized controlled study conducted to compare the effect of balloon blowing, coughing, and ball squeezing methods applied during venous blood sampling from on pain and fear level in 7-12 year-old children. The population of the study consisted of all 7-12 year-old children who were referred to the blood-letting room for venous blood sampling in a state hospital. The sample of the study was determined as 120 children with confidence level of 95% and theoretical power of 95%. The children were divided into 4 groups of 30 people, including balloon blowing, ball squeezing, coughing, and control groups. Each intervention and control group was matched in terms of gender. In the study, the randomization of the sample group was performed by using stratification and block randomization methods.

The study is a randomized controlled, non-blinded, experimental trial. The population of the study consisted of all 7-12 year-old children who came to the venipuncture room in the state hospital.It is stated in the literature that the sample size should be determined as minimum 30 in both experimental and control groups in the experimental studies and parametric measurements. Therefore, in the study, each group included 30 children including three experimental groups and a control group and in the power analysis, power of the study was found as 0.95 at the confidence level of 95%. In order to prevent bias and increase the validity of the data, the pain and fear scores of the children before and after the procedure were assessed by three different groups as children participating in the study (n:120), their parents as the people who know the children best (n:120), and a researcher specialized in pediatric nursing (n:1), and the inter-observer agreement was examined. The level of pain was assessed by the Wong Baker Faces Scale and the fear of pain was assessed by the Children's Fear Scale.

In this experimental study, the children and their parents who came to the venipuncture room for venous blood sampling were evaluated in terms of the inclusion criteria and the children and parents who did not meet the criteria were excluded from the study. The children and parents complying with the inclusion criteria were informed about the study and their written and verbal consents were received. The children were included in one of the 4 study groups, including the balloon blowing, coughing, ball squeezing, and the control group without any intervention. In the studies, it was determined that gender had an important effect on evaluation of pain.39,40 In order to control the effect of gender on pain, the children were stratified into study groups based on their gender and selected by using block randomization method in four study groups. The children were randomized to the related study group by drawing one of the study groups in the cloth bags prepared for the girls (pink) and the boys (blue). Papers with the same color and folding pattern representing the four groups (1,2,3,4) were thrown in the bags. In order to provide a randomized distribution and to reduce all negative effects, the children were asked to take randomly a paper from the bag according to the gender after making the necessary explanation to the parents and their children so that the groups became self-balancing. A total of 30 children including 15 girls and 15 boys were included in each group after intervention and control groups were matched in themselves in terms of gender. The study followed the CONSORT guideline for reporting randomized controlled trials.

Inclusion Criteria:

The children,

• who were aged between 7-12 years,
• were healthy,
• did not receive any analgesic within the last 6 hours before venipuncture procedure,
• had no history of syncope during venipuncture procedure,
• agreed to participate in the study and gave the verbal and written consent.

Also, the parents were eligible for participation when meeting the following inclusion criteria:

• be healthy in terms of neurological functions,
• communicate verbally,
• understand and read Turkish,
• voluntarily sign the written informed consent.

Exclusion Criteria:

The children;

• who had neuro-developmental disorder,
• could not communicate verbally,
• had hearing and visual impairment,
• suffered from acute pyretic disease,
• received topical anesthesia, took any analgesic within the last 6 hours before venipuncture procedure,
• had chronic disease requiring frequent venipuncture.