Comparison of the effectiveness of two active distraction methods in reducing pain, fear, and anxiety in children during venipuncture: a randomized controlled trial

Abstract

Background

Pediatric venipuncture is one of the most stressful invasive procedures for children, often accompanied by intense pain, fear, and anxiety. This study aimed to compare the effects of two active distraction methods—bubble blowing and a material-free cognitive distraction/positive reinforcement technique—on pain, fear, and anxiety.

Methods

This randomized controlled parallel-group trial was conducted between April and July 2025 in the pediatric venipuncture unit of a university hospital in western Türkiye. The sample comprised 207 children who met the inclusion criteria. The experimental arm included 135 children allocated to either Positive Reinforcement (n = 72) or Bubble Blowing (n = 63), and the control group consisted of 72 children who received standard care without any additional intervention during venipuncture. Data were collected using the Wong–Baker FACES Pain Rating Scale, the Child Fear and Anxiety Scale, and a Visual Analog Scale. Children’s self-reported pain, fear, and anxiety scores were used as the primary outcome data. Parametric and nonparametric tests and effect sizes were used in the analyses.

Results

In the control group, postprocedural pain and anxiety scores increased significantly (p < .001), whereas the increase was attenuated in the bubble-blowing and positive reinforcement groups. Because baseline fear/anxiety scores differed between groups, ANCOVA was performed using preprocedural fear/anxiety scores as a covariate; the adjusted group effect remained statistically significant. In the positive reinforcement group, the increase in fear- anxiety scores was small and did not reach statistical significance. Bubble blowing was more effective than positive reinforcement in reducing pain.

Conclusion

Both distraction techniques were associated with lower postprocedural pain and psychological distress scores compared with standard care. Bubble blowing showed a stronger effect on pain outcomes, whereas the positive reinforcement group showed only a small, statistically non-significant increase in fear/anxiety scores. These findings support the integration of simple, low-cost distraction strategies into pediatric nursing practice and skills training.

Trial Registration

The clinical trial registration number is NCT07249723. Registered 18 November 2025 - Retrospectively registered.

Introduction

Distraction is an effective nonpharmacological nursing intervention used to reduce pain, fear, and anxiety in children during invasive procedures. This approach aims to redirect the child’s attention away from the perceived threat and thereby lessen emotional distress [1, 2]. Venipuncture, which is frequently performed in pediatric clinical settings, is often perceived by children as a painful experience associated with loss of control. This perception heightens emotional reactions during the procedure and may negatively influence their future experiences with health care services [3, 4].

Although numerous nonpharmacological strategies have been developed to reduce pain and anxiety, distraction techniques offer practical, low-cost interventions that are easily integrated into clinical environments [5–9]. Active distraction techniques, in particular, increase the child’s engagement in the procedure and can reduce perceived pain and anxiety [10, 11]. In children aged 7–12 years, procedure-related fear and avoidance behaviors may be heightened by previous medical experiences [12]. Therefore, there is a need for comparative evaluation of distraction strategies that are specifically tailored to this developmental stage [13, 14]. Sensory–kinesthetic methods such as bubble blowing promote active participation, whereas material-free cognitive techniques can be implemented in any setting and offer highly accessible options. Bubble blowing and material-free cognitive distraction/positive reinforcement were selected because they represent two distinct active distraction pathways. Bubble blowing combines motor engagement, visual focus, and rhythmic breathing, thereby providing a sensory–kinesthetic and respiratory-based form of distraction [15–18]. In contrast, the material-free cognitive distraction/positive reinforcement technique relies on verbal interaction, simple cognitive tasks, and encouraging feedback to redirect attention and support coping [7, 11, 12]. Children aged 7–12 years are developmentally able to follow instructions, engage in simple cognitive activities, and participate in motor-based distraction; therefore, this age group is appropriate for comparing cognitive/verbal and motor/respiratory distraction strategies during venipuncture [13, 19]. However, studies directly comparing these methods remain limited [15–18, 20].

Pediatric venipuncture is a technically and emotionally demanding procedure because children may have limited cooperation, heightened pain sensitivity, and strong fear responses during needle-related procedures [21, 22]. Therefore, nurses and other healthcare professionals need feasible, child-centered strategies that can reduce procedural pain and distress without increasing the complexity of routine care. In this context, simple, low-cost, and easily implemented distraction techniques may be particularly valuable in pediatric clinical settings [23–26].

Aim

This study aimed to determine the most effective strategy by comparing the effects of bubble blowing and a material-free active distraction method on fear, anxiety, and pain in children aged 7–12 years undergoing venipuncture.

Materials and methods

Study design

This study was designed as a randomized controlled experimental trial.

Setting and time frame

The study data were obtained from April to July 2025 in the pediatric phlebotomy unit situated within the pediatric outpatient clinics of Kocaeli University Hospital.

Population and sample

The study population consisted of all children aged 7–12 years who presented to the pediatric phlebotomy unit of the hospital for venous blood sampling between April and July 2025. Four nurses were working in the unit, each with approximately 20–30 years of professional experience. The phlebotomy unit consisted of a single room with four blood-drawing chairs. There was no dedicated pediatric blood-drawing chair; instead, parents held their children on their laps during the procedure.

Inclusion Criteria: Children were included if they were 7–12 years old, literate, free from diagnosed visual, auditory, intellectual, or neurological impairments, had not used analgesic, sedative, or narcotic medication in the previous 24 h, and voluntarily agreed to participate along with their parent/caregiver.

Exclusion Criteria: Children were excluded if they did not meet the inclusion criteria, withdrew from the study at any stage, their parent/caregiver requested withdrawal, or venipuncture was not successful on the first attempt. This criterion was applied to standardize procedural exposure across groups and to minimize variability attributable to repeated needle insertions.

Sample size determination

The sample size was determined based on an a priori power analysis using G*Power. The effect size was estimated from a previous randomized experimental study evaluating pain, fear, and anxiety during pediatric venipuncture [26]. In that study, a large between-group effect was reported for child-reported fear during the procedure (Cohen’s d = 0.714). This value was converted to Cohen’s f for the present three-group ANOVA design using the approximate conversion f = d/2, resulting in an estimated effect size of f = 0.35. With an alpha level of 0.05, a power of 0.95, and three study groups, the minimum required total sample size was calculated as 132 children. To account for possible attrition and post-randomization exclusions, a larger sample was recruited. A total of 240 children were randomized; however, 33 children were excluded after randomization because the blood sample could not be obtained on the first attempt or the intervention was discontinued. The final analysis included 207 children (intervention: 135, control: 72), which exceeded the minimum required sample size (Fig. 1).

Fig. 1.

Flow chart of research

Randomization

To prevent allocation bias, stratified block randomization was used. Children were stratified by age group (7–9 and 10–12 years) and sex (girl/boy), as these variables have been reported to influence procedural pain and anxiety [5, 27, 28]. For each stratum, random allocation lists were generated using Randomizer.org to assign children to the three study groups. The allocation sequence was prepared by an independent researcher who was not involved in eligibility assessment, intervention delivery, or outcome measurement. To ensure allocation concealment, the randomization list was kept inaccessible to the researcher assessing eligibility until the child had been enrolled in the study. Although equal allocation was planned, the final group sizes differed because some children were excluded after randomization due to unsuccessful first-attempt venipuncture or discontinuation of the intervention. To minimize contamination between the intervention and control groups, procedures were scheduled so that only one child was present in the unit at a time.

Blinding and bias mitigation

Because of the visible and interactive nature of the distraction interventions, blinding of the children, parents, intervention providers, and the researcher collecting outcome data was not feasible. To minimize observer-related bias, standardized instructions were used for all participants, outcome measurements were obtained at the same time points immediately before and after venipuncture, and validated age-appropriate assessment tools were administered in a consistent manner. In addition, all venipuncture procedures were performed by the same pediatric nurse to standardize the procedure and reduce inter-operator variability. However, this approach may also have introduced operator-related bias, as the outcomes could have been influenced by the nurse’s procedural skill, communication style, and interaction with the child.

Outcome measures

The researcher collected the data via face-to-face interviews, employing the following instruments:

• Descriptive Characteristics Form: This form was created by the researchers in line with the relevant literature and contains questions about the sociodemographic characteristics of both the child and the parent [5, 27, 29].

• Wong–Baker FACES Pain Rating Scale (WB-FACES): The scale, originally developed by Wong and Baker (1988), is a self-report tool that evaluates pain intensity in children aged 3–18 years through a series of facial expressions and is scored on a 0–5 scale [30]. The WB-FACES has shown robust psychometric performance in Turkish pediatric populations [27, 31, 32]. In this study, children’s pain was assessed using the WB-FACES both by the children themselves and by the researcher. The instrument includes six faces that progress from a happy face indicating “no pain” to a tearful face indicating “worst pain.” Children are instructed to choose the face that best reflects how much they hurt “at that moment.” Their selection is then converted into a numerical value of 0, 2, 4, 6, 8, or 10, where 0 represents absence of pain and 10 denotes the most intense pain; higher scores indicate greater pain severity.

• Child Fear Scale (CFS): The CFS, a self-report facial rating instrument that measures children’s situational fear and anxiety. The scale was originally developed by McMurtry et al. (2011) [14] and later validated for use in Turkish children by Gerçeker et al. (2018) [32]. The CFS consists of a series of faces progressing from a calm, neutral expression (score = 0) to an intensely fearful expression (score = 4). Total scores therefore range from 0 to 4, with higher values reflecting greater fear levels.

• Visual Analog Scale (VAS): The scale is a widely used, valid and reliable tool for assessing pain intensity, consisting of a 10-cm horizontal line anchored at 0 (“no pain”) and 10 (“worst possible pain”) (Wewers & Lowe, 1990) [33]. In this study, the VAS score was obtained by measuring in centimeters the distance from the left end of the line to the point marked by the child, producing a value between 0 and 10, where higher scores represent greater pain intensity.

The use of both the WB-FACES and VAS was intended to provide complementary assessments of children’s pain intensity. The WB-FACES offers a developmentally appropriate, pictorial self-report format that is easily understood by school-age children, whereas the VAS provides a more continuous estimate of pain intensity. Using both measures allowed the pain outcome to be evaluated through two widely used approaches and supported cross-validation of the findings. In the analyses, children’s self-reported scores were used as the primary outcome data. Researcher ratings were recorded separately for observational consistency and were not combined with children’s self-reports. All scales were administered both before and after the venipuncture procedure.

Data collection procedure

As part of the study protocol, the researcher explained the purpose of the study to parents, obtained written informed consent, and requested verbal assent from the children. A single-needle insertion technique was used, and all blood draws were performed by the same pediatric nurse, who was permanently assigned to the unit, to ensure procedural standardization. Outcome measurements were obtained immediately before and immediately after venipuncture, as the study focused on children’s acute procedural pain, fear, and anxiety responses during blood sampling. Therefore, no delayed postprocedural assessment was conducted. To reduce procedure-related assessment bias, the venipuncture procedure was performed by a pediatric nurse, whereas outcome assessments were conducted independently by two researchers who were not involved in performing the procedure.

Study groups and interventions

The study included two intervention groups and one control group. Randomization into the three groups was carried out by an independent researcher.

1. Bubble-Blowing Group: Before the procedure, each child in this group was given an individual bubble toy and instructed to blow bubbles continuously throughout the venipuncture (Fig. 2). This active, motor-based distraction was used to redirect the child’s attention away from the procedural stress. Procedure duration was recorded with a stopwatch. After venipuncture, pain and anxiety were assessed using the study scales. A single-use bubble toy was provided for each child.

2. Positive Reinforcement Group: Prior to the procedure, the researcher established rapport with the child and invited the child to choose a brief, toy-free cognitive activity (counting, a short poem or song, or a simple word game etc.) to be performed during venipuncture. Parents were encouraged to provide physical and verbal support throughout the procedure. At the end of the procedure, children received verbal positive reinforcement (e.g., “Well done,” “You were very brave”).

3. Control Group: Children in the control group underwent the standard venipuncture procedure in accordance with routine clinical practice, without any additional distraction intervention. Outcome measures were obtained after the procedure. Following completion of data collection, children in the control group also received brief verbal feedback and supportive comments so that they were not disadvantaged in terms of emotional support.

Fig. 2.

Bubble blowing toy

Intervention

Before the Procedure

• The forms was administered to children and parents and completed face to face (approximately 5 min). The researcher briefly introduced the measurement tools that would be used (WB-FACES, CFS, and VAS).

During the procedure

In order to control for operator-related variability, the same pediatric nurse, who regularly worked in the unit, performed all venipuncture procedures using a single-attempt technique. Procedure time was measured with a stopwatch from the moment the child was seated to the completion of blood tube filling.

Bubble-blowing group

• Before the procedure started, each child was given a bubble toy and instructed to blow bubbles throughout the venipuncture.

• At the end of the procedure, outcome measurements were obtained (WB-FACES, CFS, and VAS).

• The parent and the researcher simultaneously performed observational ratings.

• To prevent infection risk, a single-use bubble toy was provided for each child.

Positive reinforcement group

• Before the procedure, the researcher established social interaction and rapport with the child.

• During venipuncture, the child performed a self-selected, toy-free cognitive activity (e.g., counting, reciting a short poem or song, or a simple word game).

• The parent remained next to the child and provided verbal and/or physical support. Parents were present during the procedures in all groups; however, parental involvement was more explicitly structured in the positive reinforcement group. In this group, verbal and/or physical support from parents was encouraged as part of the intervention protocol, whereas parents in the bubble-blowing and control groups remained present but were not assigned an active role in delivering the intervention. Therefore, parental support may have acted as a co-intervention and may have influenced the outcomes, particularly in the positive reinforcement group.

• When the procedure was completed, the child received encouraging verbal feedback (e.g., “Well done,” “You were very brave”).

• Postprocedural outcome measurements were then obtained.

Control group

• The control group underwent routine venipuncture only, with no extra distraction-based intervention provided. Pain and anxiety measurements were obtained after the procedure. Once the data collection was completed, the children received brief verbal feedback and supportive comments.

Adherence to the assigned distraction technique was monitored observationally by the researchers during the procedure and classified dichotomously as 0 = non-adherent and 1 = adherent. Children were considered adherent if they continued the assigned distraction technique throughout venipuncture. In the positive reinforcement group, adherence was determined by observing whether the child engaged in the verbal/cognitive activity and responded to the researcher’s prompts. In the bubble-blowing group, adherence was determined by observing whether the child actively performed bubble blowing during venipuncture. Five children in the bubble-blowing group were classified as non-adherent because they discontinued the intervention during the procedure; therefore, they were excluded from the final analysis (Fig. 1).

Ethical considerations

The study was approved by Kocaeli University Ethics Committee (Approval Number: KÜ GOKAEK-2024/16.13, Date: 10.10.2024). The study adheres to the principles of the Helsinki Declaration. Additionally, authorization to conduct the research was secured from the administration of the participating hospital. Prior to data collection, the study aims were explained to the children and their parents, the voluntary nature of participation was underlined, and written informed consent was obtained from parents together with verbal assent from the children.

Statistical analysis

Data analysis was performed using IBM SPSS Statistics version 25. Distributional assumptions were examined by considering skewness–kurtosis coefficients and visually inspecting histograms and related plots. For variables that met normality assumptions, parametric tests were employed (one-way analysis of variance [ANOVA], paired-samples t test), whereas nonnormally distributed variables were analyzed with nonparametric procedures (Kruskal–Wallis H test, Wilcoxon signed-rank test). Between-group differences were evaluated using ANOVA or the Kruskal–Wallis test, and within-group changes were assessed with the paired-samples t test or the Wilcoxon test. When statistically significant effects were detected, appropriate post hoc comparisons were conducted. Effect sizes were calculated using Cohen’s d and Rosenthal’s r, and eta-squared (η²) was computed to estimate the proportion of variance explained between groups. Because baseline fear/anxiety scores differed significantly between groups, analysis of covariance (ANCOVA) was performed to control for baseline imbalance. In this model, postprocedural fear/anxiety score was entered as the dependent variable, group as the fixed factor, and preprocedural fear/anxiety score as the covariate. A p value of < 0.05 was considered statistically significant.

Results

In the control group, the mean age of the children was 9.56 ± 1.81 years; 48.6% were between 7 and 9 years of age and 51.4% were between 10 and 12 years. Of the participants, 51.4% were girls and 48.6% were boys; 68.1% were in primary school and 31.9% were in middle school.

In the positive reinforcement group, the mean age was 9.49 ± 1.47 years; 51.4% of the children were 7–9 years old and 48.6% were 10–12 years old. In this group, 56.9% of the participants were girls and 43.1% were boys; 72.2% were in primary school and 27.8% were in middle school.

In the bubble-blowing group, the mean age was 8.56 ± 1.53 years; 47.2% of the children were between 7 and 9 years of age and 52.8% were between 10 and 12 years. In this group, 60.3% of the participants were boys and 39.7% were girls; 84.1% were in primary school and 15.9% were in middle school.

There were no statistically significant differences among the groups in terms of children’s mean age (p > .05). In addition, sex, educational level of the child, maternal and paternal age, parental education level, and family income were homogeneously distributed across the three groups (p > .05) (Table 1).

Table 1.

Baseline Demographic Features of the Participants

Variable	Category	Control (n = 72) n (%)	Positive Reinforcement (n = 72) n (%)	Bubble Blowing (n = 63) n (%)	Test value	p value
Child age (years)	7–9	35 (48.6)	37 (51.4)	30 (47.2)	5.116	0.068
	10–12	37 (51.4)	35 (48.6)	33 (52.8)
Sex	Girl	37 (51.4)	41 (56.9)	25 (39.7)	4.122ᵖ	0.127
	Boy	35 (48.6)	31 (43.1)	38 (60.3)
Educational level	Primary school	49 (68.1)	52 (72.2)	53 (84.1)	4.830ᵖ	0.089
	Middle school	23 (31.9)	20 (27.8)	10 (15.9)
Mother’s age (years)	≤ 34.00	23 (31.9)	21 (29.2)	20 (31.7)	0.354ᵖ	0.986
	35.00–44.00	37 (51.4)	40 (55.6)	34 (54.0)
	≥ 45.00	12 (16.7)	11 (15.3)	9 (14.3)
Father’s age (years)	≤ 34.00	10 (13.9)	6 (8.3)	10 (15.9)	5.529ᵖ	0.237
	35.00–44.00	42 (58.3)	39 (54.2)	40 (63.5)
	≥ 45.00	20 (27.8)	27 (37.5)	13 (20.6)
Mother’s education	Primary school	19 (26.4)	22 (30.6)	13 (20.6)	5.209ᵖ	0.735
	Middle school	12 (16.7)	14 (19.4)	16 (25.4)
	High school	16 (22.2)	17 (23.6)	13 (20.6)
	Undergraduate	21 (29.2)	18 (25.0)	17 (27.0)
	Postgraduate	4 (5.6)	1 (1.4)	4 (6.3)
Father’s education	Primary school	12 (16.7)	13 (18.1)	7 (11.1)	11.204ᵖ	0.190
	Middle school	15 (20.8)	13 (18.1)	9 (14.3)
	High school	20 (27.8)	23 (31.9)	33 (52.4)
	Undergraduate	21 (29.2)	21 (29.2)	11 (17.5)
	Postgraduate	4 (5.6)	2 (2.8)	3 (4.8)
Family income	Income less than expenses	15 (20.8)	14 (19.4)	4 (6.3)	9.299ᵖ	0.054
	Income equal to expenses	42 (58.3)	50 (69.4)	49 (77.8)
	Income greater than expenses	15 (20.8)	8 (11.1)	10 (15.9)

Variable		Mean ± SD	Mean ± SD	Mean ± SD	F test	p value
Child age (years)		9.56 ± 1.81	9.49 ± 1.47	8.56 ± 1.53	5.272	0.064

P = Pearson chi-square; FE = Fisher’s exact chi-square; F = One-way ANOVA

Within-group comparisons were performed to describe pre–post changes in pain and fear/anxiety scores within each group. WB-FACES scores increased significantly in all three groups (control: t = -16.502, p < .001; positive reinforcement: z = -6.656, p < .001; bubble blowing: z = -5.942, p < .001). Similarly, VAS pain scores increased significantly in all groups (control: t = -12.858, p < .001; positive reinforcement: z = -6.365, p < .001; bubble blowing: z = -5.907, p < .001). Although the groups were largely comparable in demographic and clinical characteristics, baseline CFS scores differed significantly among the groups. Therefore, this baseline imbalance was considered when interpreting postprocedural CFS differences, and an ANCOVA was performed to adjust for preprocedural fear/anxiety. CFS scores increased significantly in the control group (t = -10.514, p < .001) and bubble-blowing group (t = -4.195, p < .001), whereas the slight increase observed in the positive reinforcement group was not statistically significant (t = -1.976, p = .052). Across all three outcomes, the largest within-group changes were observed in the control group (Table 2).

Table 2.

Comparison of pretest and posttest measurements of the intervention groups by group and time

Variables	Time	Control Group1 (n = 72)		Positive Reinforcement Group2 (n = 72)		Bubble Blowing Group3 (n = 63)		test	p	η²
		Mean ± SD	Median (Q1–Q3)	Mean ± SD	Median (Q1–Q3)	Mean ± SD	Median (Q1–Q3)
WB-FACES	Pretest	0.24 ± 0.46	0.00 (0.00–0.00)	0.13 ± 0.37	0.00 (0.00–0.00)	0.11 ± 0.36	0.00 (0.00–0.00)	5.185 KW	0.075
	Posttest	2.76 ± 1.54	3.00 (2.00–4.00)	1.11 ± 1.12	1.00 (0.00–1.00)	1.13 ± 1.18	1.00 (0.00–1.00)	31.464F	0.000 *1>2.3	0.269
test/p		-16.502t/0.000*		-6.656 z /0.000*		-5.942 z/0.000*
Effect size		Cohen d = 1.84		r = .78		r = .75
Children’s Fear Scale	Pretest	0.33 ± 0.58	0.00 (0.00–1.00)	0.50 ± 0.53	0.00 (0.00–1.00)	0.59 ± 0.53	1.00 (0.00–1.00)	3.789 F	0.024 *3>1	0.036
	Posttest	1.85 ± 1.53	1.50 (1.00–4.00)	0.74 ± 1.20	0.00 (0.00–1.00)	1.08 ± 1.05	1.00 (0.00–2.00)	11.855 F	0.000 *1>2.3	0.121
test/p		-10.514 t /0.000*		-1.976 t/0.052		-4.195 t/0.000*
Effect size		Cohen d = 1.14				Cohen d = 0.54
Visual Analog Scale	Pretest	0.22 ± 0.45	0.00 (0.00–0.00)	0.15 ± 0.40	0.00 (0.00–0.00)	0.11 ± 0.36	0.00 (0.00–0.00)	3.338 KW	0.188
	Posttest	4.74 ± 3.13	5.00 (2.00–7.50)	2.51 ± 2.39	2.00 (0.50–4.00)	1.38 ± 1.51	1.00 (0.00–2.00)	33.439 F	0.000 *,1>2,3; 2>3	0.243
test/p		-12.858 t /0.000*		-6.365 z /0.000*		-5.907 z/0.000*
Effect size		Cohen d = 1.54		r = .75		r = .74

Footnotes.

ANCOVA was conducted for postprocedural Children’s Fear Scale scores because baseline scores differed significantly between groups. The adjusted group effect remained significant after controlling for preprocedural scores, F(2, 203) = 31.799, p < 0 0.001, partial η² =0 0.239; covariate effect, F(1.203) = 99.328, p < .001,partial η² = 0.329; R² = 0.410, adjusted R² = 0.401

z = Wilcoxon signed-rank test; t = paired-samples t test; F = one-way ANOVA; KW = Kruskal–Wallis H test

Rosenthal’s r = effect size for nonparametric tests; Cohen’s d = effect size for parametric tests; η² (eta squared) = effect size for ANOVA

WB-FACES Wong-Baker FACES pain rating scale

* Bold values indicate statistically significant results at p< .05

Between-group comparisons were conducted to evaluate whether preprocedural and postprocedural pain and fear/anxiety scores differed among the control, positive reinforcement, and bubble-blowing groups. For WB-FACES pain scores, there was no statistically significant difference among the groups at pretest (KW = 5.185, p = .075), indicating that the groups were comparable in terms of baseline WB-FACES pain scores. However, posttest WB-FACES scores differed significantly among the groups (F = 31.464, p < .001). Post hoc analysis revealed that pain scores in the control group were significantly higher than those in both the positive reinforcement and bubble-blowing groups (Group 1 > Groups 2 and 3). The eta-squared value was 0.269, indicating a notable statistical magnitude of group effect, with 26.9% of the variance in postprocedural WB-FACES pain scores explained by group membership.

For fear/anxiety scores measured using the CFS, between-group comparisons revealed a statistically significant difference at pretest (F = 3.789, p = .024). Post hoc analysis indicated that the bubble-blowing group had significantly higher baseline fear/anxiety scores than the control group (Group 3 > Group 1). The eta-squared value for this baseline model was 0.036, suggesting that 3.6% of the variance in preprocedural fear/anxiety scores was explained by group membership. Although this effect was small, the statistically significant baseline imbalance was considered important for the interpretation of postprocedural fear/anxiety differences. In the posttest measurements, fear/anxiety scores differed significantly among the groups (F = 11.855, p < .001). Post hoc analysis showed that the control group had significantly higher fear/anxiety scores than both the positive reinforcement and bubble-blowing groups (Group 1 > Groups 2 and 3). The eta-squared value for this model was 0.121, indicating a notable statistical magnitude of group effect, with 12.1% of the variance in postprocedural fear/anxiety scores explained by group membership. Because baseline CFS scores differed significantly between groups, ANCOVA was conducted with postprocedural CFS score as the dependent variable, group as the fixed factor, and preprocedural CFS score as the covariate. The adjusted group effect remained statistically significant, F(2, 203) = 31.799, p < .001, partial η² = 0.239, indicating that postprocedural differences persisted after controlling for baseline fear/anxiety scores (Table 2).

For VAS pain scores, there was no statistically significant difference among the groups at pretest (Kruskal–Wallis = 3.338, p = .188), indicating comparable baseline VAS pain scores. However, posttest VAS scores differed significantly among the groups (F = 33.439, p < .001). Post hoc analyses showed that VAS pain scores in the control group were significantly higher than those in both the positive reinforcement and bubble-blowing groups (Group 1 > Groups 2 and 3). In addition, pain levels in the positive reinforcement group were significantly higher than those in the bubble-blowing group (Group 2 > Group 3), indicating lower postprocedural VAS pain scores in the bubble-blowing group than in the positive reinforcement group. The eta-squared value for this model was 0.243, indicating a notable statistical magnitude of group effect, with 24.3% of the variance in postprocedural VAS pain scores explained by group membership (Fig. 3).

Fig. 3.

Comparison of scores obtained from different scales across groups

Discussion

Venipuncture procedures in children are described as among the medical experiences in which negative emotional responses such as pain, fear, and anxiety are most intensely experienced [19, 32]. The literature highlights that, although children are cognitively capable of understanding the procedure, their coping skills are not yet fully developed; therefore, pain perception, fear responses, and avoidance behaviors may be more pronounced during this period [3, 19, 34]. In pediatric nursing practice, the use of nonpharmacological methods to alleviate this emotional burden has gained increasing importance. In particular, active attention-based interventions that redirect the child’s cognitive focus away from procedural stress have been shown in several randomized trials to be effective in reducing pain and anxiety during short invasive procedures such as venipuncture [35, 36].

Within this context, the baseline characteristics of the groups were examined before interpreting the effects of the two active distraction methods. No significant differences were observed in age, sex, educational level, or parental sociodemographic characteristics between the control, positive reinforcement, and bubble-blowing groups. However, because baseline fear/anxiety scores differed significantly among the groups, this imbalance was taken into account when interpreting postprocedural outcomes. Age is one of the key variables influencing both pain perception and the extent to which children benefit from distraction methods. Recent randomized controlled trials have shown that attention-based distraction interventions, effectively reduce pain and fear during venipuncture in school-age children, particularly those aged 5–12 years [27, 32, 35]. These findings are consistent with developmental evidence indicating that as children’s cognitive and attentional capacities mature across the school-age years, they become increasingly able to engage with and benefit from cognitive and attention-based coping strategies [37]. Therefore, the similarity of mean ages across the groups in the present study was considered an important methodological strength.

Sex may also be a determining factor in children related to medical procedures. Studies examining how developmental and social factors influence fear and stress during procedures have reported that girls and boys may sometimes exhibit different levels of fear and avoidance [14, 38]. Therefore, the homogeneous distribution of sex across the groups in the present study reduces potential confounding effects when evaluating the impact of the interventions.

The equal distribution of family-related sociodemographic characteristics (parental education level and family income) is likewise an important finding. Parental attitudes can directly influence how children make sense of medical procedures and shape their emotional responses. Qualitative studies have shown that anxious or negative parental behaviors may heighten children’s procedure-related fear [39]. In addition, parents’ educational level and socioeconomic status may affect how well children are prepared for procedures and which coping strategies they use [40]. Thus, the similarity of parental variables across groups is another factor that strengthens the internal validity of this study.

Overall, the homogeneity of sample characteristics allowed a more reliable comparison of the effects of the two active distraction methods used in this study. The literature similarly emphasizes that achieving sociodemographic equivalence is critical when evaluating the effectiveness of nonpharmacological interventions in pediatric blood-drawing procedures [11, 41]. Accordingly, our initial findings provide an important methodological foundation for interpreting the group differences in pain, fear, and anxiety discussed in the following sections as genuine intervention effects. Similarly, in a randomized controlled study comparing three distinct distraction methods, Besirik and Sahiner (2024) found that distraction interventions significantly decreased pain and anxiety in children undergoing venipuncture, which aligns with and further supports the findings of the current study [42].

A second key result of the study was that fear and anxiety evolved differently in each group over time. In the control group, fear–anxiety levels increased to a statistically significant extent, and the effect size was large (Cohen’s d = 1.14), suggesting a clinically meaningful escalation. This result is consistent with existing literature suggesting that venipuncture, in its usual course, elicits intense fear and anxiety responses in children. Recent studies have shown that procedures such as venipuncture are among the most anxiety-provoking medical interventions, particularly for school-age children [32, 40]. McMurtry et al. (2011) emphasize that the procedural pain–fear cycle is reinforced as stress during the procedure increases, leading to greater avoidance of subsequent medical care [14]. The marked increase observed in our control group underscores how strongly this cycle operates in the absence of any intervention.

Although fear–anxiety levels in the bubble-blowing group also increased significantly, the effect size was moderate. This suggests that bubble blowing, while not completely preventing anxiety, substantially attenuated the increase compared with the control group. Our findings are supported by recent systematic reviews showing that active distraction strategies that involve children’s participation, including bubble blowing, decrease anxiety by diverting cognitive focus from the medical procedure [9, 35]. The fact that bubble blowing involves rhythmic breathing and motor activity is also consistent with explanations proposing that such activities may enhance parasympathetic activation and thereby reduce anxiety [9].

In the positive reinforcement group, the mean fear/anxiety score increased slightly from pretest to posttest; however, this within-group change did not reach statistical significance (p = .052). Therefore, this finding should not be interpreted as evidence that positive reinforcement definitively prevented an increase in fear and anxiety. Rather, it suggests that fear/anxiety levels remained relatively stable in this group compared with the marked increase observed in the control group. Positive reinforcement is often explained within Bandura’s social learning theory (1965) as a strategy that shapes behavior and facilitates cognitive reframing. Previous studies have also indicated that interventions involving positive feedback, encouragement, and behavioral reinforcement may support children’s coping during procedures [16, 43]. However, given the non-significant within-group result in the present study, this finding should be interpreted cautiously. It should also be noted that parental involvement was more explicitly structured in the positive reinforcement group than in the bubble-blowing group. Although parents were present during the procedures in all groups, verbal and/or physical support was specifically encouraged as part of the positive reinforcement protocol. Previous evidence suggests that parental presence and involvement during invasive procedures may reduce children’s pain levels; however, the effect of parental involvement may vary depending on parents’ anxiety levels and the type of support provided [39, 44, 45]. Therefore, parental support in the present study should be considered a potential co-intervention that may have contributed to the relatively stable fear/anxiety scores observed in the positive reinforcement group. Therefore, the observed findings in this group may have been influenced not only by the cognitive distraction and positive feedback components, but also by parental support. This potential confounding effect should be considered when interpreting the comparative effectiveness of the two interventions. When between-group differences are considered, significant differences were observed in both pretest and posttest measurements, with the control group consistently exhibiting higher fear–anxiety levels than the two intervention groups. This aligns with current literature demonstrating the benefits of distraction and behavioral regulation techniques during pediatric venipuncture [11, 32]. In the posttest measurements, the effect size increased, indicating that 12.1% of the variance in fear/anxiety scores between groups was explained by group membership. This value indicates a moderate statistical magnitude of effect; however, it should not be interpreted as definitive evidence of clinical significance without considering broader clinical indicators such as children’s procedural experience, feasibility, and contextual relevance.

This final finding clearly demonstrates the differential impact of the distraction methods on pain management by showing that children’s pain levels during the procedure varied significantly according to the intervention received. It is particularly important in highlighting that children’s pain experiences during venipuncture differ markedly depending on the type of strategy used. The very large effect size observed in the control group indicates that, in the absence of any distraction strategy, children experience procedural pain at a highly intense level. This result is consistent with the findings of Gerçeker et al. (2020), who reported a marked increase in venipuncture-related pain in the nonintervention group [32]. Similarly, Sharp et al. (2023) noted that children with difficult venous access often associate the procedure with severe pain and stress, further supporting our findings [39].

Although pain levels increased in both the positive reinforcement and bubble-blowing groups, the moderate effect sizes obtained (r = .75 and r = .74, respectively) indicate that these interventions substantially limited the increase in pain compared with the control group. This is in line with previous literature showing that distraction-based strategies reduce procedural pain in children. Czech et al. (2021) reported that active visual and motor distraction exerts a strong effect on reducing children’s subjective pain perception [9]. In our study, the bubble-blowing method yielded the lowest posttest pain scores, consistent with these findings. By promoting rhythmic breathing and motor focus, bubble blowing appears to redirect the child’s cognitive focus away from the procedure, thereby exerting an analgesic effect.

The fact that pain levels in the positive reinforcement group were higher than those in the bubble-blowing group suggests that behaviorally based reinforcement techniques may have a more limited impact on pain perception. Muris and Ollendick (2021) state that positive feedback supports the regulation of children’s anxiety but may not be as effective as visual–motor distraction methods in directly altering pain perception [46]. Similarly, Birnie et al. (2014) emphasize that interventions that modify sensory attention tend to be more powerful in reducing pain during pediatric procedures [41]. The stronger effect of bubble blowing on postprocedural pain may be partly explained by the active motor, visual, and respiratory engagement required by this technique. By directing the child’s attention toward blowing bubbles and maintaining rhythmic breathing, this intervention may support attentional redirection and relaxation during venipuncture. However, because physiological indicators such as heart rate variability, respiratory rate, or autonomic nervous system activity were not measured in this study, parasympathetic activation should be considered only as a possible mechanism rather than a directly demonstrated effect.

The significant difference observed in posttest pain scores between the groups suggests that active distraction techniques, particularly bubble blowing, may provide practical benefits in reducing children’s pain during venipuncture. From the perspective of pediatric pain management, this finding is important because bubble blowing is a low-cost, simple, and easily applicable method that can be integrated into routine clinical care. In line with our results, Arıkan and Esenay (2020) also reported that active distraction techniques significantly reduced pain during venipuncture, providing additional evidence in support of the effectiveness of the interventions used in the present study [11]. Overall, these findings highlight the value of simple, child-centered distraction strategies in improving procedural comfort during routine pediatric care.

Implications for Practice

Because venipuncture is both painful and anxiety provoking for children, the use of nonpharmacological distraction techniques holds an important place in clinical care. The present study suggests that bubble blowing may be particularly useful for reducing postprocedural pain scores, whereas positive reinforcement may help maintain children’s fear/anxiety responses at a relatively stable level, although the within-group change in this group was not statistically significant. As low-cost and easily implemented strategies, these interventions may enhance children’s comfort during procedures and support pediatric nursing practice. Bubble blowing may be particularly feasible in planned blood sampling or outpatient settings, whereas material-free strategies such as positive reinforcement may be more practical in emergency or high-throughput clinical environments where time, space, or infection-control considerations may limit the use of additional materials. Future studies conducted with different age groups and across a variety of invasive procedures will further strengthen the evidence base regarding the effectiveness of distraction techniques.

Strengths and Limitations

This study has some limitations. First, children in whom the blood sample could not be obtained on the first venipuncture attempt were excluded in order to standardize procedural exposure across groups. However, this may have introduced selection bias, as children requiring repeated attempts may experience higher levels of pain, fear, anxiety, and behavioral distress. Therefore, the findings may underestimate the overall procedural burden and should be generalized with caution to routine clinical settings in which multiple venipuncture attempts may occur. Second, children’s pain and anxiety were measured using self-report instruments, without incorporating physiological stress markers or neurological measures. In addition, because the researcher collecting outcome data was aware of group allocation, measurement bias cannot be completely excluded. Within the Risk of Bias 2 framework, this issue represents a potential risk in the outcome measurement domain and should be considered when interpreting the findings. Third, because the study included only children aged 7–12 years, the findings cannot be generalized to other age groups. In addition, the effects of distraction techniques were not examined in relation to children’s prior medical experiences or individual differences. Another limitation is that parental involvement was not standardized to the same extent across the intervention groups, which may have acted as a potential confounding factor, particularly in the positive reinforcement group.

Nevertheless, the study also has important strengths. The comparative evaluation of two active distraction methods that can be easily integrated into routine clinical practice represents a meaningful contribution to the field. In particular, positive reinforcement is a no-cost strategy that can be implemented immediately in any clinical setting, offering a practical advantage for nursing care. Furthermore, the use of validated child self-report instruments, together with separately recorded observational ratings, allowed the procedural responses of children to be evaluated from complementary perspectives.

Conclusion

The findings showed marked increases in both fear/anxiety and pain scores in the control group, in which no intervention was applied. This result suggests that performing pediatric procedures without supportive strategies may generate high levels of psychological and physical distress in children. In the positive reinforcement group, the mean fear/anxiety score increased slightly, but this change was not statistically significant; therefore, this result should be interpreted as a non-significant stabilization trend rather than definitive evidence of prevention. Bubble blowing was associated with lower postprocedural pain scores than positive reinforcement, indicating that techniques requiring active motor, visual, and respiratory engagement may offer particular advantages for pain-related outcomes.

Overall, the results support distraction-based interventions as feasible and low-cost strategies for pediatric venipuncture. These findings suggest that integrating active distraction techniques into nursing care during brief yet stressful procedures such as blood sampling may provide meaningful benefits for both children’s procedural comfort and care experience.

Authors’ contributions

Sinem Yalnızoğlu Çaka: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision, Software, Resources, Project administration, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization. Elanur CEBECİ: Writing – original draft, Data curation. Hanife Öznur Kavi: Writing – original draft, Data curation. Nafiz Balıkcı: Writing – original draft, Data curation. Sümeyra Topal: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision, Software, Resources, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization.

Funding

This project was supported within the scope of the TÜBİTAK 2209-A Research Project Support Programme for Undergraduate Students. The publication process of this article was also supported by the Kocaeli University Scientific Research Projects Coordination Unit.

Data availability

Datasets used or analysed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by Kocaeli University Ethics Committee (Approval Number: KÜ GOKAEK-2024/16.13, Date: 10.10.2024). The study adheres to the principles of the Helsinki Declaration. Additionally, authorization to conduct the research was secured from the administration of the participating hospital. Prior to data collection, the study aims were explained to the children and their parents, the voluntary nature of participation was underlined, and written informed consent was obtained from parents together with verbal assent from the children.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.