Effect of family-centered empowerment model on self-efficacy of children with leukemia

Abstract

Childhood leukemia is the most prevalent pediatric malignancy and remains a major contributor to childhood mortality, placing multiple burdens on affected families. Family engagement, a core element of the Family-Centered Empowerment Model (FCEM), aims to strengthen caregivers’ understanding of the disease, enhance their competencies, and improve children’s quality of life and self-efficacy (SE). This study aimed to examine the impact of the FCEM on the SE of children with leukemia. A quasi-experimental design was conducted at the Pediatric Oncology Department, Oncology Center Mansoura University (OCMU), using a convenient sample of children with leukemia and their mothers. Data was collected using a structured interview questionnaire, the Family-Centered Empowerment Scale, and the Self-Efficacy Questionnaire for Children. Pre- and post-intervention assessments were performed to evaluate changes in family empowerment and children’s SE. Results indicated that implementation of the FCEM was associated with significant improvements in mothers’ knowledge, family empowerment, and children’s SE, with large effect sizes observed across outcomes. However, due to the quasi-experimental design without a control group, the findings should be interpreted with caution. In conclusion, the FCEM shows potential value as a supportive intervention in pediatric oncology settings to enhance parental knowledge and promote improvements in children’s SE.

Introduction

Cancer remains the second leading cause of death among children worldwide, with approximately 400,000 new cases diagnosed annually among individuals aged 0–19 years [1]. Leukemia is among the most common pediatric malignancies, accounting for nearly 30% of all childhood cancer cases, with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) being the predominant subtypes [2–4]. Globally, ALL alone represents about 19% of pediatric cancers and continues to pose a substantial burden across both high-income and low- and middle-income countries [5, 6]. In Saudi Arabia, leukemia constitutes 34.6% of reported childhood cancer cases, highlighting its significant national impact [7].

Despite advances in treatment, conventional therapeutic modalities, including chemotherapy, radiotherapy, and surgery, are frequently associated with considerable adverse effects. A substantial proportion of pediatric patients experience chemotherapy-related toxicities, which can compromise treatment adherence and quality of life [8]. These challenges extend beyond the child, placing considerable psychological, physical, social, and financial burdens on parents and caregivers [9]. Reduced survival and poorer outcomes have been associated with treatment-related complications, delayed detection of relapses, limited healthcare access, and inadequate caregiver knowledge regarding symptom recognition and management [10, 11]. Parents of children with leukemia often experience elevated levels of psychological distress and increased healthcare utilization, reflecting the complex demands of caregiving in pediatric oncology [12]. Moreover, families must navigate these challenges within diverse cultural and social contexts, which may further complicate their ability to meet their child’s multifaceted health needs while maintaining family stability [13, 14].

In recognition of the central role of families in pediatric oncology care, family-centered care (FCC) has been widely endorsed as a standard approach that fosters collaboration between healthcare professionals and families and emphasizes parental involvement in decision-making and daily care [15, 16]. Building upon these principles, the family-centered empowerment model (FCEM) was developed to enhance families’ knowledge, coping skills, and confidence in managing chronic pediatric illnesses through a structured, multi-stage educational and participatory framework [17, 18].

Self-efficacy (SE), defined as an individual’s belief in their capacity to organize and execute actions required to achieve desired outcomes, represents a key determinant of effective disease management [19]. In pediatric chronic illness, higher parental SE has been associated with improved treatment adherence, better symptom control, and enhanced quality of life [20]. Empowerment-based interventions, particularly those delivered by pediatric nurses, play a pivotal role in strengthening families’ SE by providing tailored education, psychosocial support, and practical skills training, ultimately contributing to more favorable clinical and psychosocial outcomes [21, 22].

Accordingly, the present study aimed to examine the effect of implementing the FCEM on SE outcomes among pediatric patients with leukemia.

Significance of the study

The abrupt onset of cancer, together with its intensive long-term treatment and the immediate—and often enduring—complications, makes it an exceptionally challenging condition for families to navigate [23]. Understanding the disease-related changes experienced by the affected child and family members may provide a greater sense of security and enable families to manage the situation more effectively [23]. Many parents of children with leukemia report a substantial caregiving burden associated with managing the illness as a chronic condition. Creating opportunities for parents to actively participate in their child’s care, engage in caregiver support groups, and maintain open communication with nurses can enhance caregiver competence and foster empowerment [24].

Within the context of FCC, nursing interventions aim to strengthen families’ abilities to overcome health-related challenges and promote overall well-being [25]. Family empowerment represents a core component of this approach, emphasizing the family’s needs as the foundation of care and encouraging active participation through structured educational strategies [14]. Integrating empowerment-based models into pediatric oncology has been shown to reduce anxiety, enhance confidence, and build resilience among families, ultimately supporting better psychological adjustment and improved adherence to treatment [26].

Therefore, this study highlights the essential role of the family as a primary support system in helping children navigate the complexities of leukemia treatment. By prioritizing family involvement, the FCEM not only strengthens children’s sense of control and SE but also equips caregivers with the knowledge and confidence needed to provide effective support, fostering a more holistic and sustainable approach to leukemia care [27].

Aim of the study

This study aimed to evaluate the effect of the family-centered empowerment model on the self-efficacy of children with leukemia.

Research hypotheses

• H1: Implementation of the family-centered empowerment model will significantly enhance mothers’ knowledge regarding leukemia and its care.

• H2: Implementation of the family-centered empowerment model will lead to a significant improvement in self-efficacy among children diagnosed with leukemia.

Operational definitions

Family-Centered Empowerment Model (FCEM)

The family-centered empowerment model is a structured framework designed to promote active family participation in the care and management of children with special health care needs. It provides a systematic approach for identifying families’ physical and psychological concerns, as well as their immediate caregiving needs [28].

Self-Efficacy (SE)

Self-efficacy refers to an individual’s perceived ability to perform novel or challenging tasks and to cope effectively with adversity across multiple domains of functioning [29]. It also encompasses the belief in one’s capacity to organize, execute, and sustain actions required to achieve designated performance outcomes [30].

Methods

Research design

A quasi-experimental design employing a one-group pretest–posttest approach was utilized in this study. This empirical design is commonly used to evaluate the effects of an intervention on a target population in situations where random assignment is not feasible. In the one-group pretest–posttest design, a single cohort of participants is assessed prior to the intervention (pretest), exposed to the treatment or independent variable, and subsequently reassessed (posttest) to determine changes in outcomes attributable to the intervention [31].

Study setting

The study was conducted at the Pediatric Oncology Department at Oncology Center Mansoura University (OCMU). The department, located on the seventh floor, had a capacity of 40 beds and provided comprehensive services for the diagnosis, treatment, and follow-up of various pediatric tumors referred to by the Children’s Hospital and other departments. Oncology cases were referred to the unit from different governorates across the Delta region, as it served as the specialized pediatric oncology center in the area. The department administered chemotherapy to children, and when surgical intervention or radiotherapy was required, patients were referred to the corresponding specialized departments.

Study subjects

A convenience sample of mothers and their children with leukemia was recruited from the previously mentioned setting. Participants were included if they met the following criteria: children aged 6–18 years, of both genders, diagnosed with leukemia at least six months prior, free from any other chronic illnesses or disabilities, free from developmental delays, neurological or behavioral problems, and willing to participate in the study. Mothers’ characteristics were not restricted.

Sample size calculation

Based on the total number of children with leukemia admitted to the previously mentioned setting, which was 90 patients per year, the sample size was calculated using Steven Thompson’s formula [32] as follows:

where, n = sample size, N: population size (90) pediatric patients, Z: the standard score for the level of significance (0.05), the level of confidence (0.95) is equal to (1.96), d: the error rate is equal to (0.05) and the probability value is (0.50).

Based on this calculation, the total sample size required for the study was 73 children with leukemia.

Data collection tools

After reviewing the relevant literature, the researchers developed the data collection tools. The tools were subsequently written and translated into clear Arabic to ensure comprehension by the participating parents.

The instruments were translated into Arabic using a forward–backward translation method. The translated versions were reviewed by a panel of bilingual experts to ensure semantic and conceptual equivalence and pilot-tested for cultural appropriateness.

• Tool (1): structured interview questionnaire

This tool was developed by researchers after an extensive review of recent and relevant literature. It was composed of three main parts as follows:

• Part 1: Characteristics of the mothers and family socio demographic profile:

This part assessed maternal and family-related characteristics, including the mother’s age, marital status, educational level, employment status, and family income. It also included household size, number of family members, family history of leukemia, presence of any physical or psychological problems among caregivers, and distribution of caregiving responsibilities between parents.

• Part 2: Characteristics and medical data of the children

This section covered key child-related variables such as age, gender, birth order, type of leukemia, duration since diagnosis, presence of any comorbid conditions, and the number of chemotherapy cycles received.

• Part (3): Mothers' knowledge assessment sheet

This part was designed to evaluate mothers’ knowledge regarding the following:

• aChildhood leukemia and its related care: This section consisted of 20 multiple-choice questions designed to assess mothers’ knowledge regarding childhood leukemia and its essential aspects of care. The questions covered core domains including the definition, incidence, types, causes, clinical manifestations, diagnostic procedures, and potential complications of leukemia, in addition to the psychosocial impact of the disease on family members. The tool also evaluated mothers’ understanding of treatment modalities and treatment-related complications. Further items assessed caregivers’ knowledge about day-to-day management, including medication regimens, nutritional requirements, management of chemotherapy-related side effects and changes in physical appearance, infection prevention strategies, hygienic measures, daily living activities, and follow-up care. The development of this section was informed by evidence from recent studies [24, 33–35].
• bThe family-centered empowerment model (FCEM): This section consisted of 13 closed-ended items assessing participants’ knowledge regarding the definition and significance of FCEM, its essential steps, and the social and psychological support systems available for families. It also covered strategies for managing disease-related challenges and treatment demands, as well as the impact of family support on parents’ health, self-confidence, and caregiving efficacy. In addition, the items explored children’s SE—particularly among leukemic patients—and the degree of family participation in treatment and decision-making processes [18, 36–38].

Scoring system

Mothers’ knowledge was evaluated using a structured scoring system in which each response was assigned 2 points for a fully correct answer, 1 point for a partially correct answer, and 0 points for “don’t know” responses. The cumulative knowledge score for each participant was used to categorize overall knowledge levels: a score exceeding 75% was considered good, a score between 50% and less than 75% was considered average, and a score below 50% was regarded as poor.

• Tool II: Family-Centered Empowerment Scale (FCES)

The FCES, originally developed by Koren, DeChillo and Friesen (1992) [39], was adopted by the researchers to evaluate family empowerment in the context of caring for children with chronic illnesses, such as leukemia. The scale consisted of 34 self-reported items grouped into several domains and was administered twice: initially before the implementation of the empowerment model and subsequently during the follow-up phase. The instrument assessed key aspects of family empowerment across three main domains:

• aFamily: This domain included 12 items designed to evaluate parents’ confidence in managing their child’s care and handling day-to-day challenges related to the child’s condition.
• bChild Services: This domain also included 12 items assessing the family’s access to healthcare resources and supportive services.
• cInvolvement in the Community: This domain consisted of 10 items measuring the family’s participation in treatment decisions and their ability to advocate effectively for their child’s needs.

Scoring system

The total FCES score was calculated by summing the scores of the three domains and dividing by the total number of items. Each response was rated on a five-point Likert-type scale, where 1 = never, 2 = seldom, 3 = sometimes, 4 = often, and 5 = very often. Higher scores indicated greater levels of family empowerment in the corresponding domain. All items were scored in the same direction, with no reverse-coded items. The total score was calculated by summing all item scores, yielding a theoretical range from 34 to 170. Family empowerment levels were categorized as high (≥ 127.5; ≥ 75% of the maximum score), moderate (102– < 127; 60– < 75%), and low (< 102; < 60%). The Arabic version of the scale was developed through forward–backward translation, reviewed by bilingual experts for semantic and conceptual equivalence, and pilot-tested for cultural appropriateness.

• Tool III: Self-Efficacy Questionnaire for Children (SEQ-C): The Self-Efficacy Questionnaire for Children (SEQ-C), developed by Muris [40], was adopted by the researchers to assess children perceived SE across three domains: academic, social, and emotional. Academic SE referred to the child’s perceived ability to cope with learning tasks, school material, and meet academic expectations. Social SE evaluated the perceived ability to interact effectively with peers and demonstrate perseverance in social contexts. Emotional SE assessed the child’s perceived ability to manage negative emotions. The questionnaire consisted of 24 items, with 8 items measuring academic SE, 9 items measuring social SE, and 7 items measuring emotional SE. Children rated their ability to perform each task on a five-point Likert scale, where 1 indicated “not at all” and 5 indicated “very well.” Higher scores reflected greater perceived SE in the corresponding domain.

Scoring system

The subscales of the SEQ-C were calculated by summing the item scores within each domain and dividing by the number of items, thereby obtaining the average score for each subscale. A total SE score was derived by summing the scores across all 24 items. The possible total scores ranged from 24 to 120, with higher scores indicating greater perceived SE. This scoring system allowed for both domain-specific and overall assessment of children’s self-perceived capabilities in academic, social, and emotional contexts.

Tools validity

To establish content validity, a panel of five experts, two from the field of Community Health Nursing and three from Pediatric Nursing, reviewed the tools for content relevance, clarity, applicability, and comprehensiveness. Their feedback was incorporated to refine the instruments.

Tools reliability

The reliability of the data collection tools was assessed using Cronbach’s Alpha coefficient. The results indicated that the tools included homogeneous items, reflecting moderate to high internal consistency. Specifically, the knowledge assessment tool demonstrated Cronbach’s alpha of 0.903. The SEQ-C showed internal consistency values of 0.697 for the academic SE subscale, 0.943 for the social SE subscale, and 0.922 for the emotional SE subscale. The FCES demonstrated a Cronbach’s alpha of 0.899, confirming the overall reliability of the instruments.

Administrative process

A formal letter from the Dean of the Faculty of Nursing, Mansoura University was submitted to the Director of OCMU to obtain written permission for conducting the study. The letter outlined the objectives of the research and requested access to the annual statistics regarding the number of children diagnosed with leukemia who attended the center.

Pilot study

A pilot study was conducted on 10% of the study sample, comprising seven mothers, to assess the clarity, feasibility, and applicability of the data collection tools. The pilot study aimed to identify any potential difficulties or limitations that might arise during data collection. Based on the findings, necessary modifications were made to refine the instruments. Participants involved in the pilot study were not included in the main study sample.

Data collection procedure

The data collection and intervention took place from the beginning of January 2025 to the end of September 2025, covering six months for the FCEM and an additional three months for follow-up. The study was structured according to the following five phases: preparatory, assessment, planning, implementation, and evaluation.

• A.Preparatory Phase

To achieve the research objectives, the researchers first conducted a comprehensive review of national and international literature on various aspects of the research problem. This review enabled the researchers to understand the scope and severity of the problem and guided the development of the data collection tools.

• B.Assessment Phase

During the assessment phase, participants were interviewed to obtain baseline data. The researchers welcomed each mother, explained the study objectives, timeline, and planned activities, and obtained informed consent at the beginning of the interview. The researchers were available two days per week from 9:00 a.m. to 2:00 p.m., meeting mothers and their children in a separate area within a large hall on the seventh floor of OCMU. This phase lasted approximately eight weeks, during which the researchers spent 20–30 min with each mother to complete the questionnaires. The total number of interviewed subjects was determined based on those who agreed to participate.

• C.Planning and designing the FCEM

Based on the baseline data obtained during the assessment phase and insights from the literature review, the researchers designed the FCEM in a simple Arabic, utilizing the FCES and tailoring it to the mothers’ needs. The researchers formulated the goals, specific objectives, and expected outcomes, confirmed the number of sessions, content, teaching methods, and media to be used in the model according to the mothers’ levels of understanding. Additionally, telephone calls were scheduled for follow-up. This phase lasted approximately eight weeks. Based on this planning, the objectives of the model were established as follows:

• General objective: The primary goal of the FCEM was to enhance the SE of children diagnosed with leukemia.

• Specific objectives and expected outcomes: At the conclusion of the FCEM, the participating mothers’ knowledge and skills were expected to improve regarding the care of their children with leukemia, while their children were anticipated to demonstrate enhanced SE. The objectives of the model included enabling mothers and their children to:

• Define leukemia.

• Describe the incidence of leukemia in children.

• Identify the different types of leukemia.

• Explain the causes of leukemia.

• Recognize the clinical manifestations of leukemia.

• List the diagnostic tests used for leukemia.

• Identify the potential complications associated with leukemia.

• Discuss the effects of leukemia on parents and other family members.

• Explain the various treatment modalities for leukemia.

• Recognize the side effects and complications of treatment.

• Discuss the role of the family in the care of a child with leukemia, including psychological support, medication administration, hygiene, nutrition, infection prevention, management of chemotherapy side effects, daily life activities, and follow-up care.

• Define the concept of family empowerment.

• Explain the importance and value of family empowerment.

• Describe the steps involved in family empowerment.

• Identify available social and psychological support systems for the family.

• Assess the family’s abilities to utilize services and manage challenges related to the disease and its treatment.

• Discuss the significance of parental involvement in enhancing care, participating in decision-making, and promoting SE in children with leukemia.

• D.Implementation phase

The FCEM was implemented through eight structured sessions, delivered at a rate of two sessions per week (This phase lasted approximately four weeks). The educational content was presented by the researchers to small groups of mothers consisting of 3–5 participants, with each session lasting approximately 30–45 min. Motivation and positive reinforcement were consistently used to encourage mothers' active engagement throughout the program. A variety of instructional strategies—including interactive lectures, group discussions, demonstrations, re-demonstrations, and PowerPoint presentations—were utilized to facilitate learning. On the first day of the intervention, all participating mothers received an instructional booklet that summarized the core concepts and guided their learning.

The implementation of the FCEM followed four sequential steps as follows:

• Step 1: knowledge enhancement

The researchers provided a series of theoretical educational sessions for the mothers:

• Session 1: Covered the definition of leukemia, its types, causes, clinical manifestations, diagnostic procedures, possible complications, and modalities of treatment.

• Session 2: Focused on the side effects and complications of leukemia treatment, particularly chemotherapy. It also addressed parents’ communication strategies with the healthcare team and encouraged sharing experiences on managing chemotherapy side effects.

• Sessions 3 & 4: Included the definition, importance, aims, and dimensions of family empowerment. The FCES was explained, along with the relationship between parental involvement in care and decision-making, child SE, and family empowerment.

• Step 2: self-efficacy enhancement

This phase concentrated on problem-solving skills and practical caregiving abilities for both parents and leukemic children to strengthen self-control. Four sessions were delivered, covering:

• Infection prevention methods.

• Pain and fatigue control strategies.

• Vaccination considerations.

• Nutritional and hygienic practices.

• Physical activity.

• Care of chemotherapy side effects.

• Techniques to enhance self-control while addressing the child’s illness and family challenges.

• Supporting other family members.

The researchers explained all model components and demonstrated each caregiving skill until mothers and children mastered them.

• Step 3: Self-Esteem (Self-Belief) Enhancement

Mothers were encouraged to ask questions about leukemia and childcare, which were discussed in the following session. Each educational session began with a brief review of previous content and a clarification of the objectives of the new session.

• Step 4: evaluation process

Evaluation was conducted throughout the model:

• At the beginning of each session, mothers answered two verbal questions to assess retention of previous content.

• Children demonstrated related caregiving skills to evaluate SE.

• Self-esteem and confidence were assessed through their level of cooperation during educational activities.

• Four weeks after the final session, the researchers contacted each mother by telephone to reassess the recommended caregiving skills and ensure her confidence in applying the FCEM materials. Additionally, scheduled follow-up visits were conducted during the mothers’ routine presence in the oncology unit, where the researchers met with the participants to further evaluate their performance, reinforce essential skills, and verify their continued application of the provided instructions.

• E.Post-Intervention Evaluation Phase

After completion of the FCEM, its effectiveness was evaluated using the same tools administered during the pre- assessment. The post-test was conducted immediately after the intervention and again three months later to assess changes in mothers’ knowledge, family empowerment and the SE of leukemic children. This follow-up assessment was conducted through scheduled visits to either the oncology outpatient clinic or the in-patient oncology department.

To ensure clarity and consistency, the timing of outcome assessments in this study was systematically organized and is summarized in Table 1. All instruments were administered at baseline (pre-intervention) to establish initial levels of mothers’ knowledge, family empowerment, and children’s SE. Mothers’ knowledge was reassessed immediately after the intervention to capture short-term improvements, while all three outcomes—mothers’ knowledge, family empowerment, and children’s SE—were reassessed at three months post-intervention to evaluate the sustained effects of the FCEM.

Table 1.

Timing of Outcome Assessments

Instrument	Baseline (Pre-Intervention)	Immediate post-intervention	3-Month Follow-Up
Structured Interview Questionnaire—Mothers’ Knowledge	✔	✔	✔
Family-Centered Empowerment Scale (FCES)	✔	––	✔
Self-Efficacy Questionnaire for Children (SEQ-C)	✔	––	✔

✔= Assessment conducted at this time point

Statistical analysis

All statistical analyses were conducted using SPSS for Windows, version 20.0 (SPSS Inc., Chicago, IL, USA). Continuous variables were assessed for normality using Shapiro–Wilk test and expressed as mean ± standard deviation (SD). Categorical variables were presented as frequencies and percentages. Comparisons between pre- and post-intervention mean scores were conducted using paired-samples t-tests.

Comparisons of categorical variables were performed using the Chi-square test, or Fisher’s exact test when appropriate. Pearson’s correlation coefficient was used to examine relationships between continuous variables. Effect sizes were calculated using Cohen’s d to estimate the magnitude of intervention effects, and 95% confidence intervals (CI) were computed for mean differences to assess the precision of the estimates. Effect sizes were interpreted as small (0.2), medium (0.5), and large (0.8) according to Cohen’s criteria.

The internal consistency of the study questionnaires was assessed to evaluate reliability. Statistical significance was considered at P < 0.05.

Results

Table 2 presents the personal characteristics of the children included in the study. The results indicate that less than two-thirds of the participants (64.4%) were aged between 11 and 15 years, with a mean age of 13.5 ± 3.3 years. Males accounted for a slightly higher proportion (54.8%) compared to females (45.2%). Regarding birth order, half of the children (50.7%) were second-born. Additionally, 17.8% of the children had other chronic illnesses in addition to leukemia.

Table 2.

Distribution of the Studied Children & their Mothers According to Their General Characteristics (n = 73)

Children’s Characteristics	n	%
Age (Years)
6–10	18	24.7
11–15	47	64.4
16 or more	8	11.0
Mean ± SD	13.5 ± 3.3
Gender
Male	40	54.8
Female	33	45.2
Birth Order
1st	18	24.7
2nd	37	50.7
3rd	18	24.7
Leukemia Type
Acute Lymphoblastic Leukemia	61	83.6
Acute Myeloid Leukemia	12	16.4
Duration of diagnosis
6–12 months	10	13.7
More than a year	63	86.3
Other illnesses in child
Yes	13	17.8
No	60	82.2

Mothers’ Characteristics	n	%
Age (Years)
31–40	37	50.7
41 or more	36	49.3
Mean ± SD	36.9 ± 5.3
Educational level
Primary	29	39.7
Secondary	11	15.1
University	23	31.5
Higher than university	10	13.7
Occupation
Employee	33	45.2
Housewife	40	54.8
Family income
Enough	19	26.0
Not enough	54	74.0

Also, the general characteristics of the mothers are also summarized in Table 2 The mothers’ ages were distributed with 50.7% falling within the 31–40 years range, and the mean age was 36.9 ± 5.3 years. All mothers were reported to be married. Nearly three-quarters of the mothers (74.0%) reported insufficient monthly income, and more than two-thirds of the families (69.9%) consisted of 4 to 5 members.

Figures 1 & 2 show that the majority of children were diagnosed with ALL, representing 83.6% of cases, whereas 16.4% had AML. Regarding the duration since diagnosis, a substantial proportion of children (86.3%) had been diagnosed for more than one year.

Fig. 1.

Distribution of the Children’s Leukemia Types

Fig. 2.

Distribution of the Studied Children According to Duration Since Diagnosis

Figures 3 & 4 present the educational and occupational characteristics of mothers. A considerable proportion had only a primary education (39.7%), and more than half (54.8%) were housewives.

Fig. 3.

Distribution of the Studied Mothers According to Their Educational Level

Fig. 4.

Distribution of the studied Mothers by Occupation

Table 3 summarizes the family psychosocial status. The majority of families (84.9%) reported not receiving any psychological or social support, and 19.2% indicated the presence of other health or psychological issues within the household. Notably, none of the families received external financial support. Caregiving responsibilities were predominantly assumed by mothers, with 75.3% reporting primary responsibility, while only 24.7% indicated shared caregiving between both parents.

Table 3.

Distribution of the Families According to Their Psychosocial Status (n. 73)

	n	%
Number of family members (including the affected child)
4–5	51	69.9
6 or More	22	30.1
Presence of any other health or psychological problems in the family
Yes	14	19.2
No	59	80.8
Presence of financial support provided by external sources
Yes	0	0.0
No	73	100.0
Presence of psychological or social support for mothers
Yes	11	15.1
No	62	84.9
Distribution of child caregiving responsibilities between the father and mother
Mother only	55	75.3
Both parents equally	18	24.7

Table 4 illustrates mothers’ total knowledge scores about leukemia before and after the intervention. Prior to the intervention, over two-thirds of mothers (69.9%) demonstrated poor knowledge, and only 8.2% exhibited good knowledge. Following the intervention, a marked improvement was observed, with 74% and 69.9% of mothers achieving high knowledge scores immediately and at three months post-intervention, respectively, while only 12.3% and 11% remained in the poor knowledge category. A statistically significant difference was found between pre-intervention and both immediate and three-month post-intervention total knowledge scores (P < 0.001). The calculated effect size was large (Cohen’s d = 1.82), reflecting a strong intervention effect.

Table 4.

Distribution of Mothers’ Total Knowledge Levels About Leukemia Pre-Intervention, Immediately Post-Intervention, and After 3 Months

	Pre		Post		After 3 months		Significance test
	n	%	n	%	n	%	Sig. 1	Sig. 2
Knowledge about Leukemia
Poor knowledge	51	69.9	9	12.3	8	11.0	X2 = 69.185, P < 0.001**	X2 = 66.998, P < 0.001**
Average knowledge	16	21.9	10	13.7	14	19.2
High knowledge	6	8.2	54	74.0	51	69.9
Mean ± SD	5.7 ± 2.7		10.8 ± 2.9		10.3 ± 3.0		T = 10.932, P < 0.001**	T = 9.737, P < 0.001**
Cohen’s d/Mean diff [95% CI]	1.821				5.1 [1.44–2.19]

X²: Chi – square test, T: Student t – test, Sig.1: Pre/Post, Sig.2: Pre/Follow

**Significant at P ≤ 0.05

Figure 5 illustrates the distribution of total FCES scores before and three months after implementation of the empowerment model. Prior to the intervention, the majority of families (80.8%) exhibited low levels of empowerment, whereas only 4.1% demonstrated high empowerment. Three months of post-intervention, a substantial improvement was observed, with 67.1% of families achieving high empowerment scores, and only 9.6% remaining in the low category. The mean total FCE score increased significantly from 86.1 ± 13.0 pre-intervention to 123.4 ± 13.0 post-intervention, with the improvement being statistically significant (P < 0.001). The effect size was also large (Cohen’s d = 1.97), suggesting a substantial improvement in family empowerment.

Fig. 5.

Distribution of the Total Family Empowerment Score Levels Pre-Intervention and After 3 Months of FCEM Application

Table 5 presents the distribution of children’s SE scores across the academic, social, and emotional domains, as well as the overall SE, before and three months after the intervention. In the academic domain, the proportion of children with high SE increased markedly from 1.4% pre-intervention to 56.2% post-intervention, while those with low SE scores decreased from 82.2% pre-intervention to 9.6% post-intervention. The mean academic SE scores improved significantly from 19.8 ± 3.8 pre-intervention to 29.1 ± 4.2 post-intervention (P < 0.001).

Table 5.

Distribution of Children’s Total Self-Efficacy Scores Across All Domains Pre- and Post-Intervention (N = 73)

	Pre						Post (3) months
Items	Low self-efficacy		Moderate self-efficacy		High self-efficacy		Low self-efficacy		Moderate self-efficacy		High self-efficacy		Significance test
	n	%	n	%	n	%	n	%	N	%	n	%
1- Academic self-efficacy	60	82.2	12	16.4	1	1.4	7	9.6	25	34.2	41	56.2	X2 = 84.588, P < 0.001**
Mean ± SD	19.8 ± 3.8						29.1 ± 4.2						T = 14.022, P < 0.001**
2- Social self-efficacy	56	76.7	17	23.3	0	0.0	9	12.3	16	21.9	48	65.8	X2 = 82.015, P < 0.001**
Mean ± SD	19.7 ± 4.2						29.0 ± 4.2						T = 13.388, P < 0.001**
3- Emotional self-efficacy	59	80.8	10	13.7	4	5.5	4	5.5	26	35.6	43	58.9	X2 = 87.489, P < 0.001**
Mean ± SD	19.4 ± 4.9						29.4 ± 3.5						T = 14.003, P < 0.001**
Total SEQ-C	58	79.5	13	17.8	2	2.7	7	9.6	23	31.5	43	58.9	X2 = 80.149, P < 0.001**
Mean ± SD	58.9 ± 8.9						87.5 ± 7.6						T = 20.923, P < 0.001**
Cohen’s d/Mean diff [95% CI]	1.890						28.6 [1.52–2.25]

**Significant at P ≤ 0.05, X2: Chi – square test, T: Student t – test

A similar trend of improvement was observed in the social domain, where the proportion of children with high SE increased from 0% pre-intervention to 65.8% post-intervention, while those with low SE decreased from 76.7% pre-intervention to 12.3% post-intervention. The mean social SE score increased significantly from 19.7 ± 4.2 to 29.0 ± 4.2 (P < 0.001).

In the emotional domain, the proportion of children with high SE rose from 5.5% pre-intervention to 58.9% post-intervention, whereas those with low SE declined from 80.8% pre-intervention to 5.5% post-intervention. The mean emotional SE score improved from 19.4 ± 4.9 to 29.4 ± 3.5 (P < 0.001).

Furthermore, the mean total SE score increased from 58.9 ± 8.9 pre-intervention to 87.5 ± 7.6 post-intervention (P < 0.001). The effect size was large (Cohen’s d = 1.89), indicating a substantial practical impact of the intervention on children’s SE.

Table 6 illustrates the association between the studied mothers’ and children’s general characteristics and the mothers’ total knowledge scores about leukemia following the FCEM intervention. The analysis revealed that mothers’ educational level and children’s duration since diagnosis exceeding one year were the only variables significantly associated with post-intervention knowledge scores (P < 0.001). Specifically, mothers with higher education (university level) were more likely to achieve good knowledge levels after the intervention. In contrast, other variables, including mothers’ age, occupation, monthly income, number of family members, as well as children’s age, gender, and type of leukemia, did not show statistically significant associations (P > 0.05).

Table 6.

Association Between Mothers’ and Children’s General Characteristics and the Total Knowledge About Leukemia Post-Intervention (N = 73)

Items	Poor knowledge (n = 9)		Average knowledge (n = 10)		Good knowledge (n = 54)		Chi – square/Fisher’s exact test
	n	%	n	%	n	%	X2	P
Age (Years)
6–10	2	22.2	3	30.0	13	24.1
11–15	5	55.6	6	60.0	36	66.7
16 or more	2	22.2	1	10.0	5	9.3	1.520	0.823
Gender
Male	4	44.4	6	60.0	30	55.6
Female	5	55.6	4	40.0	24	44.4	0.511	0.774
Birth Order
1st	4	44.4	2	20.0	12	22.2
2nd	3	33.3	6	60.0	28	51.9
3rd	2	22.2	2	20.0	14	25.9	2.512	0.642
Leukemia Type
- Acute Lymphoblastic Leukemia	7	77.8	7	70.0	47	87.0
- Acute Myeloid Leukemia	2	22.2	3	30.0	7	13.0	2.033	0.362
Duration of diagnosis
6–12 months	8	88.9	2	20.0	0	0.0
More than a year	1	11.1	8	80.0	54	100.0	51.947	< 0.001**
Any other illnesses in child
Yes	2	22.2	2	20.0	9	16.7
No	7	77.8	8	80.0	45	83.3	0.201	0.905
Mother’s Age (Years)
31–40	7	77.8	6	60.0	24	44.4
41 or more	2	22.2	4	40.0	30	55.6	3.831	0.147
Mother’s Educational level
Primary	7	77.8	8	80.0	14	25.9
Secondary	2	22.2	2	20.0	7	13.0
University	0	0.0	0	0.0	23	42.6
Higher than university	0	0.0	0	0.0	10	18.5	22.189	< 0.001**
Occupation
Employee	5	55.6	4	40.0	24	44.4
Housewife	4	44.4	6	60.0	30	55.6	0.511	0.774
Family income
Enough	2	22.2	3	30.0	14	25.9
Not enough	7	77.8	7	70.0	40	74.1	0.150	0.928

**Significant at P ≤ 0.05

Table 7 presents the association between the studied children’s and mothers’ general characteristics and the total family-centered empowerment levels three months after the intervention. Among the examined variables, only mothers’ educational level demonstrated a statistically significant relationship with family empowerment scores (P < 0.001). Mothers with primary education were predominantly represented in the low and moderate empowerment categories, whereas those with higher education (university and postgraduate) were more likely to report high family empowerment levels.

Table 7.

Association Between Children’s and Mothers’ General Characteristics and Family Empowerment Total Scores Post-Intervention (N = 73)

Items	Poor empowerment (n = 7)		Moderate empowerment (n = 17)		High empowerment (n = 49)		Chi – square/Fisher’s exact test
	n	%	n	%	n	%	X2	P
Age (Years)
6–10	3	42.9	4	23.5	11	22.4
11–15	3	42.9	11	64.7	33	67.3
16 or more	1	14.3	2	11.8	5	10.2	1.723	0.787
Gender
Male	5	71.4	12	70.6	23	46.9
Female	2	28.6	5	29.4	26	53.1	3.715	0.156
Birth Order
1st	2	28.6	4	23.5	12	24.5
2nd	3	42.9	10	58.8	24	49.0
3rd	2	28.6	3	17.6	13	26.5	0.840	0.933
Leukemia Type
Acute Lymphoblastic Leukemia	7	100.0	13	76.5	41	83.7
Acute Myeloid Leukemia	0	0.0	4	23.5	8	16.3	2.000	0.368
Duration of diagnosis
6–12 months	2	28.6	3	17.6	5	10.2
More than a year	5	71.4	14	82.4	44	89.8	2.040	0.361
Any other previous illnesses in children
Yes	0	0.0	3	17.6	10	20.4
No	7	100.0	14	82.4	39	79.6	1.743	0.418
Mother’s Age (Years)
31–40	5	71.4	7	41.2	25	51.0
41 or more	2	28.6	10	58.8	24	49.0	1.822	0.402
Mother’s Educational level
Primary	6	85.7	11	64.7	12	24.5
Secondary	1	14.3	4	23.5	6	12.2
University	0	0.0	2	11.8	21	42.9
Higher than university	0	0.0	0	0.0	10	20.4	21.54	< 0.001**
Occupation
Employee	4	57.1	8	47.1	21	42.9
Housewife	3	42.9	9	52.9	28	57.1	0.535	0.765
Family income
Enough	1	14.3	5	29.4	13	26.5
Not enough	6	85.7	12	70.6	36	73.5	0.609	0.738

**Significant at P ≤ 0.05

No significant associations were found between total family empowerment levels and children’s age, gender, birth order, leukemia type, duration since diagnosis, or the presence of other illnesses. Similarly, mothers’ age, occupation, monthly income, and household size were not significantly associated with family empowerment outcomes.

Table 8 illustrates the distribution of SE levels among children across different demographic and clinical characteristics following three months of the FCEM intervention. The analysis shows that most children exhibited moderate to high SE after the intervention, regardless of age, gender, birth order, duration of diagnosis, or presence of comorbidities, with no statistically significant differences observed (p > 0.05). Notably, the type of leukemia demonstrated a significant association with children’s SE scores (P = 0.009), where children diagnosed with ALL were more likely to achieve moderate to high SE while a higher proportion of children with AML remained in the low SE category.

Table 8.

Association Between Children’s and Mothers’ General Characteristics and Total Score of Self-Efficacy Scale Post Intervention (N.73)

Items	Low self-efficacy (n = 7)		Moderate self-efficacy (n = 23)		High self-efficacy (n = 43)		Chi – square/Fisher’s exact test
	n	%	n	%	n	%	X2	P
Age (Years)
6–10	1	14.3	8	34.8	9	20.9
11–15	5	71.4	11	47.8	31	72.1
16 or more	1	14.3	4	17.4	3	7.0	4.495	0.343
Gender
Male	3	42.9	9	39.1	28	65.1
Female	4	57.1	14	60.9	15	34.9	4.530	0.104
Birth Order
1st	2	28.6	4	17.4	12	27.9
2nd	3	42.9	13	56.5	21	48.8
3rd	2	28.6	6	26.1	10	23.3	1.085	0.897
Leukemia Type
Acute Lymphoblastic Leukemia	3	42.9	20	87.0	38	88.4
Acute Myeloid Leukemia	4	57.1	3	13.0	5	11.6	9.361	0.009*
Duration of diagnosis
6–12 months	1	14.3	4	17.4	5	11.6
More than a year	6	85.7	19	82.6	38	88.4	0.423	0.809
Any other previous illnesses in children
Yes	0	0.0	4	17.4	9	20.9
No	7	100.0	19	82.6	34	79.1	1.806	0.405
Mother’s Age (Years)
31–40	3	42.9	14	60.9	20	46.5
41 or more	4	57.1	9	39.1	23	53.5	1.426	0.490
Mother’s Educational level
Primary	5	71.4	15	65.2	9	20.9
Secondary	2	28.6	2	8.7	7	16.3
University	0	0.0	6	26.1	17	39.5
Higher than university	0	0.0	0	0.0	10	23.3	21.142	< 0.001**
Occupation
Employee	4	57.1	9	39.1	20	46.5
Housewife	3	42.9	14	60.9	23	53.5	0.775	0.679
Monthly income
Enough	2	28.6	4	17.4	13	30.2
Not enough	5	71.4	19	82.6	30	69.8	1.309	0.520

*, **Significant at P ≤ 0.05

Moreover, mothers’ educational level was significantly associated with children’s SE post-intervention (p < 0.001). Children of mothers with higher education (university and postgraduate) were more likely to attain high SE, whereas children of mothers with primary education tended to remain in the low to moderate categories. In contrast, no significant associations were found between children’s SE and mothers’ age, occupation, monthly income, family size, presence of other health or psychological issues in the family, psychosocial support, or caregiving responsibility distribution (P > 0.05). These findings highlight the critical role of mothers’ education in enhancing the efficacy of FCEM, potentially by facilitating better understanding, engagement, and reinforcement of caregiving strategies.

Table 9 illustrates the correlations between mothers’ knowledge about leukemia, family-centered empowerment, and children’s SE levels of three months post-intervention. Statistically significant positive correlations were observed: higher maternal knowledge scores were associated with increased family empowerment (r = 0.308, P = 0.008) and higher child SE (r = 0.253, P = 0.031). Moreover, a significant positive correlation was found between family empowerment and children’s SE (r = 0.286, P = 0.014), indicating that improvements in mothers’ knowledge and family empowerment were linked to enhanced SE in children.

Table 9.

Correlation Between Mothers’ Knowledge Scores, Family Empowerment Levels, and Children’s Self-Efficacy Scores Post-Intervention

Items	Mothers Knowledge about Leukemia		Family Empowerment Scale		Self-Efficacy Domains of children
	r	P	r	P	r	P
Total Knowledge about Leukemia			0.308	0.008*	0.253	0.031*
Total Family Empowerment	0.308	0.008*			0.286	0.014*
Total Self-Efficacy domains	0.253	0.031*	0.286	0.014*

*Significant at P ≤ 0.05, r: Correlation coefficient

Discussion

Leukemia remains the most prevalent childhood malignancy and a leading cause of cancer-related mortality, requiring prolonged and complex management that depends heavily on collaboration between children, families, and multidisciplinary healthcare teams [41, 42]. In this context, the FCEM has been proposed as a potentially effective approach to strengthen family involvement, enhance disease-related knowledge, and promote children’s SE [43], Sargazishad et al., 2018; [44]. Accordingly, the present study explored the impact of FCEM on children’s SE among those with leukemia.

The demographic profile of the studied children, characterized by a predominance of males and adolescents aged 11–15 years, is consistent with earlier findings [29, 34]. This distribution may reflect the higher biological susceptibility of males to hematologic malignancies and the increased detection of leukemia during pre-adolescence and adolescence. Such patterns highlight the importance of designing age-appropriate and gender-sensitive educational and empowerment interventions.

With respect to clinical characteristics, most children had been diagnosed with leukemia for more than one year, and acute lymphoblastic leukemia represented the predominant subtype. This finding aligns with Khanjari et al. [45] and supports existing epidemiological evidence that ALL remains the most common pediatric leukemia subtype. Prolonged disease duration may intensify caregiving demands, emphasizing the importance of sustained parental education and psychosocial support.

The sociodemographic characteristics of participating mothers revealed multiple vulnerabilities, including limited income, low educational attainment, and minimal external support. These factors may compound caregiving burden and influence parents’ capacity to manage complex treatment regimens. Consistent with Shoghi et al. [46], the predominance of housewives among caregivers highlights the central role of mothers in pediatric oncology. Differences observed compared with Kharyal et al. [29] likely reflect contextual socioeconomic factors that can affect parental coping abilities and access to resources.

Psychological distress among parents of children with leukemia is well documented [47, 48]. In this study, the limited psychological, social, and financial support reported by most mothers suggests an unmet need that may increase emotional strain and hinder effective caregiving. Enhanced social support has been shown to buffer stress, reduce anxiety and depression, and improve adaptive coping among caregivers [49, 50], emphasizing the importance of integrating psychosocial support within pediatric oncology services.

The implementation of the FCEM was associated with notable improvements in mothers’ knowledge regarding leukemia, reflecting the potential effectiveness of structured educational interventions. This improvement aligns with previous studies demonstrating gains in parental knowledge following empowerment-based interventions [49, 51, 52]. Enhanced parental knowledge may facilitate better symptom recognition, adherence to treatment regimens, and timely healthcare seeking, which collectively contribute to improved clinical outcomes.

Furthermore, the significant increase in family empowerment scores after the intervention supports the core principles of the FCEM, which emphasizes participatory learning, skill development, and reinforcement strategies [53]. These findings are consistent with Arief et al. [14], Crespo et al. [54], Boshagh et al. [36], and Nachshen & Mines [55], who reported improvements in caregiving competence and family functioning following empowerment-based interventions. Such improvements underscore the pivotal role of pediatric nurses in fostering family resilience and adaptive coping.

A central finding of the present study was the enhancement of children’s SE following FCEM implementation. This result is consistent with previous evidence linking empowerment strategies to improved psychosocial and clinical outcomes [56–58]. Improved SE may help children cope more effectively with treatment-related challenges, adhere to therapeutic regimens, and maintain psychological well-being, ultimately supporting better quality of life.

Recent controlled studies have further highlighted the potential effectiveness of structured family empowerment interventions. Randomized controlled trials and systematic reviews indicate that family-centered educational programs can enhance caregivers’ knowledge of pediatric leukemia and improve children’s psychosocial outcomes, including coping skills and adherence to treatment regimens [59–61]. These findings reinforce the value of integrating evidence-based empowerment strategies in pediatric oncology care, while also emphasizing the need for additional rigorously designed controlled studies to strengthen causal conclusions.

Moreover, the observed positive correlations between maternal knowledge, family empowerment, and children’s SE further highlight the interconnected nature of family functioning and pediatric health outcomes. These findings are in line with Alhani et al. [18], who reported that empowerment-based interventions positively influence multiple aspects of family and child well-being.

Conclusion

Based on the findings of the present quasi-experimental study, the implementation of the FCEM was associated with significant improvements in the SE of children with leukemia and their families, as well as in mothers’ knowledge levels. The intervention emphasizes self-empowerment, active participation, and shared decision-making, which may contribute to improved psychosocial and health-related outcomes. However, due to the absence of a control group and randomization, the findings should be interpreted with caution.

Recommendations

In light of the findings of the current study, the following recommendations are suggested:

1. Integrate the FCEM into nursing curricula: Nursing education planners and healthcare providers should incorporate this model to strengthen nursing education and support accreditation requirements, ensuring that future nurses are adequately prepared to engage families in care.

2. Tailor empowerment interventions based on mothers’ educational backgrounds: Additional support should be provided to less-educated mothers to ensure equitable outcomes and enhance their capacity to engage effectively in their child’s care.

3. Establish structured support networks for families: Developing organized psychosocial and educational support systems can provide continuous guidance and empowerment, helping parents of leukemic children maintain positive attitudes and proactive caregiving practices.

4. Integrate family-based care models into routine clinical practice: Healthcare institutions may consider integrating family-centered approaches within standard care protocols. Nurses should be trained to collaborate closely with caregivers to optimize clinical outcomes for pediatric leukemia patients.

5. Conduct further research on factors influencing family empowerment: Additional studies are needed to explore the determinants that shape the empowerment process among families of children with cancer, with the aim of enhancing the effectiveness and applicability of empowerment interventions.

Implications for nursing practice and future research directions

The findings of the present study have important implications for nursing practice and future research. Integrating the FCEM into pediatric oncology can significantly enhance parents’ knowledge, confidence, and engagement, thereby improving clinical outcomes for children with leukemia. Nurses play a crucial role in this process by adopting a collaborative, family-centered approach that promotes shared decision-making and provides tailored educational interventions, particularly for less-educated caregivers who may require additional support. Strengthening communication, offering continuous guidance, and establishing structured support networks can further sustain empowerment and reduce caregiver stress. Additionally, the results highlight the need for incorporating empowerment-focused competencies into nursing curricula and ongoing professional development.

For future research, employing randomized controlled designs with appropriate control groups with larger, multi-center samples is strongly recommended to strengthen causal inference and enhance the methodological rigor of intervention studies in pediatric oncology settings. Furthermore, longitudinal follow-up assessments are also suggested to evaluate the sustained effects of the FCEM on SE and other psychosocial and clinical outcomes over time.

Comparative studies exploring alternative psychosocial interventions, as well as the use of digital or technology-based platforms for delivering empowerment programs, are also needed. Furthermore, investigating the social, cultural, and psychological factors influencing empowerment will help refine and tailor future interventions for families of children with cancer.

Limitations and strengths of the study

Several limitations should be acknowledged when interpreting the findings of this study. First, the quasi-experimental one-group pretest–posttest design without a control group limits the ability to establish causal relationships between the intervention and the observed outcomes. The absence of randomization also increases the possibility of selection bias.

Second, the study was conducted in a single oncology center, which may limit the generalizability of the findings to other healthcare settings or populations. The relatively small sample size further restricts the external validity of the results.

Third, the reliance on self-reported measures for assessing mothers’ knowledge, family empowerment, and children’s SE may introduce response bias and social desirability bias. Additionally, participants’ awareness of being involved in an intervention study may have influenced their responses (Hawthorne effect).

Finally, the follow-up period was relatively short, and therefore the long-term sustainability of the intervention effects could not be determined. Future randomized controlled trials with larger, multi-center samples and longer follow-up periods are recommended to confirm and extend these findings.

However, study also possesses notable strengths. The use of a structured FCEM allowed systematic and consistent intervention delivery, enhancing the reliability of the results. The study comprehensively examined both caregiver and child outcomes, including knowledge, family empowerment, and children’s SE across multiple domains. Additionally, the findings provide practical and evidence-based insights that can inform nursing practice, curriculum development, and the design of future interventions aimed at improving care for children with leukemia and supporting their families.

Abbreviations

ALL

Acute lymphoblastic leukemia

AML

Acute myeloid leukemia

FCC

Family-centered care

FCEM

Family-Centered Empowerment Model

FCES

Family-Centered Empowerment Scale

OCMU

Oncology Center Mansoura University

SE

Self-efficacy

SEQ-C

Self-Efficacy Questionnaire for Children

Authors’ contributions

Abozed, HW; Hashem, SF & Abu Samra, OM, contributed to the conceptualization of the study, designing the research methodology, and supervising the overall study. Abozed, HW. was responsible for data collection and interpretation of the results and submission of the manuscript. Hashem, SF. & Abu Samra, OM. drafted the manuscript, performed the literature review, discussion and coordinated the references. All authors contributed to revising the manuscript critically for important intellectual content and approved the final version for submission.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or non-profit sectors.

Data availability

The anonymized data from this study is available from the corresponding author upon reasonable request, in accordance with ethical guidelines to ensure participant confidentiality.

Declarations

Ethics approval and consent to participate

Ethical approval for this study was obtained from the Nursing Research Ethics Committee, Faculty of Nursing, Mansoura University, Egypt. The study was conducted in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments.

Written informed consent was obtained from all participating mothers on behalf of themselves and their children prior to data collection. Participants were informed about the purpose of the study and were assured that participation was voluntary, that confidentiality and anonymity would be maintained, and that they had the right to withdraw from the study at any time without any consequences.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.