Introduction
Burns are one of the most important injuries that threaten children’s health [1]. Almost 18% of victims of burn accidents are children [2]. Children, especially at the age of <4 years, are one of the high-risk groups facing burn injuries [2]. Burn care has significantly progressed in the last few decades [3]. Only half of the children with a 50% burn level were expected to survive 40 years ago, but now more than half of children with an 85% burn level survive [4].
Burn intervention, which starts from the moment of injury, requires the cooperation of many experts from different fields of the health system. According to the latest clinical guide for burn intervention in 2017, physiotherapists are one of the main members of the burn intervention team who provide various treatment services for people with burn injuries during and after hospitalization [5]. Despite the efforts of many specialists, children saved from burns experience severe physical and movement, mental-cognitive, and social complications that affect various functional dimensions. The most commonly identified consequences due to burns in children are as follows: Pain; itching; hypertrophic scar; alignment disorder; contracture; neuropathy; bone deviations; sleep disorders; mental stress; depression, anxiety; cognitive disorders, such as memory impairment and problem-solving ability; behavioral problems [6]; negative social consequences including, interaction impairments, such as impairments in playing and seeing friends; and difficulties of going back to school [7]. In addition to the variety of burn complications, the long-term effects of these complications are another problem that children with burn injuries experience. Accordingly, they may suffer from the permanent effects of burns during the entire period of middle age and old age [8]. The results of a previous study showed the limitation in the range of motion in one-fifth of all people with burns even after five years of the injury [8]. Therefore, in recent years, the focus of burn interventions in children has changed from the issue of mortality to their functional consequences [9].
In addition, childhood is an important time for children’s growth and development because during this period, children acquire many skills in different areas of motor, cognitive, and social performance [10]. According to the points that were mentioned concerning the complications of burns, burn injury may interfere with children’s developmental status. Most studies have investigated the quality of life of children with burn injuries and its consequences in the short- and long-term. However, there is little information about the effect of burns on the normal growth and development of children at different ages. 
According to the results of the only available study, the mean motor development score of children 6 months to 6 years old was at the lowest level of the normal range after one month of burn injury. Also, in 46% of participating children, suspicious findings were observed in the developmental status [11]. Hence, it is necessary to constantly check the developmental status of children during the recovery period after burns. Also, it is essential to attract the attention of different treatment groups in identifying the possible contributors to developmental problems in children with burn injuries, because this can be effective in the early participation of parents in the treatment plan and improvement of children’s developmental activities [12]. In previous studies, the short-term and long-term effects of identifying and performing early interventions in children’s developmental disorders have been investigated from various personal, family, economic, and social aspects, and the timely diagnosis and treatment of such disorders have been emphasized [13-15].
One of the most common and widely used tools for measuring children’s developmental status is the ages and stages questionnaire (ASQ) which is completed by parents. This tool evaluates the developmental status of children aged 4 to 60 months in 19 age groups and 5 developmental areas in comparison with the determined cut-off points [16]. The results of many studies show that parents, regardless of their socioeconomic status, the geographical area in which they live, or the level of health they enjoy, can provide accurate information about the developmental process of their children [17-19]. Therefore, according to the points raised regarding the effect of age on the expected growth and development of children, as well as the possible effects that burns have on children’s developmental status, and in addition to the role of physiotherapy services in the treatment of complications caused by burns, this study investigates the effects of age, burns, and the amount of receiving physiotherapy services on the developmental status of children under 5 years of age with burn injuries using ASQ.

Materials and Methods
This cross-sectional study was conducted based on the descriptive-analytical epidemiological method from October 2021 for 6 months. Using the medical documents available in the archive section, information about children under 5 years of age who were hospitalized due to second and third-degree burns in Ahvaz Accident and Burn Hospital, in Ahvaz City, Iran, was extracted. The information included age, burn depth, burn percentage, hospitalization date, number of surgeries, type of surgery during hospitalization, burn area, number of physiotherapy sessions during hospitalization, and parents’ contact number. Through a phone call, the objectives and steps of the research were verbally provided to the parents. After selecting the subjects based on the entry and exit criteria, the subjects entered the study after declaring their consent. Then, the link of the ASQ, according to the child’s age group, was sent to one of the parents (preferably the mother) through one of the virtual platforms available on mobile phones (mostly WhatsApp). Also, sufficient explanations were given to them on how to complete and resend the questionnaire. In addition to the information obtained from the hospital file and the completed questionnaire, the number of physiotherapy sessions that the child received after being discharged from the hospital was also asked and recorded by the parents over the phone. 
The inclusion criteria comprised the following items: 1) Children <5 years old, hospitalized in the Ahvaz Accident and Burn Hospital of Ahvaz City, Iran, 2) Having a minimum level of literacy in elementary school in one of the parents, 3) Having an Android mobile phone, and 4) Familiarity by completing an online questionnaire. Meanwhile, the exclusion criteria were: 1) The use of anti-scar cover due to restricting the child’s movements, 2) Prematurity of the baby at birth, 3) Presence of concomitant diseases, such as asthma, allergies, epilepsy, heart disease, hyperactivity, intestinal problems, diabetes, 4) Presence of hearing, vision, and speech problems before the burn, and 5) Consumption of alcohol and cigarettes by the mother during pregnancy.
ASQ was standardized for Iranian children by Sajedi et al. in 2013 [20]. This questionnaire has been introduced in many studies and different populations of children as a valid and reliable screening test. Based on one study conducted in 18 countries located in Asia, Africa, Europe, and North and South America, the sensitivity and specificity of ASQ were reported at 88 and 82.5, respectively [21]. The questionnaire includes children from 4 to 60 months in 19 age groups (4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 27, 30, 33, 36, 42, 48, 54, and 60 months old). Questions for each age are designed in 5 main sections as follows: 1) Communication section (mainly related to speaking and listening), 2) Gross movement section (mainly related to leg and arm movements), 3) Fine movement section (mainly related to hand and finger movements), 4) Problem-solving section (mainly related to understanding concepts), and 5) Personal-social section (mainly related to individual and social behaviors of the child). There is also a general section at the end of the 5 main sections where the topics of the questions are general. A total of 30 questions (6 questions for each developmental area) have been designed for each age group. In each section, each question has 3 answers, namely “yes”, “sometimes”, and “not yet”. The answer “Yes”, which has 10 points, means that the child can currently perform the desired activity. The answer “Sometimes” has 5 points and indicates that the child has just started doing the desired activity. The answer “not yet” is without points and shows that the child has not yet started the desired activity. Accordingly, each developmental section has 60 points. Finally, the scores related to each of the developmental sections are compared with the cut-off point determined for the same developmental area in the desired age group. If the scores in each of the developmental sections are less than or equal to the cut-off point was considered a section with developmental disorder [20, 21].
The data of this research was analyzed using the SPSS software, version 22. In this study, in addition to using descriptive methods due to the non-normality of the data, the Mann-Whitney test was used to compare the age, the time elapsed since the burn, and the number of physiotherapy services in two groups of children under 5 years old with and without burn injury. The significance level in this study was considered P<0.05.

Results
Overall, 93 children participated in this study with a mean age of 46.02±11.92 months and a mean burn percentage of 13.21±9.49%. On average, 32.02±13.99 months had passed since the burn. On average, the number of sessions receiving physiotherapy services during hospitalization was reported at 4.47±3.21 and after discharge at 1.64±0.62. Table 1 demonstrates the frequency and frequency percentage of the demographic and clinical characteristics of the participants.


Based on this, children in the age group of 60, 36, and 42 months formed the largest number of participants with a frequency of 31.2%, 17.2%, and 17.2%, respectively. Meanwhile, 81.7% of the participants had second- and third-degree burns. Also, Table 2 shows the frequency and percentage of participants based on the presence or absence of developmental disorder obtained by the points of each questionnaire section and comparing it with the cutoff point.


Based on the obtained results, the fine movements section showed the highest frequency of developmental delay. Accordingly, 24 people (25.8%) out of 93 children participating in this study showed developmental disorders in this area. The frequency of disorders in other developmental areas was less in the participants. Only 11 of the participants showed problem-solving disorder and 82 of them reported a normal developmental process in this area. Also, only 8 of the children with burn injury in this study showed developmental disorder of gross movements and 85 of them had a normal developmental process in this area. In the personal-social and communication areas, 4 and 2 of the participants showed developmental delay, respectively.
Hence, based on the frequency of developmental disorder in different sections of the ASQ, and considering the sample size of the participants, to report reliable results, the characteristics of age, duration of hospitalization, and the number of sessions receiving physiotherapy between the two groups with and without developmental fine movements disorder were examined and these features were not examined between participants with and without developmental disorders in other sections. Thus, the results of the Mann-Whitney analysis showed that the mean age of children with a fine movement disorder (zone 3) compared to people without disorders in this area is higher (P=0.016) and the duration of burns is longer (P=0.019). However, there was no statistically significant difference between the number of physiotherapy sessions during hospitalization (P=0.74) and discharge (P=0.69) between these two groups (Table 3).



Discussion
This study investigated the effects of age, burns, and the amount of physical therapy services received on the developmental status of children under 5 years of age with burn injuries using the ASQ. The results showed the developmental delay in different areas of the ASQ in some of these children. The greatest developmental delay was observed in the area of fine movements, which was reported in approximately 26% of the participating children. Also, developmental delay in the areas of problem-solving (approximately 12%) and gross movements (approximately 8.5%) was another frequent finding in the present study.
The comparison of the results of the present study and the many screenings conducted in different populations of Iranian children indicates a high level of impairment in most developmental areas in children with burn injuries. In the screening conducted on 593 one-year-old children in Jahrom City, Iran, the area of gross movements with 4.2% and the area of problem-solving with 2.3% showed the highest developmental delay [22]. Also, in another study conducted on 210 children from Pakdasht City, Iran, the social personal area showed the highest delay with 8.6%. In addition, in the study of children <5 years of age with a history of being hospitalized in the neonatal intensive care unit, the areas of communication at 20%, fine movements at 19%, and gross movements at 17% were the highest developmental disorders in the studied population [23]. Therefore, from the review of the studies, burns are one of the most influential factors in the delay in the developmental status of children, which involves the areas of motor development (fine and gross movements) and problem-solving. In the present study, approximately 52% of the participants had burn injuries in the upper limbs and 48% had burn injuries in the lower limbs. Therefore, the higher developmental disorder in the area of fine movements in this population that examines the movements of the fingers can be justified. It is suggested to investigate the relationship between burn areas and developmental disorders in future studies.
Childhood is an unrepeatable, effective, and sensitive period in the process of children’s growth and development, and any deficiency in this period will cause irreversible damage to the child [10]. Therefore, early diagnosis and timely intervention of developmental disorders in children with burn injuries can reduce the doubling of the adverse effects of developmental delay on the wide and long-term consequences of burns.
Additionally, children with a fine motor delay compared to children without delay in this area had a higher mean age and a longer period had passed since their burns. According to previous studies, movement disorder manifests itself mostly in old age, because the need and necessity of performing delicate finger movements, such as holding a pencil and drawing shapes is greater and these movements have more complex movements [24]. Also, as more time passes since the burn, the delay of fine movements is more visible. This can be caused by the long-term effects of burn complications, such as hypertrophic scars, adhesions, reduced range of joint movements, and abnormal skin sensation. Therefore, it is necessary to follow the developmental status of children even after months of the initial injury.
Moreover, there was no difference in the number of sessions of receiving physiotherapy services during hospitalization and afterward in children with burn injuries with and without delayed fine movements. In many studies, the effect of using different physiotherapy methods on reducing scars, increasing range of motion, and improving functional activities in people with burn injuries has been reported [25-27]. Also, based on the available scientific evidence, it is necessary to pay more attention to the effectiveness of physiotherapy interventions in the treatment of burn complications. Therefore, by increasing the number of physiotherapy sessions and receiving more effective services, the consequences of burns will decrease and as a result, the possibility of developmental disorders in children will be eliminated. In the present study, the mean number of physiotherapy sessions during hospitalization was 4 sessions and <1 session after discharge. Although the mean percentage of burns of the participants in this study was low (approximately 13%), considering that the variety and extent of complications caused by burns are influenced by other factors such as the depth and area of the burn, the presence of accompanying injuries, and so on. The number of sessions receiving physiotherapy services for this population is insufficient and it is not possible to accurately compare the services between children with and without developmental disorders. It is suggested that in future studies, the developmental status of children with extensive burns should be investigated.

Conclusion
Burns are one of the influential factors in children’s development delay, which probably involves the areas of motor development (fine and gross movements) and problem-solving. Movement disorder manifests itself mostly in old age. Also, as more time passes since the burn, the delay of fine movements is more visible.

Study limitations
The present study faced several limitations. Among the limitations of the present study, we mention the collection of information using questionnaires and self-reporting, which may mean that some respondents did not complete the questionnaires honestly. Another limitation is the limited statistical population studied. Conducting research in a larger statistical population is suggested in future studies.

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ethics Committee of Ahvaz Jundishapur University of Medical Sciences (Code: TIR.AJUMS.REC.1399.956).

Funding
This research was supported by the research project funded by Ahvaz Jundishapur University of Medical Sciences (Grant No. PHT-0002).

Authors' contributions
Conceptualization and sources: Neda Orakifar, Maryam Kiani Haft Lang, and Razieh Mofateh; Data collection: Noshin Kashisaz and Maryam Kiani Haft Lanf; Data analysis: Amal Saki Malehi; Research and writing the original draft: Neda Orakifar; Review and editing: Neda Orakifar and Maryam Kiani Haft Lang; Supervision: Neda Orakifar. 

Conflict of interest
The authors declared no conflict of interest.



Acknowledgments
The authors consider it necessary to express their gratitude to Ahvaz Jundishapur University of Medical Sciences for their financial support.



References