Children’s Pain assessment can be conducted by three means: selfevaluating, selfless-evaluating by behaviour observation and recording, Physiological measurements [1]. However, according to some scientists; the ideal evaluation is the combined evaluation which includes self-evaluating for pain associated with one of the methods stated above [2], but this approach can be considered unpractical, inapplicable and useless for children in the phase before talking or whom are unable to talk, or those have perceptual problems, so some of scientists said that it is better to evaluate pain by selfless methods that depends on watching Child’s reaction against pain alarm and registering it. The demand for using self-pain evaluating as “The gold standard” is a clear exaggeration due to the complications and factors that contribute in prejudicing the rather for himself when he asked to evaluate his pain by his self [3-5].

And FLACC scale, this scale was developed by Merkel et al in 1997, consists of five clauses, each clause’s value ranges between (0-2) so the whole scale has a value between (0-10) [6], it is convenient for young children; their ages below 3 years, and it is used for low perceptual ability’s children [7], and it has chosen with CHEOPS scale as the best pain evaluating scales by Von Baeyer and Spagrud systematic review [8]. FLACC scale was translated into four languages (Chinese, Thai, Swedish, and Brazilian Portuguese) [9-12].

SEM (Sound-Eye-Motor) scale has been used in many recent studies [13-17] and Baghdadi study in Syria [18], this scale concentrates on the changes in patient’s sound, eyes and movement to evaluate patients relax or pain during treatment [19].

To study the Psychometric properties (validity and reliability) of the Arabic version of selfless pain measurement FLACC.

An ethical approval was obtained from the local ethics committee prior to the commencement of the study, CONSORT Statement was followed when the current study was designed and conducted.

Current study had started On February 2014, and ended on March 2015. The sample included (250) children from the Department of Pediatric Dentistry of the Dentistry-Faculty of Damascus University. Their ages ranged between 6 and 14 years. Each of them needed intraoral local anesthesia for various treatment purposes (e.g: pulptomy, dental extraction, restorative treatment). Informed consent from one of the parents or the guardian of the child has been taken after the current study and its purposes had been explained. The included children were fit and healthy with no nervous disturbances, cooperative and classified as (absolute positive or positive) on Frankel’s classification scale. All children needed treatments that require intraoral anesthesia. None received any sedative or analgesic drugs in the last three hours prior to intraoral injection, and there was no abscess (acute or chronic) in the site of injection.

Randomisation

The randomization was conducted in this study by alternating the order of injection and placebo (see below) on the child according to the randomization distributing tables.

The injections

A local anesthetic injection has been given to each child after drying the oral mucosa by sterilized cotton sticks and applying Benzocaine gel (20%) for two minutes, traditional local anesthetic has been given on the side that needed the dental treatment.

The operator has also pretended to give the child another “placebo” local anesthesia injection by touching lightly the oral mucosa by the injection site (while the injection needle was capped) without any pressure. So, the child has received one local intraoral injection, whereas he thought he has received two injections.

Hiding local anesthesia syringe from child’s sight pattern has been applied on all sample’s children in all ages, that because of the positive effects of hiding the syringe on the child’s behaviour, those effects were approved by many global recent and old studies [20-23].

Recording

The child reaction was recorded during the injection procedure (in both groups) using a high definition digital camera (14 Mega pixel). The recordings were then edited to mask the type of injection given and therefore blind the assessors. All edited recordings were evaluated by external raters, each independently completes two clinician-based pain evaluation scales (SEM and FLACC).

Arabisation (Translation) of the FLACC scale

The FLACC pain scale has been Arabized using foreword-backward translation, and was used for the first time in Arabic in the current study.

Methods of studying the psychological properties of measurement scale:

Validity

The content and construct validities were tested as follows:

Content validity: This has been checked by a number of experts in the field of pain and education to ensure the content safety, language fluency, and the measurement ability to reflect its parts and purpose; which is defining the pain level.

Construct validity: This was examined by testing rising pain intensity during injection in comparison with placebo. The internal consistency between the scale’s five elements was examined by checking their individual relation with the whole measurement. The construct validity was tested also by detecting Discrimination validity and the measurement ability on retrieving differences between children who suffered from the maximum pain level relatively with their companions who suffered from minimum pain level, and the criterion validity was detected by exploring the convergent validity, which conducted by detecting the engagement level of FLACC scale with other scales that applied.

Reliability: The reliability has been checked by: the method of testing and retesting, and calculating Cronbach's alpha factor, and inter-rater reliability, so the raters were tested (inter-rater reliability) to ensure their ability on evaluating pain trustfully, and to study the reliability of FLACC scale in selfless pain evaluating.

The sample included (250) children, and the pain level was evaluated selflessly on selfless scales by external raters, which means there was (1000) selfless evaluation for pain for both in injection and placebo, so they were (2000) selfless pain evaluation in total, as shown in Table 1.

Table 1: shows the sample’s distribution according to pain assessments by the external raters using selfless pain scales.

Content validity study’s result suggested making no adjustments on test clauses and instructions because its clearance, and appropriateness for the purpose that they have been put for.

Construct validity for the Arabic version of FLACC scale was studied by testing the rising pain level during injection procedure in comparison with Placebo, and the results of this kind of validity was gained by calculating the degree of pain intensity in both procedures (injection, and placebo) then compared between these two values using t-student test.

Table 2 shows the result of that statistical test, it is clear from the previous table that the value of pain intensity was raised with injections into (3.6) in comparison with placebo (0.13) which was significant statistically on the significance level (0.05), which means FLACC test measures what it was put for, that indicates on Construct validity of FLACC test.

Table 2: Shows the correlation coefficient between pain level during placebo and injection procedure according to FLACC scale.

Internal Consistency Validity showed correlation between every clause of FLACC scale clauses, those correlations ranged between (0.792-0.723) as shown in Table 3, and it is positive and statistically significant on the significance level (0.01) which indicates high Internal Consistency for FLACC scale.

Table 3: correlation coefficients between each part and the total grade of FLACC scale.

External Criterion Validity study (convergent validity) showed strong correlation between FLACC and SEM selfless scales.

Table 4 shows FLACC scale’s correlation factor with SEM scale (external criterion) which was (0.799), that indicates criterion validity for FLACC scale.

Table 4: shows correlation coefficient’s values between FLACC and SEM scales (external criterion).

Reliability study by testing and retesting method, which has been conducted through external raters examining the same investigated people at the same time independently, has shown strong correlation which indicates good reliability for FLACC scale, as shown in Table 5 rater’s correlation coefficient value has reached (0.805).

Table 5: shows the correlation coefficient value between the first and the second ratters.

Cronbach’s Alpha factor has been calculated for FLACC scale and its value was high and reached (0.809), as shown in Table 6.

Table 6: reliability factors for FLACC scales using Cronbach’s Alpha factor.

Inter-rater reliability test for each rater showed high and positive Kappa’s factors for both raters as shown in Table 7. They were close to complete one and reached (0.952) for the first one and (0.893) for the second rater, which means high compatibility for both raters, and indicates high inter-rater reliability for FLACC scale.

Table 7: Inter-rater reliability of FLACC scale using Kappa compatibility factor’s method.

FLACC scale has been chosen as the best, first, easiest and the most compatible scale with self-evaluating scales, which their grades ranges between 0 and 10 simultaneously with FLACC scale, and that was according to von Baeyer’s systematic review [8].

FLACC scale has been appointed as a standard scale for convergent validity investigations for some common scales [24], or recently innovate [25,26] so the researcher tries to approve its innovated scale’s convergence or exceeding in comparison with FLACC scale, to get the acceptance and propagation for his scale [27].

In the current study, FLACC scale has fulfilled the construct validity, due to the rising of pain level during injection procedure in comparison with placebo, which agreed with many studies like Voepel- Lewis et al., Tsze et al., and Tomlinson et al. [6,28-30].

According to this study’s results, FLACC showed criterion validity, so it converged to SEM scale, and this validity was assured according to various studies like Tomlinson et al. in 2010 who indicated to the correlation between FLACC scale and parent’s scale, correlation coefficient value ranged between (0.65-0.87), Malviya in 2006 also registered strong correlation for FLACC scale with self-pain evaluating for the sample’s children and their parents, the correlation coefficient ranged between (0.65-0,87), Voepel-Lewis et al. registered the value of (0.84) for FLACC scale’s correlation coefficient with selfless COMFORT scale, and that study indicated good criterion convergent validity [6,27,28,31].

In the way of studying the reliability of FLACC scale by testing and retesting, the correlation value between the external raters, who defined the pain level in this study, has reached (0.805), this value converged with the value that Gomez et al. has gained in 2013, which was (0.95) [32]. Nevertheless, an indicator of the scale reliability was Cronbach's alpha factor’s value, which was (0.809), and its convergence with many studies like Voepel-lewis et al. their factor’s value was (0.882) [6], it was higher than Cronbach’s alpha factor in Fathi et al. study in 2010, which was (0,85) [28].

Internal consistency validity study cleared high values for each part of the scale, those values ranged between (0.723-0.792), and it was convergent to the values registered by Tomlinson et al. in 2010, which ranged (0.76-0.9) [31].

The Arabic version of FLACC scale showed good psychometric properties, so the scale was valid and reliable, which made it applicable scale in selfless pain level assessment.

The authors gratefully acknowledge Damascus University and Prof. Adel Moufti for great help and support.