All 4 faces pain scales were found to be adequately supported by psychometric data .
When given a choice between faces scales , children preferred the WBFPRS .
Confounding of pain intensity with affect caused by use of smiling and crying anchor faces is a disadvantage of the WBFPRS .
: For clinical use , we found no grounds to switch from 1 faces scale to another when 1 of the scales is in use .
CONTEXT : Numerous faces scales have been developed for the measurement of  pain intensity in children .
It remains unclear whether any one of the faces scales is better for a particular purpose with regard to validity , reliability , feasibility , and preference .
OBJECTIVES : To summarize and systematic ally review faces pain scales most commonly used to obtain self-report of pain intensity in children for evaluation of reliability and validity and to compare the scales for preference and utility .
Facial Expression of Children Receiving Immunizations: A Principal Components Analysis of the Child Facial Coding System
Objective To identify the structure of facial reaction to procedural pain and to determine the subset of facial actions that best describe the response . Design Observational . Setting Five rural and five urban physicians ' offices . Patients One hundred twenty-three children aged 4 to 5 years undergoing routine diphtheria , pertussis , tetanus , and polio immunization .  Outcome Measures The Child Facial Coding System , comprising 13 discrete facial actions , was used to code each second of five 10-second phases from videotape : baseline , preneedle , needle , postneedle , and posth and ling . Parents and a technician provided visual analog scale ratings of children 's pain . Children provided a self-report using a  Faces Pain Scale  , and parents and nurses rated the children 's pain and anxiety using visual analog scales . Results A “ pain face ” similar to that reported in adults emerged with the onset of pain . Principal component analyses revealed the frequency and intensity of facial action during the needle phase could be represented by components reflecting pain sensation , a “ brave face , ” and the children 's expectations for pain . Children 's Faces Pain Scale and adult visual analog scale ratings were best predicted by components reflecting pain sensation and expectations of high pain . Conclusions These results provide a preliminary indication that the Child Facial Coding System can be reduced to components that reflect several aspects of children 's acute pain experience and predict self-reports and observer reports of children 's pain
All 4 faces pain scales were found to be adequately supported by psychometric data .
When given a choice between faces scales , children preferred the WBFPRS .
Confounding of pain intensity with affect caused by use of smiling and crying anchor faces is a disadvantage of the WBFPRS .
: For clinical use , we found no grounds to switch from 1 faces scale to another when 1 of the scales is in use .
CONTEXT : Numerous faces scales have been developed for the measurement of  pain intensity in children .
It remains unclear whether any one of the faces scales is better for a particular purpose with regard to validity , reliability , feasibility , and preference .
OBJECTIVES : To summarize and systematic ally review faces pain scales most commonly used to obtain self-report of pain intensity in children for evaluation of reliability and validity and to compare the scales for preference and utility .