The Psychometric Characteristics Of Neonatal Oral-motor Assessment Scale

Research backgroundSuck is considered the most import and basic activity of infants，Theprerequisite of successful feeding is coordinated sucking-swallowing-breathing, in order to ensure adequate nutrient intake to meet growth. Thestudies have shown that sucking disorder can predict infant feedingproblems that may occur later, also is the first sign of neurodevelopmentalproblems in infants. So recognition of normal and deficient sucking patternsand intervention in time is especially important in preterm infants. Recently,with the development of the research on the sucking function, the foreignresearchers through the direct or indirect observation to assess neonatalsucking functions and developed some assessment tools. The NeonatalOral-Motor Assessment Scale is more mature, has acceptable levels ofconvergent validity and responsiveness and can be used to assess eitherbottle-feeding or breastfeeding and either preterm or full-term infants.Because of its non-invasive and pediatric nurse can master it throughshort-term training, it is commonly used in the clinical practice. But thesamples in the studies were come from Neonatal Intensive Care Unit, weresmall and limited the scope of generalization. So it is important to increasesample size to examine the psychometric characteristics of the NOMAS inorder to provide advice for the application of oral-motor assessment in clinicpractice and lay a foundation for future research.ObjectiveTo examine the psychometric characteristics (reliability, validity and responsiveness) of the Neonatal Oral-motor Assessment Scale (NOMAS)and evaluation time on the influence of assessment results of oral motorskills for preterm infants, and to provide advice for the application oforal-motor assessment in clinic practice.Methods1We had asked Palmer’s consent who was the original author andtranslated the English version of Neonatal Oral-Motor Assessment Scale(NOMAS) into Chinese.2Observers’ training: The observers participated in online trainingwhich was held by America and passed the exam. To examine the trainingeffect, we selected25infants’ sucking videos. The two observers who hadbeen trained and certified assessed for blind review respectively, andanalyzed assessment result of consistency between the reviewers.3We selected91cases from November2011to July2012in theneonatal ward in children’s hospital in Chongqing. Following Palmer’smethod, a video recording was made for the preterm infants at different ageduring the first2min of nutritive sucking (NS). We stored the recordings ona digital videodisc and assessors assessed each recording by NOMAS. Thenanalyzed reliability，validity and responsiveness of the NOMAS andanalyzed the effect of evaluating time on the assessment results。Results1.Evaluation score results between ICC （Intra-class CorrelationCoefficient）is0.91, the inter-rater reliability is good.2. The test-retest reliability is good (ICC=0.89).3. The NONAS had acceptable internal consistency (Cronbach’s a＞0.7）for less than35weeks’ PMA(Postmenstrual Age) and moderate internalconsistency(Cronbach’s a=0.65) in the normal category for more than35 weeks’ PMA. But the disorganized category had satisfactory internalconsistency (Cronbach’s a=0.85)for PMA≥35weeks’. Moderate correlationwere found between scores on the NOMAS and feeding performance for lessthan35weeks’ PMA, but the correlation of more than35weeks’ PMA waspoor. The NOMAS demonstrated low responsiveness to changes inoral-motor skill in a week period, ranging from33to36weeks’ PMA（SRM=0.11-0.49）.4. The NOMAS scores for evaluating30seconds and2minutes werenot consistent, the former scores was higher.ConclusionThe inter-rater reliability and test-retest reliability are good. Thereliability and validity of NOMAS were acceptable in assessing theoral-motor function of preterm infants for less than35weeks’PMA andmoderate for PMA≥35weeks’.Due to unstable of preterm infants’ suckingfunction, the evaluation time was not only limit in the30s, we shouldobserve several continuous sucking process which could get moreappropriate oral motor function assessment. Further validation research isneeded to investigate the internal consistency of later PMA and to includeinfants with abnormal oral–motor skills in order to examine items in thedysfunction category.