Reliability, Validity Of Preterm Infant Oral Feeding Readiness Assessment Scale And Its Application

BackgroundPreterm infants converting from parenteral nutrition to full enteral feedings usually need to go through5to7stages, from total parenteral nutrition→parenteral nutrition+tube feeding→tube feeding→tube feeding+bottle feeding→bottle feeding→bottle feeding+breastfeeding→breastfeeding. One of the most critical stage is the transition from tube feeding to full oral feeding, at this stage, readiness to oral feeding and full oral feeding are the two critical things preterm infants have to face.Oral feeding readiness refers to the premature whether can start oral feeding, or from gavage to oral feeding. Oral feeding is a complex sensorimotor process that needs integration, maturation and coordination of nerve, motor and other system. However comprehensive objective measurement of preterm oral feeding readiness in the NICU does not exist. The complexity of the mechanism of oral feeding and individual differences lead to difficulties of ssessment of oral feeding readiness.Foreign scholars have developed a variety of premature oral feeding readiness assessment tool through a series of objective indicators to determine whether preterm infants can begin oral feeding, mainly including An Evidence-based Guideline for Introducing Oral Sucking to Promote Feeding to Healthy Preterm Infant which was developed in2003,Preterm Infant Nipple Feeding Readiness Scale, Early Feeding Skills assessment. These three scales are based on trial feeding which may cause aspiration and other adverse consequences. Preterm Infant Oral Feeding Readiness Assessment Scale, PIOFRA scale was designed for premature oral feeding readiness, its author has applied it to preterm infants oral breastfeeding readiness assessment, and proved it good reliability and validity. The PIOFRA scale analyzing whether preterm infants could be fed orally by quantization ratings, in a certain extent, could avoid adverse effects by trial feeding.In Chinese NICUs, there is a big difference on premature oral feeding readiness and we lack a unified oral feeding readiness assessment standards. Mother-to-child wards have not been carried out extensively in China so we need a standard on premature oral bottle feeding. There is Neonatal Oral Motor Assessment Scale,(NOMAS) introduced by Peng Wentao, but the scale is not specified for premature oral feeding readiness assessment. Due to the limitation of assessment tools, we lack effective, objective, quantifiable assessment instrument on preterm infant oral bottle feeding readiness.Therefore, it is necessary to introduce PIOFRA scale and apply it to domestic preterm infants oral bottle feeding readiness assessment.Due to unsufficient development, premature tend to have complications which may cause a long hospital stay. Oral motor intervention may improve their oral feeding ability and shorten their hospital stay. The main method is oral stimulation. NNS and NNS with oral movement could promote the sucking reflex maturation, improve coordination of sucking and swallowing. However, the methods are different, with small sample sized, and improper control of confounding factors in different papers. Current studies have not paied attention to the adverse effects those oral stimulatiom may lead to, and have not found a proper persistent time to carry out the intervention and without assessment of infants’ oral motor ability. Oral stimulation method used by Sandra Fucile has a duration of15min, one time/day, for ten days. It has a great effect on preterm infants oral feeding procedure.Therefore, it is necessary to introduce Sandra Fucile oral stimulation method into China, by randomly controlled method to evaluate the effect to oral bottle feeding in preterm infants, and find a proper intervention persistent time to promote oral feeding ability for premature.Objectives1. To assess the reliability and validity of Preterm Infant Oral Feeding Readiness Assessment Scale.2. To evaluate the application of Preterm Infant Oral Feeding Readiness Assessment Scale.(1) to study the relationship between the assessment result of Preterm Infant Oral Feeding Readiness Assessment Scale and preterm infants’oral feeding performance.(2) to study the factor that affects preterm infants oral feeding readiness.3. To study the effect of oral stimulation to preterm infants’oral feeding readiness and ability.Subjects and Methods1. Validity and reliability of Preterm Infant Oral Feeding Readiness Assessment Scale.1.1SubjectsPremature (n=154;79females) completed the study. All were recruited in convenience from the Neonatal Intensive Care Unit of one three A Hospital, Guangzhou between July,2011and July,2012.1.1.1Inclusion criteriaInfants were enrolled if they were(1) born between29weeks to36weeks’GA as determined by obstetric ultrasonogram and clinical examination;(2) weight are in the10to90percentile of the average weight of the same gestational age children;(3) are stable with body temperature at36℃～37.3℃, respiratory<60beats/min, heart rate110-150beats/min, SpO285%～93%, blood pressure about70/50mmHg,without mechanical ventilation;(4) not starting oral feeding. 1.1.2Exclusion criteria(1) had chronic medical complications, such as BPD, IVH, NEC etc(2) had congenital anomalies (eg, oral, heart, etc),1.2MethodsTranslate thescale from English into Chinese and apply it on154preterm infants to test its relibility and vality. We chose30premature randomly by SPSS13.0(starting opint is2000000) and assessed twice by two evaluators to test the inter-rater reliability. By comparing the consistency between the scale score and5mL, we tested its criterion validity.1.2.1GroupsAccording to the doctors’ order for premature’s situation, infants who had not started oral feeding were arranged into Group A(n=47) and infants who had been ordered to start oral feeding to Group B(n=107). Infants in Group A were performed the scale evaluation only; infants in Group B were preformed a5mL milk feeding besides the scale evaluation on the day of starting feeding.1.2.2Data collectionUse the premature assessment data sheet designed by researchers to collect the general information of preterm children, including gestational age, birth weight, correct the gestational age and PIOFRA scale score for infants in group Aand group B,5mLmilk feeding results for group B.1.2.3Scale evalulation methodWe started formal study after learning the scale’s instruction and scoring method. Inside the incubator, the infant was quiet,15minutes before first bottle feeding. The evaluator helped the infant wake up, using auditory, visual and tactile stimuli and evaluated the infant as following instructions. The biting and sucking reflexes and non-nutritive suction were assessed by means of the gloved little finger. Non-nutritive suction was evaluated during1minute. We had two to evaluate the infants if the baby was chosen to do the inter-rater reliability test. The first observer stimulated the infant to wake up and manipulated the infant to verify behavioral organization, oral posture and presence of oral rooting and vomiting reflexes. Both examiners simultaneously observed these behaviors. The biting and sucking reflexes and non-nutritive suction were assessed twice. The observers had no verbal contact for an independent result. The evaluator should not interfere in doctors’ decision, and doctors didn’t know the infants’evaluating results.1.2.45mL milk feeding methodA neonatal nurse was in charge of the babies’5mL milk bottle feeding who didn’t know the babies’evaluating results. Premature who ingested an initial milk volumn of5mL, with suction but without stress signs, such as skin color changes, apnea, tonus variation etc, were considered they could start oral feeding safely; conversely suggested they couldn’t start oral feeding safely.1.3StatisticsSignificance analysis of the data used the SPSSR13.0package from Southern Medical University, Guangzhou, China. Descriptive and basic statistical analysis of the data were performed. Significance was defined at the0.05level using a type I error of0.05and a power of0.80.Cronbach’s a was used to evaluate the scale’s internal consistency reliability. ICC and spearman rs were used for inter-rater reliability. Content validity index (I-CVI and S-CVI) was used to evaluate the scale the content validity. Independent samples t-test was used for discriminant validity. The consistency of the evaluated scale resuils and5mL milk feeding results were used for scale criterion validity (diagnostic validity). ROC(receiver operating characteristic) curve data analysis was used for diagnosis efficiency.sensitivity, specificity and Youden index were used to evaluate diagnostic accuracy and confirm the diagnosis cut value.2. Evaluation the PIOFRA scale in clinic2.1Correlations between scale assessment results and feeding performance2.1.1SubjectsPreterm infants in Group B and not been reordered gastric tube.2.1.2MethodsUse the premature assessment data sheet designed by researchers to collect the general information of preterm children, including gestational age, birth weight, correct the gestational age and PIOFRA scale score and5mLmilk feeding results and three days of feeding performance after starting oral feeding, and whether reordered gastric tube.Three days of feeding performance after starting oral feeding includes:sucking rate (3consecutive days, every morning at9AM, and the average sucking rate of premature finished the milk orderd),3days of ordered milk finishing rate (the ratio of premature finished time and the ordered time), assessed the correlations between scale assessment results and feeding performance.2.1.3StatisticsRelation between scale score and premature’s suction rate as well as scale score and3days ordered milk finish rate were done by Spearman Correlation Analysis. Treat Scale score30points as the cut point, infants with score≧30were thought can oral feeding, and score<30can not. The suction rate and3days ordered milk finishing rate at different cut point were analysed by2Independent Samples Tests (Mann-Whitney U).2.2Analysis the influencing factors for preterm infants feeding readiness2.2.1SubjectPreterm infants in Group B (n=107).2.2.2MehtodsUse the premature assessment data sheet designed by researchers to collect the general information of preterm children, including gestational age, birth weight, correct the gestational age and PIOFRA scale score and5mLmilk feeding results.2.2.3StatisticsUnivariate analysis:whether can start oral feeding safely (5mL milk feeding results) as dependent variable and apply multivariate analysis:whether could start oral feeding safely as dependent variable, other indicators as independent variable to finish multivariate Logistic regression analysis by LR:Forward regression method, αin=0.05,αout=0.10.3. Effect of oral stimulation to prematures’ oral motor ability3.1Subjects Premature (n=65;24females) completed the second study. All were recruited in convenience from the Neonatal Intensive Care Unit at one Hospital, Guangzhou between July,2012and December,2012.3.1.1Inclusion criteriaInfants were enrolled if they were(1) born between29weeks to34weeks’GA as determined by obstetric ultrasonogram and clinical examination;(2) the Weight are in the10to90percentile of the average weight of the same gestational age children;(3) are stable with body temperature at36℃～37.3℃, respiratory<60beats/min, heart rate110～150beats/min, SpO285%～93%, blood pressure about70/50mmHg[1], without mechanical ventilation for at least two days;(4)5min Apgar>7point;(5) PIOFRA scale score<30points;(6) Infants’family agreed to accept oral stimulation.3.1.2Exclusion criteria(1) had chronic medical complications, such as BPD, IVH, NEC etc,(2) had congenital anomalies (eg, oral, heart, etc);(6) Infants’family did not agree to accept oral stimulation.3.1.3Eliminate criteria(1) having serious illness changes during the study;(2) were discharged in advance as the family demand.3.2Methods3.2.1GroupsFor a randomized control principle, we used SPSS13.0to do completely randomly design (starting opint is2000000). Object were divided into control group (receiving routine nursing) and intervention group (on the basis of routine nursing, received15minutes oral stimulation,1time/day for10days.3.2.2Intervention method.(1) determination of the intervention method Sandra Fucile15min oral stimulation method was translated into Chinese. Neonatal doctors, newborn physical therapist and neonatal nurse specialists discussed the process and feasibility of the intervention, at last we changed the original program "sucking a pacifier as NNS" to "sucking operator’s finger as NNS".(2) implemention of the interventionOral stimulation is total15minutes including a former12minutes for oral external and internal massage and3minutes for NNS. Oral external massage includes cheek, upper lip and lower lip massage which lasts for5min with the purpose to improve the oral strength, activity and oral close. Oral internal massage including the upper and lower gums, cheeks, tongue side and middle parts of the tongue followed by raising sucking activity. Finally, we would give the infants3min NNS by a gloved finger.3.2.3Evaluation(1) oral motor ability:PIOFR Scale score;(2) vomiting, infections, incidence of gastro-oesophageal reflux.3.2.4Data CollectionUse an oral stimulation Form designed by researcher, includinggeneral information:ID, gender, birth weight, gestational age,5min Apgar score.monitoring data:(1) before the intervention:whether use of pulmonary surfactant (Curosurf, Ke Li Su), with or without intracranial lesions (intracranial hemorrhage, hypoxic-ischemic encephalopathy with or without), with or without low-protein hyperlipidemia, with or without anemia, with or without the use of PICC or deep venous catheter, with or without infection and GER;(2) after the intervention:with or without infection, GER or vomiting; PIOFRA scale score on the day of intervention began, and7days,10days,14days after the start of the intervention.3.3StatisticsFor the difference of general information, qualitative variables used Pearson X2test; quantitative variables with normal distribution and homogeneity of variance use the two-sample t-test, unequal variances use two-sample t’test. PIOFRA scale score at different time used repeated measures analysis of variance. The incidence of vomiting, infections, and gastro-oesophageal reflux was compared by the X2test.Results1. Validity and reliability of Chinese version of Preterm Infant Oral Feeding Readiness Assessment ScaleThe Cronbach’s a coefficient of the scale was0.817. The ICC between two examiners for the scale was0.917(P<0.01) and the Spearman rs was0.927(P<0.01). I-CVIs of the scale were between0.83to1.00. S-CVI/UA was0.889and S-CVI/Ave0.981which suggested the scale had good content validity.The structure of the scale was reasonable and the difference whether the premature can start oral bottle-feeding was statistical significant (P<0.001). Area under the ROC (receiver operating characteristic) curve was0.858(P<0.001,95%CI:0.775-0.941). The sensitivity of the scale was0.756, and the specificity was0.800when a cut of30point was set by ROC curve analysis. Therefore,30point is suggested as the cut point for preterm infant oral bottle feeding readiness.2. Evaluation the scale in clinic2.1Correlation between scale evaluating result and the premature’s feeding performanceThe rs between scale score and premature’s suction rate was0.674(P<0.001), the higher score, the faster the premature’s suction rate would be. The rs between scale score and3days of ordered milk finish rate was0.352(P<0.001). Preterm infants had a faster suction rate and higher finish rate of3days of ordered milk when evaluated a higeher points (Z=-4.514, P<0.001; Z=-2.305, P=0.021).2.2Factors affected the premature’s oral feeding readinessMultivariate analysis:the preterm infants’ weight when evaluation and scale point were the protecting factors (OR<1) for starting of oral feeding (P=0.015; P<0.001).3. Effect of oral stimulation to prematures’oral motor ability PIOFRA scale score was statistically different at different time in both groups which suggested the time would affect the score (F=169.062, P<0.001). The first day ratings are minimum in two groups, after with an upward trend over time. The control and intervention groups rated a statistically significant difference (F=5.538, P=0.022). Except no difference on the first and seventh day(P=0.204; P=0.369) in two groups, the intervention group had a higher score than the controlled group(P<0.001). Group and time had an interaction effect (F=11.561, P<0.001). The incidence of vomiting, infections, and gastro-oesophageal reflux were not significantly different in two groups(P>0.05)Conclusion1. The Chinese version of Preterm Infant Oral Feeding Readiness Assessment Scale has a good reliability and validity and it is a favorable tool to assess whether the premature can begin bottle-feeding safely.2. Scale evaluating result can predict the premature’s feeding performance at the first three days. Scale evaluating result and weight could reflect preterm infant oral feeding readiness. It is useful to apply it in clinic.3. Saudra Fucile oral stimulation method can significantly promote the development of premature oral feeding ability in the10days after the intervention, and will not increase vomiting, gastroesophageal reflux, infection as well. It is suitable for clinical application.