Validity and reliability of the Mastication Observation and Evaluation (MOE) instrument

The Mastication Observation and Evaluation (MOE) instrument was developed to allow objective assessment of a child's mastication process. It contains 14 items and was developed over three Delphi rounds. The present study concerns the further development of the MOE using the COSMIN (Consensus based Standard for the Selection of Measurement Instruments) and investigated the instrument's internal consistency, inter-observer reliability, construct validity and floor and ceiling effects. Consumption of three bites of bread and biscuit was evaluated using the MOE. Data of 59 healthy children (6-48 mths) and 38 children (bread) and 37 children (biscuit) with cerebral palsy (24-72 mths) were used. Four items were excluded before analysis due to zero variance. Principal Components Analysis showed one factor with 8 items. Internal consistency was >0.70 (Chronbach's alpha) for both food consistencies and for both groups of children. Inter-observer reliability varied from 0.51 to 0.98 (weighted Gwet's agreement coefficient). The total MOE scores for both groups showed normal distribution for the population. There were no floor or ceiling effects. The revised MOE now contains 8 items that (a) have a consistent concept for mastication and can be scored on a 4-point scale with sufficient reliability and (b) are sensitive to stages of chewing development in young children. The removed items are retained as part of a criterion referenced list within the MOE.