Predictive value of clinical feeding evaluation
A flow diagram of the patient population including the results of CFE
and VFSS is shown in figure 2. When VFSS was normal, this had been
predicted by prior normal CFE in 51 out of 67 (76%) cases. Most
abnormal VFSS included an element of silent aspiration with at least one
food texture although there may have been overt aspiration with other
textures. This occurred in 37 out of 46 (80%) children with aspiration.
Of those 37, 31 (84%), had a prior abnormal CFE although18 out of 31,
58%, had been classified as overt aspirators, possibly due to overt
aspiration which was observed with some of the food textures while
silent aspirations were missed. Of greatest concern, a total of 10
patients had been deemed free of aspiration according to CFE and later
found to have abnormal VFSS (4 overt and 6 silent).
Considering
VFSS as the gold standard for the diagnosis of aspirations, CFE
demonstrated an overall sensitivity and specificity of 71% and 84%
respectively (table 3), suggesting that the OT was fairly reliable in
discerning pathology from normalcy. However, when overt and silent
aspiration were considered separately, the detection sensitivity fell
markedly, as reflected by the low positive predicted value (PPV) of CFE
for both overt and silent aspirations of 15% and 35% respectively,
indicating a high number of false positive assessments for both these
categories.