According to the MTDI, 67 children (53%) did not have any decay; while according to the VDHS, 87 children (69%) did not have any decay.
The dental hygienists (VDHS) identified 79 decayed teeth in 39 children; the dentist (MTDI) identified 195 decayed teeth in 59 children.
The sensitivity and specificity for the VDHS in detecting decay was 61% and 96% for all teeth, 64% and 100% for primary teeth, and 15% and 97% for permanent teeth, respectively.
Of the 36 locations where decay was detected by the MTDI, the VDHS identified subjects as having decay in 32 of these locations.
Results of testing for the 3 explanations for possible discrepancies between the VDHS and the MTDI are as follows.
For single-surface decay in primary teeth, the ability of the VDHS to identify posterior decay was significantly less than the ability to identify anterior decay.
With regard to the position of decay in the maxillary versus mandibular arch, the VDHS was not significantly different from the MTDI in identifying either: 1) single-surface maxillary decay in the primary (0.7204) or permanent (0.4462) dentition, or 2) multiple-surface maxillary decay in the primary (0.5708) or permanent (0.3869) dentition.
For the primary teeth, the ability of the VDHS to identify pitted surfaces (including the occlusal surfaces) was not significant for either single-surface instances of pitted decay (p=0.2920) or instances in which a non-smooth surface was involved in any carious lesion (p=0.3715).
As Beltran et al discussed at length, the level of congruence necessary to state that the VDHS is valid has not been widely discussed) Landis established that kappa values <0.39 are "low," 0.4 to 0.6 are "moderate," and >0.61 are "substantial." (17) Stamm states that a test should have a sensitivity level of 0.75 or higher and a specificity level of 0.85 or higher.
(19,20) But, the purpose of this study was to investigate the VDHS in typical, local community situations.
(21) The present study and Beltran's study indicate that with short study-specific preparation, dental hygienists, as educated under current US accreditation standards, can achieve moderate to high levels of sensitivity and specificity with VDHS. (8) This suggests that that yearly clinical licensing tests and yearly continuing education are not necessary for dental hygienists to participate in oral health screenings.
These findings do suggest directions for further research on the VDHS. Larger sample sizes and a wider age group of children are needed to test the effects of location and size of decay on ability to detect decay with the VDHS.