Caries Risk Assessment Tools: The Evidence

Abstract

Background Various caries risk assessment tools (CRATs) are currently used in the management of early childhood caries. The evidence to inform the selection of a specific tool is unclear, as CRATs differ in their content and development methodology, mostly due to the absence of a standard reporting and testing guideline. Risk-based and outcomes focused (the shift from volume to value) models of caries management have been gaining popularity in recent times as they attempt to prevent and manage the disease itself rather than its sequela. Risk-based models of oral health care attempt to stratify populations, with those most at-risk prioritised for care, while concurrently reducing unnecessary care for low-risk people. This becomes an important consideration when allocating resources in limited resource settings such as public dental services. If new models of caries management depend on an accurate and precise risk assignment, then evidence is needed to inform each step of the development and selection of CRATs. Without this essential body of work, risk-based models of caries management run the risk of not delivering the intended positive outcomes, for either the patient or the health care organisation. The aim of this PhD was to generate new knowledge on caries risk assessment tools for young children, to demonstrate their utility in models of caries management.

Methods The philosophical underpinnings of my PhD research were informed by the value-based health care (VBHC) agenda. The theoretical foundations, including the intent, motivation and expectations for the research were guided by two socio-ecological conceptual frameworks – National Institute for Health and Clinical Excellence’s (NICE) conceptual framework for public health and the Fisher-Owens conceptual model of influences on child oral health. The PhD research was conducted as three separate research strands: Strand 1. The systematic review – provided evidence for the current state of knowledge including knowledge gaps for CRATs for young children, relating to content, development process, and testing methods, risk categorisation and use in practice; Strand 2. The calibration study – provided evidence for examiner inter- and intra-examiner reliability for the VicGen data and also generated new knowledge related to the process for calibrating clinical examiners in caries diagnosis when conducting research with young children; and Strand 3: The CRAT testing – provided the evidence, based on an assessment of the reliability and validity required to inform the selection of a CRAT (CAMBRA CRAT used as the case study) for young children in the State of Victoria.

Results The CRATs reported in the literature for use among children less than 6 years were: Caries Management By Risk Assessment (CAMBRA), Cariogram, National University of Singapore CRAT (NUS-CRAT), MySmileBuddy, Dundee Caries Risk Assessment Model, University of North Carolina Risk Assessment Models, University of Michigan pediatric dental clinic caries risk assessment sheet and American Academy of Pediatric Dentistry (AAPD) CRAT. For examiner reliability in the calibration study, Kappa scores for inter-examiner reliability ranged from 0.56 to 0.70 (moderate to good). In the in vivo community examination, using ICDAS caries codes only, weighted Kappa scores for inter-examiner reliability ranged from 0.50 to 0.64 (moderate to good). In the CRAT testing study, good reliability (inter and intra) was observed when using the CAMBRA CRAT. For the classic CAMBRA three-level risk categorisation (low, moderate and high), at 36 and 48 months of age, respectively, the area under the receiver operating curve was close to 0.50, which is indicative of a low ability for the CRAT to predict future caries development.

Conclusion To conclude, this PhD study identified a major knowledge gap in the current state of evidence on the subject of caries risk assessment tools (CRATs); which was the lack of methodologically sound studies to provide the evidence to inform decision making on tool selection, for use in practice. The PhD study addressed this knowledge gap through methodologically rigorous research to demonstrate the process required to generate the evidence to inform the selection of a CRAT. The CAMBRA CRAT which was used as the case study in the PhD research was shown to be ineffective in predicting a caries outcome among young Victorian children.