Editorial Expression of Concern

In March 2019, the JDR CTR published the report “Dental Fluorosis Trends in US Oral Health Surveys: 1986 to 2012” (Neurath et al. 2019), in which the National Health and Nutrition Examination Survey (NHANES) data from the Centers for Disease Control and Prevention (CDC) were analyzed.

The following month, the CDC published “Data Quality Evaluation of the Dental Fluorosis Clinical Assessment Data from the National Health and Nutrition Examination Survey, 1999–2004 and 2011–2016” (US Department of Health and Human Services 2019). In its report, the CDC assessed the quality of those NHANES data and questioned their validity. The CDC reported a similar increase in dental fluorosis prevalence between 2001–2004 and 2011–2014 as that reported in Neurath et al. (2019). Because the NHANES is not longitudinal, the CDC authors constructed a synthetic cohort and concluded that this increase was not biologically plausible. In an effort to interpret this finding, the CDC examined other sources. Specifically, the CDC tested the variability of fluorosis measurements in a small population sample and found that examiner agreement was problematic. This suggested that there may have been changes in the way examiners evaluated fluorosis, resulting in intra- and interexaminer errors. Furthermore, they suggested that possible oversampling of certain populations was a plausible reason for the fluorosis increase. In addition, the CDC recognized that impact of geographical variables associated with exposure to water fluoridation at the time of tooth development was not available. Therefore, the CDC suggested that the above limitations, especially related to data quality assessment, should be considered for prevalence studies.

The JDR CTR is publishing this Editorial Expression of Concern to alert our readers to this issue. We urge readers to review the CDC report (US Department of Health and Human Services 2019), in conjunction with Neurath et al. (2019), for a fuller understanding of the NHANES data.