V. The effect of fluorida-tion and social class on caries experience in 5 year old Newcastle children in 1994 compared with results over the previous 18 years by Evans DJ, Rugg-Gunn AJ, Tabari ED, Butler T.
IX. Water fluoridation, tooth decay in 5 year olds, and social deprivation measured by the Jarman score; analysis of data from British dental surveys by Jones CM, Taylor GO, Whittle JG, Evans D, Trotter P.
Survey design was used for the study. The design collects and considers data in its naturally existing forms, without efforts for treatment and randomization. It is also suitable for descriptive measures that the study focused on (Riley, Lennon, & Ellwood 300, 301).
“Residency,” “other sources of fluoride,” and “ethnicity” are the discussed confounding factors. The factors are likely threats to validity through confusing classification of participants into the classes of the independent variable. The children could have migrated across regions of different social classes, there could be other sources of fluoride than water, and while ethnicity is not an accurate indicator of social inequality (Riley, Lennon, & Ellwood 303, 304).
The authors conclude that a significant relationship exists between water fluorination and dental carries and social inequality is a mediator. The relationship is stronger in low classes (Riley, Lennon, & Ellwood 304).
Riley, Jane, Lennon, Michael, & Ellwood, Roger. “The effects of water fluorination and social inequalities on dental caries in 5-year-old children.” International Journal of Epidemiology 28.2 (199). Print.
Jane C Riley, Michael A Lennon, and Roger P Ellwood. "The effect of water fluoridation and social inequalities on dental caries in 5-year-old children." International Journal of Epidemiology 1 1999. ,