Odum Institute for Research in Social Science, University of North Carolina, Chapel Hill, North Carolina, USA.
Department of Dental Ecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
BMJ Open. 2019 Feb 1;9(2):e022580. doi: 10.1136/bmjopen-2018-022580.
To explore health literacy as a marker of voter confusion in order to understand the basis for public opposition to community water fluoridation.
A cross-sectional study.
Conducted in three large US cities of San Antonio, Texas (602 voting precincts); Wichita, Kansas (171 voting precincts); and Portland, Oregon (132 voting precincts). Precinct-level voting data were compiled from community water fluoridation referendums conducted in San Antonio in 2002, Wichita in 2012 and Portland in 2013.
Voter turnout expressed as a percentage of registered voters was 38% in San Antonio (n=2 92 811), 47% in Wichita (n=129 199) and 38% in Portland (n=164 301).
The dependent variable was the percentage of votes in favour of fluoridating drinking water. Precinct-level voting data were mapped to precinct scores of health literacy, and to US Census and American Community Survey characteristics of race/ethnicity, age, income and educational attainment. Multilevel regression with post-stratification predicted the precinct mean health literacy scores, with weights generated from the National Association of Adult Literacy health literacy survey, with item response theory computed scoring for health literacy. Predictive models on voter support of community water fluoridation were compared using robust linear regression to determine how precinct-level characteristics influenced voter support in order to determine whether health literacy explained more variance in voting preference than sociodemographic characteristics.
Precinct-level health literacy was positively associated with voter turnout, although sociodemographic characteristics were better predictors of turnout. Approximately 60% of voters opposed community water fluoridation in Wichita and Portland, whereas in San Antonio, a small majority (53%) voted in favour of it. Models suggest that a one SD increase in health literacy scores predicted a 12 percentage point increase support for community water fluoridation.
Educational attainment and health literacy are modifiable characteristics associated with voting precincts' support for community water fluoridation.
探讨健康素养作为选民困惑的标志，以了解公众反对社区水氟化的基础。
横断面研究。
在美国三个大城市进行，分别是得克萨斯州圣安东尼奥市（602 个投票区）、堪萨斯州威奇托市（171 个投票区）和俄勒冈州波特兰市（132 个投票区）。圣安东尼奥市（2002 年）、威奇托市（2012 年）和波特兰市（2013 年）社区水氟化公投中收集了投票区一级的投票数据。
圣安东尼奥市（n=292811）、威奇托市（n=129199）和波特兰市（n=164301）的选民投票率分别为 38%、47%和 38%，均以登记选民的百分比表示。
因变量为赞成饮用水氟化的选票百分比。投票区一级的投票数据与健康素养评分、美国人口普查和美国社区调查的种族/民族、年龄、收入和教育程度特征进行了映射。采用后分层的多层次回归预测了投票区平均健康素养评分，权重来自全国成人识字协会健康素养调查，采用项目反应理论计算健康素养得分。使用稳健线性回归比较了社区水氟化投票支持的预测模型，以确定投票区特征如何影响投票支持，从而确定健康素养是否比社会人口特征更能解释投票偏好的差异。
投票区一级的健康素养与选民投票率呈正相关，尽管社会人口特征是投票率的更好预测指标。在威奇托市和波特兰市，约有 60%的选民反对社区水氟化，而在圣安东尼奥市，略过半数（53%）的选民投票赞成。模型表明，健康素养得分提高一个标准差，就会增加 12 个百分点的社区水氟化支持率。
教育程度和健康素养是与投票区支持社区水氟化相关的可改变特征。
