Aida Jun, Matsuyama Yusuke, Tabuchi Takahiro, Komazaki Yuko, Tsuboya Toru, Kato Tsuguhiko, Osaka Ken, Fujiwara Takeo
Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan.
Cancer Control Center, Osaka International Cancer Institute, Osaka, Japan.
Community Dent Oral Epidemiol. 2017 Oct;45(5):407-412. doi: 10.1111/cdoe.12304. Epub 2017 Apr 26.
The longitudinal trend of dental health inequalities among preschool children has not been described. In this study, we aimed to measure the trajectory of both relative and absolute inequalities in caries treatment among preschool children in Japan.
We used data from the Longitudinal Survey of Babies in the 21st Century (LSB21), which is an ongoing national representative longitudinal study. The target population was families residing in Japan with newborn baby/babies born between 10 January and 17 January or 10 July and 17 July 2001. Data regarding caries treatment history and socioeconomic status (SES) were collected using a self-reported questionnaire. SES was assessed on the basis of the parents' educational attainment. In total, 35 260 children were followed from 2.5 to 5.5 years through annual surveys. To evaluate absolute and relative inequalities, we calculated the slope index of inequality (SII) and relative index of inequality (RII), respectively.
The rate of caries treatment at the age of 2.5 years was <10% for all SES groups; this increased to more than 30% at 5.5 years of age. Children with lower SES received more frequent caries treatment, and both absolute and relative social inequalities were statistically significant. SII showed a significant increase throughout the follow-up period, with values of 4.13% (95% confidence interval [CI], 3.16; 5.09) and 15.50% (95% CI, 13.68; 17.32) at 2.5 and 5.5 years of age, respectively. In contrast, RII decreased with an increase in the treatment rate for all groups, with values of 1.83 (95% CI, 1.59; 2.11) and 1.53 (95% CI, 1.46; 1.61) at 2.5 and 5.5 years of age, respectively.
Our results suggest that the rate of caries treatment is higher for preschool children with lower SES in Japan, with significant widening of absolute inequalities along with the growth of the children.
学龄前儿童口腔健康不平等的纵向趋势尚未得到描述。在本研究中，我们旨在衡量日本学龄前儿童龋齿治疗方面相对不平等和绝对不平等的轨迹。
我们使用了21世纪婴儿纵向调查（LSB21）的数据，这是一项正在进行的全国代表性纵向研究。目标人群是居住在日本、于2001年1月10日至17日或7月10日至17日出生的有新生儿的家庭。使用自我报告问卷收集有关龋齿治疗史和社会经济地位（SES）的数据。SES根据父母的教育程度进行评估。通过年度调查，总共对35260名儿童从2.5岁跟踪到5.5岁。为了评估绝对不平等和相对不平等，我们分别计算了不平等斜率指数（SII）和不平等相对指数（RII）。
所有SES组在2.5岁时的龋齿治疗率均<10%；在5.5岁时这一比例增加到30%以上。SES较低的儿童接受龋齿治疗的频率更高，绝对和相对社会不平等均具有统计学意义。SII在整个随访期间显著增加，在2.5岁和5.5岁时的值分别为4.13%（95%置信区间[CI]，3.16；5.09）和15.50%（95%CI，13.68；17.32）。相比之下，RII随着所有组治疗率的增加而下降，在2.5岁和5.5岁时的值分别为1.83（95%CI，1.59；2.11）和1.53（95%CI，1.46；1.61）。
我们的结果表明，日本SES较低的学龄前儿童龋齿治疗率较高，随着儿童成长，绝对不平等显著扩大。
