哈尔滨、广州、北京部分小学生啃咬铅笔情况调查

The investigation on the situation of biting pencils among part pupils in Harbin, Guangzhou, and Beijing

目的 调查哈尔滨、广州、北京小学生啃咬铅笔情况并比较其啃咬情况的差异.方法于2015年4月至2016年4月,采用分层整群随机抽样的方法,在哈尔滨、广州选取4所小学,采用单纯随机抽样,在每所学校的每个年级（1-5年级）中选取3-4个班,共71个班级,最终对3052名学生及其监护人进行问卷调查;同时在4个学校的每年级选取1个班,共20个班;另外在北京的2所小学校,每年级选取1个班级,共10个班,最终共对30个班级的1627名学生进行现场齿痕测量.问卷内容包括学生及监护人的一般信息、学生啃咬铅笔情况、啃咬危害的知晓等;现场测量铅笔是否存在齿痕及齿痕程度.采用χ^2检验比较不同城市、不同性别间学生发生啃咬铅笔的比例、齿痕率,以及学生及其监护人对啃咬危害知晓率及齿痕程度差异.结果哈尔滨和广州参加问卷调查并提供有效问卷的小学生分别为1842和1210名.哈尔滨[18.0%（333/1842）]小学生啃咬铅笔的发生率高于广州[11.3%（137/1210）]（χ^2=29.16,P=0.001）;哈尔滨男生啃咬铅笔发生率为21.9%（212/965）,高于女生[13.8%（121/877）]（χ^2=27.04,P=0.001）;广州男生的发生率为14.5%（92/632）,也高于女生[7.7%（45/578）]（χ^2=15.34,P=0.001）;哈尔滨和广州学生对啃咬铅笔危害的知晓率分别为88.5%（1611/1819）和90.8%（1098/1208）,差异有统计学意义（χ^2=4.39,P=0.020）;监护人对危害的知晓率分别为74.7%（1339/1791）和79.4%（832/1047）,差异有统计学意义（χ^2=9.83,P=0.007）.哈尔滨、广州、北京学生的铅笔齿痕率分别为30.5%（187/613）、14.8%（79/534）、28.3%（136/480）,差异有统计学意义（χ^2=42.68,P=0.001）;齿痕程度均以轻度为主,而且广州[54.4%（43/79）]和北京[41.2%（56/136）]轻度的比例明显高于哈尔滨[39.0%（73/187）],但差异无统计学意义（χ^2=7.01,P=0.136）.结论哈尔滨、广州、北京的小学生存在啃咬铅笔的行为,但广州学生啃咬铅笔情况轻于哈尔滨、北京的学生.

Objective To investigate the prevalence of biting pencils among pupils living in Harbin, Guangzhou, and Beijing and to compare the differences among these cases. Methods Stratified sampling method was used to select four elementary schools in Harbin and Guangzhou from April 2015 to April 2016.Firstly, Simple random sampling method was used in every grade （grade 1-grade 5） to select 3 or 4 classes （71 classes in total）.After the sample selection, questionnaire surveys were conducted among pupils and their guardians （anyone of their guardians） who belonged to these classes. Secondly, the study extracted part of these pupils to conduct a field survey. Every school was classified by grade, and every grade adopted the method of random sampling to select one classes （20 classes in total）. Meanwhile, the study randomly selected pupils from 10 classes in 2 elementary schools in Beijing. All together, 1627 pupils participated in the field survey. The questionnaire included general information about the students and their guardians, the situation of biting pencils, the awareness of the harm of biting pencils, etc.;the field survey considered if participates＇ pencils have tooth marks and the severity of the marks, etc.χ^2 was applied to test and compare the differences among pupils of different genders and different cities. The comparison focused on the proportion of students who bited pencils, the proportion of pencils with tooth marks and the proportion of students and guardians already awared of the harm of biting pencils, etc. Results The number of the valid questionnaires in Harbin and Guangzhou were 1842, and 1210, respectively. The occurrence rate of pupils biting pencils in Harbin （18.0%（333/1842）） was higher than that in Guangzhou （11.3%（137/1210）） （χ^2=29.16, P=0.001）. Specifically, in Harbin, the rate of boys biting pencils was 21.9%（212/965）, which was higher than girls （13.8% （121/877）） （χ^2=27.04, P=0.001）. Similarly, in Guangzhou, the rate of boys biting pencils was 14.5% （92/632）, which was also higher than girls （7.7% （45/578）） （χ^2=15.34, P=0.001）. The awareness rate of the harm of biting pencils among students from these two cities were 88.5%（1611/1819）, and 90.8% （1098/1208）, respectively, and the difference was statistically significant as well （χ^2=4.39, P=0.020）. Compared with these data, the awareness rate of the harm of biting pencils among guardians from these two cities were 74.7% （1339/1791）, and 79.4% （832/1047）, respectively as well as the statistically significant difference appeared （χ^2=9.83, P=0.007）. The result of field survey showed the rate of tooth-marked pencils in Harbin, Guangzhou and Beijing was 30.5%（187/613）, 14.8%（79/534）, and 28.3%（136/480）, respectively. The difference was also statistically significant （χ^2=42.68, P=0.001）. The degree of tooth marks was mainly mild, while the percentage of mild degree in Guangzhou （54.4%（43/79）） and Beijing （41.2% （56/136）） was apparently higher than that of Harbin （39.0% （73/187））. The difference was not statistically significant （χ^2=7.01, P=0.136）. Conclusion The behavior of biting pencils existed universally among pupils in Harbin, Guangzhou, and Beijing , which the situation of pupils biting pencils in Harbin and Beijing was more serious than that in Guangzhou. Pupils, parents and teachers should pay attention to such a behavior.