Epidemiological Characters Of Vision Care Behaviors And Intervention Study In Shanghai Primary Schools

BackgroundNearly several decades, the phenomenon of higher near-sight prevalence, lower age incidence and higher near-sight seriousness prevailed in primary and high school in China. Near-sight problem acts as one of three key health issues which negatively impacted child and adolescent health development in China.In order to tackle student's near sight problem, several administration departments worked together and developed a comprehensive near-sight prevention and treatment outline in 1996. The outline was then integrated into routine school health work required by government administration departments. The practice effects have not yet been evaluated since then.This study systemically examined the practice issues, especially shortages, and then focused key prevention measures on student vision care behaviors changes. After references review, we found the contents of vision care behaviors have got certain developments in past several years. However, due to the lack of scale measures, it's difficult for us to make the comparability between/among different studies on near-sight issues. So, we developed the "Child Vision Care Behaviors Scale" (CVCBS) based on the logical and factors analysis ways. The epidemiological characters of vision care behaviors in Shanghai primary schools were then measured by the CVCBS. Thus, we tried to understand the multiple influence factors on vision care behaviors by health behavior ecology theories, and proposed targeted intervention strategies. AimBased on effect analysis of the near-sight prevention and treatment outline, to focus intervention on student's vision care behavior changes; To develop "Child Vision Care Behaviors Scale" (CVCBS) and study the epidemiological characters of vision care behaviors in Shanghai primary schools, and correlation between near-sight and vision care behaviors; To understand multiple influence factors on vision care behaviors from health behavior ecology theories, and propose intervention strategies, then evaluate intervention effects.MethodsThe Delphi's method was adopted in the beginning of this study. After three rounds expert consultancy, we gathered 30 experts'ideas and proposed strategies and tactics on near-sight intervention in metropolitan primary and middle schools. The feasibility and acceptability of strategies and tactics were also studied. By personal interview, we systemically examined shortages of the Outline practice.The aim of CVCBS was to analyze the characters of student's vision care behaviors and provide measuring tools for behavior intervention evaluation. Based on the main questionnaire development ways, i.e. logical way and factors analysis way, we reviewed references, held focus group discussion meetings and consulted experts via mail. We carefully defined behaviors contents and drafted the prototype scale after two tests. Then,585 students were measured by the prototype. After analysis and refine, another 840 students participated the Scale examination, and finally the"Child Vision Care Behaviors Scale"(CVCBS) was developed. 11431 primary school students from 2 urban districts and 2 suburb districts took the investigation adopted by CVCBS. The investigation showed main epidemiological characters of vision care behaviors in Shanghai primary schools. Analysis methods such as Canonical Correlation, Multinomial Logistics were used to understand the correlation strength and structure between vision care behavior and sight. The Hierarchical Cluster method helped to know the correlation cluster between schools, and then provided proof or signs to intervention strategies.On the basis of sectional investigation, health behavior ecology model was applied to clarify the multiple influence factors on vision care behaviors. Then, an intervention proposal was developed and put into practice in XuHui District primary schools since September, 2008. In the study, 737 students (2008 grade) from 5 primary schools in XuHui District classified as intervention group, and 575 students (2008 grade) from 5 primary schools in ChangNing District as controlled group. The study lasted 3 semester terms. The Mixed Models method was used to explain impacts from behavior intervention.ResultsBy 3 rounds Delphi's consultancy, 4 aspects of first level intervention strategies and 16 means of second level intervention strategies were screened out after results analysis on expert views on intervention strategies validity, feasibility and acceptability. The first level intervention strategies embody setting up policy supporting ambiance, improving study condition, cultivating correct vision care habits, and formulating vision protection and near-sight screening regulation. It's glad to understand that 16 means of second level intervention strategies basically coincide with the practicing Outline developed in 1996. Some third level intervention strategies proposed recently were all ticked out in the first round Delphi's consultancy. The results from focus group discussion and personal interviews participated by district education administrators, optical diseases prevention and control center chiefs, school principals, school sanitary teachers, class teachers showed that: the policy supporting ambiance is relatively formulated, the school environment and study condition is improving under government investment and support, and the sight screening regulation is polished under the direction from municipal optical diseases prevention and control center. However, in the respect of cultivating vision care habits, we found that whose responsibility was not clear, and there's no supervision and inspection, and so the results were uncertain.After reference review and Delph's consultancy, core vision care behaviors in primary school were defined as following 6 aspects: nearwork, nearwork intermission rest, outdoors activity, nearwork gesture, nearwork environment condition, life habit, and vision care exercise. The CVCBS (include 9 aspects and 31 items) developed by logical way and factors analysis way performed very well on credibility test, validity test and other examinations, met strict metrology requirements and could act as basic evaluation tool for primary school student vision care behaviors. The detail 9 aspects refer to:vision relax behaviors, vision distance, reading and studying environment, vision duration, outdoors activities, reading and writing gesture, diet habits, vision care exercise, and pen-holding gesture.Four types of grade characters were found in the vision care behaviors study. Type 1, "opposite":reflected on "vision relax behaviors" and "vision duration". In the CVCBS, "vision relax behaviors" refers to any behaviors to try to relax vision or sight; and "vision duration" refers to no rest behavior during vision time. The results showed more "vision relax behaviors" and less "vision duration" with increase of students'grade level. Type 2, "U type":reflected on "vision distance", "pen-holding gesture" and "reading and writing gesture" aspects. The results showed that grade 1 and grade 5 got better marks and others lower marks. Type 3, "outdoors activities":Grade 1 had more outdoors activities than any other grades. Type 4, "vision care exercise":good high marks with high grades.We defined nearwork as two parts, one was reading and writing activities, and another was screen watching activities (TV watch, PSP game play, and computer screen watch). With high grade, we found more times on reading and writing activities, especially in grade 2. As to screen watching activities, more TV watch time in grade 2, and more computer and PSP play time in grade 4.Multi-factors analysis suggested that, (1) vision status correlated with vision relax behaviors, vision distance, vision duration and pen-holding gesture, lower marks worse vision status; (2) vision status correlated with outdoors activity time and screen watching time, and both interact. Generally, less outdoor activities time worse vision status. However, we found from this study that grade 1 and 2 students with vision status less than 4.5 had more compensated outdoor activities during weekend. And more, less screen watching time among worse vision status students. That's contradictory with common sense.Canonical Correlation analysis suggested that, (1) vision distance more impact vision status; (2) vision duration more impact refractive status; and (3) nerwork strength more impact both of vision status and refractive status.Multinomial Logistics analysis suggested that, (1) vision relax behaviors, vision distance, pen-holding gesture and outdoors activities were weak protection factors for vision status, and its impacts not disturbed by the status of vision decrease (in other words, there's no difference among light, medium and severe vision decrease groups); (2) reading and writing time, female and early writing behavior were weak risk factors for vision status; (3) heredity and grade factors have more impacts than factors mentioned above, especially in severe vision decrease group.Hierarchical Cluster analysis suggested that schools with high incidence of severe vision decrease, had less outdoors activities and more vision duration; vice versa.Based on health behavior ecology model, we developed intervention strategies for behaviors predisposing, enabling, and reinforcing factors standing on personal, class, family, school and community levels. Combined with vision care behaviors and high incidence, we formulated whole process intervention and stage intensified means. The whole process intervention focused on outer ambiance from the point of health behavior ecology model, including related district government administration policy support, supervision and inspection system development. The stage intensified means focused on school, and the target group was grade 1 and grade 3. In grade 1, behavior intervention included cultivating correct reading and writing gesture and vision relax skills, focus on all levels. In grade 3, behavior intervention included more outdoors activities, less screen watching and nearwork, sight rest, good reading and writing gesture, focus on personal, class and family level.The intervention was implemented since September,2008. The study targeted student group who attended school in 2008 (grade 2008). Up to now, we had 3 times behavior investigation, and Mixed Model analysis found that, intervention had good impact on reading environment condition, vision care exercise and pen-holding gesture. Conclude(1) In current vision care intervention, the responsibility of cultivating good vision care habits was not clear, and there's no supervision and inspection, and so the intervention results were uncertain.(2) The "Child Vision Care Behaviors Scale" (CVCBS) was formulated, and could act as a tool for vision care behavior measurement in primary school.(3) Four type of grade characters were existed in vision care behaviors. Targeted intervention strategies should seriously consider those characters.(4) There're correlation between vision decrease and nearwork strength and some certain vision care behaviors. And there're school cluster on the correlation between vision decrease and outdoors activities, vision duration.(5) Behavior intervention developed from health behavior ecology suggested certain good results on reading environment condition, vision care exercise and pen-holding gesture.