A Case-control Study About The Relationship Between Health-related Behaviors And Sub-health Symptoms In Middle-school Students In Chongqing

Objective: Discuss the causal relationship and its strength betweenhealth-related behaviors and sub-health condition in middle-school studentsby combined utilization of prospective nested case-control study, to provideguidance for the further intervention study.Methods: A baseline survey was done by questionnaire in3151middle school students who were selected in6junior and seniormiddle-schools in Chongqing by multistage stratified cluster randomsampling. Chose students whose sub-health condition were negative inbaseline to proceed a nine month follow-up observation, then detected theincidence rate of sub-health condition and the exposure of health-relatedbehaviors by using questionnaire after observation period ended. MSQAand the health-related behaviors questionnaire for middle-school studentsin Chongqing were used in both baseline and follow-up investigation.Results: The positive rate of physical sub-health symptoms in all3151middle-school students in baseline survey was33.10%, while the positive rate of junior middle-school students was29.23%and the positiverate of senior one was36.86%. Psychological sub-health’s positive rate inthis group was45.13%,37.22%, and52.82%respectively. Chi-square andmulti-Logistic regression showed that grade in personal basic informationand alcohol intake, drunkenness, exercise in high or low sports intensity,accidental injury, intentional injury, and suicide in health-related behaviorshad a significant relationship with physical sub-health symptoms; gradeand residence in personal basic information and smoking, exercise in highor low sports intensity, accidental injury, intentional injury, suicide, andInternet addiction in health-related behaviors had a significant relationshipwith psychological sub-health symptoms.With all1208middle-school students who joined the nine monthsfollow-up observation, the incidence rate of body sub-health symptoms was9.11%, while10.76%in junior middle-school students and7.05%in seniormiddle-school students. The incidence rate of psychological sub-healthsymptoms was9.27%, while10.31%in junior middle-school students and7.98%in senior middle-school students.Chi-square and multi-Logistic regression showed that:1. For junior middle-school students:(1) Accidental injury (OR=1.855) and suicide (OR=4.828) were risk factorsto physical sub-health symptoms; intentional injury (OR=6.092),suicide(OR=11.834) were risk factors of psychological sub-health symptoms.(2) Exercise in low sports intensity (OR=0.521) was protective factor tophysical sub-health symptoms, and exercise in high sports intensity(OR=0.484) was protective factor of psychological sub-health symptom.2. For senior middle-school students:(1) Accidental injury (OR=5.296) was risk factor of physical sub-healthsymptoms; intentional injury (OR=3.220), suicide (OR=5.384) were riskfactors to psychological sub-health symptoms.(2) The study failed to find any health-related behavior which wasprotective factor to sub-health symptoms.Conclusion: The accumulate incidence rate of sub-health symptomsin middle-school students was high in Chongqing, and that in seniormiddle-school students was significant higher than that in juniors. Theincidence rate in nine months follow-up observation showed a significantdecrease, and was higher in junior middle-school students than that inseniors. The baseline survey of the study provided a guideline to furtherrisk factors study and the follow-up result could help the intervention in thefuture.