ABSTRACT
Objective@#To investigate visual acuity of pupils of grade 4-6 in Liaoning Province in 2019 and to analyze its influencing factors, and to provide the scientific basis for myopia prevention and intervention.@*Methods@#A total of 16 716 students of grade 4-6 in 14 cities of Liaoning Province were selected by multi-stage stratified random cluster sampling, and the long-range visual acuity and refraction was evaluated and a questionnaire survey was conducted. Logistic regression analysis was used to analyze the in-fluencing factors of myopia in primary school students.@*Results@#The myopic rate of grade 4-6 pupils in Liaoning Province was 49.17%. Multiple Logistic regression analysis found that the main factors affecting vision included urban and rural division, sex, recess, restriction of electronic products usage from parents, and heredity(OR=0.93, 1.29, 0.90, 0.82, 3.12, 1.61, 1.64, P<0.05). Among them, rural areas, outdoor activity during recess and restriction of electronic product usage from parents was associated with lower risk of myopia, in contrast, being girl and parental myopia was associated with higher risk of myopia.@*Conclusion@#The incidence of myopia among primary school students in Liaoning Province is relatively high, exterting high pressure on prevention and control. In order to prevent myopia in primary school students, Composite interventions should be developed including change students’ lear-ning style, eliminate unhealthy living habits and targeted propaganda and education.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the significance of cardiac output (CO) response against exercise determined by IGR method and LVEF, 6 MWT distance in patients with chronic heart failure (CHF).</p><p><b>METHOD</b>To adopt 6 MWT, and before and after the test measuring the CO by the IGR method, furthermore, measure LVEF to 36 patients (heart failure group) with CHF, compare with the health groups (control group).</p><p><b>RESULTS</b>The 6MWT distance of heart failure group (333.00 +/- 49.64) m decrease compared with the control group (582.56 +/- 67.97) m (P < 0.01), moreover, the distance of NYHA class III (314.82 +/- 36.27) m is significantly shorter than II (361.57 +/- 55.42) m (P < 0.05). The LVEF of heart failure group (47.0 +/- 0.4)% reduce compared with the control group (66.9 +/- 5.2)% (P < 0.01), and the data of NYHA class III (43.3 +/- 10.3)% is significantly lower than II (52.8 +/- 7.6)% (P < 0.01). The increase in CO response against exercise of heart failure group (5.97 +/- 1.89) L/min decrease compared with control group (8.88 +/- 0.52) L/min (P < 0.01), furthermore, the value of NYHA class III (5.31 +/- 1.52) L/min, compared with II (7.01 +/- 1.98)L/min, is obviously lower (P < 0.01). The 6MWT distance correlates positively with the increase in CO response against exercise (r = 0.63, P < 0.01), but the correlation is not found between the increase CO response against exercise and the LVEF (r = 0.11, P > 0.05).</p><p><b>CONCLUSION</b>Our results show that CO response against exercise measured by IGR method, with the advantages of being noninvasive, safe, convenient and accurate, combining with the 6MWT can evaluate cardiac reserve in patient with CHF.</p>