摘要
目的建立虫卵计量变异的随机模型,并估计描述虫卵计量变异特征的参数。方法随机模型把人群中虫卵计量总变异分成两个来源:①虫卵计量在个体间的变异;②个体内虫卵计量的变异。用具有重复虫卵计数的实际资料对模型的参数进行估计。结果参数M、r值在各年龄组中不同,k值在各年龄组中近于相同;r和M值的最佳年龄分割点分别为8和12岁;模型E中假定k值在各年龄组中相同,r值在2~7岁和8岁以上年龄组间不同,M值在2~11岁和12岁以上年龄组间不同,AIC值最小。结论年龄可能为影响M,r值的重要因素。
Objective To establish a stochastic model suitable for interpreting the variation in fecal Schistosoma japonicum egg count, and to estimate its parameters and to describe it. Methods Total variation in fecal egg count with a stochastic model can be divided into two kinds of sources, ① inter individual variation, and ② intra individual variation. Parameters in the model were estimated with the data collected in actual fecal egg count. Results Parameters M and r differed and k kept nearly the same in various age groups. The best cut off point of r and M for age splitting was at eight and 12 years, respectively. Parameter k was assumed the same in different age groups in the model E, and r differed in the groups of 2~7 years and 8~years of age, and M differed in the groups of 2~11 years and 12~years of age, with a minimum value of Akaike information criterion ( AIC ). Conclusion Age may be an important factor contributing to the estimations of parameters M and r , and the model E was the best one.
出处
《中华预防医学杂志》
CAS
CSCD
北大核心
1999年第1期37-39,共3页
Chinese Journal of Preventive Medicine