Grigoletto F, Anderson D W, Rocca W A, Meneghini F, Morgante L, Reggio A, Savettieri G, Di Perri R
Institute of Hygiene, University of Padua, Italy.
Am J Epidemiol. 1994 Jan 15;139(2):219-28. doi: 10.1093/oxfordjournals.aje.a116983.
Two-phase prevalence surveys with screening (phase 1) and examination (phase 2) are useful for some chronic diseases. Attrition, which may bias estimates, occurs in either phase because some eligible subjects die before contact, some refuse to cooperate, some are incapacitated, and some are unreachable. This investigation relates to a survey of neurologic diseases conducted in three municipalities of Sicily (prevalence date, November 1, 1987) and considers the attrition experienced and the use of proxy respondents in phase 1 and auxiliary information in phase 2 to offset, in part, this attrition. Regarding case finding, the salvage effort was more productive for decreased and incapacitated subjects. The age, sex, and household size of the subject were related to phase 1 attrition, but only age was related for all four attrition groups--deceased, refusing, incapacitated, and unreachable subjects. On the basis of information from proxy respondents, the educational levels of refusing and unreachable subjects were compared with those of subjects screened directly. Refusing subjects were less educated, and unreachable subjects were more educated. The proxy respondent performance, as indicated by "don't know" responses, was better with screening items concerning facial paralysis and mouth drooping (and not limb sensory abnormalities or impaired consciousness), better with younger subjects, and worse with refusing or incapacitated subjects.
采用筛查（第一阶段）和检查（第二阶段）的两阶段患病率调查对某些慢性病是有用的。在任一阶段都会出现可能使估计产生偏差的损耗，因为一些符合条件的受试者在被联系之前就已死亡，一些拒绝合作，一些丧失行为能力，还有一些无法联系到。本调查涉及在西西里岛的三个城市进行的神经系统疾病调查（患病率调查日期为1987年11月1日），并考虑了所经历的损耗以及在第一阶段使用替代受访者和在第二阶段使用辅助信息来部分抵消这种损耗。关于病例发现，挽救努力对减少和丧失行为能力的受试者更有成效。受试者的年龄、性别和家庭规模与第一阶段的损耗有关，但只有年龄与所有四个损耗组（死亡、拒绝、丧失行为能力和无法联系的受试者）有关。根据替代受访者提供的信息，将拒绝和无法联系的受试者的教育水平与直接接受筛查的受试者的教育水平进行了比较。拒绝的受试者受教育程度较低，无法联系的受试者受教育程度较高。以“不知道”的回答所表明的替代受访者的表现，在关于面瘫和口角下垂（而非肢体感觉异常或意识障碍）的筛查项目中更好，在年轻受试者中更好，而在拒绝或丧失行为能力的受试者中更差。
