Morris S S, Cousens S N, Kirkwood B R, Arthur P, Ross D A
Maternal and Child Epidemiology Unit, London School of Hygiene and Tropical Medicine, United Kingdom.
Am J Epidemiol. 1996 Sep 15;144(6):582-8. doi: 10.1093/oxfordjournals.aje.a008968.
A number of different outcome measures have been proposed for use in prospective studies of morbidity associated with childhood diarrhea. These include the number of episodes experienced by each child over a defined period (a measure of incidence) and the number of days of diarrhea divided by the total number of days of observation for each child (a measure denoted "longitudinal prevalence"). The authors examined data from Ghana to determine which of these measures is more strongly associated with weight gain over a 4-month period and subsequent mortality. Both diarrhea incidence and longitudinal prevalence were associated with weight gain in children aged 6-23 months, but a statistically stronger association was observed with longitudinal prevalence (likelihood ratio statistic 28.95 on 1 degree of freedom against 19.70 for incidence). Neither measure was associated with weight gain in younger or older children. Longitudinal prevalence, but not incidence, was strongly associated with subsequent mortality (p = 0.002 for longitudinal prevalence; p = 0.557 for incidence). Although many epidemiologic studies of diarrhea focus on incidence, these data suggest that longitudinal prevalence is more strongly predictive of long-term health outcome. The authors conclude that longitudinal prevalence merits greater attention as a measure of outcome in diarrhea studies.
已经提出了许多不同的结局指标，用于与儿童腹泻相关的发病率前瞻性研究。这些指标包括每个儿童在规定时期内经历的发作次数（发病率的一种衡量指标），以及每个儿童腹泻天数除以观察总天数（一种称为“纵向患病率”的指标）。作者研究了来自加纳的数据，以确定这些指标中的哪一个与4个月期间的体重增加以及随后的死亡率关联更强。腹泻发病率和纵向患病率均与6至23个月大儿童的体重增加有关，但观察到纵向患病率的统计学关联更强（自由度为1时，似然比统计量为28.95，而发病率为19.70）。这两个指标均与年龄较小或较大儿童的体重增加无关。纵向患病率而非发病率与随后的死亡率密切相关（纵向患病率p = 0.002；发病率p = 0.557）。尽管许多腹泻的流行病学研究都集中在发病率上，但这些数据表明纵向患病率对长期健康结局的预测性更强。作者得出结论，纵向患病率作为腹泻研究中的结局指标值得更多关注。
