Statistical inference in Epidemiology : Analysis of Gastro-intestinal disease in day-nurseries

Abstract

Abstract : This study was aimed at giving a picture of gastro-enteritis among children in the community as opposed to in hospital, and also studying the main agents of infection and the amount of asymptomatic carriage of disease. A follow-up study of a one-year period was conducted in two different day nursery schools in a socially deprived area of Greater Manchester. A total of one hundred and sixty-seven children were en- rolled in the study. Faecal specimens were collected fortnightly from the children and were tested for certain agents of infection. Three dif- ferent types of microorganisms and twenty-one agents were isolated. Presence of any symptoms of illness was recorded. Demographic in- formation on the children and their families was also acquired. A set of simple statistical analyses were conducted on the data such as cal- culation of means and standard deviations of the number of times each agent was isolated per child or an episode of a particular symptom was reported. Correlation coefficients between the number of times each agent was isolated per child and occurrence of symptoms were also cal- culated. Further comprehensive statistical analyses such as fitting lo- gistic regression models and survival analysis were also conducted. This was aimed at estimating the attributable fraction of gastro-intestinal disease due to different agents, the force of infection and the basic re- productive rate Ro, where feasible. This study was useful in two ways . in gaining an understanding of the causes of childhood diarrhoea in the community; and