A Pattern Analysis Study of Weanling Diarrhoeal Disease of Infants

Abstract

Methods of pattern analysis based on statistical signal procedures have been applied to (512-day) records of daily defaecation rate obtained in an ensemble of weanling infants. Careful analysis of the records using several different methods has established the potential significance of the signal. A technique of coherent averaging has produced a stable consistent age-dependent baseline of average behaviour, referred to as an average profile. Extensions have been proposed for the application of statistical methods for the acquisition of standard patterns of diarrhoeal behaviour. Numerical low pass filtering the signal allows a dichotomization of cases, the significance of which is confirmed by differences of class average profiles. Removing the class average profile from the records shows that the majority of cases exhibit consistent individual signal patterns; standardized patterns of behaviour can also be discussed. It is tentatively concluded that objective specification of normal and abnormal defaecation behaviour could be based on spontaneous patterns identified in the records. Several methods have been suggested. Methods similar to those applied here would appear, on the evidence of this study, to be applicable to a variety of other longitudinal epidemiological studies.