Most epidemiologists use the Poisson model for deaths. In the old days we used it (and a slide rule) to calculate the standard errors of death rates and indirect standard mortality ratios. Now you can get exact limits from the Internet and Poisson regression analysis has made multivariate analyses of mortality and incidence data possible. It seems reasonable to ask who first introduced the mode...

Multivariate longitudinal data are common in medical, industrial and social science research. However, statistical analysis of such data in the current literature is restricted to linear or parametric modeling, which is inappropriate for applications in which the assumed parametric models are invalid. On the other hand, all existing nonparametric methods for analyzing longitudinal data are for ...

To date, most genetic analyses of phenotypes have focused on analyzing single traits or, analyzing each phenotype independently. However, joint epistasis analysis of multiple complementary traits will increase statistical power, and hold the key to understanding the complicated genetic structure of the complex diseases. Despite their importance in uncovering the genetic structure of complex tra...

Educational level is most often used to identify social groups with increased prevalence of smoking. Other indicators of socioeconomic position (SEP) might, however, be equally or even more discriminatory. This study examined the extent to which smoking behavior is related to other socioeconomic indicators in addition to educational level. Data were derived from the European Household Panel. We...

CONTEXT Given that many communities are implementing community-wide initiatives to reduce teenage pregnancy or childbearing, it is important to understand the effects of a community's characteristics on adolescent birthrates. METHODOLOGY Data from the 1990 census and from California birth certificates were obtained for zip codes in California. Regression analyses were conducted on data from z...

BACKGROUND Increasing evidence suggests that patient safety is a serious concern for older patients with long-term conditions. Despite this, there is a lack of research on safety incidents encountered by this patient group. In this study, we sought to examine patient reports of safety incidents and factors associated with reports of safety incidents in older patients with long-term conditions. ...

We consider panel count data which are frequently obtained in prospective studies involving recurrent events that are only detected and recorded at periodic assessment times. The data take the form of counts of the cumulative number of events detected at each inspection time, along with explanatory covariates. Examples arise in diverse areas such as epidemiological studies, medical follow-up st...

(Note that this is technically a regression hyperplane, not a regression line.) This model is estimated by choosing estimates β̂0, ..., β̂p to minimize sum of squared residuals, ∑n i=1(yi − (β̂0 + β̂1x1i + ... + β̂pxpi)). In this model, β̂j is the estimated expected change in the response variable associated with a one-unit change in the j predictor, holding all the other predictors constant (this is...

Multivariate adaptive regression splines (MARS) are a useful tool to identify linear and nonlinear effects and interactions between two covariates. In this dissertation a new proposal to model survival type data with MARS is introduced. Martingale and deviance residuals of a Cox PH model are used as response in a common MARS approach to model functional forms of covariate effects as well as pos...