Assessing the impact of potentially influential observations in weighted logistic regression

Influential observations in logistic regression are those that have a notable effect on certain aspects of the model fit. Large sample size alone does not eliminate this concern; it is still important to examine potentially influential observations, especially in complex survey data. This paper describes a straightforward algorithm for examining potentially influential observations in complex survey data using SAS software. This algorithm was applied in a study using the 2005 Canadian Community Health Survey that examined factors associated with family physician utilization for adolescents.