Conceptual and technical considerations when combining large data sets

Secondary analysis provides a useful method for the development of new know ledge. Larger samples can be constructed and secondary analysis can be enha nced when data sets are combined. A standardized method for combining large data sets is crucial yet literature on methods for combining large data se ts for secondary analysis is lacking. The purpose of this article is to out line and explain the process of combining two or more large data sets (n = 276, n = 125)for secondary analysis by using these authors' previous work w ith large oncology and AIDS care-giver data sets.