Medication use is recognized as the least expensive, most cost-effective health care intervention. In older adults this is especially important, as they are the largest consumer of prescription medications. We describe the use of a linked data set including pharmaceutical, medical, and hospital claims to examine pharmaceutical use in the population of older adults and then give several examples of its application. Indicators to describe the population's overall use of medication and the appropriate use of specific medication have been developed. Indicators of appropriate use are characterized using the dispensation of benzodiazepines to older adults. We have found that a significant proportion of new users of benzodiazepines are still prescribed a long-acting version (over 10%), signifying potential inappropriate use. The data are also able to describe some significant outcomes from the use of pharmaceuticals such as death, fracture, and population-based clinical measures where available.