as canada's population ages, the proportion of the population that is taking multiple medications will increase. a way to limit the number of adverse drug reactions for those on multiple medications is to have their medication regime reviewed by a health professional regularly. the current study utilizes both traditional and mixed linear analyses to examine the relationship between the lack of medication review and a number of health outcome measures on a dataset containing 76 810 subjects. the results indicate that differences exist for those who have not had their medications reviewed, clustering effects are significant, and the health outcome measures examined are influenced by whether or not one has received a medication review in the last 6 months.