A study conducted by the Boston University School of Public Health says Missourians spend a bigger percentage of their incomes on prescription drugs than residents of all but five other states. The study says average drug spending in Missouri reached nearly 2.5-percent of personal income in 2002, a huge jump from four years ago. Spending per person in Missouri was 29-percent above the national average. Tennessee fared the worst in the study, which says residents there spend slightly more than three percent of their income filling prescriptions. The study’s authors advocate governmental intervention to place a cap on drug prices.