Development of a Cannabis Assessment Tool (CAT-1) to measure current and lifetime marijuana use among older Veterans

OBJECTIVE: To develop a tool to assess current (past 30 days) and lifetime marijuana use in older Veterans. SETTING: US Veteran’s Affairs Healthcare System. PARTICIPANTS: 704 older Veterans were screened, 339 completed the initial survey, 100 completed the follow-up. PRIMARY OUTCOME MEASURE: Pearson’s correlation coefficient to assess strength of association between initial and follow-up survey on measures of current and lifetime marijuana use. RESULTS: Both a ‘gram-month’ measure of marijuana smoked in the past 30 days (r=0.83) and a frequency-based measure assessing total number of times smoked in the past 30 days were reliable (r=0.89). Both a simple categorical measure of lifetime use (agreement=85%) and a continuous measure of lifetime use (r=0.82) were reliable. CONCLUSIONS: The Cannabis Assessment Tool offers a reliable assessment of past 30 days and lifetime assessments of smoking cannabis in older adults.