Evaluating cannabis exposure in survey items: Insights, strategies, and remaining challenges identified from cognitive interviewing

•Recall difficulty on survey items varied with participant's use frequency.•Difficulties emerged in reporting quantity of cannabis used over the past 7 days.•Few issues were found with comprehension of items key to reporting THC exposure.•Responses revealed several cannabis products previously unaddressed in the survey.•Survey items were modified to address points of ambiguity identified in interviews. The diversity in characteristics of cannabis products and behavior patterns make evaluation of cannabis exposure in population-based, self-report surveys challenging. Accurate identification of cannabis exposure and related outcomes necessitates a thorough understanding of participants’ interpretations of survey questions assessing cannabis consumption behaviors. The current study utilized cognitive interviewing to gain insight on participants’ interpretation of items in a self-reported survey instrument used to estimate the quantity of THC consumed in population samples. Cognitive interviewing was used to evaluate survey items assessing cannabis use frequency, routes of administration, quantity, potency, and perceived “typical patterns” of use. Ten participants ≥18 years (n = 4 cisgender-men; n = 3 cisgender-women; n = 3 non-binary/transgender) who had used cannabis plant material or concentrates in the past week were recruited to take a self-administered questionnaire and subsequently answer a series of scripted probes regarding survey items. While most items presented no issues with comprehension, participants identified several areas of ambiguity in question or response item wording or in visual cues included in the survey. Generally, participants with irregular use patterns (i.e., non-daily use) reported more difficulty recalling the time or quantity of cannabis use. Findings resulted in several changes to the updated survey, including updated reference images and new quantity/frequency of use items specific to the route of administration. Incorporating cognitive interviewing into cannabis measurement development among a sample of knowledgeable cannabis consumers led to improvements in assessing cannabis exposure in population surveys, which may otherwise have been missed.