A search algorithm for identifying likely users and non-users of marijuana from the free text of the electronic medical record.

BACKGROUND: The harmful effects of marijuana on health and in particular cardiovascular health are understudied. To develop such knowledge, an efficient method of developing an informative cohort of marijuana users and non-users is needed. METHODS: We identified patients with a diagnosis of coronary artery disease using ICD-9 codes who were seen in the San Francisco VA in 2015. We imported these patients' medical record notes into an informatics platform that facilitated text searches. We categorized patients into those with evidence of marijuana use in the past 12 months and patients with no such evidence, using the following text strings: "marijuana", "mjx", and "cannabis". We randomly selected 51 users and 51 non-users based on this preliminary classification, and sent a recruitment letter to 97 of these patients who had contact information available. Patients were interviewed on marijuana use and domains related to cardiovascular health. Data on marijuana use collected from the medical record was compared to data collected as part of the interview. RESULTS: The interview completion rate was 71%. Among the 35 patients identified by text strings as having used marijuana in the previous year, 15 had used marijuana in the past 30 days (positive predictive value = 42.9%). The probability of use in the past month increased from 8.8% to 42.9% in people who have these keywords in their medical record compared to those who did not have these terms in their medical record. CONCLUSION: Methods that combine text search strategies for participant recruitment with health interviews provide an efficient approach to developing prospective cohorts that can be used to study the health effects of marijuana.

Nicotine dependence, abuse and craving: dimensionality in an Israeli sample.

AIMS: Evidence-based changes planned for Diagnostic and Statistical Manual 5th edition (DSM-5) substance use disorders (SUDs) include combining dependence and three of the abuse criteria into one disorder and adding a criterion indicating craving. Because DSM-IV did not include a category for nicotine abuse, little empirical support is available for aligning the nicotine use disorder criteria with the DSM-5 criteria for other SUDs. DESIGN: Latent variable analyses, bootstrap tests and likelihood ratio tests were used to explore the unidimensionality, psychometric properties and information of the nicotine criteria. SETTING AND PARTICIPANTS: A sample of household residents selected from the Israeli population register yielded 727 life-time cigarette smokers. MEASUREMENTS: DSM-IV nicotine dependence criteria and proposed abuse and craving criteria, assessed with a structured interview. FINDINGS: Three abuse criteria (hazardous use, social/interpersonal problems and neglect roles) were prevalent among smokers, formed a unidimensional latent trait with nicotine dependence criteria, were intermixed with dependence criteria across the severity spectrum and significantly increased the diagnostic information over the dependence-only model. A craving criterion was shown to fit well with the other criteria. CONCLUSION: Similar to findings from research on other substances, nicotine dependence, abuse and craving criteria appear to derive from a common underlying dimension. The results support alignment of nicotine criteria with those for alcohol and drug use disorders in Diagnostic and Statistical Manual 5th edition.