OBJECTIVE Increasing numbers of substance users report simultaneous alcohol and marijuana (SAM) use such that their effects overlap. More research is needed to understand what motivates this behavior, especially to inform interventions that address SAM use. A 26-item measure of SAM motives was designed and tested in previous research. The purpose of the current study was to validate that measure and create a briefer version of it. METHOD Using two waves of data from a multi-site sample of college students (n = 1,014), exploratory and confirmatory factor analyses were conducted to develop a brief 11-item SAM Motives Measure (B-SMM). Negative binomial regression analyses were conducted to assess the reliability and validity of both the original and brief measures. RESULTS The brief measure contains four subscales (conformity, positive effects, calm/coping, and social) that match the empirically supported motivational model of substance use. Internal consistency of the subscales ranged from .77 to .87. Most subscales significantly predicted frequency and consequences of SAM use both concurrently and prospectively. CONCLUSIONS The psychometrically sound measure developed in this study facilitates the examination of SAM motives in clinical settings with time-constrained patient contact and can be valuable for research involving frequent and repeated measures of substance use behaviors.

中文翻译：

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同时使用酒和大麻：动机的简要衡量

目的越来越多的物质使用者报告同时使用酒精和大麻（SAM），以致其作用重叠。需要更多的研究来了解是什么促使这种行为，尤其是为解决SAM使用问题的干预措施提供信息。在先前的研究中，设计并测试了26个项目的SAM动机。当前研究的目的是验证该度量并创建一个简短的版本。方法利用来自多地点大学生（n = 1,014）的两波数据，进行探索性和验证性因素分析，以制定一个简短的11项SAM动机测度（B-SMM）。进行了负二项式回归分析，以评估原始和简短度量的可靠性和有效性。结果简要测量包含四个子量表（合格，积极影响，冷静/应对和社交），以符合经验支持的物质使用动机模型。量表的内部一致性范围从0.77到0.87。大多数次级量表均能有效地预测SAM的同时使用和预期使用的频率和后果。结论在这项研究中开发的从心理上合理的措施有助于在时间受限的患者接触中检查临床环境中的SAM动机，这对于涉及频繁和反复测量物质使用行为的研究可能是有价值的。