Department of Addictology, 1st Faculty of Medicine, Charles University in Prague and General Teaching Hospital in Prague, Prague, Czech Republic.
French Monitoring Centre for Drugs and Drug Addiction, Paris, France.
Drug Alcohol Rev. 2020 Mar;39(3):278-286. doi: 10.1111/dar.13036. Epub 2020 Feb 20.
New psychoactive substances (NPS) represent hundreds of novel compounds. However, the general public might not be familiar with the overarching term NPS. This can result in both under- and over-reporting of NPS use.
The study analysed the last-year prevalence of NPS use in an online survey conducted across I-TREND project countries (the Czech Republic, the Netherlands and Poland). Self-reported NPS use was assessed within two types of questions-a generic and a checklist question. We analysed prevalence for each question separately, incorporated the free-text probe 'other' that followed them, and combined the two questions into a conservative and an inclusive estimate.
Including free-text responses to the 'other' categories increased prevalence of NPS use (from 51% to 56% for the checklist question and 25% to 32% for the generic question). Taking an inclusive approach to estimating prevalence (i.e. indicating NPS use in either a generic list or from the checklist) yielded a higher prevalence estimate (60%, 95% confidence interval 58-62%), compared to a more conservative approach in which NPS use had to be affirmed by both questions (27%, 95% confidence interval 26-29%).
Generic questions might lead to notably lower estimates of self-reported NPS use in comparison to checklists. However, creating relevant checklists is challenging and lengthy survey instruments have limitations. Further surveys might benefit from featuring a combination of the strategies used in this study-a single (generic) question involving a number of locally specific NPSs and a free-text 'other' probe.
新精神活性物质（NPS）代表了数百种新型化合物。然而，普通大众可能并不熟悉 NPS 这一总称。这可能导致 NPS 使用的报告不足或过度。
本研究分析了 I-TREND 项目国家（捷克共和国、荷兰和波兰）进行的在线调查中过去一年 NPS 使用的流行率。自我报告的 NPS 使用情况在两种类型的问题中进行评估——通用问题和清单问题。我们分别分析了每个问题的流行率，纳入了紧随其后的自由文本探针“其他”，并将两个问题结合成保守和包容的估计。
包括对“其他”类别的自由文本回复增加了 NPS 使用的流行率（清单问题从 51%增加到 56%，通用问题从 25%增加到 32%）。采用包容性方法估计流行率（即在通用列表中或从清单中表明使用 NPS）会产生更高的估计值（60%，95%置信区间 58-62%），而采用更保守的方法，即只有两个问题都肯定 NPS 使用时，流行率估计值才更高（27%，95%置信区间 26-29%）。
与清单相比，通用问题可能导致自我报告的 NPS 使用估计明显较低。然而，创建相关的清单具有挑战性，并且冗长的调查工具具有局限性。进一步的调查可能受益于结合本研究中使用的策略——一个包含一些本地特定 NPS 的单一（通用）问题和一个自由文本“其他”探针。
