BACKGROUND Single time-point assessments of psychological distress are often used to indicate chronic mental health problems, but the validity of this approach is unclear. The aims of this study were to investigate how a single assessment of distress relates to longer-term assessment and quantify misclassification from using single measures to indicate chronic distress. METHODS Data came from the Household, Income and Labour Dynamics in Australia Survey, a nationally representative study of Australian adults. Psychological distress, measured with the Kessler10 and categorised into low (scores:10- < 12), mild (12- < 16), moderate (16- < 22) and high (22-50), has been assessed in the Survey biennially since wave 7. Among respondents who were aged ≥25 years and participated in all waves in which distress was measured, we describe agreement in distress categories, and using a mixed linear model adjusting for age and sex we estimate change in scores, over a two-, four-, six- and eight-year follow-up period. We applied weights, benchmarked to the Australian population, to all analyses. RESULTS Two-years following initial assessment, proportions within identical categories of distress were 66.0% for low, 54.5% for mild, 44.0% for moderate and 50.3% for high, while 94.1% of those with low distress initially had low/mild distress and 81.4% with high distress initially had moderate/high distress. These patterns did not change materially as follow-up time increased. Over the full eight-year period, 77.3% of individuals with high distress initially reported high distress on ≥1 follow-up occasion. Age-and sex- adjusted change in K10 scores over a two-year period was 1.1, 0.5, - 0.7 and - 4.9 for low, mild, moderate and high distress, respectively, and also did not change materially as follow-up time increased. CONCLUSION In the absence of repeated measures, single assessments are useful proxies for chronic distress. Our estimates could be used in bias analyses to quantify the magnitude of the bias resulting from use of single assessments to indicate chronic distress.

中文翻译：

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通过单一措施确定长期的心理困扰：来自全国代表性的澳大利亚人口纵向调查的证据。

背景技术心理困扰的单个时间点评估通常用于指示慢性心理健康问题，但是这种方法的有效性尚不清楚。这项研究的目的是调查单一的痛苦评估与长期评估之间的关系，并通过使用单一的方法指示慢性困扰来量化误分类。方法数据来自澳大利亚家庭，收入和劳动力动态调查，该调查是澳大利亚成年人的全国代表性研究。使用凯斯勒（Kessler）10测得的心理困扰分为两年（低分（10- <12），轻度（12- <16），中度（16- <22）和高（22-50））。从第7浪起。在年龄≥25岁且参与了所有测量遇险的浪潮中的受访者中，我们描述了困扰类别中的共识，并使用针对年龄和性别进行调整的混合线性模型，在两年，四年，六年和八年的随访期内，估计分数的变化。我们将以澳大利亚人口为基准的权重应用于所有分析。结果初步评估后的两年，在相同类别的苦难中，低度苦恼的比例为66.0％，轻度为54.5％，中度为44.0％，高危为50.3％，而低度苦恼的患者中最初有低/轻度苦恼的比例为94.1％。最初有中度/重度痛苦的高危患者为81.4％。随着随访时间的增加，这些模式没有实质性的改变。在整个八年中，有77.3％的高危患者最初在≥1次随访中报告了高危。两年期间按年龄和性别调整的K10分数变化为1。低度，轻度，中度和高度困扰分别为1、0.5，-0.7和-4.9，并且随着随访时间的增加，也没有实质性的改变。结论在没有重复措施的情况下，单项评估是治疗慢性病的有用代理。我们的估计可以用于偏差分析中，以量化由于使用单一评估来表明长期困扰而产生的偏差的幅度。