Clinicians diagnosing autism rely on diagnostic criteria and instruments in combination with an implicit knowledge based on clinical expertise of the specific signs and presentations associated with the condition. This implicit knowledge influences how diagnostic criteria are interpreted, but it cannot be directly observed. Instead, insight into clinicians’ understanding of autism can be gained by investigating their diagnostic certainty. Modest correlations between the certainty of an autism diagnosis and symptom load have been previously reported. Here, we investigated the associations of diagnostic certainty with specific items of the ADOS as well as other clinical features including head circumference. Phenotypic data from the Simons Simplex Collection was used to investigate clinical correlates of diagnostic certainty in individuals diagnosed with Autistic Disorder (n = 1511, age 4 to 18 years). Participants were stratified by the ADOS module used to evaluate them. We investigated how diagnostic certainty was associated with total ADOS scores, age, and ADOS module. We calculated the odds-ratios of being diagnosed with the highest possible certainty given the presence or absence of different signs during the ADOS evaluation. Associations between diagnostic certainty and other cognitive and clinical variables were also assessed. In each ADOS module, some items showed a larger association with diagnostic certainty than others. Head circumference was significantly higher for individuals with the highest certainty rating across all three ADOS modules. In turn, head circumference was positively correlated with some of the ADOS items that were associated with diagnostic certainty, and was negatively correlated with verbal/nonverbal IQ ratio among those assessed with ADOS module 2. The investigated cohort was heterogeneous, e.g. in terms of age, IQ, language level, and total ADOS score, which could impede the identification of associations that only exist in a subgroup of the population. The variability of the certainty ratings in the sample was low, limiting the power to identify potential associations with other variables. Additionally, the scoring of diagnostic certainty may vary between clinicians. Some ADOS items may better capture the signs that are most associated with clinicians’ implicit knowledge of Autistic Disorder. If replicated in future studies, new diagnostic instruments with differentiated weighting of signs may be needed to better reflect this, possibly resulting in better specificity in standardized assessments.

中文翻译：

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患有自闭症的儿童和青少年诊断确定性的临床相关性

诊断自闭症的临床医生依赖于诊断标准和仪器，以及基于与该病症相关的特定体征和表现的临床专业知识的隐性知识。这种隐性知识会影响诊断标准的解释方式，但无法直接观察到。相反，可以通过调查诊断的确定性来深入了解临床医生对自闭症的理解。先前已经报道过自闭症诊断的确定性与症状负荷之间的适度相关性。在这里，我们研究了诊断确定性与 ADOS 特定项目以及包括头围在内的其他临床特征的关联。来自 Simons Simplex Collection 的表型数据用于调查诊断患有自闭症的个体（n = 1511，年龄 4 至 18 岁）的诊断确定性的临床相关性。参与者根据用于评估的 ADOS 模块进行分层。我们研究了诊断确定性与 ADOS 总分、年龄和 ADOS 模块之间的关系。考虑到 ADOS 评估期间是否存在不同体征，我们计算了以尽可能高的确定性进行诊断的优势比。还评估了诊断确定性与其他认知和临床变量之间的关联。在每个 ADOS 模块中，某些项目比其他项目显示出与诊断确定性更大的关联。在所有三个 ADOS 模块中具有最高确定性评级的个体的头围显着更高。反过来，头围与一些与诊断确定性相关的 ADOS 项目呈正相关，并且与使用 ADOS 模块 2 评估的人的语言/非语言 IQ 比率呈负相关。研究的队列具有异质性，例如在年龄方面、智商、语言水平和 ADOS 总分，这可能会妨碍识别仅存在于人口亚组中的关联。样本中确定性评级的变异性较低，限制了识别与其他变量的潜在关联的能力。此外，临床医生之间的诊断确定性评分可能有所不同。一些 ADOS 项目可能会更好地捕捉与临床医生对自闭症的隐性知识最相关的迹象。如果在未来的研究中重复，可能需要具有不同体征权重的新诊断工具来更好地反映这一点，从而可能导致标准化评估具有更好的特异性。