ABSTRACT

The choice of cortisol sampling times in early childhood studies varies widely. Given that recommendations on sampling protocols are largely based on adults, the present study aimed to broaden current knowledge by examining how reliably cortisol measures obtained at different daytimes would reveal between-individual differences in toddlers’ cortisol levels. Parents were instructed to take 10 saliva samples consecutively (five per day) from their toddler (N = 19; M_age = 15.8 months, SD_age = 4.2 months). Intra-class correlations (ICCs) were computed to evaluate cortisol reliability. Cortisol samples taken in the morning between 30 and 80 min after awakening and bedtime samples were most reliable in differentiating between children (ICCs ≥ .80). Wake-up cortisol samples taken within the first 30 min after awakening and afternoon samples showed moderate reliabilities (ICCs = .64), whereas the reliability of noon samples was poor (ICC = .43). Therefore, when investigating cortisol in young children while being restricted to a few samples only, assessing cortisol in the morning (at least 30 min after awakening) and at bedtime would be advisable.

摘要

儿童早期研究中皮质醇采样时间的选择差异很大。鉴于有关采样方案的建议主要基于成人，本研究旨在通过检查在不同白天获得的皮质醇测量值如何可靠地揭示幼儿皮质醇水平的个体差异来扩大当前知识。父母被要求从他们蹒跚学步的孩子身上连续采集 10 个唾液样本（每天 5 个）（N = 19；M_年龄 = 15.8 个月，SD_年龄 = 4.2 个月）。计算类内相关性 (ICCs) 以评估皮质醇的可靠性。早上醒来后 30 到 80 分钟采集的皮质醇样本和睡前样本在区分儿童方面最可靠（ICC ≥ .80）。在醒来后的前 30 分钟内采集的唤醒皮质醇样本和下午的样本显示出中等的可靠性（ICC = .64），而中午样本的可靠性很差（ICC = .43）。因此，在仅限于少数样本的情况下调查幼儿的皮质醇时，建议在早上（至少在醒来后 30 分钟）和睡前评估皮质醇。