Department of Economics and Econometrics, University of Notre Dame, Notre Dame, IN 46556, USA.
J Health Econ. 2010 Sep;29(5):657-73. doi: 10.1016/j.jhealeco.2010.07.005. Epub 2010 Aug 4.
We exploit the discontinuity in age when children start kindergarten generated by state eligibility laws to examine whether relative age is a significant determinant of ADHD diagnosis and treatment. Using a regression discontinuity model and exact dates of birth, we find that children born just after the cutoff, who are relatively old-for-grade, have a significantly lower incidence of ADHD diagnosis and treatment compared with similar children born just before the cutoff date, who are relatively young-for-grade. Since ADHD is an underlying neurological problem where incidence rates should not change dramatically from one birth date to the next, these results suggest that age relative to peers in class, and the resulting differences in behavior, directly affects a child's probability of being diagnosed with and treated for ADHD.
我们利用儿童开始上幼儿园的年龄临界点由州立资格法产生的不连续性，来检验相对年龄是否是 ADHD 诊断和治疗的重要决定因素。利用回归不连续性模型和确切的出生日期，我们发现，刚过截止日期出生的、相对年级较大的儿童，与刚在截止日期前出生的、相对年级较小的类似儿童相比，ADHD 诊断和治疗的发病率明显较低。由于 ADHD 是一种潜在的神经问题，发病率不应从一个出生日期到下一个出生日期有显著变化，因此这些结果表明，与同学相比的年龄，以及由此产生的行为差异，直接影响儿童被诊断和治疗 ADHD 的概率。
