This article caught my eye, because the authors were reporting on how often clinicians followed guidelines for ordering spinal ultrasonography on newborns with sacral dimples. The problem is, I'm not sure there is such a guideline.
Source: Wilson P, Hayes E, Barber A, et al. Screening for spinal dysraphisms in
newborns with sacral dimples. Clin Pediatr. 2016;55(11):1064-1070; doi:10.1177/0009922816664061. See AAP Grand Rounds commentary by Dr. Jonathan Mintzer (subscription required).
The authors looked back at newborns under 7 days of age who underwent spinal sonography at a single children's hospital over a 6 1/3 year period.* They ended up with 151 infants, of which 2 had tethered cords and 1 required neurosurgical intervention. Although both of them had simple sacral dimples, they also both had other anomalies that probably would have led to imaging studies. The authors' main point was that many infants with "simple" sacral dimples (single sacral dimple less than 5 mm in diameter and less than 25 mm from the anus) underwent imaging, and, according to guidelines, those infants shouldn't be imaged because they have such a low risk of having any important underlying defect.
The authors are absolutely correct that we are probably over-imaging newborn infants with sacral dimples, but where I differ from them is their use of the term "guideline." The article they refer to is actually a review article in Pediatrics in Review, that I would argue is not at all a practice guideline. Pediatrics in Review is a fine journal, but the articles published there do not have the rigor of practice guidelines which usually are based on a systematic review of the literature and an assessment, at least for diagnostic testing, of optimizing receiver operator characteristic (ROC) curves to determine the best yield for a testing strategy.
The article in Pediatrics in Review was written by 2 pediatric neurosurgeons who I am sure are experts in their field, but all they are doing is presenting their own approach to the subject of imaging of sacral dimples, as part of a standard review article. Review articles are like textbook chapters - written presumably by experts in the field who provide their own view of a subject. However, that approach is subject to bias in that the authors are free to pick whatever articles they feel support their approach. This is very different from a systematic review, where researchers perform a more precise research study where articles are chosen for inclusion only if they meet certain quality standards. Many features of a systematic review (and its mathematical cousin, meta-analysis) are intended to minimize bias. It is somewhat misleading to elevate what is essentially a nice review article into the status of a practice guideline.
Thus, I think it's a little unfair for the authors of the present study to state that "guidelines need revision," when in fact we don't really have guidelines for sacral dimple management. The current study shows that the practice at their institution likely can be improved, but more precise and preferably prospective studies are needed to develop high-quality guidelines.
By the way, a good place to start in looking for guidelines on any subject is the National Guideline Clearinghouse from the Agency for Healthcare Research and Quality. I couldn't find any sacral dimple guidelines listed there.
*An odd time interval for a study always raises my eyebrows a bit. I suspect the authors picked this time period for convenience - maybe the start of use of a new electronic medical records system, coupled with an end point to make sure a trainee finished the study prior to finishing his/her training program in June of the next year. It probably isn't an issue here, but would be if studying a condition where seasonality is important, such as influenza or rotavirus infections.
