EVIDENCE-BASED ANSWER
There is adequate evidence for screening neonates for hemoglobinopathies, congenital hypothyroidism, phenylketonuria (strength of recommendation [SOR]: A), and cystic fibrosis (SOR: B). Vision screening should be done for those younger than age 5 years (SOR: B). High-risk children should be tested for tuberculosis (TB) (SOR: B) and lead toxicity (SOR: B). Few data exist to guide frequency and timing of these screening tests, so the following timing recommendations are based on consensus opinion (SOR: C): test for visual acuity yearly starting at age 3 years; test for TB and lead once between the ages of 9 and 12 months, and repeat for high risk or exposure.
CLINICAL COMMENTARY
Obtain family history; order additional screening tests if history suggests them
Vince WinklerPrins, MD, FAAFP
Michigan State University, East Lansing
Why do states differ so much in the neonatal screening tests that they routinely perform? Some states screen for only a few genetic diseases, others for more than 40. Most states do neonatal hearing screening despite limited evidence of utility, while only one quarter of all states have neonatal cystic fibrosis screening programs, a condition for which there is probably better evidence for screening. While we might like to think that good science alone would dictate screening policy, the economic circumstances of each state, variable interpretation/quality of the research reviewed, and legislative priorities (among many reasons) probably play at least as much a roll. For any test, its accuracy is only as good as the pretest probability of the disease for which it is being used. Our yield for cystic fibrosis screening will be higher in families with a history of cystic fibrosis. This is the key point—you still need to obtain a family history and order additional screening tests if the history suggests them.
Evidence summary
There are many opinions and recommendations about what constitutes quality health surveillance for children. However, many screening tests for children lack evidence of effectiveness and information on harms.1 The scope of this question required use of evidence published in high-quality systematic reviews. The US Preventive Services Task Force (USPSTF) provides the most rigorous evidence on which to base recommendations.2 Medline was searched for any additional individual studies of interest. The USPSTF has conducted reviews for selected screening tests for children; the TABLE summarizes those with sufficient evidence to recommend them. We identified 1 additional evidence-based recommendation from the Centers for Disease Control and Prevention. This report, based on a systematic review, recommends cystic fibrosis screening in neonates based on moderate benefits and low risks of harm.3
The TABLE summarizes the evidence supporting universal childhood screening for hemoglobinopathies, congenital hypothyroidism, phenylketonuria, and visual defects; and high-risk childhood screening for tuberculosis and lead toxicity. The TABLE also lists the recommendations from the American Academy of Pediatrics (AAP) on frequency and timing of screening as guided by consensus opinion.
The USPSTF recommendations supporting screening for hemoglobinopathies, congenital hypothyroidism, and phenylketonuria are considered standard of care. The USPSTF believes that updating these 1996 recommendations would have little impact on clinical practice.
The USPSTF recommendations supporting vision screening found no direct evidence supporting screening for visual acuity. One fair-quality controlled study (N=3490) showed a decreased prevalence of amblyopia in the screened group and evidence that treatment of amblyotic risk factors prevents amblyopia. A Cochrane review of this topic showed insufficient evidence for visual screening of older (school-aged) children; for amblyopia, no data sufficient for analysis was found.4,5
The USPSTF recommendation to screen asymptomatic high-risk children for TB is based on the effectiveness of early intervention (14 controlled trials) and the accuracy of the Mantoux test.
TABLE
US Preventive Services Task Force evidence-supported testing for children
| TEST(SOR) | POPULATION | USPSTF COMMENTS | AAFP | AAP |
| UNIVERSALSCREENING | ||||
| Neonatal hemoglobinopathy (A) | Newborns | Strongly recommends | Recommends once at 2 to 4 days of life, but before age 1 month | |
| Neonatal phenylketonuria (A) | Newborns—repeat at 2 weeks if <24 hrs old at discharge | Strongly recommends | ||
| Congenital hypothyroidism (A) | Newborns | Strongly recommends | ||
| Vision screening for strabismus, amblyopia, and refractive error (B) | Before age 5 | Type of screening tests vary with age; evidence inadequate to recommend specific test | Recommends | Start objective testing yearly at age 3 |
| HIGH-RISK SCREENING | ||||
| PPD test for tuberculosis (A) | Children at high-risk for TB | Risks for TB: HIV,close contacts of persons with TB, immigrants from countries with high TB prevalence, low income populations, and residents of long-term care facilities | Strongly recommends screening high-risk Children | Screen high-risk children at 12 months and or upon recognition of high-risk factors |
| Lead toxicity (B)* | Infants at risk at 12 months of age at risk for lead exposure | Risks for lead† | Screen infants at high risk | Screen high-risk infants at 9 to 12 months. Repeat at age 24 months for those at high-risk |
| * This document is currently being updated; the recommendation may or may not change. | ||||
| † Risk are living in a house older than 1950 with peeling paint or remodeling, living near heavy traffic or lead industry, living with someone who has elevated lead levels or whose job/hobby involves lead exposure, using lead-based pottery, or taking remedies that contain lead. | ||||
| AAFP: American Academy of Family Practice recommendations from: www.aafp.org/PreBuilt/RCPS_August2005.pdf. | ||||
| AAP: American Academy of Pediatrics recommendations from: aappolicy.aappublications.org/cgi/content/full/pediatrics;105/3/645. | ||||