Despite their convenience and low cost, , a systematic review and meta-analysis reports in JAMA Pediatrics. Lauren E.H. Westenberg, MD, of the division of neonatology at Erasmus MC Sophia Children’s Hospital in Rotterdam, the Netherlands, and colleagues reported that POC meters tended to underestimate neonatal bilirubin levels, compared with conventional laboratory-based quantification.
A.H. Westenberg
Dr. Lauren E.H. Westenberg
Furthermore, pooled estimates from 10 studies found these devices to be too imprecise overall, with substantial outer-confidence bounds. On the plus side, Dr. Westenberg’s group said POC bilirubin testing was as much as 60 times faster than lab measurement, and used 40-60 times less blood. “Conventional laboratory-based bilirubin quantification usually requires up to 500 mcL, but sometimes even 1,500 mcL, while POC tests require up to 50 mcL, which means less stress for the baby,” Dr. Westenberg said in an interview. “Especially when infants are cared for at home, it usually takes a few hours between deciding to quantify bilirubin and obtaining the test result. Meanwhile, bilirubin levels may rise unnoticed.”
On the positive side, POC devices are useful where laboratories in low-resource areas may be remote, poorly equipped, and not always able to provide an accurate bilirubin level. “As a result, the diagnosis of jaundice relies mainly on visual inspection, which is known to be unreliable,” she said. POC devices, however, need near-perfect conditions for optimal use, and results can be affected by humidity, preanalytic conditions such as test strip saturation, and hematocrit.
Yet results from these devices have recently proven to have acceptable accuracy, resulting, for example, in the same clinical decisions as the reference standard in 90.7% of times according to a 2022 study in a hospital in Malawi.
Nevertheless, the authors concluded that the devices’ imprecision limits their widespread use in neonatal jaundice management, especially when accurate lab-based bilirubin quantification is available. Results from these POC tests should be interpreted with caution, Dr. Westenberg said. In terms of clinical decision-making, POC devices entail a risk of missing neonates with jaundice who need phototherapy or, in the case of overestimation, of starting phototherapy too early.
The study
The meta-analysis included nine cross-sectional and one prospective cohort study representing 3,122 neonates in Europe, Africa, and East and Southeast Asia. Two tests with 30-minute turnaround times were evaluated in neonates 0-28 days old. The Bilistick device was evaluated in eight studies and the BiliSpec (now called BiliDX) in just two studies. Three of the studies had a high risk of bias.
A total of 3,122 measurements paired with lab quantification showed a pooled mean difference in total bilirubin levels for the POC devices of –14 micromol/L, with pooled 95% confidence bounds (CBs) of –106 to 78 micromol/L. For the Bilistick, the pooled mean difference was –17 micromol/L (95% CBs, –114 to 80 micromol/L). Of the two devices, the Bilistick was more likely to have a failed quantification against the reference standard.