Subthreshold newborn phototherapy limits readmissions for that treatment

Last Updated: 2018-02-26

By Will Boggs MD

NEW YORK (Reuters Health) - Subthreshold newborn phototherapy can reduce the number of readmissions for phototherapy, but as many as 60 newborns could require treatment to prevent 1 readmission, according to a retrospective study.

"I was surprised by how many babies needed to be treated with phototherapy during the birth hospitalization to prevent one from being readmitted," Dr. Andrea C. Wickremasinghe from Kaiser Permanente Santa Clara Medical Center, in California, told Reuters Health by email. "In our unit, we avoid administering phototherapy at bilirubin levels below the phototherapy threshold."

Many clinicians use phototherapy for newborns with total serum bilirubin levels (TSB) below established thresholds in order to prevent future readmissions for hyperbilirubinemia and their associated copays and inconvenience to parents. Whether such subthreshold phototherapy has a favorable risk-benefit profile remains unclear.

Dr. Wickremasinghe's team used data from 16 Kaiser Permanente Northern California hospitals to estimate the efficacy of using phototherapy to treat newborns with TSB levels from 0.1 to 3.0 mg/dL below the appropriate phototherapy threshold during the birth hospitalization, with the goal of preventing readmissions for phototherapy.

Among the 25,895 newborns with TSB levels 0.1 to 3.0 mg/dL below threshold, 19.1% received subthreshold phototherapy during the birth hospitalization and 11.3% were readmitted for phototherapy.

The mean length of hospital stay, after adjustment for other factors, was nearly 1 day longer (22 hours) for newborns who received subthreshold phototherapy than for those who did not, according to the February 26 JAMA Pediatrics online report.

Significantly fewer newborns that received subthreshold phototherapy (4.9%) than not treated (12.8%) were readmitted for phototherapy. After multivariable adjustment, this represented a 72% decrease, but the overall number needed to treat (NNT) to avoid 1 readmission was 14.1.

Factors associated with increased odds of readmission for phototherapy included male sex, lower gestational age, Asian race/ethnicity, assisted vaginal delivery, family history of phototherapy, a qualifying TSB level closer to the phototherapy threshold, lower chronological age at the time of the qualifying TSB level, and exclusive breastfeeding.

In contrast, low birth weight, cesarean delivery, direct antiglobulin test (DAT) positivity, and home phototherapy were associated with decreased odds of readmission for phototherapy.

The NNT to avoid 1 readmission varied widely according to the newborn's estimated risk of readmission based on these other factors, from 6.3 for those in the highest quintile of risk to 60.8 for those in the lowest quintile of risk.

Subthreshold phototherapy during the birth hospitalization also lowered the odds of having a TSB level at or above the phototherapy threshold after discharge.

"Phototherapy should be considered a treatment, with the potential for both risks and benefits," Dr. Wickremasinghe concluded. "Don't use phototherapy for low-risk infants with bilirubin levels below the phototherapy threshold."

"Although limited information on the clinical course of those newborns who were readmitted was provided, it is very likely that the costs of initiating phototherapy for all the infants treated at subthreshold levels were substantially higher than the costs of readmitting the group of infants with similar TSB levels during their birth hospitalization who weren't treated initially," write Dr. James A. Taylor and Dr. Pearl W. Chang from University of Washington, Seattle, in a related editorial.

The study "should give all of us who care for newborns pause," the editorial concludes. "Their results provide testimony that, in our quest to provide the safest and best care possible to a population of patients who are overwhelmingly healthy, we may get on the slippery slope and treat increasingly more newborns needlessly. If a large number of healthy babies are exposed to unnecessary care, the cumulative risks of overtreatment, even if the treatment is as benign as phototherapy, might outweigh the risks of undertreatment and, paradoxically, lead to worse care."

SOURCES: http://bit.ly/2t1C2fG and http://bit.ly/2GKR1wj

JAMA Pediatr 2018.