34 - Finding the Balance: Optimizing Metabolic Bone Disease of Prematurity Detection

Publication Number: 4033.34

Lyndsay D. Long, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; Juyun Lee, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; Lynn M. Iwamoto, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; Emmanuel R.E.. Kling, Kapiolani Medical Center for Women and Children - - Honolulu, HI, Honolulu, HI, United States; Lauren K. Suzuki, Tufts University, Pearl City, HI, United States; Hana Trent, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; Leo Wu, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; Arlene Kiyohara, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States

Background: Very low birthweight (VLBW) and very preterm (VPT) infants are at high risk for metabolic bone disease of prematurity (MBDP). However, incidence rates and definitions vary widely. In 2021, our NICU implemented a protocol to standardize screening, diagnosis, and treatment. Although standardization is expected to enhance identification and improve outcomes, there may be unintended effects on other aspects of care.

Objective: To evaluate the impact of the screening protocol on the incidence of MBDP and resource utilization in at risk preterm infants in the NICU.

Design/Methods: This is a retrospective study, exempt from full IRB review. VPT (≤32 weeks gestation at birth) or VLBW (≤1500 grams birthweight) infants from before and after protocol implementation were compared (2018-2020 vs 2022-2024, respectively). Data collected included demographics, MBDP diagnosis, alkaline phosphatase (ALP) values, and radiographic evidence of demineralization. Infants who expired or transferred out were excluded, as were infants with congenital anomalies known to impact bone mineralization. ALP is not included in the routine laboratory order sets at the study hospital and must be ordered separately; therefore, it serves as an indicator of MBDP screening. Continuous variables were analyzed using t-tests, while chi-square analysis was used for categorical variables. P values < 0.05 were considered significant.

Results: No significant differences in BW or GA were observed between groups. As a result of the protocol, screening using ALP increased from 16% of VPT and VLBW patients in 2018-2020 to 81% in 2022-2024. This resulted in an increase in incidence of MBPD from 1.7 to 4.6 per 100 infants screened (p = 0.0105). Notably, many more patients had evidence of demineralization on radiographs than were diagnosed, 54/541 and 64/502 in the pre and post period, respectively (NS). 96% of those with the diagnosis of MBDP or radiographic changes were ≤30 weeks GA and < 1250g BW (Figure 1). The 3 exceptions had other risk factors that would prompt screening. Infants born at 31-32wga and 1250-1500g made up 11.3% of infants studied in 2022-2024, highlighting an opportunity to refine screening criteria to reduce blood draws and healthcare costs.

Conclusion(s): The implementation of a protocol to screen for MDBP in the NICU increased the level of awareness and identification of the disease. However, this also resulted in a significant increase in the number of ALP labs drawn. Results of this study suggest that narrowing the GA and BW risk population could increase efficiency of detection without missing cases.

Figure 1
Figure 1: Scatterplot of the gestational ages vs. birthweights of infants born VPT or VLBW at KMCWC in 2022 through 2024 with some evidence of demineralization on a radiograph during their NICU admission (n=87). 3 infants were >30w GA and >1250g BW (red circles). The 3 infants in this range did have additional risk factors that would prompt screening for MBDP.
⏶ Infants diagnosed with Metabolic Bone Disease of Prematurity (MBDP) (n = 23)
⏺ Infants with evidence of osteopenia on radiograph, not diagnosed with MBDP (n=64)