Choice of Diffusing Capacity Hemoglobin Correction Equation and
Prediction of Mortality and Pulmonary Outcomes in Children Receiving
Hematopoietic Stem Cell Transplantation
Abstract
Objectives: The objective of this study is to compare the Dinakara and
Cotes equations in their ability to predict post hematopoietic stem cell
transplant (HSCT) pulmonary complications and mortality. Hypothesis We
hypothesize the pre-transplant diffusing capacity adjusted for
hemoglobin (DLCOHgb) by the Cotes equation in pediatric patients
undergoing HSCT will predict morbidity and mortality more accurately
than the Dinakara equation. Study-Design: Data was collected
retrospectively from chart review of patients who underwent their first
HSCT at Riley Hospital for Children using a database maintained by the
Pediatric Stem Cell Transplant Program. Patient-Subject Selection:
Patients who performed pre-transplant diffusing capacity for carbon
monoxide (DLCO) that met ATS criteria, and a hemoglobin recorded within
7 days of their pulmonary function testing were included. Methodology:
Paired t-tests and ANOVA models were used to define any differences
between the two equations at baseline and when stratifying by hemoglobin
level. Logistic regression models were used to determine associations
between the Dinakara and Cotes equation with mortality at one- and
three-years post-transplant. Results: 90 patients underwent HSCT during
the study period, and 69 patients met inclusion criteria. Odds ratios
for mortality using DLCO corrected for the Dinakara (1.08 SD 0.98-1.19)
and Cotes (1.09 SD 0.97-1.22) were similar (p-value >
0.05). Neither Dinakara or Cotes corrective equation was superior at
predicting pulmonary complications. (p-values 0.1388 and 0.5246
respectively) Conclusions: The Dinakara and Cotes equations differed in
their calculation of DLCOHgb at lower Hb levels, their ability to
predict mortality and pulmonary complications after HSCT was not
different.