Statistical Analysis Plan
Numerical summaries for continuous demographic variables were reported
with medians and IQR (interquartile range, 75% th - 25% th) and
frequencies and percentages for categorical variables. Demographic,
baseline disease, disease complication, and treatment variables between
SCD genotype groups and weight status groups were compared using
Chi-square tests or Fisher’s exact test with Monte Carlo estimates for
categorical variables and Kruskal–Wallis tests for continuous
variables. The weight status of patients with SCD at UMMC, who were
10-17 years, was compared to state and national proportions of 10-17
year olds from the 2016-2017 National Survey of Children’s Health using
two-sample tests of proportion. Variables that were found to be related
to weight status (p < 0.10) were identified as
potential risk factors. To examine how these potential risk factors may
affect the relationship between SCD genotype and weight status, multiple
logistic regressions models were conducted with risk factor groups
accounted for sequentially. The odds ratio (OR) and 95% confidence
intervals for genotype [HbSS/HbSβ° (ref) vs HbSC/
HbSβ+] were reported for each model. All statistical
analyses were performed using Stata 16.0.