Statistical analysis
Descriptive statistics were calculated for all exposures, outcomes, and covariates. Differences between study variables by short sleep duration were reported by using Chi-square statistics for categorical variables and t-tests for continuous variables. Modified Poisson regression models with robust error variance28 were used to examine associations between phenotypes of short sleep duration and health outcomes. Separate models were conducted for each phenotype of short sleep and each health outcome, while adjusting for age at evaluation, sex, race/ethnicity, age at diagnosis, BMI, physical inactivity and condition-specific treatment exposures. When examining the associations between phenotypes of short sleep duration and the composite burden score of physical health outcomes, multinomial logistic regression was employed. Burden models were adjusted for age at evaluation, sex, race/ethnicity, BMI, and physical inactivity. All analyses were completed using SAS v9.4. All tests were two-sided and a p-value ≤ .05 was considered statistically significant.