Clinical and demographic characteristics.
hematoma, CSDH
REGRESSION, HEMATOMA, RECURRENCE
Data are median (InterQuatile Range, IQR) or number (%) followed by their respective p-values obtained by ANOVA analysis. ml (millilitres), min (minutes).*Some data missingTwo multivariable logistic regression models were used to investigate the effects of independent variables on CSDH recurrence in the three groups. The dependent variable for the first model was recurrence of CSDH as a binary variable regardless of timeframe. Independent variables for the model were age, gender, drain-cessation group as a categorical variable (A, B, and C), size of hematoma (converted to centiliters for easier interpretation of coefficients), type of hematoma (unilateral or bilateral), use of any type of anticoagulants, pre-operative GCS and midline shift.The second multivariable logistic regression model also had recurrence of CSDH as the dependent variable. Independent variables for this model were age, gender, hours of drain production, size of hematoma, type of hematoma (unilateral vs. bilateral), use of anticoagulants, pre-operative GCS and midline shift. This model was employed to independently analyze hours of production as a covariate; this could not be estimated correctly in the first model due to confounding with drain-cessation groups.In addition, a third multivariable logistic regression model examined the relationship between recurrence and volume drained with the same covariates.Significant findings were reported as odds ratios with a discrepancy of α = 0.05 and no adjustment to protect the results of this explorative study from type II errors.Data analyses were performed using Stata 16. (StataCorp. 2018. Stata Statistical Software: Release 16. College Station, TX: StataCorp LLC).