Table 3.

Linear regression models for treatment type as a predictor of log_e-transformed length of stay – 2002-2014 Nationwide Inpatient Sample ^*

TPE vs. IVIG: †	β	95% CI
OVERALL:
Model 1 – Unadjusted	0.56	0.52, 0.59
Model 2 – Risk-Adjusted	0.53	0.49, 0.58
Model 3 – Propensity-score adjusted	0.54	0.50, 0.58
Model 4 – Propensity-score matched	0.56	0.52, 0.61
MALE:
Model 1 – Unadjusted	0.56	0.51, 0.62
Model 2 – Risk-Adjusted	0.53	0.47, 0.59
Model 3 – Propensity-score adjusted	0.54	0.48, 0.59
Model 4 – Propensity-score matched	0.56	0.51, 0.62
FEMALE:
Model 1 – Unadjusted	0.56	0.50, 0.63
Model 2 – Risk-Adjusted	0.54	0.48, 0.61
Model 3 – Propensity-score adjusted	0.55	0.48, 0.61
Model 4 – Propensity-score matched	0.56	0.49, 0.63
Period 1 (2002-2007):
Model 1 – Unadjusted	0.54	0.48, 0.61
Model 2 – Risk-Adjusted	0.50	0.44, 0.56
Model 3 – Propensity-score adjusted	0.53	0.46, 0.59
Model 4 – Propensity-score matched	0.58	0.52, 0.63
Period 2 (2008-2014):
Model 1 – Unadjusted	0.56	0.52, 0.61
Model 2 – Risk-Adjusted	0.54	0.49, 0.58
Model 3 – Propensity-score adjusted	0.54	0.49, 0.59
Model 4 – Propensity-score matched	0.58	0.52, 0.63

^*Note 1: No significant interaction by sex or time period in unadjusted, risk-adjusted or propensity-score adjusted models.

^†Note 2: Risk-adjusted models include age group, Charlson comorbidity index and admission status as covariates. Propensity score adjustment or matching was based on a logistic regression model that includes age group, Charlson comorbidity index and admission status as covariates.

Abbreviations: CI=Confidence Interval, IVIG=Intravenous Immunoglobulin, TPE = Therapeutic plasma exchange.