Characteristics of full and matched samples by acute hemodialysis status, Pennsylvania 2005–2007.

Continuous variables expressed as mean ± standard deviation; categorical variables expressed as n (%).T-tests used for continuous variables; chi-squared tests used for categorical variables.aAll means and proportions are based on admissions, not individual patients.bDue to rounding, percentages may not add up to 100.cBased upon proprietary MediQual mortality model using key clinical findings abstracted from the chart during the first 48 hours of admission.