On multivariable regression , adjusting for preoperative variables , a better TPS was an independent predictor of a shorter interval to first extubation ( P = @ ) , better transplant-free survival before Norwood discharge ( P < @ ; odds ratio , @ for inadequate vs optimal ) , shorter hospital length of stay ( P < @ ) , fewer unplanned reinterventions between Norwood discharge and stage II ( P = @ ) , and a higher Bayley II psychomotor development index at @ months ( P = @ ) .