A. A case-control study of patients receiving Vincristine conducted in multiple centers.

B. A randomized, double-blind, placebo-controlled study of gabapentin administered concomitantly with Vincristine.

C. A nonrandomized, open-label study of patients receiving vincristine with or without concomitant gabapentin.

D. A retrospective chart review using pharmacy records to determine which patients received Vincristine concomitantly with gabapentin.