1. Johnson & Johnson Pharmaceutical Research and Development; Pharmacoepidemiology; PO BOX 200, M/S K304 Titussville NJ USA 08560
2. Javeriana Unviersity School of Medicine; Anesthesia; Bogota Colombia
3. Javeriana Unviersity; Anesthesia; Bogota Colombia
4. Javeriana University; Anesthesia; Bogota Colombia