<qa>  What was the length of the study that participants completed 24 months of the base study were invited toParticipants who completed 24 months of the base study were invited to continue in three extensions: MK0822-004-10, which extended the study to 36 months, MK0822-004-20 NCT00112437 which extended the study to 60 months, and MK0822-004-30 NCT00112437, which extended the study to 120 months. 