CPR Skill Retention: Is Two Years Too Many?

Across the board, there is no universal standard for CPR certification length. Some training providers, such as the American Red Cross, require annual recertification, while other providers require certification every two years. Although some decision-makers consider two-year recertification programs more economical, is there a point at which someone is no longer prepared to respond effectively in an emergency? How long after testing does skill retention really last?