Indicator madness: a cautionary reflection on the use of indicators in healthcare.

Indicators are increasingly being used to monitor and evaluate health system performance. However, although indicators can provide valuable information, they also have limitations. The benefits of indicators are vitiated when they are seriously flawed (unreliable, invalid or easily "gamed"), selected before the right question has been posed or used to the exclusion of other sources of information. This critical assessment of the use and misuse of indicators employs practical examples from a Canadian health authority to illustrate common pitfalls. It concludes with some solutions to optimize the benefits of indicator use.