Occupational medicine practice guidelines.

Practice guidelines have become accepted "rules of the road" for many illnesses and injuries. Guidelines can be the basis for performance measures if they include a development step summarizing the available evidence for efficiency and effectiveness of maneuvers, tests, and treatments. They are particularly valuable for entities that have high degrees of variance in diagnostic accuracy, testing, and treatment. Periodic revision of guidelines can keep professional knowledge bases up to date. One must keep in mind that guidelines are just that--descriptions of normative data, observed best practices, expert consensus, or high-grade evidence. While they provide benchmarks for assessment and improvement, there may be good reasons why they do not apply to some patients. However, the exercise of justifying the differences can sharpen clinical judgment and improve outcomes.