Which of the foliowing generalizations is true of practice pattern variations?

In high usage areas for a medical procedure, the procedure is more often done for inappropriate reasons than in low usage areas.

Areas that use one procedure at a rate higher than the average also tend to use other procedures at high rates.

Doctors are usually unaware that their use of certain medical procedures is higher or lower than the average.

Patients who are treated by doctors in areas with low usage rates for a procedure tend to have poorer outcomes