“…Seventeen reports described OC use in defined populations, 15,21,[25][26][27]29,31,33,35,37,39,42,47,[53][54][55][56] 15 reports identified predictors of OC use, 14,23,24,30,32,40,41,45,46,48,50,51,[54][55][56] 7 were randomized trials that evaluated some aspect of OC use, 29,34,36,38,43,44,49 and 2 were validation studies that evaluated approaches to measuring OC use. 22,52 All studies except 2 were conducted in clinic-based settings; the remaining 2 used population-based samples.…”