TABLE 1.

Overall and Race-Specific Ages at Menarche in Years by Probit Analysis for Selected Percentiles of US Girls in NHANES III Who Were Menstruating

10%Fiducial Limits25%Fiducial Limits50% MedianFiducial Limits75%Fiducial Limits90%Fiducial Limits
Overall11.1110.95–11.2511.7311.62–11.8412.4312.33–12.5313.1313.01–13.2513.7513.61–13.92
By race
 Non-Hispanic whites11.32*10.91–11.6111.90*11.60–12.1412.55*12.31–12.7913.2012.95–13.5213.7813.47–14.22
 Non-Hispanic blacks10.52*10.15–10.8111.25*10.98–11.4812.06*11.84–12.2812.8712.63–13.1613.6013.30–13.99
 Mexican Americans10.8110.46–11.0911.4911.23–11.7112.2512.04–12.4613.0112.78–13.2913.6913.40–14.07
  • * Significant racial difference, P value <.017 for each pair-wise comparison yielding a P value <.05 for the overall comparison-wise error rate. The fiducial limits for overall were based on 95% confidence limits.

  • Race-specific fiducial limits were computed at 98.3% confidence limits so that the multiple (3) fiducial limits combined yielded a 95% confidence limit.