ERRATUM
In the February 2013 issue, there were two errors on the right column of page 56 of the Biostatistics in Psychiatry (13) article. (Lê Cook B, Manning WG. Thinking beyond the mean: a practical guide for using quantile regression methods for health services research. Shanghai Archives of Psychiatry 2013; 25(1): 55-59.) The phrase ‘...a 75th quantile regression fits a regression line through the data so that 90 percent of the observations...’ should read: ‘...a 75th quantile regression fits a regression line through the data so that 75 percent of the observations...’ And the phrase ‘...and the observed values above the line (positive residuals) by 1.75.’ should read: ‘...and the observed values above the line (positive residuals) by 1.5.’ We apologize for the errors.