However, in an earlier study of 317 elderly hip fracture patients, no correlation between Hb and LOS was found after adjusting for age and gender (P = .130).[41] This inconsistency in results may be due to differences in sample size, adjustment variables, and the fact that previous studies did not use nonlinear fitting methods to explore the relationship between Hb and LOS. The gene discussed is GSTM1; the disease is hip fracture.