GSTM1 and anemia (phenotype): The presence of anemia (Hb < 8) (aRR = 1.376, CI = 1.159–1.634, P =  < 0.001) and having a perforated appendix (aRR = 1.263, CI = 1.026–1.555, P = 0.027) were independently associated with occurrence of complications while being HIV positive (aRR = 1.379, CI = 1.105–1.721, P = 0.005) and having a perforated appendix (aRR = 1.258, CI = 1.019–1.554, P = 0.033) were independently associated with prolonged hospital stay.