TY - JOUR AU - Nicholl, J TI - Case-mix adjustment in non-randomised observational evaluations: The constant risk fallacy JO - J Epidemiol Community Health VL - 61 PY - 2007 DO - 10.1136/jech.2007.061747 L3 - PubMed-ID: 17933961 SP - 1010 EP - 1013 ER -