anchor.diff:  "52","Suicide"
   "53","ERF treatment ceased for any other reason"
   "54","ERF treatment withdrawn for medical reasons"
  -"61","Uraemia caused by graft failure"
  +"61","Ureamia caused by graft failure"
   "62","Pancreatitis"
  -"63","Bone marrow depression (Aplasia)"
  +"63","Bone marrow depression (Aplosia)"
   "64","Cachexia"
   "66","Malignant disease in patient treated by immunosuppressive therapy"
   "67","Malignant disease: solid tumors (Except those of 66)"
  
positive.code: "104","Calciphylaxis"
  "105","Ischaemic bowel"
  "106","Ruptured AAA"
  "107","Advanced CKD not on dialysis (conservative management)"
  "108","Acute kidney injury"
  "109","C Diff colitis"
  "110","Line related sepsis"
  
negative.code: "72","Perforation of colon"
  "73","COPD"
  "79","Multi-system failure"
  "81","Accident related to ESRF treatment (not 25)"
  "82","Accident unrelated to ERF treatment"
  "99","Other identified cause of death"
  "100","Peritonitis (bacterial, with peritoneal dialysis)"
  