Table 1 : Demographics and baseline characteristics of chronic hepatitis
C (CHC) patients and possible pure red cell aplasia (PRCA) identified in
the claims data.
| N (%) unless otherwise specified | Overall | Possible PRCA* | ||
| N | (%) | N | (%) | |
| Total | 36,164 | -- | 25 | -- |
| Age, years, mean±SD | 51.2 | ±11.6 | 51.6 | ±18.1 |
| Gender, female | 14,118 | (39.0) | 11 | (44.0) |
| Year of CHC cohort entry (index date†) | ||||
| 2006 | 9,840 | (27.2) | 15 | (60.0) |
| 2007 | 6,232 | (17.2) | 4 | (16.0) |
| 2008 | 5,246 | (14.5) | 4 | (16.0) |
| 2009 | 4,191 | (11.6) | -- | (0.0) |
| 2010 | 3,837 | (10.6) | 1 | (4.0) |
| 2011 | 4,197 | (11.6) | -- | (0.0) |
| 2012 | 2,621 | (7.2) | 1 | (4.0) |
| Co-morbidities prior to index date† | ||||
| Cytomegalovirus infection | 15 | (0.0) | -- | (0.0) |
| Infectious mononucleosis | 29 | (0.1) | 1 | (4.0) |
| Hepatitis A virus infection | 176 | (0.5) | -- | (0.0) |
| Hepatitis B virus infection | 911 | (2.5) | 2 | (8.0) |
| Mumps | 1 | (0.0) | -- | (0.0) |
| Parvovirus B19 | -- | (0.0) | -- | (0.0) |
| Chronic renal insufficiency | 1,202 | (3.3) | 2 | (8.0) |
| End-stage renal disease | 497 | (1.4) | -- | (0.0) |
| Medical history prior to index date† | ||||
| Anemia | 4,005 | (11.1) | 12 | (48.0) |
| Neutropenia | 467 | (1.3) | 7 | (28.0) |
| Pancytopenia | 266 | (0.7) | 1 | (4.0) |
| Thrombocytopenia | 1,371 | (3.8) | 10 | (40.0) |
| Myelodysplastic syndrome | 16 | (0.0) | -- | (0.0) |
| Possible PRCA | 14 | (0.0) | 4 | (16.0) |
| Autoimmune diseases | ||||
| Collagen vascular disease | 791 | (2.2) | 3 | (12.0) |
| Autoimmune disease | 319 | (0.9) | 1 | (4.0) |
| Neoplasm | ||||
| Thymoma | 1 | (0.0) | -- | (0.0) |
| Hematologic malignancy | 254 | (0.7) | 6 | (24.0) |
| Solid tumor | 137 | (0.4) | 3 | (12.0) |
| Co-medication use prior to index date† | ||||
| Erythropoietin (EPO) | 624 | (1.7) | 2 | (8.0) |
| Anti-epileptic medications | 403 | (1.1) | 1 | (4.0) |
| Azathioprine | 102 | (0.3) | -- | (0.0) |
| Chloraphenicol | -- | (0.0) | -- | (0.0) |
| Immunosuppressive therapy | 3,751 | (10.4) | 5 | (20.0) |
| Sulfonamides | 2,849 | (7.9) | -- | (0.0) |
| Isoniazid | 20 | (0.1) | -- | (0.0) |
| Procainamide | 1 | (0.0) | -- | (0.0) |
| Protease inhibitor | 56 | (0.2) | -- | (0.0) |
CHC: Chronic hepatitis C; EPO: Erythropoietin; ICD-9-CM: International Classification
of Diseases, Ninth Revision, Clinical Modification; PRCA: Pure red cell aplasia; SD:
Standard deviation
*Possible PRCA cases from claims data are patients with any medically-attended
claim for aplastic anemia (ICD-9-CM 284.8x or 284.9x) and any medical claim for a
bone marrow biopsy in the 30 days prior to and including the date of the claim for
aplastic anemia.
†Earliest date a patient satisfied either of two algorithms for identifying CHC in the
claims data.