Table 2.

Patients with a final diagnosis of primary ITP

Primary ITP (n = 269)
Age at initial presentation, median (IQR), y 50 (33-64) 
Female, n (%) 168 (62.5) 
Follow-up from initial diagnosis, >1 visit, median (IQR), y 7.0 (2.9-14.8) 
Nadir platelet count, median (IQR) 15 (4-48) 
Number of ITP treatments received (IQR) 3 (1-4) 
 Splenectomy, n (%) 83 (30.9) 
ITP disease stage at the time of registration,* n (%)  
 Newly diagnosed (within first 3 mo) 28 (10.4) 
 Persistent (3 to 12 mo) 23 (8.6) 
 Chronic (>12 mo) 122 (45.4) 
 Relapsed 5 (1.9) 
 Refractory 24 (8.9) 
 Remission off therapy 52 (19.3) 
 Patients with a diagnosis other than ITP at registration 10 (3.7) 
 Unknown 5 (1.9) 
Patients with refractory ITP at last follow-up, n (%) 8 (3.0) 
Worst bleed ever, n (%)  
 None 40 (14.9) 
 Grade 1 only 77 (28.6) 
 Grade 2 152 (56.5) 
Primary ITP (n = 269)
Age at initial presentation, median (IQR), y 50 (33-64) 
Female, n (%) 168 (62.5) 
Follow-up from initial diagnosis, >1 visit, median (IQR), y 7.0 (2.9-14.8) 
Nadir platelet count, median (IQR) 15 (4-48) 
Number of ITP treatments received (IQR) 3 (1-4) 
 Splenectomy, n (%) 83 (30.9) 
ITP disease stage at the time of registration,* n (%)  
 Newly diagnosed (within first 3 mo) 28 (10.4) 
 Persistent (3 to 12 mo) 23 (8.6) 
 Chronic (>12 mo) 122 (45.4) 
 Relapsed 5 (1.9) 
 Refractory 24 (8.9) 
 Remission off therapy 52 (19.3) 
 Patients with a diagnosis other than ITP at registration 10 (3.7) 
 Unknown 5 (1.9) 
Patients with refractory ITP at last follow-up, n (%) 8 (3.0) 
Worst bleed ever, n (%)  
 None 40 (14.9) 
 Grade 1 only 77 (28.6) 
 Grade 2 152 (56.5) 
*

The ITP stages at registration were based on physician assessment because patient recall of dates of initial presentation was often unreliable. Disease stages were mutually exclusive.