The Dynamic International Prognostic Scoring System (DIPSS) for myelofibrosis was developed by Passamonti and colleagues in 2010 as a dynamic improvement over the original IPSS (which only used presentation data). DIPSS uses the same five risk factors as IPSS but weights anaemia (Hgb <10 g/dL) twice, reflecting its stronger prognostic impact discovered in follow-up analyses. DIPSS can be applied at any time during the disease course, not just at diagnosis — making it "dynamic." DIPSS-Plus (2011) added three additional independent adverse factors (platelet count <100, unfavourable karyotype, transfusion need) for further refinement. Primary myelofibrosis (PMF) has an annual incidence of ~0.5-1.5 per 100,000, predominantly affecting patients aged 60-70.