A Retrospective Observational Comparison of Comorbidities Between Myeloproliferative Neoplasm (MPN) Patients and Matched Controls in a Commercially Insured US Population

Three subtypes of MPN (myelofibrosis (MF), polycythemia vera (PV) and essential thrombocythemia (ET)) are characterized by activation of JAK2 signaling, with the majority having the JAK2 V617F mutation. Patients diagnosed with MF, PV or ET are typically at higher risk for infections, cardiovascular complications, anemia and other comorbid diseases (Barosi Blood 2007, Vannucchi Blood 2007). However, comparative rates of these comorbidities are not well described in the literature.

To compare comorbidity rates from three subtypes of MPN patients (MF, PV, ET) with matched non-cancer control groups using a large US commercial claims database.

Data were drawn from Thomson Reuters MarketScan, which contains claims for insured employees, retirees, and dependents from approximately 100 US payers. Index date was the first claim with a diagnosis code for MPN in the time period 2005 to 2008. Eligible patients had 1 year of continuous enrollment post-index with no evidence of non-AML secondary malignancy. Patients were deemed to have a comorbidity if they had an ICD-9 diagnosis code that was on a list of pre-specified codes likely to be related to MPN for each comorbidity category. Controls had one year of continuous enrollment after their match date and were matched to patients in a ratio of 5 :1 based on gender, year of birth, geographic region and insurance type (Comprehensive, Health Maintenance Organization, Preferred Provider Organization, etc.). Controls were excluded if they had a service claim with diagnosis for cancer or a pharmacy claim for chemotherapy.

A total of 25, 145 MPN patients were included and assigned matching controls. For MF, PV and ET cases, respectively, mean age was 64.4, 54.4. 52.3 years and % female was 51.7, 36.1 and 70.7. Comorbidity rates during the study period for some diseases of interest in MPN patients and matched controls are shown in the table.

Patients diagnosed with an MPN typically experienced significantly higher rates of comorbidities than non-MPN matched controls. These findings have implications for both the clinical management of MPN patients as well as for health economic assessments, since a substantial portion of the cost of care for MPN patients may reside in treatment of comorbidities not directly coded to MPN.

Restricting patients and controls in this study to a single matching year of observation helped to align risk between cases and controls, but may have underestimated the total comorbidity burden that MPN patients could experience in their lifetime.

Price:Elil Lilly and Company: Employment; Eli Lilly and Company: Equity Ownership. Pohl:Eli Lilly and Company: Employment; Eli Lilly and Company: Equity Ownership. Xie:Eli Lilly and Company: Employment; Eli Lilly and Company: Equity Ownership. Walgren:Eli Lilly and Company: Employment; Eli Lilly and Company: Equity Ownership.