Gruschkus, S.K., Lairson, D., Dunn, J.K., Risser, J., & Du, X.L. (2010). Comparative effectiveness of white blood cell growth factors on neutropenia, infection, and survival in older people with non-Hodgkin's lymphoma treated with chemotherapy. Journal of the American Geriatrics Society, 58, 1885–1895.
To examine the effect of colony-stimulating factors (CSFs) used as primary and secondary prophylaxis on incidence of febrile neutropenia, infection, and survival in older adults.
The study used data from the Surveillance, Epidemiology, and End Results (SEER) Medicare database. ICD-9 codes were used to define inclusion diagnoses and definition of febrile neutropenia.
Use of CSF, the type of chemotherapy administered, and the use of antibiotics were defined in terms of CPT codes. Regression analysis was used to analyze effects of primary and secondary CSF prophylaxis on outcomes of interest. Primary prophylaxis was defined as CSF during chemotherapy before occurrence of fever, infection, or neutropenia. Secondary prophylaxis was CSF administration that occurred after these events. Study used data from 1992–2002.
Multi-site (SEER data)
There were mutliple phases of care
Application is for elder care
Retrospective cohort study
Sixty percent of cases did not receive any CSF. Those who had 5–9 CSF administrations for primary prophylaxis has a 42% lower risk of febrile neutropenia (OR = 0.58, 95% confidence interval [CI] [0.41, 0.83]) and those with 10 or more administrations had a 48% lower risk after data were adjusted for age, marital status, stage, and other characteristics. Those with 5–9 administrations had a 27% lower incidence of infection, and those with 10 or more administrations had a 52% lower risk (OR = 0.48, 95% CI [0.35, 0.66]). Primary prophylactic CSF was not associated with longer overall survival. Secondary prophylaxis was associated with improved overall survival, with a strong dose-response effect. A range of 11–23 administrations was associated with a 23% lower risk of mortality (HR = 0.77, 95% CI [0.71, 0.84]), and those with more than 23 administrations had a 13% lower risk of mortality than others. Protective effects of primary prophylaxis was highest in those receiving the largest number of chemotherapy administrations and in those with large B-cell lymphoma.
Primary prophylaxis with CSF in older adults is effective in preventing febrile neutropenia and infection, but was not associated with improved survival. Secondary prophylaxis was associated with longer overall survival.
Findings support the use of primary prophylactic CSF for prevention of infection and febrile neutropenia, and secondary prophylaxis in improving survival in this group of patients. Limitation of retrospective statistical analysis using medical records code data only need to be considered in interpretation and application of these results.