Table 14

Study Characteristics and Subgroup Analyses of RCTs Reporting Hematologic Responses (as defined in Scope and Key Questions)

OutcomeEpoetin versus ControlDarbepoetin versus Control
Subgroup# Studies# Total Patients#Epo/#Ctl PatientsRR95% CI (p- value)# Studies# Total Patients#Darb/#Ctl PatientsRR95% CI (p- value)
Hb Response 153,2931844/14493.423.03; 3.863659427/2323.362.48; 4.56
Subgroup Analyses: Patient Baseline Characteristics
Baseline Hb <10112,3721,329/1,0433.242.82; 3.73(all)659427/232
Baseline Hb 10–124921515/4063.983.11; 5.10
Baseline Hb >12
Baseline Hb ?
(Group difference1)(0.563)
Solid tumors7*1,660925/7353.302.80; 3.881249198/513.511.74; 7.08
Hematologic6*1,093643/4503.302.68; 4.062410229/1813.312.37; 4.63
Mixed3450276/2644.323.04; 6.13
(Group difference1)(0.136)(0.9715)
(Group difference1)
Subgroup Analyses: Treatment Protocols
Chemo, all plat3584347/2372.892.18; 3.84
Chemo, some plat51,053535/5183.122.56; 3.81
Chemo, no plat71,656962/6943.843.21; 4.58
Chemo, plat ?
Chemo+RT or RT
(Group difference1)(0.212)
Iron, fixed2441222/2192.431.92; 3.07
Iron, as needed102,2491,244/1,0054.133.51; 4.85
Iron ?3603378/2252.251.94; 3.35
(Group difference1) (0.002)
Epo tx 6–9 weeks18657/298.912.30; 34.50
Epo tx 12–16 weeks112,5601,376/1,1843.312.91; 3.77(all)659427/232
Epo tx >20 weeks4647411/2363.652.62; 5.05
Epo tx ? weeks
(Group difference1)(0.1509)
Subgroup Analyses: Reporting and Study Quality
High quality61,530864/6662.942.53; 3.43(all)659427/232
Low quality91,763980/7834.133.40; 5.01
(Group difference1) (0.0414)
Data from full text919661,055/9143.39; 4.71(all)659427/232
Data from abstract1314211/1042.251.66; 3.04
Data unpublished51012578/4343.052.45; 3.80
Data from FDA
(Group difference1) (0.0416)

p value for differences among subgroup categories calculated by inverse variance method (see Methods/Data Extraction and Analysis/Statistical Data Analysis)


Note: Littlewood 2001 was split into two subsets for malignancies: solid and hematologic malignancies since Hb responses were reported separately

CI: confidence interval; Ctl: control; darb: darbepoetin; epo: epoetin; Hb: hemoglobin; plat: platinum;

RT: radiotherapy; tx: treatment

From: 3, Results

Cover of Comparative Effectiveness of Epoetin and Darbepoetin for Managing Anemia in Patients Undergoing Cancer Treatment
Comparative Effectiveness of Epoetin and Darbepoetin for Managing Anemia in Patients Undergoing Cancer Treatment [Internet].
Comparative Effectiveness Reviews, No. 3.
Seidenfeld J, Piper M, Bohlius J, et al.

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