Table 31

Characteristics and Subgroup Analyses of RCTs Reporting Thromboembolic Events

OutcomeDarbepoetin versus EpoetinEpoetin versus Control
Subgroup# Studies#Total Patients#Darb/#Epo PatientsPoint Estimate95% CI (p-value)# Studies#Total Patients#Epo/#Ctl PatientsPoint Estimate95% CI (p-value)
ThromboembolismRR31,879948/9310.860.61; 1.21306,0923,355/2,7371.691.36; 2.10
(Heterogeneity)(0.98)(0.67)
Subgroup Analyses: Patient Baseline Characteristics
Bsln Hb <10102,1721,205/9671.530.98; 2.39
Bsln Hb 10–12(all)71,394782/6121.781.12; 2.83
Bsln Hb >12151,505771/7341.711.08; 2.70
Bsln Hb unclear181,021597/4241.741.18; 2.56
(Group difference2)(0.93)
Solid tumors2670337/333204,1082,200/1,9081.701.33; 2.16
Hematologic5898509/3893.001.10; 8.12
Mixed/unknown11,209611/59851,086646/4401.330.76; 2.32
(Group difference2)(0.34)
Subgroup Analyses: Treatment Protocols
Children
Adults(all)(all)
(Group difference2)
Chemo, all plat91,439861/5781.150.77; 1.71
Chemo, some plat(all)2478237/2412.020.83; 4.89
Chemo, no plat72,4941,362/1,1321.461.04; 2.05
Chemo, plat unknown
Chemo+RT or RT81,187601/5863.001.77; 5.10
Unknown4494294/2003.991.28; 12.41
(Group difference2) (0.036)
Iron, fixed1333168/1651.470.54; 4.05
Iron, as needed142,7301,513/1,2171.561.09; 2.23
Iron unknown(all)153,0291,674/1,3551.801.35; 2.39
(Group difference2)(0.97)
Epo tx 6–9 weeks4646329/3171.910.78; 4.64
Epo tx 12–16 weeks(all)152,8361,546/1,2901.481.11; 1.98
Epo tx >20 weeks81,9531,107/8461.851.26; 2.72
Epo tx ? Weeks3657373/2842.891.11; 7.55
(Group difference2)(0.43)
Subgroup Analyses: Reporting and Quality
High quality184,2242,292/1,9321.551.21; 1.99
Low quality(all)121,8681,063/8052.181.38; 3.44
(Group difference2)(0.21)
Data from full text1312157/15591,388764/6241.731.01; 2.95
Data from abstract21,567791/7764732422/3103.611.21; 10.74
Data unpublished
Data from FDA173,9722,169/1,8031.591.25; 2.03
(Group difference2)(0.29)
1

The N93-004 trial was published in full in December, 2005 (Grote, Yeilding, Castillo, et al., 2005) and included information on baseline Hb which classified it into subgroup Hb >12. A re-categorized analysis resulted in subgroup Hb>12 HR 1.36 (95% CI, 0.97; 1.89); the p-value for the group difference changed from 0.93 to 0.1381. Because this did not alter the interpretation of results, we did not alter our presentation of the overall analysis.

2

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

The N93-004 trial was published in full in December, 2005 (Grote, Yeilding, Castillo, et al., 2005) and included information on baseline Hb which classified it into subgroup Hb >12. A re-categorized analysis resulted in subgroup Hb>12 HR 1.36 (95% CI, 0.97; 1.89); the p-value for the group difference changed from 0.93 to 0.1381. Because this did not alter the interpretation of results, we did not alter our presentation of the overall analysis.

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

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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