Article type
Year
Abstract
Background: In a previous Cochrane Review on the effects of erythropoiesis stimulating agents (ESAs) in cancer patients (1) we identified potential publication and outcome reporting biases for several outcomes.
Objectives: We collaborated with European Medicines Agency (EMA) to retrieve clinical study reports (CSRs) and investigated whether inclusion of data reported in these CSRs may help to reduce reporting bias.
Methods: We identified all randomised controlled trials (RCTs) on the effect of ESAs on cancer patients from our previous Cochrane Review (1) and updated literature searches. We set up a collaborative agreement with EMA and requested the CSRs for all identified RCTs. We conducted random-effects meta-analyses and compared the pooled estimates based on data as reported in the public domain (i.e. articles, abstracts, other public sources) with the pooled estimates based on data from the public domain and the CSRs. We present preliminary results for the outcomes: number of patients receiving red blood cell transfusions (RBCTs); anaemia symptoms measured with the Functional Assessment of Cancer Therapy-Anaemia (FACT-An); and hypertension; analyses for additional outcomes are on-going.
Results: From the review (1) and updated literature searches we identified 92 RCTs, the EMA identified two additional, unpublished studies. For these 94 RCTs the EMA had the CSRs for 16 RCTS. The number of studies and participants analysed and the pooled effect estimates per outcome are shown in Table 1. For RBCTs and hypertension the inclusion of two and nine additional studies, respectively, based on data reported in CSRs did not alter the overall effect estimates. For FACT-An the inclusion of six additional studies based on data reported in CSRs reduced the pooled mean difference of changes from 5.93 (95% CI 4.37, 7.49) to 2.79 (95% CI 0.88, 4.70), which is below the threshold (defined as ≥ 4) of a clinically important difference for FACT-An (1). This result will change the conclusion of the review (1).
Conclusions: Unpublished clinical study reports held by EMA may be a useful source to reduce outcome reporting bias.
Reference: (1) Tonia et al CD003407
Objectives: We collaborated with European Medicines Agency (EMA) to retrieve clinical study reports (CSRs) and investigated whether inclusion of data reported in these CSRs may help to reduce reporting bias.
Methods: We identified all randomised controlled trials (RCTs) on the effect of ESAs on cancer patients from our previous Cochrane Review (1) and updated literature searches. We set up a collaborative agreement with EMA and requested the CSRs for all identified RCTs. We conducted random-effects meta-analyses and compared the pooled estimates based on data as reported in the public domain (i.e. articles, abstracts, other public sources) with the pooled estimates based on data from the public domain and the CSRs. We present preliminary results for the outcomes: number of patients receiving red blood cell transfusions (RBCTs); anaemia symptoms measured with the Functional Assessment of Cancer Therapy-Anaemia (FACT-An); and hypertension; analyses for additional outcomes are on-going.
Results: From the review (1) and updated literature searches we identified 92 RCTs, the EMA identified two additional, unpublished studies. For these 94 RCTs the EMA had the CSRs for 16 RCTS. The number of studies and participants analysed and the pooled effect estimates per outcome are shown in Table 1. For RBCTs and hypertension the inclusion of two and nine additional studies, respectively, based on data reported in CSRs did not alter the overall effect estimates. For FACT-An the inclusion of six additional studies based on data reported in CSRs reduced the pooled mean difference of changes from 5.93 (95% CI 4.37, 7.49) to 2.79 (95% CI 0.88, 4.70), which is below the threshold (defined as ≥ 4) of a clinically important difference for FACT-An (1). This result will change the conclusion of the review (1).
Conclusions: Unpublished clinical study reports held by EMA may be a useful source to reduce outcome reporting bias.
Reference: (1) Tonia et al CD003407