TY - JOUR
T1 - A third of systematic reviews changed or did not specify the primary outcome
T2 - a PROSPERO register study
AU - Tricco, Andrea C.
AU - Cogo, Elise
AU - Page, Matthew J.
AU - Polisena, Julie
AU - Booth, Alison M
AU - Dwan, Kerry
AU - MacDonald, Heather
AU - Clifford, Tammy J.
AU - Stewart, Lesley A
AU - Straus, Sharon E
AU - Moher, David
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Objectives To examine outcome reporting bias of systematic reviews registered in PROSPERO. Study Design and Setting Retrospective cohort study. The primary outcomes from systematic review publications were compared with those reported in the corresponding PROSPERO records; discrepancies in the primary outcomes were assessed as upgrades, additions, omissions, or downgrades. Relative risks (RRs) and 95% confidence intervals (CI) were calculated to determine the likelihood of having a change in primary outcome when the meta-analysis result was favorable and statistically significant. Results Ninety-six systematic reviews were published. A discrepancy in the primary outcome occurred in 32% of the included reviews and 39% of the reviews did not explicitly specify a primary outcome(s); 6% of the primary outcomes were omitted. There was no significant increased risk of adding/upgrading (RR, 2.14; 95% CI: 0.53, 8.63) or decreased risk of downgrading (RR, 0.76; 95% CI: 0.27, 2.17) an outcome when the meta-analysis result was favorable and statistically significant. As well, there was no significant increased risk of adding/upgrading (RR, 0.89; 95% CI: 0.31, 2.53) or decreased risk of downgrading (RR, 0.56; 95% CI: 0.29, 1.08) an outcome when the conclusion was positive. Conclusions We recommend review authors carefully consider primary outcome selection, and journals are encouraged to focus acceptance on registered systematic reviews.
AB - Objectives To examine outcome reporting bias of systematic reviews registered in PROSPERO. Study Design and Setting Retrospective cohort study. The primary outcomes from systematic review publications were compared with those reported in the corresponding PROSPERO records; discrepancies in the primary outcomes were assessed as upgrades, additions, omissions, or downgrades. Relative risks (RRs) and 95% confidence intervals (CI) were calculated to determine the likelihood of having a change in primary outcome when the meta-analysis result was favorable and statistically significant. Results Ninety-six systematic reviews were published. A discrepancy in the primary outcome occurred in 32% of the included reviews and 39% of the reviews did not explicitly specify a primary outcome(s); 6% of the primary outcomes were omitted. There was no significant increased risk of adding/upgrading (RR, 2.14; 95% CI: 0.53, 8.63) or decreased risk of downgrading (RR, 0.76; 95% CI: 0.27, 2.17) an outcome when the meta-analysis result was favorable and statistically significant. As well, there was no significant increased risk of adding/upgrading (RR, 0.89; 95% CI: 0.31, 2.53) or decreased risk of downgrading (RR, 0.56; 95% CI: 0.29, 1.08) an outcome when the conclusion was positive. Conclusions We recommend review authors carefully consider primary outcome selection, and journals are encouraged to focus acceptance on registered systematic reviews.
KW - Bias
KW - Methodology
KW - Outcome reporting bias
KW - Quality
KW - Reporting
KW - Systematic reviews
UR - http://www.scopus.com/inward/record.url?scp=85006412382&partnerID=8YFLogxK
U2 - 10.1016/j.jclinepi.2016.03.025
DO - 10.1016/j.jclinepi.2016.03.025
M3 - Article
C2 - 27079845
AN - SCOPUS:85006412382
SN - 0895-4356
VL - 79
SP - 46
EP - 54
JO - Journal of Clinical Epidemiology
JF - Journal of Clinical Epidemiology
ER -