Assessing the risk of bias associated with missing participants in randomized controlled trials: a systematic review and meta-analysis in autologous cell therapy for peripheral arterial disease




Poster session 3


Tuesday 18 September 2018 - 12:30 to 14:00

All authors in correct order:

Jeong H1
1 Catholic University of Korea, South Korea
Presenting author and contact person

Presenting author:

Hyunsuk Jeong

Contact person:

Abstract text
Randomization minimizes the chance of bias by balancing both known and unknown prognostic factors between trial arms. However, the results can be biased when the data from ‘non-adherent’ participants are excluded from the analysis to evaluate treatment effect.

The aim of the study is to demonstrate the risk of bias associated with missing participants in a randomized controlled trial of cell therapy for peripheral vascular disease (PVD) patients.

We performed systematic searches from inception to December 2017 in MEDLINE and Embase. We conducted meta-analysis using complete case analysis as the primary analysis. To test the robustness of the results, we conducted sensitivity analyses using both worst-case scenario and adjusting zero events to evaluate the magnitude of impact of risk of bias on the reported results.

In the complete case analysis, the cell therapy showed a reduced the risk of amputation by 43% (risk ratio (RR) 0.43; 95% confidence interval (CI) 0.27 to 0.68). In the worst-case scenario, the treatment effect on prevention of amputation was decreased (RR 0.61 0.36; 95% CI 0.39 to 0.97). In addition, adjusting zero events yielded a wide confidence interval (RR 0.44; 95% CI 0.20 to 0.97).

Even when we assumed a worst-case scenario, the results remained statistically significant; cell therapy for PVD may reduce the risk of amputation and may be guaranteed as a true treatment effect for cell therapy.

This research was supported by a grant (18172MFDS182) from the Ministry of Food & Drug Safety in 2018.

Patient or healthcare consumer involvement:


Relevance to patients and consumers: 

The aim of the study is to demonstrate the risk of bias associated with missing participant in Randomized controlled trials of cell therapy for Peripheral Arterial Disease patients. This study will provide the best evidence of cell therapy for patients with Peripheral Arterial Disease,