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Open Access Highly Accessed Research article

Association between framing of the research question using the PICOT format and reporting quality of randomized controlled trials

Lorena P Rios1, Chenglin Ye3 and Lehana Thabane12*

Author Affiliations

1 Biostatistics Unit, Father Sean O'Sullivan Research Centre, St Joseph's Healthcare, 50 Charlton Avenue East, Hamilton ON L8N 4A6, Canada

2 Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton ON, Canada

3 Department of Mathematics and Statistics, McMaster University, Hamilton ON, Canada

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BMC Medical Research Methodology 2010, 10:11  doi:10.1186/1471-2288-10-11

Published: 5 February 2010



Experts recommend formulating a structured research question to guide the research design. However, the basis for this recommendation has not been formally evaluated. The aim of this study was to examine if a structured research question using the PICOT (Population, Intervention, Comparator, Outcome, Time-frame) format is associated with a better reporting quality of randomized controlled trials (RCTs).


We evaluated 89 RCTs reports published in three endocrinology journals in 2005 and 2006, the quality of reporting of which was assessed in a previous study. We examined whether the reports stated each of the five elements of a structured research question: population, intervention, comparator, outcome and time-frame. A PICOT score was created with a possible score between 0 and 5. Outcomes were: 1) a 14-point overall reporting quality score (OQS) based on the Consolidated Standards for Reporting Trials; and 2) a 3-point key score (KS), based on allocation concealment, blinding and use of intention-to-treat analysis. We conducted multivariable regression analyses using generalized estimating equations to determine if a higher PICOT score or the use of a structured research question were independently associated with a better reporting quality. Journal of publication, funding source and sample size were identified as factors associated with OQS in our previous report on this dataset, and therefore included in the model.


A higher PICOT score was independently associated with OQS (incidence rate ratio (IRR) = 1.021, 95% CI: 1.012 to 1.029) and KS (IRR = 1.142, 95% CI: 1.079 to 1.210). A structured research question was present in 33.7% of the reports and it was associated with a better OQS (IRR = 1.095, 95% CI 1.059-1.132) and KS (IRR = 1.530, 95% CI 1.311-1.786).


Better framing of the research question using the PICOT format is independently associated with better overall reporting quality - although the effect is small - and better reporting of key methodologies.