Discrepancies between registered protocol and final publication in exercise interventions for chronic low back pain: a meta-research study

Background Evidence of selective reporting bias is common in randomized controlled trials (RCTs) of various medical fields, undermining their integrity and credibility. However, this has not yet been assessed in exercise for chronic low back pain (cLBP) RCTs. Therefore, we will aim to assess the prevalence of discrepancies between the registered protocol and final publication in this field and the characteristics of RCTs with and without such discrepancies. Methods We will start from the RCTs included in the 2021 Cochrane review (n=249) and identified in its update (n=172) to select all RCTs reporting a protocol registration. Standardized data collection form will be developed to record information from both registration and publication. We will then detect discrepancies for primary and secondary outcomes, outcomes measures, timepoints, number of arms and statistical analysis plans between the registered protocol and final publication. We will use descriptive statistics to assess the proportion of RCTs with and without a discrepancy as well as to compare their characteristics. Ethics and dissemination We will offer insights and recommendations for future RCTs avoiding selective reporting that can reflect in subsequent inaccuracies in systematic reviews or guidelines for clinical practice. Results of this study will be shared through conference presentations and publication in a peer-reviewed journals. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research received no specific grant from any funding agency in the public, commercial or not for profit sectors. SB, SG, GC were supported by the Italian Ministry of Health Linea 2, Studi metodologici in ortopedia e riabilitazione; L2085. The funding source had no controlling role in the study design, data collection, analysis, interpretation, or report writing ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript