Loss to Follow-up in Head and Neck Cancer: A Systematic Review of Randomized Controlled Trials

Objective: To evaluate the reporting and rates of loss to follow-up (LTFU) in head and neck cancer (HNC) randomized controlled trials based in the United States. Data Sources: Pubmed/MEDLINE, Cochrane, Scopus databases. Review Methods: A systematic review of titles in Pubmed/MEDLINE, Scopus, and Cochrane Library was performed. Inclusion criteria were US-based randomized controlled trials focused on the diagnosis, treatment, or prevention of HNC. Retrospective analyses and pilot studies were excluded. The mean age, patients randomized, publication details, trial sites, funding, and LTFU data were recorded. Reporting of participants through each stage of the trial was documented. Binary logistic regression was performed to evaluate associations between study characteristics and reporting LTFU. Results: A total of 3255 titles were reviewed. Of these, 128 studies met the inclusion criteria for analysis. A total of 22,016 patients were randomized. The mean age of participants was 58.6 years. Overall, 35 studies (27.3%) reported LTFU, and the mean LTFU rate was 4.37%. With the exception of 2 statistical outliers, study characteristics including publication year, number of trial sites, journal discipline, funding source, and intervention type did not predict the odds of reporting LTFU. Compared to 95% of trials reporting participants at eligibility and 100% reporting randomization, only 47% and 57% reported on withdrawal and details of the analysis, respectively. Conclusion: The majority of clinical trials in HNC in the United States do not report LTFU, which inhibits the evaluation of attrition bias that may impact the interpretation of significant findings. Standardized reporting is needed to evaluate the generalizability of trial results to clinical practice.