ABSTRACT
OBJECTIVE: To synthesize participant retention data and related reporting in studies evaluating post-hospital outcomes of survivors of critical illness after an intensive care unit (ICU) stay. REVIEW METHOD USED: A synthesis of literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews checklist. DATA SOURCES: PubMed, EMBASE, PsycINFO, Cumulative Index of Nursing and Allied Health Literature, and the Cochrane Controlled Trials Registry. Hand searched reference lists and personal files of relevant narrative and systematic review articles. REVIEW METHODS: Articles were screened by pairs of independent reviewers. Similarly, data were abstracted by pairs of data collectors, with conflicts resolved by consensus or by a third reviewer. RESULTS: We included 243 publications, from 225 unique studies of 87,602 participants. Participant retention could not be calculated for any time-points in 13% of studies nor in 22% of all follow-up time-points. Retention ranged from 18-100%. When compared to follow-up before 1-month, retention at each later timepoint was not significantly different. Age and sex were not associated with retention and more recent studies had decreased retention (odds ratio: 0.94 [95% confidence interval: 0.92-0.96; p < 0.001]). Reporting of retention-related study methodology was inconsistent. CONCLUSION: Retention rate could not be calculated for 22% of study follow-up time-points, with retention at the remaining time-points generally being high (≥85%), but with high variability (18% - 100%). ICU survivorship research could be improved via: (i) more detailed guidance on reporting participant retention, and (ii) use of existing resources and best practices to facilitate better study design and to improve participant retention to preserve statistical power and reduce selection bias.
ABSTRACT
BACKGROUND: The study aimed to synthesize participant retention-related data for longitudinal follow-up studies of survivors from trauma intensive care units (ICUs). METHODS: Within a published scoping review evaluating ICU patient outcomes after hospital discharge, two screeners independently searched for trauma ICU survivorship studies. RESULTS: There were 11 trauma ICU follow-up studies, all of which were cohort studies. Twelve months (range: 1-60 months) was the most frequent follow-up time point for assessment (63% of studies). Retention rates ranged from 54% to 94% across time points and could not be calculated for two studies (18%). Pooled retention rates at 3, 6, and 12 months were 75%, 81%, and 81%, respectively. Mean patient age (OR 0.85 per 1-year increase, 95% CI 0.73 to 0.99, p=0.036), percent of men (OR 1.07, 95% CI 1.04 to 1.10, p=0.002), and publication year (OR 0.89 per 1-year increase, 95% CI 0.82 to 0.95, p=0.007) were associated with retention rates. Early (3-month) versus later (6-month, 12-month) follow-up time point was not associated with retention rates. DISCUSSION: Pooled retention rates were >75%, at 3-month, 6-month, and 12-month time points, with wide variability across studies and time points. There was little consistency with reporting participant retention methodology and related data. More detailed reporting guidelines, with better author adherence, will help improve reporting of participant retention data. Utilization of existing research resources may help improve participant retention. LEVEL OF EVIDENCE: Level III: meta-analyses (post-hoc analyses) of a prior scoping review.
ABSTRACT
BACKGROUND: With an increasing number of follow-up studies of acute respiratory failure survivors, there is need for a better understanding of participant retention and its reporting in this field of research. Hence, our objective was to synthesize participant retention data and associated reporting for this field. METHODS: Two screeners independently searched for acute respiratory failure survivorship studies within a published scoping review to evaluate subject outcomes after hospital discharge in critical illness survivors. RESULTS: There were 21 acute respiratory failure studies (n = 4,342 survivors) over 47 follow-up time points. Six-month follow-up (range: 2-60 months) was the most frequently reported time point, in 81% of studies. Only 1 study (5%) reported accounting for loss to follow-up in sample-size calculation. Retention rates could not be calculated for 5 (24%) studies. In 16 studies reporting on retention across all time points, retention ranged from 32% to 100%. Pooled retention rates at 3, 6, 12, and 24 months were 85%, 89%, 82%, and 88%, respectively. Retention rates did not significantly differ by publication year, participant mean age, or when comparing earlier (3 months) versus each later follow-up time point (6, 12, or 24 months). CONCLUSIONS: Participant retention was generally high but varied greatly across individual studies and time points, with 24% of studies reporting inadequate data to calculate retention rate. High participant retention is possible, but resources for optimizing retention may help studies retain participants. Improved reporting guidelines with greater adherence would be beneficial.
