Peritoneal dialysis access outcomes reported in randomized controlled trials: A systematic review

Background: Functional peritoneal dialysis (PD) access is critical to the success of PD therapy. The aim of this review is to describe the spectrum of definitions and methods employed in the measurement of unique outcomes across PD access trials particularly focusing on the outcomes of PD access flow restriction and operative-related outcomes. Methods: Using Cochrane CENTRAL registry, MEDLINE, and EMBASE, we searched for studies restricted to randomized controlled trials (RCTs) involving interventions related to PD access without restrictions on age, language, or publication year. Studies were screened and data abstracted by two independent reviewers. Definitions, outcome measures, and time points of measurements were captured and documented separately. Unique combinations of these variables resulted in reporting the different ways of measurements. Results: Of the 1768 screened studies, 47 RCTs were included among which 817 PD access outcomes were grouped into 7 broad categories. Interventions evaluated in the RCTs were catheter type/configuration (n = 17), insertion technique (n = 15), multiple interventions (n = 3), and other (6 interventions, n = 12). PD access flow restriction (a subcategory of mechanical outcomes) and operative-related outcomes were reported in 91% and 58% of the included trials, respectively. Tip migration was the most frequently reported flow restriction outcome (59% of RCTs) followed by catheter dysfunction (23% of RCTs). Of the components utilized in definition of flow restriction, description of the impaired flow was reported in 37% of RCTs, need for intervention in 42% of RCTs, and presumed etiology of flow restriction in 60% of RCTs. Conclusion: Variability exists in the definitions, reporting methods, choice of outcomes, and analysis of the PD access outcomes across RCTs. Operative-related outcomes remain underreported across RCTs. Outcomes relating to PD access flow restriction were the most common complications reported in the included RCTs but were reported heterogeneously with variability in reporting of the three key components of its definition including description and severity of the flow restriction, the need for intervention and etiology of flow restriction. In the future, defining PD access flow restriction should include all of these components to better evaluate the comparative effect of various PD access interventions.