Assessing the uncertainty of treatment outcomes in a previous systematic review of venous leg ulcer randomized controlled trials: Additional secondary analysis

Identifying outcomes reported in trials of interventions in venous leg ulceration for a core outcome set development: A scoping review

BACKGROUND

Venous leg ulceration is a chronic, recurring, condition causing significant patient morbidity. Randomised controlled trials evaluating treatments for venous leg ulceration provide evidence for clinical decision-making. For trial findings to be useful, outcomes measured need to be clinically meaningful, and consistently and fully reported across trials. A core outcome set is an agreed and standardised set of outcomes which should be, as a minimum, reported in all trials for a given indication.

AIM

To identify the outcome domains and outcomes reported in trials of interventions for venous leg ulceration.

METHODS

A scoping review of the literature was carried out. Randomised controlled trials within Cochrane systematic reviews looking at venous leg ulceration interventions and qualitative studies exploring venous leg ulceration were included.

RESULTS

The review identified 807 outcomes from randomised controlled trials and 15 outcomes from qualitative studies, and these were grouped into 11 outcome domains: healing, patient reported symptoms, clinician reported symptoms, carer reported symptoms, life impacts, clinical signs, clinical measurement, performance of the intervention, resource use (supplies and clinician time) and adverse events. The outcome domain 'healing' included 111 outcomes, 'symptoms' 109, 'life impacts' 30, 'clinical signs' 88, 'clinical measurement' 184, 'performance of the intervention' 58, 'resource use' 52 and 'adverse events' 190.

CONCLUSION

The scoping review identified a large number of outcomes (n = 822) across 11 related outcome domains, supporting the need for a core outcome set.

Assessing the uncertainty of treatment outcomes in a previous systematic review of venous leg ulcer randomized controlled trials: Additional secondary analysis

In this secondary analysis of a previous systematic review, we assessed randomized controlled trials evaluating treatments of venous leg ulcers in terms of factors that affect risk of bias at the study level and thus uncertainty of outcomes obtained from the interventions. Articles that assessed the wound bed condition in venous leg ulcers and that were published in English between 1998 and May 22, 2018 were previously searched in PubMed, Embase, CINAHL, CENTRAL, Scopus, Science Direct, and Web of Science. Duplicates and retracted articles were excluded. The following data were extracted to assess the risk of bias: treatment groups; primary and secondary endpoints that were statistically tested between groups, including their results and p values; whether blinding of patients and assessors was done; whether allocation concealment was adequate; whether an intention‐to‐treat analysis was conducted; whether an appropriate power calculation was correctly done; and whether an appropriate multiplicity adjustment was made, as necessary. Pre‐ and post‐study power calculations were made. The step‐up Hochberg procedure adjusted for multiplicity. Results were analysed for all studies, pre‐2013 studies, and 2013/post‐2013 studies. We included 142 randomized controlled trials that evaluated 14,141 patients. Most studies lacked blinding (72.5–77.5%) and allocation concealment (88.7%). Only 49.3% of trials provided a power calculation, with 27.5% having an appropriate calculation correctly done. Adequate statistical power of the primary endpoint was found in 27.2% of trials. The lack of multiplicity adjustment in 98.6% of studies affected the uncertainty of outcomes in 20% of studies, with the majority of the secondary endpoints (67.7%) in those studies becoming non‐significant after multiplicity adjustment. Recent studies tended to weakly demonstrate improved certainty of outcomes. Venous leg ulcer randomized controlled trials have a high degree of uncertainty associated with treatment outcomes. Greater attention to trial design and conduct is needed to improve the evidence base.