ObjectivesThe aim of the DiaFu study was to evaluate effectiveness and safety of negative pressure wound therapy (NPWT) in patients with diabetic foot wounds in clinical practice.DesignIn this controlled clinical superiority trial with blinded outcome assessment patients were randomised in a 1:1 ratio stratified by study site and ulcer severity grade using a web-based-tool.SettingThis German national study was conducted in 40 surgical and internal medicine inpatient and outpatient facilities specialised in diabetes foot care.Participants368 patients were randomised and 345 participants were included in the modified intention-to-treat (ITT) population. Adult patients suffering from a diabetic foot ulcer at least for 4 weeks and without contraindication for NPWT were allowed to be included.InterventionsNPWT was compared with standard moist wound care (SMWC) according to local standards and guidelines.Primary and secondary outcome measuresPrimary outcome was wound closure within 16 weeks. Secondary outcomes were wound-related and treatment-related adverse events (AEs), amputations, time until optimal wound bed preparation, wound size and wound tissue composition, pain and quality of life (QoL) within 16 weeks, and recurrences and wound closure within 6 months.ResultsIn the ITT population, neither the wound closure rate (difference: n=4 (2.5% (95% CI−4.7% – 9.7%); p=0.53)) nor the time to wound closure (p=0.244) was significantly different between the treatment arms. 191 participants (NPWT 127; SMWC 64) had missing endpoint documentations, premature therapy ends or unauthorised treatment changes. 96 participants in the NPWT arm and 72 participants in the SMWC arm had at least one AE (p=0.007), but only 16 AEs were related to NPWT.ConclusionsNPWT was not superior to SMWC in diabetic foot wounds in German clinical practice. Overall, wound closure rate was low. Documentation deficits and deviations from treatment guidelines negatively impacted the outcome wound closure.Trial registration numbers NCT01480362 and DRKS00003347.