Prophylactic Negative Pressure Wound Therapy in Obese Women After Cesarean: a Pilot Randomized Trial

Overview of the Proposed Trial

This will be a pilot randomized controlled trial. The investigators chose a randomized controlled trial, the 'gold standard' of clinical research design, with the goal of obtaining the highest quality evidence to inform clinical practice. Randomly allocating subjects to different interventions minimizes selection bias and results in groups that are comparable with regards to important confounding variables, both measured and unmeasured. Additionally, the broad inclusion criteria, simplicity of the interventions, and evaluation of effects of typical use of prophylactic NPWT make this a pragmatic trial. The investigators will follow the Consolidated Standards of Reporting Trials (CONSORT) guidelines in the conduct and reporting of this trial. We will use computer-generated block randomization stratified by study site and BMI category to assign participants to the two interventions. All subjects will receive standard infection prevention measures including skin antisepsis and weight-adjusted prophylactic antibiotics. Analysis will follow the intention-to-treat principle. The use of broad inclusion criteria and intention-to-treat analysis will allow a more conservative estimate of the effect of prophylactic NPWT and allow a better estimate of effectiveness and public health implications of practice change than would pure estimate of efficacy alone.

Conduct of the Trial Recruitment of study subjects: All women admitted to the labor and delivery units of the participating medical centers will be screened against inclusion and exclusion criteria. Eligible subjects will be approached by trained research staff for written consent to participate in the study. Subjects will be randomized only when the decision is made for cesarean delivery.

Randomization and allocation concealment: Enrolled subjects will be randomly assigned in a 1:1 ratio to NPWT or standard care using a computer-generated random sequence generated by the study statistician. A subject's group assignment will be revealed only after the decision is made to perform cesarean delivery.

Blinding: Although blinding of both subjects and physicians would be ideal, blinding is not possible in this trial. We will minimize systematic bias by applying the same standard infection prevention measures in all patients at each site. Further, the research personnel collecting outcomes data will be blinded to the group assignments of the subjects after the standard dressing or NPWT device have been removed. Importantly, diagnosis of the primary outcome will be objectively reviewed centrally by the PI in a blinded fashion using to CDC criteria.