4.1
The committee noted considerable evidence to show the effectiveness of PICO in reducing rates of surgical site infections (18 studies) and seromas (7 studies). The company did meta-analyses using a fixed-effect model, whereas the external assessment centre (EAC) used a random-effects model. The committee considered that the EAC's approach was more appropriate because of the wide variation in the study populations, interventions and the definitions of surgical site infections. The committee concluded that there was convincing evidence that using PICO dressings reduces surgical site infections and seromas in people with closed surgical incisions. The committee considered that there was less certainty about how PICO dressings affect other surgical site complications (such as wound dehiscence, haematoma, delayed healing or excessive scarring) because of the small number of studies in the analyses.