Study strengths and limitations
hematoma, hematomas, haematomas
HEMATOMA, RECURRENCE, HEMATOMAS, HAEMATOMAS
A strength of this study is that all patients received the national standard treatment and care for CSDH. The observation period was relatively short, and no patients were lost to follow up. The study design was simple, and the parameters of interest were easy to observe.One of the limitations is the relatively low number of patients/cases. The patients participated in a randomized trial, why this observational substudy wasn’t designed nor powered for the analyses performed. This probably explains why we only observed a trend towards increased risk of recurrence in drain group B compared to group A. We were also not able to identify special characteristics for the cases in group A. Unfortunately, we did not examine the drains after they were removed, and this might have indicated whether they were obstructed or not.Another limitation could be that we included patients with bilateral hematomas and registered each hematoma as a single case. It has been proposed that bilateral hematomas have different clinical and prognostic characteristics compared to unilateral haematomas. However, there were no demographic or prognostic differences between our groups, and only four patients (giving 6 cases) with bilateral hematomas, experienced symptomatic recurrence, thus justifying the approach of perceiving each hematoma as a single case.