Page 37 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Statistical analysis
Descriptive statistics will include median and interquartile range for continuous variables, and absolute numbers (with %) for categorical variables. Randomized groups will be compared for imbalance without formal statistical testing. Analysis will be by intention-to-treat. Di erences between randomized groups will be tested with appropriate statistical methods, including t-tests or Mann- Whitney tests for continuous variables (considering whether the normality assumption is rejected by the Kolmogorov-Smirnov test with Lilliefors correction test), and chi-square tests for categorical variables. The primary outcome (incisional hernia) will be analyzed with Kaplan–Meier analysis and a Cox regression analysis, to adjust for any loss to follow up between 30 days and 1 year after surgery. The primary analysis is a covariate adjusted Cox model, which includes the following prede ned, well-establihed predictors of incisional hernia: abdominal aneurysm aorta (AAA), obesity, diabetes, corticosteroid usage, radiotherapy, COPD, smoking, age, cancer, inguinal hernia, cardiovascular disease and collagen disorders.
Subgroup e ects will be assessed by tests of interaction to prevent overinterpretation of apparent di erences in e ectiveness. Quality of life data will be analyzed by paired T-tests, comparing baseline with follow-up measurements, and repeated measures analysis. A two-sided p<0•05 will be taken to indicate statistical signi cance.
Monitoring
The Erasmus University Medical center is the sponsor of this trial. Adverse events are de ned as any undesirable experience occurring to a subject during a clinical trial, whether or not considered related to the investigational intervention. All adverse events reported spontaneously by the subject or observed by the investigator or his sta will be recorded. A serious adverse event (SAE) is any untoward medical occurrence or e ect that at any dose results in death; is life threatening (at the time of the event); requires hospitalization or prolongation of existing inpatients’ hospitalization; results in persistent or signi cant disability or incapacity; is a new event of the trial likely to a ect the safety of the subjects, such as an unexpected outcome of an adverse reaction, major safety nding from a newly completed animal study, etc. All SAEs will be reported to the accredited Medical Ethical Committee (MEC) that approved the protocol, according to the requirements of that MEC. Serious Adverse events are death and burst abdomen. Adverse Events are readmission and reoperations.
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STITCH protocol
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