Quality Assessment of Colorectal Cancer Surgery

The StuDoQ|Colon carcinoma and StuDoQ|Rectal carcinoma registers are prospectively documented databases for surgical interventions in colorectal carcinomas, which were set up by the DGAV in January 2010 (www.dgav.de/studoq, www.en.studoq.de). They were developed to facilitate the assessment of the quality and risk factors of colorectal cancer surgery in Germany. The declaration of consent, ethic approvment and the data security procedures were approved by the Society for Technology, Methods and Infrastructure for Networked Medical Research (http://www.tmf-ev.de). Written consent was obtained from all participants. The publication guidelines were determined by the DGAV (http://www.dgav.de/studoq/datenschutzkonzept-und-publikations guidelines.html). The data from participating centers are entered prospectively in pseudonymized form using a browser-based tool and subjected to automatic plausibility checks. Validation by cross-checking with institutional medical control data is part of the annual certification process. For the present study, all cases that underwent curative resection due to colorectal cancer were identified in the StuDoQ|Colon cancer and StuDoQ|Rectal cancer registry, and relevant demographic data, comorbidities, as well as information on operations, histology and perioperative history for analysis extracted in anonymous form. Full wall excision, simple polypectomy, endoscopic mucosal resection, and other endoluminal procedures, as well as palliative interventions regardless of the size of the operation, were excluded. Basic registration structures are comparable to the StuDoQ|Pancreas registration [14 (link)].
Postoperative complications included anastomotic leakage (grade C) [15 (link), 16 (link)], infection of the surgical site [17 (link)], Clavien-Dindo classification (CDC) [18 (link)], burst abdomen, reoperation, and hospital mortality. They were defined as either present or not present. Additional postoperative parameters that were assessed were the need for unscheduled postoperative ventilation lasting more than 48 hours, pneumonia, length of stay (LOS), and readmission. Postoperative total morbidity was summarized as none (CDC 0), minor (CDC 1–2), severe (CDC 3a-4), and fatal (CDC 5) according to the CDC. Patients were counted as MTL30 positive if they had died within 30 days after index operation, the postoperative length of stay exceeded 30 days or if they had been transferred to another acute hospital or in hospital unit (e.g. transfer to a tertiary center due to surgical complications or to internal medicine due to postoperative pulmonary emboly). Transfer to a postoperative rehabilitation did not count as positive.
Statistical analysis was performed with a bilateral significance level of 0.05. Scale variables were expressed as median and range and categorical parameters as absolute frequency and percentage. Univariate analysis was performed using the chi-square test for categorical variables and the Mann-Whitney test for ratio variables.
All variables with a p-value <0.1 in the univariate analysis were included in the multivariate analysis. The multivariable analysis was carried out by logistic regression.