Data sources

According to the 10th revision of the International Classification of Diseases (ICD), C18-C21.9 (C18: Malignant neoplasm of the colon; C19: Malignant neoplasm of rectosigmoid junction; C20: Malignant neoplasm of the rectum; C21: Malignant neoplasm of anus and anal canal), D01.0-D01.3 (D01.0: Carcinoma in situ: Colon; D01.1: Carcinoma in situ: Rectosigmoid junction; D01.2: Carcinoma in situ: Rectum; D01.3: Carcinoma in situ: Anus and anal canal), D12-D12.9 (Benign neoplasm of colon, rectum, anus and anal canal), and D37.3-D37.5 (D37.3: Neoplasm of uncertain or unknown behavior: Appendix; D37.4: Neoplasm of uncertain or unknown behavior: Colon; D37.5: Neoplasm of uncertain or unknown behavior: Rectum) codes were selected as CRC death, which was mapped to B.1.6 GBD code as CRC [13, 17]. In addition, ICD-10 codes of C18-C19.0, C20, C21-C21.8, Z12.1-Z12.13 (Z12.1: Special screening examination for neoplasm of the intestinal tract), Z85.03-Z85.048 (Z85.0: Personal history of malignant neoplasm of digestive organs), and Z86.010 (Z86.0: Personal history of other neoplasms) were mapped to define CRC new cases [18].

Here, we focus on the QCI to show the inequity in the quality of CRC care by using GBD 1990–2019 data [19]. The details of utilized methods have been explained somewhere else [20]. In brief, we used four stages in order to compute QCI, which were data acquisition (e.g. retrieving data from GBD, retrieving primary measures like DALY, YLL, YLD, death, incidence, prevalence, and manually inspection of each measure for zero estimates), data curation (this step was optional and aimed to reduce the size of the retrieved data), data analysis (i.e. secondary measures calculation and implementation of the principal component analysis (PCA)), and data visualization.