# GATHER checklist (Supporting File 10)

**Manuscript:** Estimated Burden of Bladder Cancer in the United States and Its States, 1990–2021: A Descriptive Analysis of the Global Burden of Disease Study 2021

**Reporting guideline:** Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) (Stevens et al., *Lancet* 2016;388:e19–e23).

**Nature of the study:** secondary, descriptive analysis of published GBD 2021 estimates. The authors did not synthesise primary data sources or fit the GBD models; items about data inputs and model building therefore refer to the GBD 2021 publications.


| # | GATHER item | Where reported | 
| --- | --- | --- | 
| **Objectives and funding** | | |
| 1 | Define the indicator(s), populations (age, sex, geographic entities) and time period(s) for which estimates were made | Abstract; Introduction (final paragraph); Section 3.1 (measures, sexes, age groups, 50 states + DC, comparator regions, y measure) | |
| 2 | List the funding sources | Declarations – Funding (none) |
| **Data inputs – synthesised in the study** | | |
| 3 | Describe how data were identified and accessed | Not applicable to the authors’ analysis (no primary data synthesised). Access to GBD 2021 outputs: Section 3.1 (GHDx GBD Results Tool) |
| 4 | Inclusion/exclusion criteria; ad-hoc exclusions | Not applicable (GBD input-data criteria are described in refs [Ferrari 2024; Naghavi 2024]). Authors’ extraction scope: Section 3.1 |
| 5 | Information on all included data sources and their characteristics | Not applicable; see GBD 2021 publications and the GHDx input-source catalogue |
| 6 | Categories of input data with potentially important biases | Not applicable; modelled-data limitations in Section 5.6 |
| **Data inputs – not synthesised in the study** | | |
| 7 | Describe and give sources for any other data inputs | Census Bureau figure on population aged ≥65 (Section 5.3) is cited to the Census Bureau; ACS/SEER figures in the Introduction and Section 5.2 are cited to their sources |
| **All data inputs** | | |
| 8 | Provide data inputs in a file format from which data can be extracted | Cleaned GBD extracts (RDS) in the GitHub repository (`data/`); Section 3.4; Declarations – Availability of data and materials |
| **Data analysis** | | |
| 9 | Conceptual overview of the analysis method | Section 3.1 and Section 3.3.1 (summary measures: percent change, male:female ratio, ranks) |
| 10 | Detailed description of all analysis steps, including formulae | Section 3.2 (age-standardization formula); Section 3.3.2 (log-ratio formulae for percent change and rate ratios) |
| 11 | How candidate models were evaluated and final models selected | Not applicable: no statistical models were fitted by the authors; no trend model (Section 3.3.1) |
| 12 | Results of model-performance evaluation and sensitivity analyses | Not applicable (no models fitted; no sensitivity analyses performed) |
| 13 | Methods for calculating uncertainty; sources of uncertainty included and excluded | Section 3.3.1 (GBD UIs) and Section 3.3.2 (approximate UIs for derived quantities; assumptions of independence and log-symmetry; direction of bias unknown) |
| 14 | How analytic/statistical source code can be accessed | Section 3.4; Declarations – Availability of data and materials (GitHub repository, commit and archived DOI) |
| **Results and discussion** | | |
| 15 | Published estimates in a file format from which data can be extracted | Supporting Files 1 and 2 (CSV); repository RDS data |
| 16 | Quantitative measure of uncertainty | 95% UIs for all rates; approximate 95% UIs for percent changes and ratios (Abstract; Section 4; Tables 1 and 2) |
| 17 | Interpret results in light of existing evidence; reasons for changes if updating previous estimates | Sections 5.1–5.5; GBD 2021 versus GBD 2023 in Section 5.6 |
| 18 | Limitations, including modelling assumptions and data limitations that intersect the estimates | Section 5.6; Section 3.3.2 |