Table 2. Methodological characteristics of oral cancer cost studies from 2001 to 2020.
| Study | Type of study* | Study design | Data source | Cost-of-illness based approach | Estimation of resources and cost | Time horizon (years) | Perspective |
|---|---|---|---|---|---|---|---|
| Longitudinal studies | |||||||
| 1. Kim, 2011 [19] | Cost-of-illness | Retrospective longitudinal | Secondary data | Incidence | Single study-based | 5 | Government |
| 2. Polesel, 2019 [26] | Cost-of-illness | Prospective longitudinal | Secondary data | Incidence | Single study-based | 2 | Unclear |
| 3. Jacobson, 2012 [24] | Cost analysis | Retrospective longitudinal | Secondary data | Incidence | Single study-based | 1 | Government and health insurance provider |
| 4. Pollaers, 2019 [25] | Cost analysis | Retrospective longitudinal | Secondary data | Incidence | Single study-based | 5 | Government |
| 5. Huang, 2020 [27] | Cost-of-illness | Retrospective longitudinal | Secondary data | Incidence | Single study-based | 5 | Societal and Government |
| Cross-sectional and case control studies | |||||||
| 6. Rezapour, 2018 [29] | Cost-of-illness | Cross-sectional | Primary and secondary data | Prevalence | Single study-based | 1 | Societal |
| 7. van Aghtoven, 2001 [35] | Cost analysis | Cross-sectional | Primary and secondary data | Prevalence | Model-based | 10 | Hospital |
| 8. Fisher, 2018 [36] | Cost analysis | Cross-sectional | Primary and secondary data | Prevalence | Single study-based | 3 | Government and health insurance provider |
| 9. Nijdam, 2005 [32] | Cost-of-illness | Cross-sectional | Primary data | Prevalence | Single study-based | 4 | Hospital |
| 10. Amarasinghe, 2019 [18] | Cost-of-illness | Cross-sectional | Primary data | Prevalence | Single study-based | 1 | Societal |
| 11. Goyal, 2014 [33] | Cost analysis | Cross-sectional | Primary data | Prevalence | Single study-based | ~1 year 9 months | Hospital |
| 12. Zavras, 2002 [37] | Cost analysis | Cross-sectional | Primary data | Not clear | Single study-based | at least 6 months | Hospital |
| 13. van der Linden, 2016 [38] | Cost analysis | Cross-sectional | Primary data | Not clear | Single study-based | 1 | Hospital |
| 14. Epstein, 2008 [34] | Cost analysis | Cross-sectional | Secondary data | Prevalence | Single study-based | 1 | Government |
| 15. Lafuma, 2019 [30] | Cost-of-illness | Cross-sectional | Secondary data | Prevalence | Single study-based | 5 | Societal |
| 16. Patterson, 2020 [31] | Cost-of-illness | Cross-sectional | Secondary data | Incidence | Model-based | 1 | Societal |
| 17. Han, 2010 [39] | Cost analysis | Cross-sectional | Secondary data | Prevalence | Single study-based | 1 | Hospital |
| 18. Enomoto, 2015 [40] | Cost analysis | Cross-sectional | Secondary data | Prevalence | Single study-based | 1 | Government |
| 19. Lairson, 2017 [41] | Cost-of-illness | Case-control | Secondary data | Not clear | Single study-based | 2 | Government and health insurance provider |
| 20. Kim, 2020 [19] | Cost-of-illness | Cross-sectional | Secondary data | Prevalence | Single study-based | 5 | Societal and Government |
| Cross-sectional studies based on information system data | |||||||
| 21. Vatanasapt, 2012 [20] | Cost-of-illness | Cross-sectional | Secondary data | Incidence | Single study-based | 1 | Government |
| 22. Klussmann, 2013 [28] | Cost-of-illness | Cross-sectional | Secondary data | Prevalence | Single study-based | 1 | Societal |
| 23. Keeping, 2018 [21] | Cost-of-illness | Cross-sectional | Secondary data | Prevalence | Single study-based | 5 | Hospital |
| 24. Milani, 2021 [22] | Cost-of-illness | Cross-sectional | Secondary data | Prevalence | Single study-based | 9 | Government |
* We classified the type of study according to the comprehensiveness of the cost estimation. If the cost estimation was restricted to a small sample, the study was classified as cost analysis, generally a group of patients from one hospital; and if the cost estimation included a city, state or country, the study was classified as cost-of-illness.