Table 3.
Characteristics of the cost-of-illness studies included in the review
| Characteristic | Number of studies (%) |
|---|---|
| Prevalence or incidence-based estimation | |
| Prevalence | 59 (94%) |
| Incidence | 4 (6%) |
| Design | |
| Cross-sectional | 40 (63%) |
| Cohort | 10 (16%) |
| Cohort compared with a control cohort | 7 (11%) |
| Mathematical model | 5 (8%) |
| Cost study nested in a clinical trial | 1 (2%) |
| Prospective or retrospective | |
| Retrospective | 55 (87%) |
| Prospective | 4 (6%) |
| Source of patients | |
| Registries or databases | 32 (51%) |
| Hospital or other centres | 24 (38%) |
| Patients’ organisations | 18 (29%) |
| Source of data | |
| Questionnaires | 42 (67%) |
| Registries or databases | 30 (48%) |
| Other | 4 (6%) |
| Bottom-up or top-down approaches | |
| Bottom-up | 59 (94%) |
| Top-down | 0 (0%) |
| Mixed | 4 (6%) |
| Time horizon | |
| A year | 52 (83%) |
| Lifetime | 4 (6%) |
| Other | 11 (17%) |
| Perspective | |
| Societal | 40 (63%) |
| Third payer/health system/government | 17 (27%) |
| Patients and families | 7 (11%) |
| Hospital | 3 (5%) |
| Costs included in the analysis | |
| Medical costs | 63 (100%) |
| Non-medical costs | 38 (60%) |
| Lost productivity costs | 43 (68%) |
| Informal care costs | 27 (43%) |
| Method for the estimation of lost productivity costs | |
| Human capital approach | 34 (54%) |
| Friction cost approach | 2 (3%) |
| Other | 8 (13%) |