Table 2.
Distribution of 138 included studies reporting costs associated with VI and its major causes by super-region, study participants age-range, study design, perspective of analysis and epidemiological approach.
| Studies characteristics | General VI studies |
Condition-specific studies |
Total |
|||
|---|---|---|---|---|---|---|
| n | % | n | % | n | % | |
| Number of super-regions estimates (n = 147)a | ||||||
| High Income | 30 | 70% | 66 | 63% | 96 | 65% |
| South Asia | 2 | 5% | 8 | 8% | 10 | 7% |
| Southeast Asia, East Asia, and Oceania | 3 | 7% | 5 | 5% | 8 | 5% |
| Latin America and Caribbean | 1 | 2% | 6 | 6% | 7 | 5% |
| Sub-Saharan Africa | 1 | 2% | 6 | 6% | 7 | 5% |
| Central Europe, Eastern Europe, and Central Asia | 1 | 2% | 2 | 2% | 3 | 2% |
| North Africa and Middle East | 0 | 0% | 2 | 2% | 2 | 1% |
| Global | 5 | 12% | 9 | 9% | 14 | 10% |
| Study participants age-range (n = 138) | ||||||
| All ages | 21 | 55% | 16 | 16% | 37 | 27% |
| Youth, Adults and Seniors (all > 15 years) | 16 | 42% | 64 | 64% | 80 | 58% |
| Children and Youth only (all < 20 years) | 1 | 3% | 3 | 3% | 4 | 3% |
| Age range not stated | 0 | 0% | 17 | 17% | 17 | 12% |
| Study design (n = 138) | ||||||
| Cost of illness study | 28 | 74% | 56 | 56% | 84 | 61% |
| Cost analysis | 4 | 11% | 24 | 24% | 28 | 20% |
| Cost effectiveness study | 0 | 0% | 17 | 17% | 17 | 12% |
| Other b | 6 | 16% | 3 | 3% | 9 | 7% |
| Study perspective (n = 138)c | ||||||
| Societal | 21 | 55% | 27 | 27% | 48 | 35% |
| Healthcare system | 4 | 11% | 21 | 21% | 25 | 18% |
| Third party payer | 1 | 3% | 22 | 22% | 23 | 17% |
| Patient | 7 | 18% | 7 | 7% | 14 | 10% |
| Hospital | 0 | 0% | 7 | 7% | 7 | 5% |
| Other d | 4 | 11% | 2 | 2% | 6 | 5% |
| Multiple e | 0 | 0% | 11 | 11% | 11 | 8% |
| Not applicable f | 1 | 3% | 3 | 3% | 4 | 3% |
| Study epidemiological approach (n = 138) | ||||||
| Prevalence-based | 34 | 89% | 90 | 90% | 124 | 90% |
| Incidence-based | 3 | 8% | 5 | 5% | 8 | 6% |
| Incidence and prevalence-based | 0 | 0% | 3 | 3% | 3 | 2% |
| Not applicable f | 1 | 3% | 2 | 2% | 3 | 2% |
Studies reported costs estimates in more than one super-region therefore the sum of studies distributed by super-region (n = 147) is greater than the number of studies (n = 138);
Includes 4 case control studies, 2 case reports, 1 study reporting each of a method to collect personal costs, employment data and data on informal care;
We assigned a study perspective in 52 studies when authors had not;
Includes studies adopting a governmental (n = 4), caregiver (n = 1) and employer (n = 1) perspective;
Includes economic evaluation results from 2 perspectives, most often (societal or healthcare system perspective together (n = 3) or combined with other perspectives (n = 6). Other combinations included patient perspective reported with other perspectives (n = 2);
These studies reported an estimate of the impact of vision impairment on the labour market in terms of well-being and thus did not require a study perspective or an epidemiological approach.