Study | Date range and location | Number of EE cases | Prevalence of KPEE among EE (%) | |
---|---|---|---|---|
Asian studies | Wong et al. [6] | 1994 to 1997; Singapore | 27 | 60 |
Chen et al. [5] | 1992 to 2002; Taiwan | 74 | 61 | |
 | Ang et al. [9] | 1986 to 2007; Singapore | 113 | 54 |
Average prevalence in Asian countries | 58 | |||
Non-Asian studies | Jackson et al. [1] | 1984 to 2001; England | 19 | 5 |
Okada et al. [3] | 1980 to 1990; USA | 28 | 3.6 | |
 | Average prevalence in western countries | 4.3 |