| Rate ratio | RII | ||
---|---|---|---|---|
None/Primary | Secondary | Tertiary | ||
1983-1987 | 0.66 (0.54-0.82) | 0.67 (0.54-0.82) | 1 (reference) | 0.84 (0.68-1.03) |
1988-1992 | 0.60 (0.51-0.70) | 0.63 (0.54-0.73) | 1 (reference) | 0.72 (0.60-0.85) |
1993-1997 | 0.96 (0.84-1.10) | 1.03 (0.91-1.16) | 1 (reference) | 0.92 (0.80-1.07) |
1998-2002 | 0.86 (0.77-0.96) | 0.87 (0.79-0.95) | 1 (reference) | 0.88 (0.77-1.00) |
2003-2007 | 1.38 (1.25-1.52) | 1.05 (0.97-1.13) | 1 (reference) | 1.45 (1.29-1.63) |
2008-2012 | 1.31 (1.19-1.43) | 0.91 (0.86-0.97) | 1 (reference) | 1.23 (1.10-1.36) |
p value for trend | Â | Â | Â | <.0001 |