Table 5.

Incremental cost effectiveness of policy of tight control of blood pressure compared with less tight control. Means (95% confidence intervals) calculated with Fieller’s method, costs based on 1997 values

Cost and outcome measure	Costs and health effects discounted			Costs only discounted
	6% discount	3% discount		6% discount	3% discount
Time free from diabetes related end points:
Costs for standard practice	1049 (−4635 to 52 373)	599 (−3400 to 13 226)		434 (−1663 to 6255)	390 (−2086 to 6255)
Costs driven by trial protocol*	−333 (−10 767 to 23 882)	NA		NA	NA
Life years gained**:
Costs for standard practice	720	422		291	261
Costs driven by trial protocol*	−229	NA		NA	NA

NA=Not applicable. 

^*Negative ratios costs indicate tight control is both more effective and cost saving. 

^**Estimated life years gained from tight control were not significant at 5% level (see table 4), hence 95% confidence intervals cannot be defined.