Table 5: Proportion of advertisement claims supported or not supported by different kinds of evidence, distinguished by year.

 

Supported by

2000

(n = 1518)

2004

(n = 1494)

2008

(n = 785)

All years

(n = 3797)

High-quality evidence

9%

15%

37%

17%

Low-quality evidence

3%

5%

4%

4%

Expertsí opinion

7%

3%

2%

4%

Reference not available

15%

27%

11%

19%

Not supported by stated evidence

9%

5%

5%

6%

No evidence stated

57%

46%

42%

49%