Table 1

Pairwise association (chi-square test statistics and corresponding p-values) between reason to use and type of supplements used (all athletes who use supplements n = 520), testing H₀: independence

No time preparing meal

Avoid sickness

Over-come injury

Doctors' advice

Iron

χ² = 1.798

χ² = 11.940

χ² = 0.350

χ² = 35.004

p = .180

p = .001

p = .554

p <.001

Ginseng

χ² = 7.636

χ² = 0.757

χ² = 3.238

χ² = 4.055

p = .006

p = .384

p = .072

p = .044

Multi Vitamin

χ² = 9.103

χ² = 6.427

χ² = 0.970

χ² = 0.190

p = .003

p = .011

p = .325

p = .892

Vitamin C

χ² = 0.104

χ² = 54.671

χ² = 0.012

χ² = 0.005

p = .747

p <.001

p = .912

p = .944

Magnesium

χ² = 1.267

χ² = 0.140

χ² = 6.997

χ² = 1.883

p = .260

p = .708

p = .008

p = .170

Echinacea

χ² = 1.206

χ² = 40.343

χ² = 0.806

χ² = 0.003

p = .272

p <.001

p = .369

p = .959

*Statistically significant associations (at p ≤ .001) are in bold.

Petróczi et al. Nutrition Journal 2007 6:34   doi:10.1186/1475-2891-6-34