Using television 'info-tainment' to promote health: Evaluation of a programme to reduce dietary sodium intake

The impact of materials sent to viewers of an Australian national television programme urging them to reduce dietary sodium was evaluated, with pre-trial and 3 month post-trial changes in sodium: potassium (Na: K) ratio in a first morning urine specimen, and in scores on the Sodium Avoidance Checklist (SAC) as dependent variables. Two hundred and twenty two intervention subjects were randomly allocated to four groups, each with increasing levels of educational intervention. Differences in the intervention groups' pre- and post-trial Na: K ratios and their estimates of dietary sodium intake were compared with those of a control group of non-viewers. Two intervention groups, both of which received 28 days supply of urine chloride self-testing dipsticks achieved statistically significant > 10% reductions in Na: K (P = 0.02). One of these groups, which also received a single session of education about reducing sodium in the diet, achieved statistically significant >20% reductions in Na: K (P < 0.001). This pattern of results was also obtained for the SAC, with differences between groups being statistically significant for reductions in SAC scores at the 20, 40 and 50% levels. In addition, the SAC scores suggested that frequency of television viewing did have a significant effect on the intake of dietary sodium. The chloride urinary dipstick may be an important motivational adjunct to efforts at dietary sodium reduction.