Topical Area: Nutrition Education and Behavioral Science
To test the construct validity of the Sodium Advice Score (SAS). The SAS is a tool developed to measure the quality of brief advice provided by health care providers (HCP) about dietary sodium reduction. The validation of this tool will support its implementation in a behavioural intervention trial.
Methods : Thirty English speaking patients with a diagnosis of hypertension and no memory impairments were recruited from a primary care clinic in Ontario, Canada. Patients were randomized to a high quality dietary sodium advice group or to a low quality dietary sodium advice group. Each intervention was delivered by a registered dietitian and took no longer than 5-7 minutes for high quality advice and 1-2 minutes for low quality advice. After the dietary sodium advice was provided the patient completed the SAS tool (< 5 minutes). Frequency, type and duration of advice was assessed by the SAS tool, which had a maximum score of 16. Therefore, the high quality advice had an expected SAS score of 16. The low quality advice had an expected SAS score of 5.
Results : Patients included were 71.3 ± 7.9 years old and 53% were male. Overall, 43% and 47% of patients had received previous counseling from a dietitian and family doctor, respectively. Mean daily sodium intakes of 2593 ± 1403mg/day and 3040 ± 2283mg/day were similar between high and low quality advice groups. The mean SAS score was 6.9 ± 3.6 (range: 2 to 14) in the low quality advice group and 14.5 ± 1.5 (range: 10 to 16) in the high quality advice group. The high quality advice scores observed were statistically similar to the expected scores (p=0.001), however the low advice scores were not. Overall, the low quality advice score was significantly lower than the high quality advice score (p< 0.000).
The SAS tool showed evidence of construct validity as it can differentiate between high and low quality sodium reduction advice provided by HCPs. It can be used as a valid tool for measuring quality of brief sodium reduction advice by HCPs in future research.
Funding Sources : Heart and Stroke Foundation of Canada