Table 3 Effects of nudging and pricing strategies on the outcome measures for the total samplea and stratified by pricing arms
Conditions | 25% increase arm (n = 128) | 25% discount arm (n = 136) | 25% increase and discount arm (n = 136) | Total sample (n = 400) | ||||
|---|---|---|---|---|---|---|---|---|
B | 95%CI | B | 95%CI | B | 95%CI | B | 95%CI | |
Percentage of healthy purchases (primary outcome) | ||||||||
 Control | Ref. | Ref. | Ref. | Ref.   | ||||
 Nudging | −0.5 | −2.5; 1.5 | 0.2 | −1.8; 2.2 | 1.8 | −0.1; 3.7 | 0.5 | −0.6; 1.6 |
 Pricing | 0.0 | −1.9; 2.0 | 0.5 | −1.5; 2.5 | 0.7 | −1.2; 2.6 | 0.4 | −0.7; 1.6 |
 Price salience | 1.4 | −0.6; 3.4 | 1.9 | −0.1; 3.9 | 4.5b | 2.6; 6.4 | 2.6a | 1.4; 3.7 |
 Price salience and nudging | 3.0 | 1.1; 5.0 | 2.3 | 0.3; 4.3 | 4.0 | 2.0; 6.0 | 3.1 | 1.9; 4.3 |
Healthy purchases in grams (secondary outcome) | ||||||||
 Control | Ref. | Ref. | Ref. | NA | ||||
 Nudging | − 416.3 | − 1173.7; 341.2 | − 286.4 | − 1050.4; 477.5 | 68.4 | − 741.1; 877.9 | NA | NA |
 Pricing | − 695.5 | − 1451.2; 60.1 | 44.2 | − 720.7; 809.0 | −125.8 | − 949.5; 697.8 | NA | NA |
 Price salience | −29.0 | − 791.2; 733.2 | 1038.5b | 274.6; 1802.3 | 1025.7b | 180.8; 1870.5 | NA | NA |
 Price salience and nudging | −41.1 | − 804.1; 721.9 | 440.6 | − 320.3; 1201.5 | 1646.3 | 734.7; 2557.8 | NA | NA |
Unhealthy purchases in grams (secondary outcome) | ||||||||
 Control | Ref. | Ref. | Ref. | NA | ||||
 Nudging | − 534.6 | − 1480.6; 411.5 | − 756.4 | − 1781.4; 271.9 | − 907.4 | − 1868.4; 53.6 | NA | NA |
 Pricing | − 1194.0 | − 2134.6; − 253.3 | −534.7 | − 1569.2; 499.9 | − 608.8 | − 1576.6; 358.9 | NA | NA |
 Price salience | − 991.5 | − 1935.6; −47.3 | 90.0 | − 941.9; 1122.0 | − 1680.8b | − 2657.0; − 704.5 | NA | NA |
 Price salience and nudging | −1802.7 | − 2742.3; − 863.2 | − 993.0 | − 2028.8; 32.9 | − 885.5 | − 1917.1; 146.0 | NA | NA |