Valence, sources, arguments and use of research evidence in Mexican newspaper articles about the food labelling policy, overall and by newspaper political orientation: four Mexican Newspapers, 2019–2020
| Total (N=361) n (%) | Centre left (N=129) n (%) | Centre right (N=232) n (%) | P value* | |
| Overall valence towards the policy | ||||
| Neutral | 195 (54.0) | 72 (55.8) | 123 (53.0) | 0.61 |
| In favour | 96 (26.6) | 37 (28.7) | 59 (25.4) | 0.05 |
| Against | 70 (19.4) | 20 (15.5) | 50 (21.6) | 0.16 |
| Sources | ||||
| Academic | 48 (13.3) | 17 (13.2) | 31 (13.4) | 0.96 |
| Government | 72 (19.9) | 34 (26.4) | 38 (16.4) | 0.02 |
| Food industry | 82 (22.7) | 29 (22.5) | 53 (22.8) | 0.94 |
| Public health advocate | 62 (17.2) | 26 (20.2) | 36 (15.5) | 0.26 |
| Citizen | 0 | 0 | 0 | -- |
| Arguments | ||||
| Lack of evidence | 21 (5.8) | 5 (3.9) | 16 (6.9) | 0.24 |
| Labels are educational | 116 (32.1) | 49 (38.0) | 67 (28.9) | 0.08 |
| Economics | 93 (25.8) | 34 (26.4) | 59 (25.4) | 0.85 |
| Policy precedence | 114 (31.6) | 32 (24.8) | 82 (35.3) | 0.04 |
| Use of and type of research evidence | ||||
| None | 278 (77.0) | 105 (81.4) | 173 (74.6) | 0.14 |
| Any type† | 83 (23.0) | 24 (18.6) | 59 (25.4) | 0.14 |
| Type 1 | 48 (12.7) | 18 (14.0) | 28 (12.1) | 0.61 |
| Type 2 | 17 (4.7) | 6 (4.7) | 11 (4.7) | 0.97 |
| Type 3 | 23 (5.8) | 3 (2.3) | 18 (7.8) | 0.03 |
| Food label research | 38 (10.5) | 10 (7.8) | 28 (12.1) | 0.20 |
Bold indicates a statistically significant result.
*Two-sample t-test.
†Note: Consistent with Brownson et al,20 type 1 research is defined as epidemiological research, type 2 is lab-based or university-based research, and type 3 is policy implementation and context research. For these analyses, the unit of analysis is the type of research evidence cited within an article, and any single article may have included multiple types of research; as such, the total number of articles with any type of research is greater than the number of articles that had any type of research evidence (N=83).