Table 2 Study-level characteristics by study design underlying the main comparison reported in this review
Reference and country | Eligibility criteria | Recruitment strategy | Attrition and sample size (a, b) | Availability | EPHPP QATQS score (c) |
|---|---|---|---|---|---|
Randomised Controlled Trials (RCT) | |||||
 Arndt, 2016, study 1, USA [43] | Exclusion: Individuals who seldom or never ate meat, did not eat meat weekly, consumed no meat containing meal in the past 3 days, ate no serving of meat on an average day, less than 10% of what they ate on an average day is meat, believed that eating meat is bad, disliked eating meat, identified as vegetarians or vegans. | Individual recruitment through Amazon Mechanical Turk. | T1: 0% (179 to 179) | Unpublished, available online | Low |
 Arndt, 2016, study 2, USA [43] | See Arndt 2016, study 1. | See Arndt 2016, study 1. | T1: 0% (296 to 296) | Unpublished, available online | Low |
 Carfora et al., 2017, Italy [32] | Exclusion: Individuals following specific diets (such as vegan, vegetarian, protein, slimming and/or fattening diets). | E-mails were sent to a convenience sample of Italian undergraduates. | T1: 9.68% (124 to112) | Peer reviewed publication | Medium |
 Carfora et al., 2017, Italy [31] | Participants had to have a mobile phone supporting SMS. Exclusion: Individuals following specific diets or who participated to the other study by Carfora. | See Carfora et al., 2017 above. | T1: 4.2% (238 to 228) | Peer reviewed publication | Medium |
 Emmons et al., 2005, USA [25] | Participants had to be between 40 and 75 years, have an adenomatous colon polyp removed within 4 weeks of recruitment, have no personal history of CRC, be competent in English, be capable of informed consent, and be reachable by phone. | Eligible individuals were sent a letter describing the study and were later contacted by phone unless they opted out. | T1: 12.59% (1247 to 1090) | Peer reviewed publication | Strong |
 Emmons et al., 2005, USA [26] | Participants had to be 18 to 75 years old, have a visit scheduled with a participating healthcare provider, be competent in English or Spanish, and come from an eligible working-class neighbourhood. Exclusion: Individuals who had cancer at enrolment, or who were employed by the participating health centres or at a worksite participating in the companion study (Emmons et al., 2005 (a)). | See Emmons et al., 2005 above. | T1: 12% (2219 to 1954) | Peer reviewed publication | Medium |
 Fehrenbach, 2013, USA [33] | Exclusion: Individuals who were vegan, vegetarian, or pescetarian, self-reported insufficient attention to the message, previously completed part or all of the survey, had incomplete data, received the wrong intervention, and international or non-undergraduate students. | Individuals were sampled from communication classes at a large university in Arizona in exchange for extra credits. | T1: 10.1% (208 to 187) | Unpublished, not available online | Low |
 Fehrenbach, 2015, USA [37] | Participants had to be U.S. resident, 25–44 years of age and consume meat 7+ times/week. Exclusion: Individuals who took the survey on mobile devices, failed an attention filter, or completed the survey too quickly or without viewing the video. | Individual recruitment from a national panel using Qualtrics. | T1: 1.61% (373 to 367) | Unpublished, available online | Low |
T2: 58.98% (373 to 153) | |||||
 Graham et al., 2017, New Zealand [39] | Participants had to reside in New Zealand and pass an attention filter. | Individual recruitment through convenience and snowball techniques on a university campus, and advertisement outside the university campus. | T1: 0% | Peer reviewed publication | Medium |
 Klöckner et al., 2017, study 1, Netherlands [44] | Participants had to be adult Norwegians. | Individuals were randomly selected from the population registry and sent an invitation letter. | T1: 17.1% (1047 to 868) | Peer reviewed publication | Low |
 Klöckner et al., 2017, study 2, Netherlands [44] | Participants had to be adults. | Individuals were recruited from the professional online panel TNS Gallup. | T1: 8.63% (3895 to 3559) | Peer reviewed publication | Medium |
 Tian et al., 2016, study 1, France and China [49] | Exclusion: Individuals who identified as vegetarians. | Individuals were recruited using social media and internal university advertisement. | T1: 41.47% (885 to 518) | Peer reviewed publication | Low |
 Tian et al., 2016, study 2, France and China [49] | See Tian et al., 2016, study 1. | See Tian et al., 2016, study 1. | T1: 14.52% (606 to 518) | Peer reviewed publication | Low |
 Vibhuti, 2016, USA [40] | Participants had to be adults and reside in the US. | Individual recruitment through Amazon Mechanical Turk. | T1: 0,97% (412 to 408) | Unpublished, available online | Low |
Non-randomised Controlled Trials (CT) | |||||
 Allen et al., 2012, Australia [42] | N/A | The survey was sent to a random sample of individuals drawn from the telephone directory. | T1: 1.82% (220 to 216) | Peer reviewed publication | Low |
T2: 55.91% (220 to 97) | |||||
 Berndsen et al., 2005, study 1, Netherlands [34] | Participants had to be meat eaters. | Individual recruitment through internal university advertisement | T1: 0% (141 to 141) | Peer reviewed publication | Low |
T2: 0% (141 to 141) | |||||
 Berndsen et al., 2005, study 2, Netherlands [34] | See Berndsen et al., 2005, study 1. | See Berndsen et al., 2005, study 1. | T1: 0% (92 to 92) | Peer reviewed publication | Low |
T2: 0% (92 to 92) | |||||
 Bertolotti et al., 2016, Italy [38] | Participants had to be over 60 years old, had to volunteer to participate, and complete sufficient sections of the questionnaire. | Active recruitment of individuals from socio-recreational centres for the elderly in Milan, Italy. | T1: 19.17% (120 to 97) | Peer reviewed publication | Strong |
 Schiavon et al., 2015, Brazil [27] | All patients admitted for surgical treatment of suspected malignant breast tumors in the Maternidade Carmela Dutra Hospital. Exclusion: Individuals who had a history of cancer or a surgical procedure in the previous year; were pregnant or breastfeeding at the time of diagnosis; had positive results for HIV; had neoadjuvant cancer treatment, or a neurological disease. | Active recruitment of all aforementioned patients. | T1: 9.71% (103 to 93) | Peer reviewed publication | Strong |
Crossover design (CO) | |||||
 Scrimgeour, 2012, New Zealand [35] | N/A | Individuals were recruited using the University Psychology and Geography mailing lists and snowballing techniques | T1: 18.66% (434 to 353) | Unpublished, available online | Medium |
Single group pre-post design | |||||
 Cordts et al., 2014, Germany [36] | Participants had to be meat eaters. | Individual recruitment through a professional panel provider with the aim of obtaining a representative sample of the German population. | T1: 5.76% (590 to 556) | Peer reviewed publication | Strong |
 Godfrey, 2014, Canada [41] | N/A | Food stations were recruited from the University Dining Centre at the University of Calgary. | T1: N/A (16,786 meal purchases) | Unpublished, available online | Medium |
 Grimmet et al., 2016, UK [30] | Participants had to be over 18 years, have completed treatment for non-metastatic CRC within the last 6 months, be competent in English, have adequate mobility and no contraindications for unsupervised physical activity. | Consultants in 3 London hospitals referred patients to the researchers and research-nurses recruited participants from 5 London hospitals. | T1: 20.69% (29 to 23) | Peer reviewed publication | Medium |
 Hawkes et al., 2009, Australia [28] | Participants had to be 20–80 years old, approximately 6 months post-CRC diagnosis; competent in English; and have no hearing, speech, or cognitive disabilities preventing them from completing telephone interviews. | Invitation and consent packages were sent to individuals who had undergone treatment in 3 the practices of three practitioners in Brisbane. | T1: 0% (20 to 20) | Peer reviewed publication | Strong |
 Hawkes et al., 2012, Australia [29] | Participants had to be able to understand and give informed consent in English; have no current or previous diagnosis of CRC or medical conditions limiting adherence to an unsupervised lifestyle program; own a phone; and have one or more poor health behaviour(s) among: not achieving ≥150 min of physical activity/week; eating > 4 servings of red meat/week or < 2 serves of fruit/day, or < 5 servings of vegetables/day; consuming > 2 drinks/day; or if they had a BMI ≥25. Participants had to have a first degree relative with CRC. | Social media, printed material, radio and online advertisement. | T1: 0% (22 to 22) | Peer reviewed publication | Medium |
 Loy et al., 2016, Germany [45] | Participants had to be non-vegetarians and proficient in German. | Individuals were recruited through internal university advertisement. | T1: 3,33% (60 to 58) | Peer reviewed publication | Medium |
T2: 8.33% (60 to 55) | |||||
 Marette et al., 2016, France [46] | Participants had to eat ground beef, at least occasionally. | Individuals were recruited via phone to randomly select a sample representative of the age groups and socio-economic status of the population in Dijon, France. | T1: 3,23% (124 to 120) | Report, available online | Strong |
Retrospective intervention evaluation | |||||
 Leidig, 2012, study 1, USA [47] | All healthcare accounts of Sodexo’s food service in the USA were eligible. | The survey was distributed to the managers of all USA healthcare accounts. | T1: N/A (119 account managers) | Report, available online | Low |
 Leidig, 2012, study 2, USA [47] | All corporate and governmental accounts of Sodexo’s food service in the USA were eligible. | The survey was distributed to the managers of all USA corporate and government accounts. | T1: N/A (126 account managers) | Report, available online | Low |