Table 1.
Baseline characteristics of included studies.
| Study/ Authors name | Year | Country | Participants in Vegetarian/ Non-Vegetarian cohort | age | Percentage male | year of recruitment | ENd of follow-up | Mean length of follow-up | Definition of Vegetarian according to the study | Definition of Non-vegetarian according to the study | Outcomes adjusted for Factors |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Adventist Mortality study | 1965 | USA | 10,258/ 14,280 | NA | NA | 1959–1960 | December, 1965 | 5.6 years | Not defined | Not defined | Age, Sex and Smoking |
| Berkel | 1983 | Netherlands | 1972/1972 | NA | 33% | 1968–1977 | 1977 | 10 years | Not defined | Not defined | – |
| Japenese Zen Priest | 1984 | Japan | 2176/2176 | NA | NA | 1955–1978 | 1978 | 23 years | Not defined | Not defined | Unadjusted, however the control group was age and sex matched. |
| Adventist health study-1 | 1988 | USA | 8003/20,949 | 25- 100 years | 41% | 1976–1980 | December, 1988 | 11.1 years | Not defined | Not defined | Age, Sex and Smoking |
| Health food shoppers study | 1995 | United Kingdom | 3790/6088 | Median 45–46 | 40% | 1973–1979 | December, 1995 | 18.4 years | Based on a self-administered questionnaire. Participants who answered “Yes” to “Are you a vegetarian?” | Based on a self-administered questionnaire. Participants who answered “Yes” to “Are you a Non-vegetarian?” | Age, Sex and Smoking |
| Thorogood et al. | 1995 | United Kingdom | 4674/6373 | Median 32–34 | 38% | 1980–1984 | December, 1995 | 13.7 years | Not defined | Not defined | All-cause mortality and IHD mortality: Smoking BMI and social classCerebrovascular mortality: Age, Sex and smoking |
| Claude et al. | 2005 | Germany | 1225/679 | 39.2% over the age of 55 years | 45% | 1973–1979 | May, 1989 | 9.9 | Vegans(those who avoidmeat, fish, eggs, and dairy products), lacto-ovo vegetarian (those who avoid meat and fish but eat eggs and/or dairyProducts). Further, vegan constituted only 5% of this cohort and hence the study was included in the meta-analysis) | Those who occasionally orregularly eat meat and/or fish | All-cause mortality, IHD mortality and cardiovascular mortality: Age, gender, smoking, level of activity, alcohol consumption, BMI, educationCerebrovascular mortality: Age, Sex and smoking |
| EPIC- Oxford | 2009 | United kingdom | 16,081/31,173 | 44 years | 24% | 1993–1999 | 30 June, 2007 | ~10 years | Vegans, lacto-ovo vegetarian | Those who occasionally orregularly eat meat and/or fish | Age, sex, smoking, and alcohol consumption |