Table 1.
List of the included cohort study.
| Study Name | Country | Original Cohort (Established-Last Outcome Assessment) | n | Assessment Caffeine Consumption | Amount of Caffeine Consumption | The Diagnosis of PD |
|---|---|---|---|---|---|---|
| Ascherio et al. [17] | USA | Health Professionals’ Follow-Up Study and Nurses’ Health Study (1976 and 1986/1994) | 135,916 | Semiquantitative food-frequency questionnaire (SFFQ) | Caffeine was 137 mg per cup of coffee, 47 mg per cup of tea, 46 mg per can or bottle of cola beverage, and 7 mg per serving of chocolate candy. |
Self-report and medical records |
| Ascherio et al. [22] | USA | Nurses’ Health Study (1976/1998) |
121,700 women | Semiquantitative food-frequency questionnaire (SFFQ) | Caffeine was 137 mg per cup of coffee, 47 mg per cup of tea, 46 mg per can or bottle of cola beverage, and 7 mg per serving of chocolate candy. |
Medical records |
| Grandinetti et al. [21] | USA | Honolulu Heart Program-Japanese and Okinawan ancestry (1965/1991) | 8006 men | Questionnaires | NA | Medical records |
| Hu et al. [23] | FIN | Four independent cross-sectional population surveys were carried out in five geographic areas of Finland in 1982, 1987, 1992, and 1997 (1982/2002) |
29,335 | Self-administered questionnaire | Cups of coffee | National Social Insurance Institution’s Register |
| Liu et al. [18] | USA | NIH-AARP Diet and Health Study (1995/2010) | 566,401 | Diet History Questionnaire |
Nutrient calculation: 1994–1996 US Department of Agriculture’s Continuing Survey of Food Intakes by Individuals. |
Interview and copy of medical records |
| Palacios et al. [25] | USA | CPS II–Nutrition cohort (1992/2007) | 184,190 | Food Frequency Questionnaire | 137 and 47 mg per cup of coffee and tea, respectively, 46 mg per can or bottle of cola; and 7 mg per serving of chocolate. |
Interview and copy of medical records |
| Sääksjärvi et al. [15] | FIN | Finnish Mobile Clinic Health Examination Survey (1973/1994) |
7246 | Self-administered, health questionnaire |
Cups of coffee | National Social Insurance Institution’s Register |
| Tan et al. [24] | SG | Singapore Chinese Health Study (1993/2005) | 63,257 | A validated, semiquantitative food frequency section questionnaire | Singapore Food Composition Table, a food-nutrient database that lists the levels of 96 Nutritive/nonnutritive components (including caffeine) per 100 g of cooked food and beverages | Interview and linkage database to medical record |
| Wirdefeldt et al. [16] | SE | Swedish Twin Registry (1961 and 1973/without clear mentioning) | 52,149 | Questionnaires | Did not provide the formula | Inpatient Discharge Register and Cause of Death Register |