Table 5. Quality appraisal of included studies: cross-sectional studies (no control group).
| Cross-Sectional Study (First Author Name) | Prospective Design | Response Rate >80% | Confounders Controlled | Selection Bias Minimized | Appropriate Statistical Measures |
| Henderson [29] a | No | Yes | Yes | Yes | Yes |
| Greving [30] | No | Yes (96%) | Yes | Yes | Yes |
| Kreyenbuhl [31] | Yes | No (58%) | No | Yes | Yes |
| de Bakker [61] | No | Unsure | Yes | Yes | Yes |
| Steinman [62] | No | Yes | Yes | No | Yes |
| Canli [32] | Yes | No (79%) | No | Yes | Yes |
| Verdoux [63] | Yes | No (24%) | Yes | No | Yes |
| Muijrers [64] | Yes | No (71%) | Yes | Yes | Yes |
| Huang [65] | No | NA | No | No | Yes |
| Watkins [66] | Yes | No (64%) | Yes | Yes | Yes |
| Prosser [67] | Yes | No (73%) | No | Yes | No |
| Caamano [68] | Yes | No (75%) | Yes | Yes | Yes |
| Gonul [69] | Yes | NA | Yes | Unsure | Yes |
| Mansfield [82] | Yes | No (6%) | No | No | Yes |
| Jones [70] | Yes | NA | No | No | No |
| Caudill [71] | Yes | No (28%) | Yes | Yes | Yes |
| Berings [72] | Yes | No (28%) | Yes | No | Yes |
| Lurie [73] | Yes | No (75–78%) | Yes | Yes | Yes |
| Health Care Communications 1989a [80] | No | Unsure | No | No | No |
| Peay [33] | No | No (52%–70%) | Yes | Yes | Yes |
| Blondeel [81] | Yes | No (30%) | Yes | Yes | Yes |
| Haayer [74] | Yes | Yes (90%) | Yes | No | Yes |
| Walton [75] | Yes | Unsure | No | Yes | Yes |
| Dajda [76] | No | NA | No | Yes | Yes |
| Becker [77] | Yes | Yes (84%) | Yes | Yes | Yes |
a
Received research funding from a pharmaceutical company.