Table 2.
Quality rating criteria met by each study using the Cochrane Effective Practice and Organisation of Care (EPOC) guidelines
| Study author and year | Allocation sequence | Allocation concealment | Baseline measurements - participants | Baseline characteristics - providers | Incomplete data addressed | Knowledge of allocation | Contamination protected | Selective outcome reporting | Free of other bias |
|---|---|---|---|---|---|---|---|---|---|
| Smoking tobacco (n = 8) | |||||||||
| Haug et al. (2009) [63] | ✓ | ▪ | ✓ | ✓ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Travis & Lawrance (2009) [52]* | ▪ | ▪ | ✓ | ▪ | ✓ | ▪ | ✓ | ✓ | ✓ |
| O’Neill et al. (2000) [64]* | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ✓ | ✓ | ✓ |
| An et al. (2008) [60]* | ✓ | ▪ | ✓ | ▪ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Dijkstra (2005) [61] | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ✓ | ✓ | ✓ |
| Abroms et al. (2008) [59]* | ▪ | ▪ | ✓ | ✓ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Dijkstra & Ballast (2012) [62]† | ▪ | ▪ | ▪ | ✓ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Prokhorov et al. (2008) [65]* | ▪ | ▪ | ✓ | ✓ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Spit tobacco (n = 1) | |||||||||
| Masouredis (1997) [66]* | ▪ | ▪ | ✓ | ▪ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Marijuana (n = 2) | |||||||||
| Lee (2010) [68] | ✓ | ▪ | ✓ | ✓ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Elliott (2012) [67] | ▪ | ▪ | ✓ | ✓ | ✓ | ▪ | ✓ | ✓ | ✓ |
| Stress, marijuana, alcohol, and tobacco (n = 1) | |||||||||
| Moore et al. (2012) [69] | ✓ | ▪ | ▪ | ▪ | ✓ | ▪ | ✓ | ✓ | ✓ |
Note: *Studies included in the meta-analysis; †= No control group (randomized trial).