Table 2.
Results of meta-analyses of trials of high intensity nursing to reduce smoking using standard§ and 'treat-as-one-trial' methods, with relative risk as effect measure
| Setting (no. of trials) | Number quitting/total | Pooled risk ratio (95% CI) | NNT (95% CI) | |
| Intervention | Control | |||
| Hospital (7) | 435/1367 | 318/1295 | ||
| Meta-analysis | 1.30 (1.16 to 1.47) | 13.6 (8.7 to 25.5)¶¶ | ||
| Treat-as-one-trial | 1.30 (1.15 to 1.47) | 13.8 (9.4 to 25.9) | ||
| Primary Care (3)* | 111/2453 | 41/1006 | ||
| Meta-analysis | 1.01 (0.71 to 1.42) | 2454 (58.4 to H84.6¶)¶¶ | ||
| Treat-as-one-trial | 1.11 (0.78 to 1.58) | 222.5 (52.0 to H97.7¶) | ||
| Primary Care (2)** | 87/2246 | 25/958 | ||
| Meta-analysis | 1.54 (0.97 to 2.44) | 71.0 (26.6 to H1277¶)¶¶ | ||
| Treat-as-one-trial | 1.48 (0.96 to 2.30) | 79.1(39.2 to H4369¶) | ||
§ Mantel-Haenszel method (fixed effect) * as defined by Moore et al ** excluding reference [12]¶ NNT for harm [13]¶¶NNT calculated using the event rate among controls and the relative risk reduction [4]