eTable 6. Overall results for the comparison of intraoral appliances vs placebo on the Epworth Sleepiness Scale.
| Data | Trials | Effect | 95% CI | p | 95% PrI | τ2 | I2 (%) | |
| Meta-analysis | MD | 11 | –1.18 | [–2.38; 0.03] | 0.055 | –4.76; 2.40 | 2.12 | 60.6 |
| Factor | Data | Trials | Effect | 95% CI | p | τ2 | I2 (%) | |
| Follow-up (months) | Coefficient | 10 | 0.04 | [–0.21; 0.29] | 0.716 | 3.4 | 67.2 | |
| Constant | –1.56 | [–3.95; 0.83] | 0.17 | |||||
| % of maximum protrusion | Coefficient | 7 | –0.00 | [–0.13; 0.12] | 0.95 | 3.36 | 66.4 | |
| Constant | –1.48 | [–10.38; 7.42] | 0.686 | |||||
| Appliance type (thermoplastic or tongue suction versus impression-based) |
Coefficient (thermoplast) |
10 | –0.83 | [–4.38; 2.72] | 0.43 | 2.23 | 52.4 | |
| Coefficient (tongue suction) |
2.22 | [–2.34; 6.78] | ||||||
| Constant | –1.62 | [–3.31; 0.08] | 0.059 | |||||
| Appliance type (1- or 2-piece) | Coefficient | 8 | 1.57 | [–2.94; 6.07] | 0.428 | |||
| Constant | –1.87 | [–4.39; 0.65] | 0.12 | |||||
| Baseline BMI (kg/m2) | Coefficient | 11 | –0.21 | [–1.30; 0.88] | 0.671 | 2.6 | 56.5 | |
| Constant | 5.04 | [–27.15; 37.23] | 0.731 | |||||
| Baseline AHI (events/hour) |
Coefficient | 9 | –0.03 | [–0.16; 0.10] | 0.59 | 2.6 | 56.5 | |
| Constant | –0.50 | [–3.89; 2.88] | 0.735 | |||||
| Baseline age (years) | Coefficient | 11 | –0.28 | [–0.65; 0.09] | 0.119 | 1.29 | 40.9 | |
| Constant | 12.44 | [–5.41; 30.29] | 0.149 | |||||
| Ratio of male patients | Coefficient | 11 | –15.22 | [–33.47; 3.02] | 0.092 | 1.11 | 60.1 | |
| Constant | 10.78 | [–3.50; 25.05] | 0.122 | |||||
| Total sample | Coefficient | 11 | 0.01 | [–0.05; 0.06] | 0.839 | 2.7 | 58.3 | |
| Constant | –1.47 | [–4.57; 1.63] | 0.312 | |||||
| Study design (crossover or parallel) |
Coefficient | 11 | 1.87 | [–0.76; 4.50] | 0.141 | |||
| Constant | –2.63 | [–4.97; –0.28] | 0.032 | |||||
| Data type 1 | Coefficient | 11 | –1.87 | [–4.50; 0.76] | 0.141 | 1.42 | 60.3 | |
| Constant | –0.75 | [–1.93; 0.43] | 0.185 | |||||
| Data type 2 | Coefficient | 11 | –0.93 | [–4.88; 3.03] | 0.609 | 2.55 | 48.2 | |
| Constant | –1.08 | [–2.49; 0.32] | 0.115 | |||||
| Data type 1 | Coefficient | 11 | –2.12 | [–4.80; 0.55] | 0.197 | 1.27 | 41.6 | |
| Data type 2 | Coefficient | –1.52 | [–4.53; 1.49] | |||||
| Constant | –0.49 | [–1.76; 0.79] | 0.405 | |||||
| Data | Trials | Effect | 95% CI | p | ||||
| Reporting bias (Egger’s test) |
Coefficient | 11 | –0.26 | [–2.08; 1.56] | 0.752 |
CI, confidence interval; PrI, predictive interval; BMI, body mass index; AHI, apnea hypopnea index; Data type 1, origin of data used in the analysis 1 (increment calculated from parallel or crossover trials); Data type 2, origin of data used in the analysis 2 (increment calculated from final values of cross-over trials).