Characteristics of studies included in review of Z drugs (a more detailed version of this table is in appendix 3)
| Study identifier, year, country (No of sites) | No | Women | Mean (SD) age (years) | Drug | Recruitment | Baseline PSG (subjective) sleep latency | Design | Patient type | Outcome |
|---|---|---|---|---|---|---|---|---|---|
| EFC4529, 2004, US (29), Canada (5), Australia (6) | 212 | 58% | 44 (13) | Zolpidem MR 12.5 mg | Community | Intervention: 41.7 (61.4); placebo: 43.8 (62.0) | Phase II multicentre randomised double blind placebo controlled parallel group | Outpatients | Wake after sleep onset PSG, sleep latency PSG, No of awakenings PSG, No of awakenings subjective, sleep latency subjective, total sleep time PSG |
| EFC4530, 2004, Argentina (5), Canada (7), France (4), Germany (6), Mexico (2), US (16) | 205 | 57% | 70 (5) | Zolpidem MR 6.25 mg | Community | Intervention: 36.9 (56.0); placebo: 35.7 (62.9) | Randomised multicentre double blind placebo controlled | Outpatients | Wake after sleep onset PSG, sleep latency PSG, No of awakenings PSG, No of awakenings subjective, sleep latency subjective, total sleep time PSG |
| LSH17, 1988, US (4) | 75 | 64% | 38 | Zolpidem MR 10 mg and 15 mg | Community | Intervention: zolpidem 10 mg: 35.8 (38.4); zolpidem 15 mg: 47.0 (61.0); placebo: 49.9 (70.4) | Double blind parallel group | Outpatients | Sleep latency PSG, Sleep efficiency PSG, No of awakenings PSG, sleep latency subjective, total sleep time subjective, No of awakenings subjective, sleep quality subjective. |
| LSH, 1992, US (6) | 145 | 56% | 45 | Zolpidem (10 mg and 15 mg) | Community | Intervention: zolpidem 10 mg (65.1); zolpidem 15 mg (75.9); placebo: (58.2) | Double blind parallel group | Outpatients | Sleep latency subjective, total sleep time subjective, No awakenings subjective, sleep quality subjective |
| IV LSH, NR, NR | 75 | NR | NR | Zolpidem 10 mg and 15 mg | Community | Intervention: zolpidem 10 mg: 35.8 (57.0); zolpidem 15 mg: 47.0 (61.0); placebo: 49.9 (70.4) | Multicentre double blind randomised placebo controlled parallel group trial | Outpatients | Sleep latency PSG, sleep latency subjective, Sleep efficiency PSG |
| 204-EU, 1997, Spain (4), France (3), Belgium (3), Netherlands (1) | 130 | NR | NR | Zaleplon 10 mg and 20 mg vs. zolpidem 10 mg | Community | Intervention: zaleplon 10 mg: 40.4; zaleplon 20 mg: 48.0; zolpidem 10 mg: 47.8; placebo: 48 | Phase II, multicentre, double blind comparative parallel group efficacy, safety, tolerance, outpatient and sleep laboratory trial | Outpatients | Sleep latency PSG |
| Trial 301, 1998, US (27) | 586 | 58.4% | 41.8 | Zaleplon 5 mg, 10 mg and 20 mg; zolpidem 10 mg | Community | Intervention: zaleplon 5 mg: 81.5; zaleplon 10 mg: 77.7; zaleplon 20 mg: 72.5; zolpidem 10 mg: 70.5; placebo: 80.4 | Randomised placebo controlled parallel group multicentre double blind trial | Outpatients | Sleep latency PSG. |
| Trial 307, 1998, US and Canada (39) | 637 | 60.6% | 43 | Zaleplon 10 mg/10 mg, 10 mg/20 mg | Community | Intervention: zaleplon 10 mg/10 mg: 79.8; zaleplon 10 mg/20 mg: 81.9; placebo: 77.93 | Randomised placebo controlled parallel group multicentre double blind trial | Outpatients | Sleep latency PSG |
| Trial 303, 1998, Europe and Canada | 574 | 64.4% | 42.8 | Zaleplon 5 mg, 10 mg, 20 mg, zolpidem 10 mg | Community | Intervention: zaleplon 5 mg: 66.0; zaleplon 10 mg: 57.0; zaleplon 20 mg: 55.0; zolpidem 10 mg: 64.0; placebo: 58.0 | Randomised placebo controlled parallel group multicentre double blind trial | NR | Sleep latency PSG |
| Trial 306, 1998, US | 422 | 64.4% | 72.5 | Zaleplon 5 mg and 10 mg | Community | Intervention: zaleplon 5 mg: 62.1; zaleplon 10 mg: 70.7; placebo: 68.0 | Prospective randomised double blind placebo controlled five arm parallel group multicentre trial | NR | Sleep latency PSG |
| 190-049, 2003, US and Canada (69) | 791 | 63.2% | 44.1 | Eszopiclone 3 mg | NR | Intervention: NR; control: NR | Multicentre randomised trial | NR | Sleep latency subjective, total sleep time subjective, wake after sleep onset subjective |
| 190-047, 2003, USA (48), Canada (2) | 292 | 65.9% | 70.7 | Eszopiclone 2 mg | NR | Intervention: NR; control: NR | Multicentre randomised trial | NR | Sleep latency PSG, sleep efficiency PSG, wake after sleep onset PSG |
| 190-048, 2003, US and Canada (32) | 234 | 57.7% | 72.3 | Eszopiclone 1 mg and 2 mg | NR | Intervention: NR; control: NR | Multicentre randomised trial | NR | Sleep latency subjective, total sleep time subjective |
NR=not reported; MR=modified release; PSG=polysomnographic.
*Trial 307-1998 had two intervention arms: (i) zaleplon 10 mg for 14 days with outcomes measured at 7 days and 14 days compared with placebo and (ii) zaleplon 10 mg for 7 days followed by 20 mg for 7 days with outcomes measured at 7 days and 14 days compared with placebo; in both studies we used last measurement at 14 days and averaged dose at 15 mg as best approximation for study arm using 10 mg followed by 20 mg zaleplon.