Table 2. Characteristics of included studies.
| Study | Population | Intervention.
Control was placebo unless otherwise stated |
Design | Outcome
focus |
Timing | Funding Source | Conflict of
interests with relevant pharmaceutical company declared? |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Author | Date | Country | Industry &
Role |
Type of shift
work |
Hours
worked if reported |
Criteria used for
SWD or sleep disorder * |
Sample size. Total
completed (recruited and eligible) |
Duration of intervention | Duration of
study |
||||||||
| Intervention | Control | Intervention | Control | ||||||||||||||
| Hypnotics | Sadeghniiat-
Haghighi, K |
2016 | Iran | Oil refinery | Rotating, 1 week
day shift 1 week night shift. |
N/A | Sleep disturbance
assessed with ISI item 1a, PSQI item 2. |
39 (50) | Melatonin 3mg OD | Randomised,
double blind, placebo controlled crossover study |
Sleep
outcomes and other |
3 nights, 2 week wash out | 3 weeks | Tehran University of
Medical Sciences and health services; Osvah Pharmaceutical Co |
No | ||
| Sadeghniiat-
Haghighi, K |
2008 | Iran | Nursing | Unspecified. | N/A | Sleep problems
reported in a baseline questionnaire |
86 (118) | Melatonin 5mg OD | Randomised,
double blind, placebo controlled crossover study |
Sleep
outcomes |
1 night, 4 days wash out | <2 weeks | Tehran University of
Medical Sciences |
No | |||
| Bozin-
Juriacic, J |
1996 | Croatia | Security
firm |
Rotating, 7 night
shifts, week rest, week of mornings and week of afternoons. |
Night shifts
were 22:00- 06:00 |
Self reported
night work related insomnia. |
9 | 9 | Zopiclone 7.5mg OD | Parallel group | Sleep
outcomes |
1 week for each treatment, 3
week wash outs |
12 weeks | May and Becker and
Phone-Pulenc Santé |
No | ||
| 11 | Nitrazepam 5mg OD | ||||||||||||||||
| Gigli | 1993 | Italy | Nursing | 5 day rotation | Shifts:
7:00-14:00; 14:00-22:00; 22:00-7:00 |
Symptoms of
insomnia considered by subjects or physicians to be clinically relevant. |
13 (16) | Brotizolam 0.25mg OD | Double blind
crossover study |
Other | 15 days with 15 day
wash out |
45 days | Boehringer Ingelheim
Italia |
No | |||
| Monchesky | 1989 | Canada | Automobile
plant |
Rotating: Two
weeks alternating |
Shifts:
07:00- 15:30; 18:00- 02:30 Monday to Friday. |
Insomnia for 3 or
more consecutive night shifts via sleep latency, nightly awakenings, TST and poor sleep quality. |
25 (25) | 20 (25) | Zopiclone 7.5mg OD | RCT | Sleep
outcomes |
2 weeks | 2 weeks | None declared | No | ||
| Stimulants | Erman, M K ** | 2011
& 2012 |
USA | Varied | Mixture. 93%
permanent |
≥5 nights per
month, each 6-12 hours, with ≥6 hours between 22:00-08:00 and ≥3 consecutive nights |
Excessive sleepiness
late in shift associated with ICD2 SWD. Functionally impaired (GAF<70) |
158 (184) | 167
(187) |
Armodafinil 150mg
OD |
RCT | Wake
outcomes and AE |
6 weeks | 6 weeks | Cephalon Inc | Yes | |
| Tembe, D V | 2011 | India | Unspecified | Unspecified. | ICD criteria for SWSD | 104 (105) | 105
(106) |
Armodafinil 150mg
OD (Control: Modafinil 200mg OD) |
RCT | Wake
outcomes and AE |
12 weeks | 12 weeks | Emcure
Pharmaceuticals Ltd. |
Yes | |||
| Czeisler, C A | 2009 | USA &
Canada |
Varied | Mixture. 86.5%
permanent. |
ICD2 criteria; <6
minutes on MSLT during a night shift; SE of 87.5% or less on daytime polysomnography |
93 (127) | 84 (127) | Armodafinil 150mg
OD |
Randomized,
double-blind, placebo-controlled, parallel-group, multicenter study |
Sleep
outcomes, wake outcomes, other & AE |
12 weeks | 12 weeks | Cephalon Inc | Yes | |||
| Erman, M K | 2007 | USA | Varied | Unspecified. | ICD | 129 (185) | 60 (93) | Modafinil 200mg or
Modafinil 300mg OD |
Randomised
double blind placebo controlled parallel group trial |
Other | 12 weeks | 12 weeks | Cephalon Inc | Yes | |||
| Czeisler, C | 2005 | USA | Varied | Mixture. 90%
permanent. |
ICD2 criteria; <6
minutes on MSLT during a night shift; SE of 87.5% or less on daytime polysomnography |
76 (96) | 81 (108) | Modafinil 200mg OD | RCT | Sleep
outcomes, wake outcomes, other & AE |
12 weeks | 12 weeks | Cephalon Inc | Yes | |||
|
Non-
pharmacological |
Zhang, L | 2020 | China | Nursing | Forward rotating
shift nurses |
Shifts:
07:30- 17:30; 12:30-22:30; 20:00-08:00. 5/7 days a week. |
Score of ≥8 on the
PSQI. |
15 (19) | 23 (25) | Shimian granules
and sleep hygiene education (Control: sleep hygiene education only) |
RCT | Other | 1 month | 1 month | Youth Science and
Technology Innovation Personnel Training Project of Shaanxi Province; Special Support Scheme for ShaanxiProvince |
No | |
| Jarnefelt, H | 2019 | Finland | Variety:
health and social care, bakery, aviation |
Varied | ≥10% shifts
beginning 07:00 or earlier, ending 22:00 or later or at least 3 hours of a shift falling between 23:00-06:00. |
Non-organic
insomnia; difficulty initiating or maintaining sleep for >30 min and use of sleep promoting medication at least 3 nights a week for at least 3 months;full time shift work |
18 (30) | 15 (24) | Group CBT-I (Control:
Sleep hygiene education) |
RCT | Sleep
outcomes, other |
Up to 10 weeks | 1 session | 6 months | Finnish Work
Environment Fund; NordForsk, the Nordic Program on Health and Welfare |
No | |
| 16 (29) | Self help CBT-I
(Control: sleep hygiene education) |
||||||||||||||||
| Chang, Y Y. | 2017 | Taiwan | Nursing | Monthly rotating
shifts. |
N/A | A total PSQI ≥5 | 27 (27) | 23 (23) | Aromatherapy
massage |
RCT | Other | 4 weeks. 1 hour long
treatment weekly. |
5 weeks | Taichung Veterans
General Hospital |
No | ||
| Huang, L B. | 2013 | Taiwan | Nursing | Rotating shifts | 16:00-00:00;
00:00-08:00 |
ISI>14. | (46) | (46) | Bright light during
nightshift + avoid daytime sun |
RCT | Other | At least 10 days during
2 weeks. |
At least
10 days during 2 weeks. |
Chang Gung Memorial
Hospital |
No | ||
| Combination | Booker, L A | 2022 | Australia | Healthcare | Regular rotating
or permanent night shifts. |
N/A | High risk of SWD
on Australasian Sleep Trials Network Questionnaire |
19 *** | 15 **** | Fortnightly 1-to-1
coaching sessions ± caffeine/melatonin; sleep/work/driving diaries & high intensity lighting in workplace Control: coaching and education on benefits of low glycaemic diet, |
A clustered
randomised controlled trial. |
Other, Sleep
Outcomes |
10 weeks | 6 months | Cooperative Research
Centre for Alertness, Safety and Productivity (Melbourne, Australia); Austin Health and the Institute for Breathing and Sleep (Melbourne, Australia). |
No | |
Legend: Shift work disorder (SWD); insomnia severity index (ISI); Pittsburgh Sleep Quality Index (PSQI); once daily (OD); randomised controlled trial (RCT); total sleep time (TST); multiple sleep latency test (MSLT); International classification of disease (ICD); sleep efficiency (SE).
*All patients being involved in shiftwork as defined by the study, and having no other conditions which better explain their sleep disturbance was an inclusion criterion so is not repeated here.
**Different outcomes or timepoints from the same treatment population published separately.
***19 participants identified as high risk of SWD. Whole study population: 79 participants completing protocol of 101 recruited.
****15 participants identified as high risk of SWD. Whole study population: 70 completing protocol of 101 recruited.