Table 1 Summary of review and participant characteristics
Characteristic | Systematic reviews with meta-analysis (n = 35) | Systematic reviews without meta-analysis (n = 29) |
|---|---|---|
Review characteristics | ||
 Year of publication [n (%)] | ||
  1990–1999 | 1 (3) | 1 (3) |
  2000–2009 | 5 (14) | 9 (31) |
  2010–2018 | 29 (83) | 19 (66) |
 Literature search date [n (%)] | ||
  1990–1999 | 1 (3) | 2 (7) |
  2000–2009 | 7 (20) | 7 (24) |
  2010–2019 | 24 (69) | 16 (55) |
  Not reported | 3 (9) | 4 (14) |
 Literature search coverage [n (%)] | ||
  From database inception | 8 (23) | 3 (10) |
  > 50 years prior to search date | 2 (6) | 3 (10) |
  30–49 years prior to search date | 4 (11) | 9 (31) |
  10–29 years prior to search date | 1 (3) | 1 (3) |
  Not reported | 20 (57) | 13 (45) |
 Region of publication [n (%)] | ||
  Asia | 15 (43) | 2 (7) |
  Europe | 8 (23) | 6 (21) |
  North America | 11 (31) | 19 (65)a |
  Oceania | 1 (3) | 2 (7) |
  Number of included primary studies [mean (range)] | 27 (3–139) | 8 (2–22) |
 Included study designs [n (%)]b | ||
  Randomized controlled trials | 33 (94) | 23 (79) |
  Non-randomized controlled trials | – | 7 (24) |
  Quasi-experimental | 1 (3) | 3 (10) |
  Observational | – | 4 (14) |
  Not reported | 2 (6) | 4 (14) |
Population characteristics | ||
 Overall sample size [mean (range)]c | 1861 (171–6303) | 566 (34–1794) |
 Mean age [range (years)]d | 45–56.6 | 53.3c |
 Proportion of female participants [range (%)]e | 35.6–74.2 | – |
 Patients with co-morbidities [n (%)] | ||
  No co-morbidities | 12 (34) | 6 (21) |
  Mix of patients with and without co-morbidities | 9 (26) | 9 (31) |
  All patients with co-morbidities | 11 (31) | 9 (31) |
  Not reported | 3 (9) | 5 (17) |
 Types of co-morbidities [n (%)]b | ||
  Mental health conditions (various) | 9 (26) | 11 (38) |
  Cancer | 8 (23) | 6 (21) |
  Conditions causing chronic pain | 5 (14) | – |
  Chronic illness (unspecified) | 4 (11) | 2 (7) |
  Other sleep disorders | 4 (11) | – |
  Dementia | 3 (9) | 2 (7) |
  Physical disability | 2 (6) | 1 (3) |
Treatment comparisons [n (%)]b (v inactive controls) (v active controls) | ||
Benzodiazepines (flurazepam, temazepam, triazolam) | 3 (9) -- | 2 (7) 1 (3) |
Non-benzodiazepine receptor agonists (zolpidem, zopiclone) | 4 (11) -- | 5 (17) 3 (10) |
Suvorexant | 3 (9) -- | 1 (3) -- |
Antidepressants (doxepin, trazodone) | 5 (14) -- | 5 (17) 3 (10) |
Antipsychotics (quetiapine) | -- -- | 4 (14) -- |
Melatonin | 8 (23) -- | 4 (14) -- |
Diphenhydramine | 1 (3) -- | 2 (7) -- |
Cognitive behavioral therapy (CBT) (CBT, CBT + behavioral intervention, multi-component CBT) | 20 (57) 3 (9) | 8 (28) 3 (10) |
Behavioral interventions (relaxation, sleep restriction, multi-component behavioral) | 4 (11) 1 (3) | 7 (24) -- |
Mindfulness-based interventions | 1 (3) -- | -- -- |
Combination therapies (CBT + pharmacotherapy) | 1 (3) -- | 1 (3) -- |