| Methods |
Design: four group parallel trial
Purpose: examine the effect of relaxation therapy and placebo on insomnia |
| Participants |
Patients: out‐patients suffering from chronic insomnia
Baseline comparability: yes (time to fall asleep) |
| Interventions |
Placebo: 'T‐scope therapy', a sham procedure designed to induce expectancy
Untreated: no relaxation or placebo therapy (waiting list)
Experimental: relaxation therapy
(Co‐intervention: sleep inducing drugs, no difference in % days in which patients took drugs in placebo and untreated groups) |
| Outcomes |
Sleep latency (min)
Hours slept
Quality of sleep
Feelings on awakening
Minnesota Multi phasic Personality Inventory
Number of awakenings
% days taking a sleeping pill |
| Notes |
5 out of 40 participants were replaced by others approximately equivalent in age, sex and time to falling asleep. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
NS |
| Allocation concealment? |
Unclear risk |
NS |
| Blinding?
Treatment provider |
High risk |
Not described as double‐blind (placebo/relaxation therapy) |
| Blinding?
Outcome assessor |
Unclear risk |
Not relevant as patient reported outcome |
| Incomplete outcome data addressed?
All outcomes |
High risk |
Drop‐out > 15% or NS |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
High risk |
See notes |
| No signs of variance inequality or skewness? |
Low risk |
No variance inequality (F‐test not statistically significant) and no skewness (1.64 standard deviations does not exceed the mean) |
| Trial size > 49? |
High risk |
N = 20 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
