| Methods |
Design: four group parallel trial
Purpose: study the effect of thermal biofeedback and cognitive therapy on headache |
| Participants |
Patients: out‐patients with vascular headache
Baseline comparability: NS |
| Interventions |
Placebo: sessions of 'pseudomeditation'
Untreated: no sessions
Experimental:
‐sessions of thermal biofeedback and cognitive therapy
‐sessions of thermal biofeedback
(Co‐intervention: headache medication) |
| Outcomes |
Medication Index
Headache Index
Frequency of patients with headache reduction |
| Notes |
|
| 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/thermal biofeedback) |
| 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? |
Low risk |
|
| No signs of variance inequality or skewness? |
High risk |
Either variance inequality (F‐test statistically significant) or skewness (1.64 standard deviations exceeds the mean) |
| Trial size > 49? |
High risk |
N = 42 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
