| Methods |
Design: Two group, two period cross‐over trial
Purpose: examine the effect of placebo intervention on blood pressure |
| Participants |
Patients: previously untreated out‐patients suffering from essential arterial hypertension
Baseline comparability: yes (age, sex, blood pressure) |
| Interventions |
Placebo: 'tablet x 2 daily'
Untreated: no tablet
Experimental : no
(Co‐intervention: no) |
| Outcomes |
Diastolic blood pressure reduction (mm Hg) |
| Notes |
The first period was considered a parallel trial. Results from the second period were disregarded. |
| 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/ultrasound) |
| Blinding?
Outcome assessor |
Unclear risk |
NS |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
Drop out < 15% |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
Unclear risk |
Not relevant (not naturally positive continuous outcomes e.g. change) |
| Trial size > 49? |
High risk |
N = 21 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
