| Methods |
Design: five group parallel trial
Purpose: examine the effect of three types of behavioural therapy on snake phobia |
| Participants |
Patients: out‐patients suffering from snake phobia
Baseline comparability: yes |
| Interventions |
Placebo:
‐posted instructions of factual information about snakes ('systematic re‐learning' )
Untreated: no behavioural or placebo procedure (waiting‐list)
Experimental:
‐systematic desensitization procedure by posted instructions
‐systematic desensitization procedure by therapist
‐systematic desensitization procedure by minimal therapist contact through telephone
(Co‐intervention: No) |
| Outcomes |
Anxiety score and heart rate and at slide provocation test
Snake Attitude Questionnaire (SNAQ)
Behavioural Approach test
Fear Survey Schedule
Rate of fear change |
| Notes |
38% drop‐outs |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
NS |
| Allocation concealment? |
Unclear risk |
NS |
| Blinding?
Treatment provider |
Low risk |
'.... a self‐administered double‐blind placebo control...' |
| Blinding?
Outcome assessor |
Low risk |
'... follow‐up assessments... were conducted by assistants blind to subjects' group assignment' |
| 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? |
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 = 14 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
