Evidence Table 2Key Question #2 Randomized Controlled Trials

Study CharacteristicsResearch Objective
Study Design
Patient Baseline CharacteristicsInclusion/Exclusion CriteriaOutcome ResultsAdverse Events (%)Analysis
Quality Rating
Author: Kocsis et al., 2007[37]

Country and Setting:
United States

Funding: Wyeth (manufacturer of venlafaxine)
Research Objective: To compare time to recurrence of depression with venlafaxine ER versus placebo

Duration of Study: 12-month maintenance phase for venlafaxine ER responders

Study Design:
Placebo controlled

Overall Total N: 258 (randomized)

Group 1: Venlafaxine ER 75–300 mg daily
Group 2: Placebo
Mean Age:
Venlafaxine ER 42.0
Placebo 42.6

Sex (% female):
Venlafaxine ER 69%
Placebo 67%

Race (% white):
Venlafaxine ER 81%
Placebo 88%

Baseline (HDRS)
Venlafaxine ER 4.3
Placebo 4.9
Inclusion Criteria:
• ≥ 18 years old
Depression symptoms for ≥ 1 month
• ≥ 3 prior depressive episodes, 2 in the past 5 years
• Two months between episodes
• HDRS-17 score ≥ 20 at screening and ≥18 at randomization
• Response or remission of intake episode at end of continuation phase

Exclusion Criteria:
• Failed trial of study medications
Treatment resistant, defined as failure of three med trials, ECT, or psychotherapy
• Hypersensitivity to study medications
• Alcohol or illicit drug use within 6 months
Seizure disorder
• Other serious medical diseases
• Other mental illnesses
• Pregnant or lactating
• ECT within 3 months
Fluoxetine or MAO-I within 30 days
• Other antidepressant within 14 days
• Any other psychotropic drug 7 days
Venlafaxine ER was associated with significantly lower risk of recurrence in comparison to placebo.

Probability of recurrence:
Month 6:
Venlafaxine ER: 18.8%
Placebo: 28.4%

Month 12:
Venlafaxine ER: 23.1%
Placebo: 42%
Venlafaxine ER 25
Placebo 24

Upper Respiratory Infection:
Venlafaxine ER 17
Placebo 12

Dry Mouth:
Venlafaxine ER 15
Placebo 11

Venlafaxine ER 14
Placebo 13

Venlafaxine ER 14
Placebo 12

Weight Gain:
Venlafaxine ER 12
Placebo 7

Venlafaxine ER 11
Placebo 21

Venlafaxine ER 11
Placebo 10

Sexual Problems:
Venlafaxine ER 11
Placebo 7
Overall Attrition Rate:
Venlafaxine = 50%
Placebo = 73%

ITT Analysis:

Quality Rating: fair?
Grps similar at baseline? Yes
Outcomes used valid methodology & criteria?
Yes, HDRS-17
Subjects & providers blind to intervention status of participants? Yes
Outcome assessors blind? Yes
Incomplete outcome data adequately addressed? Yes, ITT
>10% differential loss to f/up between grps? Yes
Overall >30% loss to f/up?
Yes, 40%
Conflict of interest? Funded by venlafaxine manufacturer
Adequate randomization methods? NG
Allocation concealment adequate? NG


Cover of Evidence Synthesis for Determining the Responsiveness of Depression Questionnaires and Optimal Treatment Duration for Antidepressant Medications
Evidence Synthesis for Determining the Responsiveness of Depression Questionnaires and Optimal Treatment Duration for Antidepressant Medications [Internet].
Williams JW Jr, Slubicki MN, Tweedy DS, et al.
Washington (DC): Department of Veterans Affairs (US); 2009 Oct.

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