Table 3 Quality assessment
First author | Allocation concealment | Randomisation | Blinding | Intention to treat (ITT) and withdrawals | Attrition at primary outcome timepoint | Largest number lost to follow-up |
|---|---|---|---|---|---|---|
Larcombe (1984) [48] Australia | Unclear | Unclear | Raters for HRSD were blind to experimental conditions and assessment occasions | 1/20 (5%) withdrew (1 CBT). Participant discontinued treatment after one session. No ITT analysis | 1/20 (5%) at 7 weeks (1 CBT) | 1/20 (5%) did not complete 7 week outcome assessment (1 CBT) |
Mohr (2001) [25] USA | Inadequate | Inadequate: Quasi-random, block randomisation | None | 11/63 (18%) dropped out of treatment (1 CBT, 4 Group therapy, 6 Sertraline). ITT analysis carried out on all subjects | 9/63 (14%) at 16 weeks (3 SEG, 6 Sertraline) | 9/63 (14%) did not complete 16 week outcome assessment (3 SEG, 6 Sertraline) |
Mohr (2005) [47] USA | Unclear | Unclear: Stratified based on whether patient currently diagnosed as having MDD and using antidepressant medication | All interviewers conducting telephone assessments were blinded to treatment allocation | 7/127 (6%) did not complete the 16 weeks of therapy (3 CBT, 4 Control). 6 participants dropped out by their own choice, 1 was removed from the trial due to an irrelevant issue. ITT analysis carried out on all subjects | 5/127 (4%) at 16 weeks (2 CBT, 3 Control) | 15/127 (12%) did not complete 28 week follow-up (6 CBT, 9 Control) |
Mohr (2000) [45] USA | Unclear | Unclear | None | 5/32 (16%) dropped out of treatment (5 CBT). CBT: Inability to make phone appointments or reported conflicts with other obligations. ITT analysis carried out on all subjects using last observation carried forward for missing data | 9/32 (28%) at 8 weeks (5 CBT, 4 Control). Control: 3 declined final assessment, 1 died (medical problem unrelated to MS) | 9/32 (28%) did not complete 8 week outcome assessment (5 CBT, 4 Control) |
Forman (2010) [43] UK | Inadequate: Independent researcher held allocation schedule. Small sample made later groups predictable | Adequate: Block randomisation, computer-generated list of random numbers | Single blind. Outcome questionnaires scored and entered onto computer by an independent researcher | 7/20 (35%) randomised to group CBT intervention did not attend the group sessions. No ITT analysis | 2/40 (5%) at 12 weeks (1 CBT, 1 Control). CBT: Did not return due to bereavement. Control: Did not return due to MS relapse | 3/40 (7.5%) did not complete 26 week follow-up (2 CBT, 1 Control) |
Lincoln (2011) [44] UK | Adequate: Web-based randomisation system | Adequate: Block randomisation, computer-generated | Data scored and entered onto database by researcher blind to treatment allocation | 1/151 subject withdrew (1 Control) shortly after randomisation. ITT analysis carried out on all subjects using last observation carried forward for missing data | 20/151 (13%) at 16 weeks (11 CBT, 9 Control). CBT: 2 patients were too ill, 9 failed to return outcome assessment. Control: 1 patient withdrew, 1 was too ill, 7 failed to return outcome assessment | 24/151 (16%) did not complete 32 week follow-up (14 CBT, 10 Control) |
Cooper (2011) [30] UK | Adequate: Web-based randomisation system | Adequate: Computer-generated | Statisticians and PI remained blind to treatment allocation codes until after the final analysis | 1/12 (8%) randomised to computerised CBT formally requested discontinuation of treatment citing time and lack of enthusiasm as reasons. ITT analysis carried out on all subjects using last observation carried forward for missing data | 3/24 (12.5%) at 8 weeks (3 CBT) | 6/24 (25%) did not complete 21 week follow-up (2 CBT, 4 Control) |