Cochrane · systematic review · MR000032
Strategies to improve retention in randomised trials
Gillies, K, Kearney, A, Keenan, C, et al. · Cochrane Database of Systematic Reviews · 2021 · Cochrane Library
MethodologyAMSTAR 2: not assessed
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
16
current version
GRADE rated
15
No studies
1
Included studies
NR
No studies 1 · 6.3%Ungraded 0 · 0%Very low 8 · 50%Low 6 · 37.5%Moderate 1 · 6.3%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Questions and results
Questionnaire design: short vs usual questionnaire
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Questionnaire design: short vs usual questionnaire | no estimate extracted | NR | No studies |
Questionnaire design: addition of diary to usual follow‐up vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Questionnaire design: addition of diary to usual follow‐up vs usual follow‐up | RR 0.97 [0.96, 0.98] | 2 studies · 9906 participants | Moderate |
Data collection location and method: telephone follow‐up vs postal questionnaire
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Data collection location and method: telephone follow‐up vs postal questionnaire | RR 1.04 [0.94, 1.17] | 2 studies · 1006 participants | Very low |
Data collection location and method: return postage
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ | RR 1.06 [0.99, 1.15] | 3 studies · 1543 participants | Low |
Reminders: electronic reminder vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Reminders: electronic reminder vs usual follow‐up | RR 1.01 [0.95, 1.09] | 3 studies · 790 participants | Low |
Prompts: Electronic prompt vs no prompt
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Prompts: Electronic prompt vs no prompt | RR 1.03 [0.98, 1.08] | 5 studies · 2897 participants | Very low |
Prompts: Telephone prompt vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Prompts: Telephone prompt vs usual follow‐up | RR 1.02 [0.85, 1.22] | 2 studies · 943 participants | Very low |
Prompts: personalised prompt vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Prompts: personalised prompt vs usual follow‐up | RR 0.97 [0.89, 1.07] | 2 studies · 701 participants | Low |
Monetary incentives: addition of monetary incentives vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Monetary incentives: addition of monetary incentives vs usual follow‐up | RR 1.2 [1.06, 1.36] | 3 studies · 3166 participants | Low |
Monetary incentives: addition of monetary incentives vs addition of a monetary reward
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Monetary incentives: addition of monetary incentives vs addition of a monetary reward | RR 1 [0.91, 1.09] | 4 studies · 3765 participants | Very low |
Monetary incentives: addition of monetary reward vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Monetary incentives: addition of monetary reward vs usual follow‐up | RR 1.02 [0.96, 1.09] | 3 studies · 1159 participants | Very low |
Non‐monetary incentives: addition of pen vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Non‐monetary incentives: addition of pen vs usual follow‐up | RR 1.02 [1, 1.05] | 5 studies · 13013 participants | Low |
Maintaining participant engagement: newsletter vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Maintaining participant engagement: newsletter vs usual follow‐up | RR 0.99 [0.95, 1.04] | 4 studies · 5622 participants | Very low |
Maintaining participant engagement: post‐it note vs usual follow‐up
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Maintaining participant engagement: post‐it note vs usual follow‐up | RR 1 [0.99, 1.01] | 3 studies · 4698 participants | Low |
Behavioural interventions: theory informed cover letter vs usual cover letter
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Behavioural interventions: theory informed cover letter vs usual cover letter | RR 1.05 [0.98, 1.12] | 4 studies · 3343 participants | Very low |
Impact of recruitment: optimised information vs standard information
Population: trial participants being followed up for data collection
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Retention [ Impact of recruitment: optimised information vs standard information | RR 0.96 [0.85, 1.09] | 2 studies · 1285 participants | Very low |