This review concluded that reminiscence interventions affected a broad range of outcomes and had therapeutic as well as preventative effects similar to other interventions. This conclusion reflects the results presented but substantive differences between the included studies and their unknown quality make the reliability of the overall conclusions unclear.

To assess the effect of reminiscence interventions (simple reminiscence, life-review or life-review therapy) on psychosocial outcomes.

MEDLINE, CINAHL, PsycINFO and PSYNDEX databases and Google Scholar were searched for studies reported up to November 2011. Search terms were reported.

Controlled studies that assessed simple reminiscence, life-review or life-review therapy were eligible for inclusion. Studies were required to have a control group that did not receive an active psychological treatment. At least one of the listed outcomes had to be reported with sufficient data for calculation of an effect size: depression, other psychological symptoms, psychological well-being, ego-integrity, purpose in life, mastery, cognitive performance, social integration and preparation for death. Details of the assessment of each of the outcomes were reported in the paper.

Most studies assessed simple reminiscence; only a few assessed life-review therapy. Most studies used a group format. Interventions programmes offered an average of 10 sessions and took place over about eight weeks. Two-thirds of participants were women. The average age of participants was 73 years. Only 28% of participants were married.

The authors did not report how many reviewers assessed the studies for inclusion in the review.

Studies were assessed for validity using a modified form of a published checklist (Cuijpers et al.). Criteria assessed were randomisation, training of therapists/group leaders, blinding of raters, use of a treatment manual, treatment integrity, use of intention-to-treat analysis, adequate power and other issues. Scores were summed to provide an overall score.

The authors did not report how many reviewers carried out the assessment.

Data were extracted in order to calculate effect sizes (d) for each outcome. These were adjusted for baseline differences between treatment groups and for the effect of small sample sizes to calculate Hedges g. Outliers more than two standard deviations from the mean of the effect size were re-coded to this value of two standard deviations.

It appeared that two reviewers independently extracted at least 20% of studies and differences were resolved by discussion; the procedure for the remaining studies was unclear.

A random-effects meta-analysis with inverse-variance weighting was used to calculate pooled effect sizes for each outcome. Pooled effect sizes of 0.8 or greater were considered large, 0.5 or greater were medium and between 0.2 and 0.49 were small. Statistical variation between effect sizes from different studies was tested using the Q statistic. The effect of moderating variables such as intervention type and baseline population health were explored using a method described as an analogue of analysis of variance and meta-regression. A trim-and-fill method was used to assess the possible impact of publication bias on results

There were 128 studies included in the review (8,404 participants). Ninety-five studies were randomised controlled trials and the same number were published studies. Eighty-two studies assessed reminiscence, 37 assessed life-review and only 18 used life-review therapy. Follow-up data were reported in only 27 studies; mean length of follow up was 23 weeks (range two to 156 weeks). The results of the quality assessment were not reported but the authors stated that study quality did not affect the size of treatment effects.

The largest benefit of interventions using reminiscence (measured by pooled effect size) was found for the outcome of ego-integrity (g=0.64). Significant benefits were found for depression (g=0.57), purpose in life (g=0.48), preparation for death (g=0.40), mastery (g=0.40), mental health other than depression (g=0.33), positive well-being (g=0.33), social integration (g=0.31) and cognitive performance (g=0.24). Follow-up data indicated persistence of the effects for six of the nine outcomes (depression, other mental health measures, positive well-being, ego-integrity, cognitive performance and preparation for death).

Trim-and-fill analysis did not identify a consistent pattern of over-estimation. There was heterogeneity in most analyses; only preparation for death and cognitive performance showed homogeneity. Exploration of potential moderating variables suggested that benefits in depression and well-being were greatest in studies that used the most intensive intervention (life-review therapy). Improvements in depression were greater in participants who had depression or chronic physical health problems at baseline. Stronger effects were seen in studies without an active control. Results of multiple linear regression were reported.

Reminiscence interventions affected a broad range of outcomes. Therapeutic and preventive effects were similar to those observed in other frequently used interventions.

The review addressed a clear question supported by inclusion criteria that were clear with respect to interventions, comparators and outcomes. Criteria for study design were less transparent; it appeared that any study with a control group was eligible. The search was reasonable and included unpublished studies, which reduced the chances that relevant studies were omitted and selection bias introduced. The authors did not report whether they used methods to reduce reviewer error and bias during study selection and quality assessment; it appeared that such methods were used for data extraction. The results of the quality assessment were not reported but were apparently used to inform the synthesis.

The synthesis involved statistical combining of randomised controlled trials with other (unknown) study designs. The high level of clinical differences between the included studies was reflected in significant statistical heterogeneity. This was explored but multiple testing was not adjusted for.

The unknown quality and design of the included studies together with the substantive differences between them make the reliability of the overall conclusions unclear.

Practice: The authors stated that simple reminiscence therapy or life review could be used to promote positive well-being with non-depressed participants and suggested that life review therapy should be used in depressed participants. They further stated that reminiscence interventions should be offered to older adults and other persons who were interested in remembering the past, reviewing their lives and finding ego-integrity.

Research: The authors recommended more research on the effects of reminiscence therapy in young and middle-aged adults and on the type of participant to benefit most from reminiscence interventions.

Not reported.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.