Methodological quality of the review: Medium confidence
Author: Renaud J and Bédard E.
Region: United States of America (USA), Australia, Canada, New Zealand and United Kingdom (UK).
Sector: Visual impairment
Sub-sector: Health related quality of life, depression symptoms, disability, vision-related quality of life, subjective well-being.
Equity focus: Elderly (aged >55)
Review type: Effectiveness review
Quantitative synthesis method: Narrative analysis
Qualitative synthesis methods: Not applicable
The elderly population has the highest prevalence of visual impairment. The onset of visual impairment in this population has a substantial burden and numerous consequences related to participation restriction, loneliness and limited social interaction. These consequences could lead to depression and substantially affects the quality of life of the elderly population. It is important to establish the impact of depression symptoms on older people’s quality of life. In the clinical setting, efforts to train health care practitioners to identify visually impaired elders with depression and provide appropriate treatment is essential. However, reviews on the impact of depression symptoms on older people’s quality of life are uncommon.
To describe the association between depression and quality of life (QOL) in older adults with visual impairment.
Thirteen studies reported in 18 articles were included in the review. Five studies were cross sectional, one was a case-control study, and seven were follow-up studies. There were no randomized controlled trials. Most studies originated from the USA (nine), Australia (one), Canada (one), New Zealand (one) and the UK (one). The participants in the included studies ranged from 31 to 438 participants, aged 77 to 84 years. The participants came from low vision and rehabilitation agencies or ophthalmology clinics. Although half of the studies assessed the relatioship between depression and both health-related and vision-related quality of life (QOL)(n=7), some investigated only the association with either health-related (n=2) or vision-related (n=4) QOL. Only two studies looked at the association between depression and subjective QOL.
Nearly all studies reported that better QOL was moderately to strongly correlated with less severe depressive symptoms. Effect sizes for the QOL differences between the groups with and without depression ranged from small to large.
The authors noted that this review highlighted the association between more severe depressive symptoms and worse QOL in older adults with visual impairment. Additionally, they stated that additional studies were necessary to pinpoint further the determinants and mediators of this relationship.
The authors conducted a search on several databases including Medline, PsycINFO, Pubmed, Embase, Social Work Abstracts and Cochrane, Google scholar was also searched in attempt to identify grey literature, and proceedings of international scientific meetings. Bibliographies of studies were manually searched for additional studies. The research was limited to elders and studies were manually sorted to keep only those with older participants (over 55 years of age) having visual impairment. Self-reported visual impairment was included if participants were receiving services from a vision rehabilitation agency. All study designs were included except for case reports. Reviews and meta-analyses were not analysed but were used to find further studies. The literature search was conducted between 1980 and 2013 for articles written in English and French.
The authors extracted data of included studies including characteristics of the population, study design, type of questionnaire, and relevant outcomes. Data were collected for every correlation odds ratio and variance related to the association between depression and QOL, QOL comparison data between groups with and without depression and prevalence of depression.
To evaluate the methodological quality of studies, the authors used the Cho and Bero scale as it also allowed assessment of observational studies. Two authors read all articles and independently assessed the methodological quality of each study using this 24-item scale. The classifications for each study level were as follows: randomized controlled trial (I), cohort (II), case control (III), and case series (IV).
Details in regards to the methods used to select studies and extract data of included studies were not reported.
The authors did not discuss the generalizability of findings from the review.
Although the authors did not restrict the search to specific income setting, only studies from high income countries were eligible for inclusion in the review. Nevertheless, authors did not discuss the applicability of the results to low/middle income countries.
Overall, there is medium confidence in the conclusions about the effects of this study. This review was based on partially comprehensive searches of the literature including relevant databases, searching international scientific meetings and manual searching of bibliographies of included studies. However, language bias was not fully avoided and the reviewers did not contact authors of included studies for further relevant studies. It is not clear if study selection was conducted independently by the two authors, and methods used to extract data of included studies was not reported, therefore, it is not possible to determine if risk of bias was avoided. Nevertheless, the authors appropriately analysed findings of included studies and this was clearly reported. They described the extent of heterogeneity and reported evidence appropriately stating which factors may explain differences in results. Overall, the authors did not draw strong policy conclusions.