Factors Related to the Quality of Life in Family Carers of People With Dementia: A Meta-Analysis

Objectives: This meta-analysis aimed to (1) quantitatively synthesize evidence of factors related to the quality of life (QoL) of family carers of people with dementia and (2) explore moderating factors that may influence the strength of the relationship between such potential predictive factors and carer QoL. Methods: Studies that investigated correlations between patient/carer factors and QoL in unpaid family carers of people with dementia and were published in English, Spanish, Portuguese, or Japanese were included. Results: Thirty-three studies were identified. The pooled correlations with carer QoL (effect size) were significantly large for depression (−0.58), significantly moderate for subjective burden (−0.47), and significantly small for people with dementia’s neuropsychiatric symptoms (−0.24). These results indicated to be robust in the context of publication bias. The results of subgroup analyses demonstrated the social and economic development status of the country where study participants resided did not moderate these effects. Conclusion: Carer depression, subjective burden, and people with dementia’s neuropsychiatric symptoms may play a critical role in maintaining QoL of family carers regardless of the social and economic circumstances.


Rationale
3 Describe the rationale for the review in the context of what is already known.

4-6
Objectives 4 Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).

METHODS
Protocol and registration 5 Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.
8 Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.

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Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.

8
Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.

8
Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).

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Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.

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Data items 11 List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.

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Risk of bias in individual studies 12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.

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Summary measures 13 State the principal summary measures (e.g., risk ratio, difference in means).

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Synthesis of results 14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis.

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Section/topic # Checklist item Reported on page # Risk of bias across studies 15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).

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Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified.

RESULTS
Study selection 17 Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.

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Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations.

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Risk of bias within studies 19 Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).
14 Results of individual studies 20 For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot.
14 Synthesis of results 21 Present results of each meta-analysis done, including confidence intervals and measures of consistency.

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Risk of bias across studies 22 Present results of any assessment of risk of bias across studies (see Item 15).

DISCUSSION
Summary of evidence 24 Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers).

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Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias).

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Conclusions 26 Provide a general interpretation of the results in the context of other evidence, and implications for future research.

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FUNDING Funding 27 Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review. Supplementary Figure 1: Forest plot for independent variables with non-significant effect.