What factors are associated with increased symptoms of depression amongst non-professional caregivers of patients with cancer?
Have any studies generated a prediction model to identify caregivers at an increased risk of depression?
The review will be conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.
Electronic database searchers:
The search strategy was developed by the authors and the following databases are to be used: MEDLINE (OvidSP), CINAHL, and PsycInfo.
Terms to be used in the searches will relate to the four core topics: cancer, caregivers, depression, and risk factors. An example of the search strategy used in MEDLINE is attached. The search terms will be adapted for use with other databases. The search will be restricted to studies published in English language. No date restriction will be applied; studies published up to the date the searches are run will be sought, and the search will be repeated just prior to final analyses, with any further studies retrieved for inclusion.
The reference lists of relevant studies will also be searched for any additional studies not found in the initial search. A citation search will also be conducted to identify any additional publications that have cited the relevant studies. We will contact authors to enquire if there are further related publications.
We will include studies with quantitative designs; due to the nature of the research question, we anticipate these will primarily be observational studies, though all quantitative-type studies will be considered. Studies with qualitative designs will be excluded from this review.
Condition or domain being studied
Depression in non-professional caregivers of patients with cancer.
The review will include studies in which the primary participants meet the following inclusion criteria:
The caregiver must be an adult, aged 18 years, or older, and responsible for providing informal care for a patient who is an adult (aged 18 years or older) and has been diagnosed with any type of cancer. "Care" may include any type of physical, practical, or emotional care or support.
The caregiver must not be a professional or paid caregiver, or a trained volunteer; however, caregivers who receive financial benefits from the government to assist with their care-giving role will be eligible for inclusion.
The caregiver must be a spouse, partner, relative or friend of the patient.
Care is provided for a patient living in their own home, and not in a hospital or hospice.
Some studies have examined the psychological needs of caregivers of cancer survivors, once they are "free" of disease. This review will exclude studies of persons who were previously caregivers for patients deemed to be in complete clinical remission.
Studies of caregiver bereavement following the patient's death will not be included in this review.
This review will include studies of non-professional caregivers of patients with cancer. Care-giving includes any form of physical, practical, or emotional care or support being provided to the patient. Examples include: transportation, administration of medications, assistance with activities of daily living (ADLs), and home nursing care.
A recent review of the effects of caring for a patient with cancer identified greater than 200 problems and burdens associated with performing this care-giving role. (Stenberg, 2009) These can collectively be termed the "carer burden". Emotional problems, including depression, both contribute significantly to the carer burden, and are influenced by other aspects of it, including the physical and social effects of performing the caregiver role.
Studies that focus on the emotional aspects of carer burden, in particular depression, will be included in this review. Studies that focus solely on the physical or social problems associated with caring for patients with cancer will be excluded from this review, if they do not include some measure of the psychological distress associated with these problems.
Care is provided for a patient living in their own home, and not in a hospital or hospice. Study participants may be recruited from outpatient or day clinics, but not from any inpatient or residential care facility.
The primary outcome is depression, but searches will initially include any measure of psychological distress, broadly defined to include constructs such as: depression, anxiety, burden, distress, mental health, coping. This broad definition will be retained throughout the search and initial screening process until full texts are retrieved. This is in order to be more inclusive of studies using different terminology to refer to the construct of "depression". Refer to the section "Data extraction" for details on how these articles will be managed.
For this review, we define depressive symptoms as those described in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, 4th Edition-Text Revision (DSM-IV-TR) or 5th Edition (DSM-5), briefly:
1. Depressed mood most of the day.
2. Diminished interest or pleasure in all or most activities.
3. Significant appetite change; unintentional weight loss or gain.
4. Insomnia or sleeping too much.
5. Agitation or psychomotor retardation noticed by others.
6. Fatigue or loss of energy.
7. Feelings of worthlessness or excessive guilt.
8. Diminished ability to think or concentrate, or indecisiveness.
9. Recurrent thoughts of death (APA 2000)
Studies using any definition, construct, or measure of depression that reviewers deem to correspond closely to this definition of depression will be included.
Data extraction, (selection and coding)
After duplicate studies have been removed, titles and, where available, abstracts of studies retrieved using the search strategy and those from additional sources will be assessed independently by two review team members (AB and JE) to identify studies that potentially meet the inclusion criteria described previously. We will exclude studies that do not meet the review's criteria. The full text of potentially eligible studies will be retrieved, as well as the full text of any studies for which a definite decision cannot be made from the title and abstract alone. The full text articles will be independently assessed for eligibility by two review team members. Studies excluded at this stage will be recorded and their reason for exclusion will be reported in the review. Any disagreement regarding the eligibility of studies for inclusion will be discussed and, where possible, resolved by consensus, or if necessary, through discussion with a third reviewer (RG).
A clarification about the selection procedure, regarding outcome measure:
The primary focus of this review is publications where depression is an outcome variable. We will initially include studies with any measure of psychological distress, broadly defined to include constructs such as: depression, anxiety, burden, distress, mental health, coping. This broad definition will be retained throughout the search and initial screening process until full texts are retrieved. This is in order to be more inclusive of studies using different terminology to refer to the construct of "depression". Full texts will then be screened independently by two reviewers (AB and JE) to determine if the study has used definitions and measures corresponding to our definitions of "depression" or "depressive symptoms" as an outcome variable. Disagreement about whether studies meet this criteria will be resolved by consensus, or through discussion with a third reviewer (RG), where necessary. Studies that have used terms, definitions, or measures that are agreed not to correspond to the review's definition of depression will be excluded at this stage.
A standardised, pre-designed data extraction form will be used to extract data from the included studies for the assessment of study quality and data synthesis. Extracted data will include:
General information: author, year of publication, title, type of publication, journal, country of origin, funding source, ethics approval.
Study characteristics: aim/objectives, study design, sample size, number enrolled, number included in analysis, number of withdrawals, exclusions, lost to follow-up.
Caregiver characteristics: age, gender, ethnicity, relationship to patient, employment status, socio-economic status, other subgroups measured/reported.
Patient characteristics: age, gender, ethnicity, diagnosis, cancer stage, other subgroups measured/reported.
Risk of bias: see Risk of bias (quality) assessment, below.
Outcome data: (for each pre-specified outcome) whether reported, definition used, psychological distress measures (depression, anxiety), number of data points, how outcome was measured, measurement tools used, length of follow-up, number and/or times of follow-up measurements.
Type of analysis used in study.
Results of analysis, for example: Dichotomous (odds ratio, risk ratio and confidence intervals, p-value), Continuous (mean and standard deviation).
Data extraction will be performed by one study author (AB), with the exception of data included in the risk of bias / quality assessment. For these items (see below), two review authors (AB and JE) will extract data independently; discrepancies will be identified and resolved by consensus, or through discussion with a third reviewer (RG), where necessary.
Risk of bias (quality) assessment
Two review authors will assess the risk of bias/quality of included studies independently; discrepancies will be identified and resolved by consensus, or through discussion with a third reviewer, where necessary. Quality/risk of bias will be assessed using a modified version of the assessment checklist developed by Downs and Black (Downs and Black 1998). Items pertaining to interventions, randomisation and trial studies were removed, as they were not appropriate for the studies included in this review, and some other items have been modified to inrease relevance. An additional item was included to assess internal validity for any studies proposing a model to predict caregiver depression.
The modified checklist consists of 15 items, distributed between 4 sub-scales:
Reporting (9 items)
External validity (2 items)
Internal validity - Bias (3 items)
Power (1 item)
Strategy for data synthesis
We will provide a narrative synthesis of the findings from the included studies, structured around caregiver and patient characteristics, and the main outcome. A summary of each study and its characteristics will be provided in a table. We anticipate (indicated by pilot searches) that there will be too limited a scope to perform a meta-analysis because of the range of outcomes measured and heterogeneity between the small number of existing studies.
Analysis of subgroups or subsets
If reported in the studies we will present results based on characteristics such as gender, age, relationship to the patient, socio-economic status, and any other subgroups that emerge as important based on what is reported in the primary studies. Since we will include caregivers of patients diagnosed with any type of cancer, it may be appropriate to present results based on cancer diagnoses; however, this will be dependent on reporting in the primary studies i.e., whether they have focused on certain types of cancers or present data in subgroups in a way that this is meaningful.
Results of this study will be made publicly available, to the medical professional and the general community, following submission for publication in an international medical journal yet to be specified.
Contact details for further information
Organisational affiliation of the review
James Cook University School of Medicine and Dentistry
Mr Alexander Bowden, School of Medicine and Dentistry, James Cook University Professor Ronny Gunnarsson, School of Medicine and Dentistry, James Cook University Dr Susan Hewitt, The Townsville Hospital, Queensland Health Miss Jasmin Ellenberger, School of Medicine and Dentistry, James Cook University
Anticipated or actual start date
05 August 2013
Anticipated completion date
11 October 2013
School of Medicine and Dentistry, James Cook University, Australia
Formal screening of search results against eligibility criteria
Risk of bias (quality) assessment
PROSPERO This information has been provided by the named contact for this review. CRD has accepted this information in good faith and registered the review in PROSPERO. CRD bears no responsibility or liability for the content of this registration record, any associated files or external websites.