Scholarly article on topic 'A literature review on the mutual impact of the spousal caregiver–cancer patients dyads: ‘Communication’, ‘reciprocal influence’, and ‘caregiver–patient congruence’'

A literature review on the mutual impact of the spousal caregiver–cancer patients dyads: ‘Communication’, ‘reciprocal influence’, and ‘caregiver–patient congruence’ Academic research paper on "Psychology"

CC BY-NC-ND
0
0
Share paper
Academic journal
European Journal of Oncology Nursing
OECD Field of science
Keywords
{Cancer / "caregiver–patient dyads" / "Reciprocal influence" / Communication / "caregiver–patient congruence"}

Abstract of research paper on Psychology, author of scientific article — Qiuping Li, Alice Yuen Loke

Abstract Purpose A diagnosis of cancer is the start of a journey of distress and adjustment for both the patient and his/her spouse. However, the dyadic phenomena are less conceptualised and related research is in the early stages. This review explores concepts of mutuality among spousal caregiver–cancer patient dyads and identifies directions for future research. Method A systematic search, including trawling through six electronic databases, a manual search, and an author search, was conducted to identity articles that had been published in English and Chinese from January 2000 to March 2013, using key terms related to caregiver–patients dyads in cancer care. An inductive content analysis approach was adopted to analyse and synthesise the concepts of spousal caregiver–cancer patient dyads. Results Thirty-one articles were identified. The findings are described according to Fletcher et al.'s proposals for conceptualising spousal caregiver–patient dyads. The proposed concepts of ‘communication’, ‘reciprocal influence’, and ‘caregiver–patient congruence’ have been found to be interrelated, and to contribute to the spousal caregiver–patient dyads' mutual appraisal of caregiving and role adjustment through the cancer trajectory. Conclusions The findings highlight the importance of a perspective that focuses on the nature of the relationship between couples coping with cancer and the quality of their communication with each other. It is recognised that communication may act as a fundamental element of the abovementioned three concepts. Better communication between couples would probably facilitate reciprocal influence and caregiver–patient congruence, which in turn would have a positive effect on intimacy between the couple and improve the caregiving outcomes.

Academic research paper on topic "A literature review on the mutual impact of the spousal caregiver–cancer patients dyads: ‘Communication’, ‘reciprocal influence’, and ‘caregiver–patient congruence’"

Contents lists available at ScienceDirect

European Journal of Oncology Nursing

journal homepage: www.elsevier.com/locate/ejon

European Journal of

Oncology Nursing

A literature review on the mutual impact of the spousal caregiver-cancer patients dyads: 'Communication', 'reciprocal influence', and 'caregiver-patient congruence'

CrossMark

Qiuping Li a, Alice Yuen Loke

a Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, China

b School of Nursing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

ABSTRACT

Keywords: Cancer

caregiver-patient dyads Reciprocal influence Communication caregiver-patient congruence

Purpose: A diagnosis of cancer is the start of a journey of distress and adjustment for both the patient and his/her spouse. However, the dyadic phenomena are less conceptualised and related research is in the early stages. This review explores concepts of mutuality among spousal caregiver—cancer patient dyads and identifies directions for future research.

Method: A systematic search, including trawling through six electronic databases, a manual search, and an author search, was conducted to identity articles that had been published in English and Chinese from January 2000 to March 2013, using key terms related to caregiver—patients dyads in cancer care. An inductive content analysis approach was adopted to analyse and synthesise the concepts of spousal caregiver—cancer patient dyads.

Results: Thirty-one articles were identified. The findings are described according to Fletcher et al.'s proposals for conceptualising spousal caregiver-patient dyads. The proposed concepts of 'communication', 'reciprocal influence', and 'caregiver-patient congruence' have been found to be interrelated, and to contribute to the spousal caregiver-patient dyads' mutual appraisal of caregiving and role adjustment through the cancer trajectory.

Conclusions: The findings highlight the importance of a perspective that focuses on the nature of the relationship between couples coping with cancer and the quality of their communication with each other. It is recognised that communication may act as a fundamental element of the abovementioned three concepts. Better communication between couples would probably facilitate reciprocal influence and caregiver-patient congruence, which in turn would have a positive effect on intimacy between the couple and improve the caregiving outcomes.

© 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

Introduction

The diagnosis of cancer and its treatment has a major impact on both patients and their family caregivers (Kayser et al., 2007). This is particularly true when the primary caregiver is the patient's spouse, who takes on an active role in decisions concerning treatment options and provides emotional and instrumental support to the patient (Hagedoorn et al., 2008). It is reported that the support

q This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Corresponding author. Tel.: +852 27666386; fax: +852 23649663.

E-mail addresses: alice.yuen.loke@polyu.edu.hk, hsaloke@polyu.edu.hk (A.Y. Loke).

from the patient's spouse is of such great significance that good support from friends or other family members does not compensate for inadequate spousal support (Pistrang and Barker, 1995). While focussing on providing support for their partners with cancer, spousal caregivers often fail to address their own needs and feelings (Chung and Hwang, 2012; Lopez et al., 2012). Studies have shown that spousal caregivers of cancer patients are at a high risk of succumbing to a wide spectrum of hidden mental, physical, and social morbidities, as a consequence of their caregiving (Li and Loke, 2013).

To varying degrees, cancer affects the couple as a unit, rather than as isolated individuals, causing couples to react to a cancer diagnosis as an "emotional system" (Hagedoorn et al., 2008). The diagnosis and treatment of cancer can change the relational dynamics between people with cancer and their intimate partners, which can have an impact on the subjective well-being and ability

1462-3889/$ - see front matter © 2013 The Authors. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ejon.2013.09.003

to cope of both parties (Dankoski and Pais, 2007). The couples have a mutual impact on each other in their quality of life (QOL), psychological health, and adjustment to their roles (Kim et al., 2008; Northouse et al., 2000).

These changes and mutual impact may affect the structure of the couple's relationship, and their roles and responsibilities, and lead to an unpredictable future (Dankoski and Pais, 2007). A diagnosis of cancer puts couples to the stress of breaking the 'bad news', negotiating changes in occupational and family roles, and managing household and childcare responsibilities (Lopez et al., 2012; Maughan et al., 2002). Throughout the cancer trajectory, both patient and partner must together cope with the practical issues and difficulties that they may encounter (Dankoski and Pais, 2007). Spouses also worry about their ability to provide emotional and practical support to the patient, and about the potential loss of their life partner (Maughan et al., 2002; Thomas et al., 2002).

The focus of cancer care and its research has shifted from the individual experiences of patients or spousal caregivers to caregiver—patient dyads (Fletcher et al., 2012). Thus, it is proposed that in the future more emphasis should be placed on the transactions between caregivers and patients as care partners (Fletcher et al., 2012). Two conceptual models have been identified that specifically target caregiver—patient dyads in the cancer population. One is the relationship intimacy model, which addresses the psychosocial adaptation of couples to cancer (Manne and Badr, 2008). This model highlights the importance of the couple's relationship and their engagement in communication that sustains and/or enhances the relationship during times of stress.

In the other conceptual model, proposed by Fletcher et al., caregiver—cancer patient dyads (CCPD) are conceptualised as a functional unit, with their mutuality involving three dyad-level concepts: 'communication', 'reciprocal influence', and 'caregiver— patient congruence' (Fletcher et al., 2012). The suggestion is that the focus and direction of research on the caregiving experiences of families with cancer should be on the caregiver—patient dyad as a unit (Fletcher et al., 2012).

To date, there has not been a review of the literature focussing specifically on the mutual impact of spousal caregiver—cancer patient dyads. This literature review was conducted for the following reasons: (i) to explore concepts relating to spousal caregiver—pa-tient dyads in the context of the cancer trajectory; (ii) to facilitate the conceptual development of CCPD by analysing the interrelat-edness of concepts on spousal caregiver—patient dyads; and (iii) to identify directions for future research and implications for interventions targeting couples coping with cancer.

Methods

Search methods for identifying studies

A systematic literature search was conducted to identity articles published in English or Chinese from January 2000 to March 2013, using key terms related specifically to spousal caregiver—patient dyads in cancer care. The key search terms used were 'cancer' or 'oncology' or 'carcinoma' AND 'caregiver' or 'caregiving' or 'carer' AND 'dyad' AND 'spouse' or 'couple' or 'partner'. The databases that were searched included MEDLINE, CINAHL, Science Citation Index Expanded, Scopus, PsychINFO, and the China Academic Journals Full-text Database. Apart from an electronic search, a manual search for related studies and an author search were also performed.

Inclusion and exclusion criteria

The studies that were included in this review met the following criteria: articles published in English or Chinese from January 2000 to March 2013, with the subject of the studies being spousal caregiver—patient dyads — i.e., couples coping with cancer — and the focus of the studies being on the mutuality or dyadic effect within couples. Commentaries, editorial comments, literature reviews, interventions or programmes, and conference proceedings were not included in this review.

Eligibility and selection process

The articles were assessed and selected by screening records and looking through the full-text versions according to predefined inclusion and exclusion criteria. A flow diagram of the search and selection process is given in Fig. 1.

Data extraction and quality assessment

Data were extracted from each of the included studies using a standard format: information on the literature, study aims, study design, samples/time points, instrument used, and significant findings. An assessment of the quality of the included studies was conducted from the impact factors of the published journal and a systematic analysis of the extracted data.

All of the 31 articles included in this review were published in peer-reviewed journals. The impact factor of these journals ranged from 0.61 to 4.77, with the exception of one journal (Gardner, 2008) affiliated with the Social Work in Hospice and Palliative Care Network. In all of the 24 quantitative articles (including one mixed methods study), the aims of the study were clearly delineated, the study design was well defined, the time point for the collection of data were specified, the characteristics of the targeted population and sample size were clearly described, the analysis for confounding variables was properly adjusted, and the outcomes and estimated significances were stated without obvious bias. For the seven qualitative studies, the research questions were clearly stated, the research approaches that were applied were appropriate for the purpose of the study, the phenomena were clearly described, the presentation of the findings was logical, consistent, and easy to follow, and the writing effectively promoted understanding. In general, the 31 articles included in this review were considered to be of high quality.

Conceptual model for caregiver—patient dyads

The three concepts proposed by Fletcher and colleagues in conceptualising spousal caregiver—patient dyads were adopted to present the results (Fletcher et al., 2012). The three concepts were: 'communication': "a transactional process in which individuals create, share, and regulate meaning" (p. 395); 'reciprocal influence': "the effect the two members of a dyad have on each other" (p. 394); and 'caregiver—patient congruence': "the concept of congruence synthesises individual data into a dyad variable, related to agreement, concordance, and their opposite, disparity" (p. 394) (Fletcher et al., 2012).

Results

A total of 23 quantitative and seven qualitative studies, as well as one mixed methods study met the criteria for inclusion in this review. The characteristics of these studies are summarised in Table 1 (Supplemental materials).

Fig. 1. The flow diagram on identifying the literature.

Characteristics of the selected studies

Communication

Most of the studies (n = 25, 80.6%) were conducted in the United States, and the remaining six studies were conducted in Australia (n = 1, 3.2%), Canada (n = 1,3.2%), the Netherlands (n = 1, 3.2%), Israel (n = 1, 3.2%), Korea (n = 1, 3.2%), and Taiwan (n = 1, 3.2%). Of the 24 quantitative studies, there were 14 cross-sectional and 10 longitudinal studies, with observation times ranging from 1 week to 2 years from baseline. The sample sizes ranged from 40 to 216 couples. The designs of the seven qualitative studies included grounded theory (n = 1), descriptive study (n = 2), and focus groups (n = 4); and the sample sizes ranged from 7 to 35 couples.

The types of cancer that the couples in these studies were coping with were: prostate cancer (n = 14, 45.2%), breast cancer (n = 7, 22.6%), prostate cancer and breast cancer (n = 1, 3.2%), multiple types of cancer (n = 3,9.7%), lung cancer (n = 3,9.7%), lung cancer and head and neck cancer (n = 1, 3.2%), gastrointestinal cancer (n = 1, 3.2%), and colon cancer (n = 1, 3.2%).

Spousal caregiver — patient dyads

It was discovered that the findings of all of the studies fell under the three concepts of mutuality for spousal caregiver—patient dyads proposed by Fletcher et al. (2012): communication (n = 13, 41.9%), reciprocal influence (n = 12, 38.7%), and caregiver—patient congruence (n = 6,19.4%).

It was found that better communication between couples, such as talking about their relationship (Badr et al., 2008; Badr and Taylor, 2006; Lindau et al., 2011), open or mutual constructive discussion between the spouses (Badr and Taylor, 2009; Manne et al., 2010), and a habit of making disclosures (Sterba et al., 2011 ; Badr et al., 2010; Manne et al., 2004; Porter et al., 2005; Zhou et al., 2011), was related to less distress and better marital adjustment.

A study that focused on the effects of relationship talk on the psychosocial adaptation of couples to lung cancer showed that patients and partners who reported talking more frequently about their relationship were less distressed (effect size r = 0.16) and made greater marital adjustments over time (effect size r = 0.21) (Badr et al., 2008) than those who did not talk as frequently about their relationship.

A qualitative study that focused on couples coping with lung cancer showed that participants who reported having open communication with their partners about the functioning of their relationship, such as about the quality of their relationship, good memories, planning for the future, and problem solving, perceived fewer social constraints and better communication about cancer (Badr and Taylor, 2006). However, in another qualitative study, Lindau et al. (2011 ) showed that most couples reported that they had not talked directly with their spouses about the effect of cancer on their relationship, although several people referred to having an

increased awareness of non-verbal cues. For some couples "oral communication became more guarded in order to protect the patient or spouse from additional fear or stress; withholding information was a commonly cited protective mechanism", while some couples reported "improved communication due to an increased awareness of time and appreciation for each other" (Lindau et al.,

2011) (p. 183).

Studies on mutual constructive communication between couples have shown that patients and partners who reported high levels (+1SD) of mutual constructive communication reported greater marital adjustment along the cancer trajectory (Badr and Taylor, 2009). The partners who did not engage in a high level of mutual constructive communication were more likely to report that the couple avoided open discussions between them when patients with prostate cancer had poor erectile function. The avoidance of discussion between the couple about the poor erectile function in turn, was associated with marital distress (Sobel's Z = 12.47, p = 0.001) (Badr and Taylor, 2009). Another study reported that patients and spouses who reported greater baseline distress reported more negative baseline communication as well as lower levels of intimacy and greater distress over time (Manne et al., 2012). Mediation analyses have shown that those patients and spouses who reported engaging in more mutual constructive communication, less mutual avoidance, and fewer patient demand-partner withdraw situations experienced less subsequent distress, largely through the effects of intimacy (Manne et al., 2010, 2012).

Boehmer and Clark (2001a) conducted a qualitative study on mutual communication between couples with prostate cancer. The findings revealed that although wives were deeply concerned about their husbands' prostate cancer, there was little communication between the spouses about the implications of prostate cancer on their lives (Boehmer and Clark, 2001a). In particular, couples did not appear to talk much about their emotions, worries, and fears, such as about physical changes, perceptions of changes in their spouse, and issues of sexuality. Usually, patients hide their feelings about the impact of the illness, and wives try to protect their husbands by hiding their emotions or avoiding questions.

Interviews of couples coping with breast cancer showed that the couples were 'learning through struggling' — that is, through mutual help and support, sharing personal views of what is important for patients, and showing mutual concern. However, husbands faced challenges communicating and were unable to read their wives' thoughts and feelings, which frustrated their wives. Consequently, both spouses felt depressed, burdened, and worried about sexual issues, and the future (Chung and Hwang, 2012).

A study of couples coping with prostate cancer showed that patterns of communication changed over time and by role, with perceived levels of open communication decreasing at a slower speed for patients than for their partners. The trajectories of change in levels of open dyadic communication about cancer differed marginally between patients and partners (p = 0.06) (Song et al.,

2012).

Gardner (2008) explored patterns of relationship, support, and communication in couples experiencing cancer. The findings showed that there were a variety of complex and interrelated changes in physical, emotional, and social experiences resulting from the diagnosis and progression of cancer. There are dyadic-level accommodations to living with advanced cancer, using the word 'we' to describe their experiences, including living with uncertainty about the illness and the future; facing illness and dying trajectories and speaking openly with their partner; and searching for shared meanings, understandings, narratives, or philosophical approaches related to the patients' illness trajectory and ultimate prognosis. Maintaining a positive or optimistic outlook was described by the couples as important in supporting in their

attempts to cope with the cancer, and in their interactions with each other (Gardner, 2008).

A study that examined patterns of disclosure about cancer-related concerns between patients with gastrointestinal (GI) cancer and their spouses showed that there were interrelationships between disclosure and levels of holding back, and intimacy (Porter et al., 2005). When patients reported high levels of disclosure to their spouse and low levels of holding back, both the patients and their spouses rated their relationship as being more intimate. Higher levels of disclosure and lower levels of holding back were also related to higher levels of intimacy with the patient, and less avoidance by the patients (Porter et al., 2005). Another study on disclosure and intimacy between couples also showed that, for patients, perceived partner responsiveness partially mediated the association between partner disclosure and patient perceived intimacy. For partners, perceived patient responsiveness also mediated the association among self-disclosure, perceived patient disclosure, and partner perceived intimacy (Manne et al., 2004).

In a qualitative study, Fergus and Gray (2009) explored the relationship challenges and vulnerabilities of couples coping with breast cancer. They reported that open communication between such couples could not take place because of the couples' personal characteristics and patterns of communication. Such characteristics of the patients as self-absorption, counter-dependency, exaggerated dependency, and being overly controlling; and the spouse caregivers' solution-driven approach, unchecked anger, and failure to reach out impeded the couples' ability to communicate and adjust to the illness. Meanwhile, withholding-withdrawal, under-burdening, and conflicting intentions were the barriers and pitfalls in relationship dynamics. Couples also faced the challenges of negotiating support, accommodating changes in the other person, coping with sexual disruption, and death and separation.

In summary, satisfactory communication between couples was linked to less distress and better marital adjustment. Levels of distress at baseline, cancer-related symptoms, roles, and cancer trajectory were identified as factors affecting communication between couples dealing with cancer.

Reciprocal influence

Multiple interrelated dimensions of well-being were illustrative of the concept of 'reciprocal influence' in that each member of a spousal caregiver-cancer patient dyad affects the other in each of these dimensions, which include: QOL (Song et al., 2012; Campbell et al., 2004; Chen et al., 2004; Galbraith et al., 2008), self-efficacy (Campbell et al., 2004), mental health or psychological stress (Kim et al., 2008; Sterba et al., 2011; Gilbar and Zusman, 2007; Kershaw et al., 2008), emotion-focused coping (Gilbar and Zusman, 2007), role adjustment (Northouse et al., 2000), and marital satisfaction (Zhou et al., 2011).

A study showed that the patients' total QOL score and the social/ family functional dimensions of QOL were both associated with the total score and each dimension of their spousal caregivers' QOL (r = 0.27—0.44) (Chen et al., 2004). It was also reported that cancer diagnosis, length of hospitalisation, caregiving intensity and duration, marital satisfaction, and self-esteem in caregiving might have a reciprocal influence on the QOL correlations between couples (Chen et al., 2004).

In their study, Song et al. (2011) showed that there were correlations in QOL between patients and partners, which remained consistent during the survival of the patient (r = 0.25, 0.24, 0.23, and 0.23, at baseline and at the 4-, 8-, and 12-month follow-up sessions, respectively). The QOL of the couples also improved with an increase in their social support (p < 0.001) and cancer-related dyadic communication (p < 0.001); and a decrease in the

couple's uncertainty of illness (p < 0.001), in the patient's cancer-specific hormonal (p < 0.001) and sexual symptoms (p < 0.05), and in the general symptoms (p < 0.001) of both partners (Song et al., 2011).

A study that focused on the self-efficacy of the couples showed that both patient and caregiver self-efficacy had an effect on the well-being of the partners (Campbell et al., 2004). Higher self-efficacy in patients, as measured in terms of physical function subscale scores, was negatively associated with anxiety (r = -0.39, p < 0.05) and caregiver strain (r = -0.38, p < 0.05) in partners. Higher self-efficacy in partners in terms of physical function sub-scale scores was associated with better adjustment on the part of patients to bowel symptoms (r = 0.66, p < 0.01), hormonal symptoms (r = 0.42, p < 0.01); and better mental health (r = 0.32, p < 0.05) (Campbell et al., 2004). However, another study on couples coping with prostate cancer showed that the patients' and spouses' appraisal of their self-efficacy strongly influenced only their own adjustment (Kershaw et al., 2008) in that the patients with lower self-efficacy (b = -0.31) appraised their illness more negatively, while the spouses with lower self-efficacy (b = -0.46) appraised their caregiving more negatively, at 4 months than those who thought more highly of their self-efficacy. However, there was no reciprocal effect between the couples in self-efficacy.

Studies on mental health and/or psychological stress also showed moderately interrelationships between couples coping with breast cancer (Gilbar and Zusman, 2007; Dorros et al., 2010), prostate cancer (Kershaw et al., 2008), prostate or breast cancer (Kim et al., 2008), and colon cancer (Northouse et al., 2000). In one study, the interdependence of distress outcomes in patients with breast cancer and their partners was explored using reciprocal dyadic data. A medium level of similarity was found between patients and their partners in the areas of depression, stress, and poor physical health (latent rs 0.37, 0.36, and 0.37, respectively) (Dorros et al., 2010). The interaction of high levels of depression and high levels of stress in patients was associated with poorer physical health and well-being in their partners. However, the stress of the partner had no effect on the physical health of the patient.

In another study on patients with prostate cancer and their spouses, a significant correlation and reciprocal effects were also found between patients and spouses in the mental dimension of QOL (r = 0.25, p < 0.05) (Kershaw et al., 2008). If a patient's spouse was elderly, the patient had a greater tendency to give a negative appraisal of his/her illness (b = +0.43) and to experience more uncertainty concerning the illness (b = +0.32). More (perhaps too much) communication from the spouse about the patient's disease was related to a higher level of hopelessness in patients (b = +0.30). Another study on couples with prostate and breast cancer showed that partners had at least moderately similar levels of psychological distress as the patients (r = 0.32 for breast cancer and r = 0.27 prostate cancer) (Kim et al., 2008).

Studies also showed positive significant correlations between patients and spouses in emotion-focused coping (Gilbar and Zusman, 2007) and role adjustment (Northouse et al., 2000). A longitudinal study focussing on couples' patterns of adjustment to colon cancer reported modest inter-correlations in the role adjustment scores of patients and spouses over time (all p < 0.05). The strongest predictors of role adjustment problems on the part of the patients were their sense of hopelessness and their spouses' problems with role adjustment; while the strongest predictors of role problems on the part of the spouses were the spouses' own baseline role problems and level of marital satisfaction (Northouse et al., 2000).

In a study that focused on couples coping with prostate cancer, it was reported that dyadic adjustment is associated with the spouses' mood disturbance (r = -0.49, p = 0.001), mental health

functioning (r = 0.35, p = 0.02), sexual function (r = 0.26, p = 0.10), and sexual bother (r = 0.44, p = 0.003) (Sterba et al., 2011). While the patients' symptoms were associated with declining physical health on the part of the spouses (b = -0.93, p = 0.02) (Sterba et al., 2011). In another study, it was shown that patients or partners who perceived their spouses as being more supportive or less unsup-portive experienced greater dyadic marital adjustment (Badr et al., 2010).

Zhou et al. (2011) examined the extent to which each partner's marital satisfaction was related to each individual's physical and mental health in a dyadic context of couples coping with prostate cancer. The results showed that the patient's mental (r = 0.33, p < 0.05) and physical (r = 0.28, p < 0.05) health were both positively related to their caregiver's marital satisfaction. However, the caregivers' mental and physical health was not significantly related to the patients' marital satisfaction (Zhou et al., 2011).

Overall, multiple interrelationships were found between the spousal caregiver—cancer patient dyads, including different dimensions of well-being and the dyadic adjustment. Factors that influence the interactions between couples were identified, including: the cancer diagnosis, cancer-related symptoms, length of hospitalisation, and caregiving intensity and duration.

Caregiver—patient congruence

Congruence of patients and spouses was found in their perceptions of the patients' health-related quality of life (HRQoL) (Green et al., 2011,Sneeuw et al., 2001), coping strategies (Green et al., 2011), disease appraisal (Merz et al., 2011), disease adjustment (Romero et al., 2008), and protective buffering (Langer et al., 2009).

In a mixed methods study on couples coping with prostate cancer, dyadic correlations were found between patient and partner ratings of the patient's HRQoL in all six dimensions (r = 0.45 - 0.73, all p < 0.001) (Green et al., 2011). Partners gave their patient's emotional functioning a significantly worse rating (m = 83.3, IQR = 66.7—100.0) than the patients gave themselves (m = 83.3, IQR = 75.0—100.0) (Z = -2.48, p < 0.05). By contrast, the partners saw their patient's social functioning as being significantly better (m = 83.3, IQR = 66.7—100.0) than the patients regarded it themselves (m = 66.7, IQR = 66.7—100.0) (Z = -2.48, p < 0.05).

The same study examined the coping strategies of the couples. The results of the study showed that there was a significant difference between the couples in their use of coping strategies, with the patients reporting a greater use of approach coping (m = 2.7, IQR = 2.0—3.1) than perceived by their partners (m = 2.3, IQR = 1.9—3.0) (Z = -2.06, p < 0.05) (Green et al., 2011). The qualitative results also showed a certain level of agreement between patients and spouses in their response to prostate cancer in terms of disease/treatment, interpersonal relationships, appreciation of life, and life priorities (Green et al., 2011).

The findings from a study on the disease appraisal of couples found that the spouses of men with prostate cancer evaluate the patient's physical and psychosocial functioning, symptoms, and overall QOL with a reasonable degree of accuracy (r = 0.40—0.75) (Sneeuw et al., 2001). The one exception was a low correlation for sexual functioning and sexual satisfaction.

In another study examining the dyadic concordance of disease appraisal among prostate cancer patients and spouses, concordance was found between most couples in appraisals of most domains of the disease, such as urinary or bowel function, and urinary or bowel bother (r = 0.41—0.83) (Merz et al., 2011). The only exception was sexual bother, for which partners perceived lower levels of sexual bother than the patients experienced. A general pattern was that couples who are in concordant dyads reported

significantly better individual HRQOL outcomes than those in dyads where spouses overestimated or underestimated characteristics of symptoms and disease. Generally, the extent of the (dis)agreement in the patient-partner appraisal of the disease was not a significant predictor of dyadic adjustment (Merz et al., 2011).

Focus group interviews of men with metastatic prostate cancer and their partners in separate groups also showed incongruence between the perceptions of the patients and their partners on the diagnosis of prostate cancer. Patients frequently mentioned pre-diagnosis urinary and erectile symptoms, whereas the accounts of the partners began with the diagnosis as the earliest event. It was also found that many men do not share their prostate-related health problems with their wives (Boehmer and Clark, 2001b).

A study of breast cancer patients and their partners reported moderate congruence between the husbands' perceptions of their wives' adjustment to breast cancer and the wives' self-reported adjustment. Incongruence within couples was related to the wives' avoidant coping behaviour (p < 0.005) and mood disturbances (p < 0.001); but was not significantly correlated with the wives' active behavioural or cognitive coping (p's > 0.005) (Romero et al., 2008).

Langer et al. (2009) examined the consequences of protective buffering and the desire to shield patient-partner couples from distress. In a study of 80 couples in which one of the partners was receiving hematopoietic stem cell transplantation treatment (HSCT) for cancer (Langer et al., 2009), moderate concordance was found between one dyad member's provision of buffering for his/ her partner and the buffering that the other dyad member received. For patient-reported buffering of the caregiver and the caregiver's report the buffering that he/she received, the correlations were r = 0.26, p = 0.019 at T1 (pre-HSCT), and r = 0.28, p = 0.031 at T2 (50 days post-HSCT); while for caregiver—reported buffering of the patient and the patient's report of the buffering that he/she received, the correlations were r = 0.38, p < 0.001 at T1 and r = 0.31, p = 0.016 at T2. Patients who buffered primarily to protect their partner at T1 (pre-HSCT) reported an increase in relationship satisfaction over time, but when they did so at T2 (50 days post-HSCT), their caregiver reported a concurrent decrease in relationship satisfaction (Langer et al., 2009). The more the participants (both the patients and their spouses) buffered their partners at T2, the more they felt buffered, the lower their concurrent relationship satisfaction, and the poorer their mental health.

To summarise, there was moderate congruence between the partners in their perceptions of the patients' HRQoL, coping strategies, disease appraisal, disease adjustment, and protective buffering. In general, concordance in dyads related to better individual HRQOL outcomes (Merz et al., 2011) and relationship satisfaction (Langer et al., 2009). The inconsistent results, however, showed that there was incongruence between the partners related to the patients' avoidant coping behaviour and mood disturbances (Romero et al., 2008), and to the extent of the (dis)agreement between patient and partner over their appraisal of the disease (Merz et al., 2011).

Discussion

The various focuses of the studies on the interrelatedness and mutuality of spousal caregiver—patient dyads that were included in this review can all be grouped under the three concepts proposed by Fletcher et al. (2012) for the conceptualisation care-giver—patient dyad couples: communication, reciprocal influence, and caregiver—patient congruence. Satisfaction with the communication between couples was found to be related to less distress and better marital adjustment. There were multiple reciprocal influences and moderate congruence between spousal

caregiver-patient dyads. Inconsistencies were also found among the studies focussing on communication between the couples and care-giver-patient congruence. While most quantitative studies showed correlation and positive outcomes (e.g., more dyadic communication and congruence between couples), the qualitative studies seemed to report less dyadic communication and lower levels of congruence (Lindau et al., 2011; Boehmer and Clark, 2001b). This inconsistency may be due the fact that the findings from the quantitative studies were generated using a structured standard questionnaire with questions based on the researchers' understanding, which might be somewhat superficial and might not go into the inner feelings and the 'real world' of these couples; while the qualitative studies were able to probe more deeply into the feelings of the couples.

A further analysis of the findings showed that the three concepts are interrelated and inseparable. For example, a moderate amount of open communication between the couples might directly (Song et al., 2012; Kershaw et al., 2008) or indirectly enhance both the patients' and their partners' sense of self-efficacy (Campbell et al., 2004), and give a boost to such positive reciprocal influences as QOL and dyadic adjustment (Manne et al., 2004; Porter et al., 2005). Improving the patterns of communication between the couples was also reported to be helpful in promoting dyadic congruence on different aspects of cancer care (Merz et al., 2011). Incongruence between the couples may have a negative impact on the spouses' mood and adaptation (Romero et al., 2008) and HRQOL (Merz et al., 2011).

Not only are the three concepts of spousal caregiver-patient dyads interrelated, but communication has also been found to act as a fundamental element underlying the three concepts. Improved communication between couples may facilitate the reciprocal influences and promote congruence between the couples, which in turn can lead to beneficial caregiving outcomes for the couples. These findings suggest that spousal caregiver-patient dyads may benefit from couple-focused interventions that address dyadic-communication, which may improve their satisfaction with dyadic adjustment and QOL. Indeed, couple-based training interventions on coping through facilitating communication have yielded promising results among dyads in which one member has cancer (Northouse et al., 2007; Manne et al., 2011; McLean et al., 2013).

Study gaps identified

Of the 31 articles included in this review, 25 were about studies conducted in the United States; only three studies were conducted in Asian countries (Chung and Hwang, 2012; Chen et al., 2004; Gilbar and Zusman, 2007). Over 70% (22/31) of the studies focused on gender-specific cancers, including prostate cancer and breast cancer. Only three studies focused on multiple types of cancer (Gardner, 2008; Romero et al., 2008; Langer et al., 2009).

It is worth mentioning that there was an imbalance in the studies focussing on the three different concepts. While most studies focused on reciprocal influence and communication, only six focused on spousal caregiver-patient congruence. It is also noteworthy that there were inconclusive findings on the three concepts, including on the reciprocal effect of self-efficacy (Campbell et al., 2004; Kershaw et al., 2008) and the effect of caregiver-patient congruence on dyadic adjustment (Merz et al., 2011; Langer et al., 2009).

Although there were 10 longitudinal studies, with observation times ranging from one week to two years from baseline, not one study explored the whole trajectory of the couples' caregiving experience as dyads from the diagnosis of cancer to the phase of bereavement.

Limitations of this review

It is essential to acknowledge that this review has several limitations. There were publication and language biases. A systemic search of the relevant literature was carried out using six electronic databases, a manual search for the related bibliography, and an author search that provided comprehensive coverage of key nursing, medical, and health-affiliated journals published in English and Chinese. However, publication bias could not be avoided, since studies that are published are mostly those with significant results. In addition, although literature in both English and Chinese were searched, no publications in Chinese on spousal caregiver— patient dyads coping with cancer were identified. Other languages were also not included.

Since most of the studies (25/31) included in this review were conducted in the United States, the result may be limited in gen-eralisability. It should also be noted that, of the 25 articles, only one study focused on African-Americans (Campbell et al., 2004); the participants in the remaining 24 studies were white and well-educated in general, which may also limit the generalisability of the results. However, these studies were considered to be of good quality, and can serve as good references for further studies in this area.

Adopting the caregiver—cancer patient dyads (CCPD) model proposed by Fletcher et al. (2012) may lead to limitations. Although to our knowledge the three dyad-level concepts of 'communication', 'reciprocal influence', and 'caregiver—patient congruence' were proposed based on a review of the literature on cancer care-giving, the dyadic phenomena are not as well conceptualised (Fletcher et al., 2012). This may have led to some limitations on their application to spousal caregiver—patient dyads. Given that the three concepts are interrelated and inseparable, as discussed earlier, the three concepts cannot be discussed independently, particularly the differences between 'reciprocal influence' and 'caregiver—patient congruence'. In addition, the correlational nature of these studies made it impossible to delineate causes and effects.

Recommendations for future research

Given that this review found that most of the studies (28/31) were conducted in a Western country, it is recommended that such studies be carried out in countries with a non-Western culture, such as Asian countries, to better understand the caregiving experiences of spousal caregiver—patient dyads in coping with cancer.

The study of spousal caregiver—patient dyads in the context of cancer care is still in the stage of infancy. As an in-depth understanding of the caregiving experience of couples coping with cancer cannot be achieved from a quantitative study (Hagedoorn et al., 2008), it would be well worth conducting a qualitative study to obtain a more in-depth understanding of the subject.

Because the conceptualisation of CCPD is at an early stage, this is an area in need of conceptual development and further research (Fletcher et al., 2012). It is recommended that studies focussing on the interrelationship of the three concepts be undertaken. Given that there have been studies exploring the effects that patients have on their caregivers (the patient-caregiver effect), studies are needed to investigate the effects that caregivers might have on their patients (the caregiver—patient effect), to gain a better understanding of the concept of 'reciprocal influence'. The inconsistency in the findings of studies on spousal caregiver—patient congruence is another concern. Further studies are needed to obtain a better understanding of caregiver—patient congruence to

improve the caregiving experience and health outcomes of couples in the context of cancer.

Recommendations for intervention programmes

The findings of this review indicate that, of the three concepts, communication might be the most crucial. That better communication between couples leads to better HRQOL, less distress, and better marital role adjustment, which in turn facilitates better caregiving outcomes and health outcomes, is supported by the suggestions made by the authors included in this review (Badr et al., 2008; Badr and Taylor, 2009; Manne et al., 2010, 2012; Sterba et al., 2011; Manne et al., 2012; Boehmer and Clark, 2001a; Kershaw et al., 2008; Dorros et al., 2010; Merz et al., 2011; Langer et al., 2009; Boehmer and Clark, 2001b). It is concluded that interventions to support couples in the context of cancer should enhance the couples' communication as a vital and essential element to improving the caregiving experience and health outcomes for both partners.

The shift in focus from the individual to spousal caregiver-pa-tient dyads raises the need to develop a dyadic model specifically on cancer caregiving (Fletcher et al., 2012). Developing such a model will not only shed further light on the related concepts in the context of couples coping with cancer, but also facilitate the development of interventions to support caregiver-patient dyads coping with cancer (Carbonneau et al., 2010). More research is needed to examine the interrelationship of the concepts of mutuality among cancer dyads, to facilitate the advancement of such a framework.

Conclusion

These findings highlight the importance of a perspective that focuses on the nature of the relationship between a couple and their communication in any study of couples coping with cancer. It is recognised that communication may act as a fundamental element among the three concepts of caregiver-patient dyads. Better communication between couples would probably have a positive effect on reciprocal influence and caregiver-patient congruence, which in turn would have a positive effect on the couple's intimacy and ability to cope, and improve caregiving outcomes. Targeting spousal caregiver-patient dyads, rather than individuals, is important since a strong spousal relationship has a protective effect on psychological distress, QOL, and marital satisfaction. Couples may benefit from interventions that include a communication component that addresses the needs of both the patient and the patient's spouse.

Conflict of interest

The authors have no funding or conflicts of interest to disclose.

Appendix A. Supplementary data

Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.ejon.2013.09.003.

References

Badr, H., Acitelli, L.K., Carmack Taylor, C.L., 2008. Does talking about their relationship affect couples' marital and psychological adjustment to lung cancer? Journal of cancer survivorship 2, 53-64. Badr, H., Taylor, C.L., 2009. Sexual dysfunction and spousal communication in

couples coping with prostate cancer. Psycho-oncology 18, 735-746. Badr, H., Taylor, C.L., 2006. Social constraints and spousal communication in lung cancer. Psycho-oncology 15, 673-683.

Badr, H., Carmack, C.L., Kashy, D.A., Cristofanilli, M., Revenson, T.A., 2010. Dyadic coping in metastatic breast cancer. Health Psychology 29,169—180.

Boehmer, U., Clark, J.A., 2001a. Communication about prostate cancer between men and their wives. Journal of Family Practice 50, 226—231.

Boehmer, U., Clark, J.A., 2001b. Married couples' perspectives on prostate cancer diagnosis and treatment decision-making. Psycho-oncology 10,147—155.

Campbell, L., Keefe, F., McKee, D., Edwards, C., Herman, S., Johnson, L., et al., 2004. Prostate cancer in African Americans: relationship of patient and partner self-efficacy to quality of life. Journal of Pain and Symptom Management 28, 433—444.

Carbonneau, H., Caron, C., Desrosiers, J., 2010. Development of a conceptual framework of positive aspects of caregiving in dementia. Dementia 9, 327—353.

Chen, M.L., Chu, L., Chen, H.C., 2004. Impact of cancer patients' quality of life on that of spouse caregivers. Supportive Care in Cancer 12, 469—475.

Chung, C., Hwang, E., 2012. Couples' experiences of breast cancer in Korea a descriptive qualitative study. Cancer Nursing 35, 211—220.

Dankoski, M.E., Pais, S., 2007. What's love got to do with it? Couples, illness, and MFT. Journal of Couple and Relationship Therapy 6, 31—43.

Dorros, S.M., Card, N.A., Segrin, C., Badger, T.A., 2010. Interdependence in women with breast cancer and their partners: an interindividual model of distress. Journal of Consulting and Clinical Psychology 78,121—125.

Fergus, K.D., Gray, R.E., 2009. Relationship vulnerabilities during breast cancer: patient and partner perspectives. Psycho-oncology 18,1311—1322.

Fletcher, B., Miaskowski, C., Given, B., Schumacher, K., 2012. The cancer family caregiving experience: an updated and expanded conceptual model. European Journal of Oncology Nursing 16, 387—398.

Galbraith, M.E., Pedro, L.W., Jaffe, A.R., Allen, T.L., 2008. Describing health-related outcomes for couples experiencing prostate cancer: differences and similarities. Oncology Nursing Forum 35, 794—801.

Gardner, D.S., 2008. Cancer in a dyadic context: older couples' negotiation of ambiguity and search for meaning at the end of life. Journal of Social Work in End-of-Life and Palliative Care 4,135—159.

Gilbar, O., Zusman, A., 2007. The correlation between coping strategies, doctor-patient/spouse relationships and psychological distress among women cancer patients and their spouses. Psycho-oncology 16,1010—1018.

Green, H.J., Wells, D.J.N., Laakso, L., 2011. Coping in men with prostate cancer and their partners: a quantitative and qualitative study. European Journal of Cancer Care 20, 237—247.

Hagedoorn, M., Sanderman, R., Bolks, H.N., Tuinstra, J., Coyne, J.C., 2008. Distress in couples coping with cancer: a meta-analysis and critical review of role and gender effects. Psychological Bulletin 134,1—30.

Kayser, K.P., Watson, L.E.M., Licsw, Andrade, J.T.M., 2007. Cancer as a "We-Disease": examining the process of coping from a relational perspective. Families, Systems, & Health 25, 404—418.

Kershaw, T.S., Mood, D.W., Newth, G., Ronis, D.L., Sanda, M.G., Vaishampayan, U., et al., 2008. Longitudinal analysis of a model to predict quality of life in prostate cancer patients and their spouses. Annals of Behavioral Medicine 36, 117—128.

Kim, Y., Kashy, D.A., Wellisch, D.K., Spillers, R.L., Kaw, C.K., Smith, T.G., 2008. Quality of life of couples dealing with cancer: dyadic and individual adjustment among breast and prostate cancer survivors and their spousal caregivers. Annals of Behavioral Medicine 35, 230—238.

Langer, S.L., Brown, J.D., Syrjala, K.L., 2009. Intrapersonal and interpersonal consequences of protective buffering among cancer patients and caregivers. Cancer 115, 4311—4325.

Li, Q.P., Loke, A.Y., 2013. A spectrum of hidden morbidities among spousal caregivers for patients with cancer, and differences between the genders: a review of literature. European Journal of Oncology Nursing 17, 578—587.

Lindau, S.T., Surawska, H., Paice, J., Baron, S.R., 2011. Communication about sexuality and intimacy in couples affected by lung cancer and their clinical-care providers. Psycho-oncology 20, 179—185.

Lopez, V., Copp, G., Molassiotis, A., 2012. Male caregivers of patients with breast and gynecologic cancer: experiences from caring for their spouses and partners. Cancer Nursing 35, 402—410.

Manne, S., Badr, H., 2008. Intimacy and relationship processes in couples' psychosocial adaptation to cancer. Cancer 112, 2541—2555.

Manne, S., Badr, H., Kashy, D.A., 2012. A longitudinal analysis of intimacy processes and psychological distress among couples coping with head and neck or lung cancers. Journal of Behavioral Medicine 35, 334—346.

Manne, S., Badr, H., Zaider, T., Nelson, C., Kissane, D., 2010. Cancer-related communication, relationship intimacy, and psychological distress among couples coping with localized prostate cancer. Journal of Cancer Survivorship 4, 74—85.

Manne, S., Ostroff, J., Rini, C., Fox, K., Goldstein, L., Grana, G., 2004. The interpersonal process model of intimacy: the role of self-disclosure, partner disclosure, and partner responsiveness in interactions between breast cancer patients and their partners. Journal of Family Psychology 18, 589—599.

Manne, S.L., Kissane, D.W., Nelson, C.J., Mulhall, J.P., Winkel, G., Zaider, T., 2011. Intimacy-enhancing psychological intervention for men diagnosed with prostate cancer and their partners: a pilot study. Journal of Sexual Medicine 8, 1197—1209.

Maughan, K., Heyman, B., Matthews, M., 2002. In the shadow of risk. How men cope with a partner's gynaecological cancer. International Journal of Nursing Studies 39, 27—34.

McLean, L.M., Walton, T., Rodin, G., Esplen, M.J., Jones, J.M., 2013. A couple-based intervention for patients and caregivers facing end-stage cancer: outcomes of a randomized controlled trial. Psycho-oncology 22, 28—38.

Merz, E.L., Malcarne, V.L., Ko, C.M., Sadler, M., Kwack, L., Varni, J.W., et al., 2011. Dyadic concordance among prostate cancer patients and their partners and health-related quality of life: does it matter? Psychology & Health 26,651—666.

Northouse, L.L., Mood, D., Templin, T., Mellon, S., George, T., 2000. Couples' patterns of adjustment to colon cancer. Social Science & Medicine 50, 271—284.

Northouse, L.L., Mood, D.W., Schafenacker, A., Montie, J.E., Sandler, H.M., Forman, J.D., et al., 2007. Randomized clinical trial of a family intervention for prostate cancer patients and their spouses. Cancer 110, 2809—2818.

Pistrang, N., Barker, C., 1995. The partner relationship in psychological response to breast cancer. Social Science & Medicine 40, 789—797.

Porter, L.S., Keefe, F.J., Hurwitz, H., Faber, M., 2005. Disclosure between patients with gastrointestinal cancer and their spouses. Psycho-oncology 14, 1030—1042.

Romero, C., Lindsay, J.E., Dalton, W.T., Nelson, D.V., Friedman, L.C., 2008. Husbands' perceptions of wives' adjustment to breast cancer: the impact on wives' mood. Psycho-oncology 17, 237—243.

Sneeuw, K.C., Albertsen, P.C., Aaronson, N.K., 2001. Comparison of patient and spouse assessments of health related quality of life in men with metastatic prostate cancer. Journal of Urology 165, 478—482.

Song, L., Northouse, L.L., Braun, T.M., Zhang, L., Cimprich, B., Ronis, D.L., et al., 2011. Assessing longitudinal quality of life in prostate cancer patients and their spouses: a multilevel modeling approach. Quality of Life Research 20, 371—381.

Song, L., Northouse, L.L., Zhang, L., Braun, T.M., Cimprich, B., Ronis, D.L., et al., 2012. Study of dyadic communication in couples managing prostate cancer: a longitudinal perspective. Psycho-oncology 21, 72—81.

Sterba, K.R., Swartz, R.J., Basen-Engquist, K., Black, P.C., Pettaway, C.A., 2011. Long-term quality of life after radical prostatectomy in wives of men in the postoperative adjuvant androgen deprivation trial. Supportive Care in Cancer 19, 1117—1124.

Thomas, C., Morris, S.M., Harman, J.C., 2002. Companions through cancer: the care given by informal carers in cancer contexts. Social Science and Medicine 54, 529—544.

Zhou, E.S., Kim, Y., Rasheed, M., Benedict, C., Bustillo, N.E., Soloway, M., et al., 2011. Marital satisfaction of advanced prostate cancer survivors and their spousal caregivers: the dyadic effects of physical and mental health. Psycho-oncology 20, 1353—1357.