Background
The global increase of cancer incidence will soon impact at least one in three people, either personally or through a relative or friend [
1,
2]. Reducing the burden of cancer and supporting those affected by cancer has become a healthcare priority demanding cost-effective and high quality solutions. These solutions need not only treat cancer, but also provide personalized care, prevent disease and maintain or even improve patients’ quality of life for as long as possible. In light of these shifting healthcare demands, research is helping to illuminate aspects of cancer patients’ experiences in order to develop improved care services.
Renewed interest in nature’s impact on human health and well-being is evident in burgeoning research on the subject across various disciplines such as public health [
3], environment and behaviour [
4], planning and design, and environmental disciplines [
5]. Although the subject is diversely conceived, emerging research shows positive associations between nature–human interactions and health promotion [
6], as well as disease prevention [
7]. Preliminary investigations into nature-based interventions across several healthcare contexts suggest their potential to ease illness related strain [
8] and to impact positively on patients [
9]. Keniger has categorized the broad spectrum of nature experiences into three levels of engagement offering a productive frame for delineating different types of nature-based interventions [
10]. They are as follows: 1) indirect engagement, e.g. views to nature and art depicting nature [
11]; 2) incidental engagement, e.g. walking and resting outdoors [
12]; and 3) intentional engagement, e.g. outdoor adventure therapy [
13]. These nature-based interventions are being trialled with mixed clinical populations across three types of settings including: indoor settings, e.g. intensive care units [
14]; organized and designed outdoor environments, e.g. rehabilitation gardens [
9]; and remote or wilderness sites, e.g. forest settings [
15].
As a relatively new field of empirical inquiry, health-nature research has favoured an evidence-based interventionist paradigm with the aim to parallel the judicious procedures of medical research and resemble the system it intends to adopt. Consequently, inquiry has prioritized research instruments, questionnaires, and audits designed a priori by researchers assuming that quality of experience can be measured quantitatively. There is little in the literature to illustrate the role of human-nature interactions in patients’ lived experiences of health and disease and whether or not, from their perspective, nature contributes to recovery, health and well-being. In the cancer setting, various bio-psychosocial challenges have been identified that impact patients’ daily living needs [
16,
17]. Research has found unmet supportive care needs related to physical functioning, information, and emotional care for both urban and rural patients [
18]. Given the commonplace availability of nature in urban and rural environments, as well as in some clinical settings, numerous opportunities exist for cancer patients to potentially utilize and benefit from contact with nature. To date, only one narrative review of the literature on cancer survivors’ nature-based experiences could be located [
19], which demonstrates a need for deeper and broader understanding of nature’s relevance across the cancer journey. To the author’s best knowledge, there is no published meta-synthesis of findings concerning the role of nature in cancer patients’ lives. Two important questions remain open for investigation, which according to Sandelowski are at the heart of practitioners’ and patients’ concerns: “a) Does it work? and b) If it works, should it be used?” [
20] (p.1368).
This meta-synthesis underpins a larger investigation, which aims to determine feasible and appropriate solutions to incorporating nature-based care opportunities in cancer care contexts. Its specific aim, and its contribution to this larger body of work, is to explore and identify the various roles of nature in the lives of cancer patients and to explore how these experiences support or detract from their recovery processes (i.e.
does it work?), and if patients value and seek these opportunities (i.e.
should it be used?). Synthesis of published qualitative research has been described as integrating research evidence to reach new theoretical understandings of a chosen topic [
21]. Accordingly, this review aimed to contribute a new conceptual representation of the existent body of knowledge grounded in an interpretative framework [
22]. Synthesized understandings can make findings more accessible to key stakeholders such as healthcare leaders and practitioners, policymakers, researchers, and consumers who require translatable knowledge if nature is to be safely and effectively incorporated into supportive care. To assist this process, the following research question was addressed: What does the published qualitative research literature contribute to understanding the role of nature in cancer patients’ lives?
Methods
Meta-synthesis is the examination, critical comparison and synthesis of published qualitative studies that concern a common topic [
21‐
23]. It is a validated research process [
24] that aims to gain a fuller knowing of a phenomenon than would be achieved from a single, isolated study [
22]. Based on previously published meta-syntheses [
23,
25], the present review followed a multi-stage approach comprising: 1) determining the review focus; 2) identification of published and relevant literature; 3) quality appraisal of the included documents; 4) data extraction and identification of key concepts grounded in the raw data contributed by research participants; and 5) development and comparison of core themes across the documents and their synthesis into a new conceptual representation. Each of these stages is detailed below.
Determining the review focus
The review focus was determined by the author’s doctoral thesis topic, which concerns the investigation of nature’s role in cancer patients’ lives and aims to determine nature-based care opportunities in cancer care contexts. The present paper reports research carried out by a sole researcher. The strategies employed to mitigate reporting bias are presented in the Limitations section below. For the purposes of this review, nature was defined as the phenomena of the physical world collectively, including various forms of vegetation and habitat, natural and humanly designed landscapes, natural cycles, processes, weather, wildlife and domestic animals, and other features and products of the earth including man-made creations which creatively organize and depict these nature elements [
6,
26‐
28].
The Cochrane Database for Systematic Reviews and the International prospective register of systematic reviews PROSPERO were first searched to ensure no identical or similar review was underway. The review was initially registered with PROSPERO as a systematic review of nature-based intervention research, however the literature searches returned insufficient studies addressing primary outcomes, which is a requirement for PROPERO registration. Consequently, the review focus shifted in order to address the available qualitative research, rather than intervention research. Registration (CRD42014015291) was withdrawn in February 2016.
Identification of published and relevant literature
A comprehensive systematic search of the published literature was conducted in following electronic database: Medline, CINAHL, PsycINFO and Cochrane Database of Systematic Reviews from January 1985 to March 2015. A research librarian was consulted for developing search strategies for the respective databases, which included combinatorial strings of Subject Headings and text word searches containing terms related to: “cancer” and “nature” (see Additional file
1 Search protocol). Electronic searches were supplemented by manual search of two relevant journals: AHTA Journal of Therapeutic Horticulture and ACTAHORT. Non-peer-reviewed articles retrieved from the electronic searches were read for the purpose of searching reference lists. The inclusion criteria for publications were: full-text, peer-reviewed journal articles published in English language, which included primary qualitative data of empirical studies conducted with cancer populations.
Initial searches retrieved titles and abstracts only. Duplicates, obviously irrelevant studies, and studies that did not meet the above inclusion criteria were removed. The next stage of the selection process was directed by reading records at full-text level and identifying whether the studies reported the use of qualitative methods to explore the experiences of contact with nature from the perspective of individuals who had experienced cancer. The study’s specific qualitative method employed or the researchers’ philosophical positioning (e.g. phenomenology, grounded theory, ethnography) were not directive because their shared focus is understood to be the elucidation of meaning and processes of a given phenomenon from the perspective of the experiencer through interpretive means [
29]. Therefore, studies based on a predominantly quantitative research design with a minor qualitative supplement were not included as their aim precluded relevant data and interpretation to explore participants’ personal experiences.
Studies were eligible if the sample included people who had directly experienced cancer; excluded were studies reporting only from the perspective of caregivers or healthcare professionals. Studies focusing on related topics such as post-occupancy evaluations of hospital gardens [
30] and physical exercise research [
31], not exploring nature experiences were excluded.
Quality appraisal of the included documents
Research synthesists are responsible for appraising the quality of included studies in order to report transparently on their validity and generalizability. Studies with methodological weakness will negatively impact on the strength of the conclusions in a meta-synthesis. Methodological discussion exists questioning the adoption of prescriptive evaluation protocols based on quantitative ontology and epistemology for evaluating qualitative research [
32,
33]. In response, instruments are being developed to better reflect appraisal criteria relevant to qualitative research such as confirmability, dependability, and credibility [
34]. Examples are the Joanna Briggs Institute Qualitative Assessment and Review Instrument (JBI-QARI) [
35] and the Critical Appraisal Skills Programme (CASP) [
36]. However, the use of prescriptive criteria remains controversial [
33]. Sandelowski and colleagues recommend not excluding papers based on quality checklists, but to focus instead on topical relevance and to employ broad evaluation criteria for the final quality reporting of included studies [
29]. Taking this discussion into account, the present meta-synthesis prioritized the following initial question to gauge topical relevance: Does this publication contribute genuine qualitative data exploring cancer patients’ nature experiences? The Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines [
37] were considered an appropriately broad framework for assessing the quality of included studies, and they were also used as a guide for reporting findings in this present meta-synthesis. The strength of the COREQ guidelines lies in outlining three general domains of methodological rigour applicable to various qualitative methods, as demonstrated in one successful example of meta-synthesis by Luker and colleagues [
38].
1.
Research reflexivity: information on the researchers’ background, biases, and relationship with the participants (confirmability).
2.
Study design: appropriate methods for data collection and documentation, information regarding sampling and recruitment, description of study setting and context (dependability).
3.
Analysis and reporting: evidence of raw data, clarity of interpretive process, consistency of raw data and findings (credibility).
Data extraction and identifying key concepts
Author SB recorded data on the following characteristics of included studies: reference details (year of publication, author, first author’s country of origin); discipline; sample size; participant characteristics; methodological approach; data collection method; and focus of the study. All data presented as ‘results’ or ‘findings’ were entered into data management software QSR International’s NVivo 10 for Mac [
39]. This included primary data (e.g. participant quotes) as well as authors’ interpretations (e.g. thematic description). All unaltered textual material was read in order to gain a general understanding of the material before inductively coding data line-by-line with the aim to glean salient underlying concepts. In this process, for example, the statement ‘escape from the fear and worry associated with cancer, a place that was safe’ [
40] was reduced and captured with the descriptive label (code) ‘safe refuge’. Next, codes were grouped into meaningful clusters from which prominent descriptive themes emerged, for example, the codes ‘losing the capacity for gardening is painful’ [
41], and ‘losing bond with garden’ [
40] were grouped as ‘losing connection’. This interpretive task reflects terminology and descriptions based on the researcher’s own understanding of the material and is presented in Additional file
2 Themes and illustrative quotes, which includes reference to raw data in order to enable the reader’s own appraisal of interpretative and conceptual congruity.
Thematic development and synthesis
Using a constant comparison approach [
42], common events and attributes of the studied phenomenon were identified and careful attention was paid to the frequency of recurrence across different studies, which strengthens emerging themes [
24]. For example, the descriptive theme ‘connecting with something outside’ arose in nine studies [
13,
27,
28,
40,
41,
43‐
46], while ‘stimulating sensory experiences’ was found in only four [
27,
28,
44,
46]. Once the entire dataset was scrutinized (primary data and authors’ interpretations) and no more themes could be teased out, the researcher returned to the included publications for a second narrative reading in order to confirm contextual relationships between the themes. This informed the final theoretical synthesis of findings into overarching, analytical themes, or ‘core themes’ [
47]. These core themes were developed in relation to the meta-synthesis’ main objective, which gave rise to a hierarchical pattern of core and descriptive themes organized according to their theoretical depth and relevance.
Discussion
The aim in this review was to describe and meaningfully synthesise the range of nature experiences reported from the cancer patient perspective and to discern its relevance in cancer patients’ lives. While exploring vastly different levels of nature engagement, the included studies’ common topic revealed overlapping layers (themes) of the shared human phenomena that occur when a person affected by cancer engages with nature. The findings shed light on the initial questions the study set out to address: how nature supports or detracts from cancer patients’ recovery experiences (does it work?); and if patients value these opportunities (should it be used?). The seven identified themes explored the values held by patients who used nature to address some of their needs. These needs included: maintaining continuity with surroundings and activities, a sense of normality and control over one’s life, social support and integration, community participation, occupational and leisure engagement, access to a familiar support structure, creating meaning and perspective, physical activity, and aesthetic and sensory enrichment. Nature represented an unburdened and uninterrupted space embedded in everyday life from which patients sourced strength and meaning to address these needs. The benefits shown here extend across bio-psychosocial dimensions, which correspond with supportive care needs identified in previous research [
17,
18]. These known impacts of cancer reveal patients’ sudden struggle and vulnerability when tasked to navigate the imminent and ambient challenges of daily living.
The present findings contribute to discourse in psycho-oncology investigating patients’ need to respond to cancer’s urgent threat by constructing new ways of handling life and accepting a “new-normal” [
56]. Drawing on Attachment theory [
57], it is theorized that secure attachment to a supportive structure or “helping system” [
58] can support patients’ stepwise process of accepting lives shaped by cancer. It is premised that when attached to a “secure base” [
57], patients are enabled to risk exploring various real and imagined future scenarios and approach a shifting normality that now includes their cancer experiences. Salander [
59] suggests the application of the Winnicottian “intermediate area” [
60] for interpreting cancer patients’ mental coping manoeuvres in this process. From this perspective, the construction of a private place between inner and outer reality unburdens patients from practical demands and immediate here-and-now reality, allowing a more creative approach to dealing with their situations. The present meta-synthesis found that nature could be seen as a potential “secure base” offering patients a familiar and nurturing context from which new perspectives can emerge and caring connections can be made with themselves, others, the past, and the future. The findings show that nature provided patients with unburdened physical and psychic space that was regarded a valued component of everyday life and invested with personal significance. As such, nature supported patients’ inner and outer manoeuvres to navigate the clinical and personal consequences of cancer.
Practical implications
Comprehensive cancer care services need to consider patients’ values and experiences. Qualitative research is designed to generate a deep and broad understanding of human experiences and processes. Meta-synthesis can improve the translation of qualitative research into practice through locating, condensing and appraising relevant findings for the medical readership and healthcare management who govern clinical practice, research, and policy [
61].
Patients’ motivations to seek nature, and the effects of these interactions were highly personal. The idiosyncratic associations between type of engagement and outcomes suggest that the benefits derived from engaging with nature cannot be predetermined nor administered. Contrary to what an interventionist approach would suggest [
62], there is no indication to utilize nature in a prescriptive manner. However, cancer patients consistently attributed importance to engaging with nature and derived, in various forms, benefit and meaning from these interactions. The findings give credence to validating and enabling cancer patients’ own resources by appraising aspects of their lives and histories from which they draw meaning, strength, and hope. A range of practical examples from the collected literature suggest pathways for patients to access nature experiences, both in cancer care and home environments. Views to nature and nature art are easily incorporated in the design of clinical settings if put on the agenda, which patients reportedly derive benefit from. Hospital courtyards and home gardens can encourage various degrees of physical activity, motivate fruit and vegetable consumption, and create opportunities for connecting socially. Organized outdoor trips and activities can powerfully connect patients on a peer level and motivate positive lifestyle behaviours. While many examples are unsurprisingly simple and commonplace, further research is required to identify, understand, and safely implement such additional care opportunities for their maximum benefit.
Limitations
The findings relate to cancer patients in westernized countries and cannot be said to transfer to other clinical or geographic populations. Although this review aimed at comprehensive sampling, the dearth of relevant literature resulted in a very small sample size (
n = 11 documents), with a correspondingly small combined participant sample (
n = 240). Based on Sandelowski’s recommendation that large sample size (exceeding 10 studies) can compromise “deep analysis” and “threaten interpretive validity” in meta-synthesis [
29], the found literature was deemed sufficient to proceed with the synthesis.
Many of the included studies have serious methodological limitations, which must be considered when assessing the credibility of this review’s findings. In particular, the absence of audit trails, negative case reporting and researcher reflexivity challenge confirmability and present the possibility of bias in the recruitment and research procedures. To increase the review’s credibility, focus was placed on raw data (participants’ words) in order to keep the interpretations closer to participants’ own experiences.
Lastly, this review lacked an inter-rater process (such as member checking or peer debriefing), which is recommended in qualitative research to aid interpretation bias in work undertaken by sole researchers [
42,
63]. While single author quantitative meta-analyses and qualitative meta-syntheses are uncommon, neither are unprecedented, see for example Dijkers [
64] and Hammell [
23]. Strategies were employed to mitigate this shortcoming and increase credibility. Firstly, it is clearly stated in the Methods section that this study represents a sole researcher study preparing the reader to navigate potential sole author bias. The findings remain traceable to their source materials by providing a considerable amount of primary data (audit trail) for internal validation and to enable the reader’s own audit of interpretations. Furthermore, detailed documentation of the search procedures and quality appraisals is made available to reflect rigour and the inclusion of topically relevant studies.
Conclusions
Awareness of cancer patients’ nature experiences can enrich communication between clinician and patient, broaden recommendations for health behavior, and guide the design of care settings and services. Through hearing the patient’s own voice, supportive cancer care can align with meaningful and relevant aspects of patients’ lives and offer effective care. This meta-synthesis contributes to the larger process of hearing and communicating patient values across sectors. Sensitizing research and practice fields to these issues may inspire different approaches to asking questions, listening carefully, and delivering care.
Acknowledgments
The author would like to thank her supervisors Prof Clare O’Callaghan and Prof Penelope Schofield for support during the study period; Matilda van den Bosch PhD, MD for critically reviewing the search protocol and study design during the initial stages of the review and; Ruby Lipson-Smith for proofreading and providing helpful comments during the final stages of the review.