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The benefits of physical activity for child and adult cancer survivors have been summarized in previous systematic reviews. However, no review has summarized the evidence for adolescent cancer survivors.
This paper describes the design of a protocol to conduct a systematic review of published studies examining the effects of physical activity on health and quality of life outcomes for adolescent cancer survivors.
Several guidelines informed the development of this protocol. The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines provided the structure by which to conduct and report the protocol; though some adaptations were made with regards to search terms, data synthesis, and evaluating the risk of bias. The Cochrane Handbook for Systematic Reviews of Interventions was used to guide research question development, search term selection, and the data extraction form. The Consolidated Standards of Reporting Trials guidelines helped inform the data extraction form. Lastly, the Guidance on the Conduct of Narrative Synthesis in Systematic Reviews informed the data synthesis. Ten electronic databases were identified and a search strategy was developed using a combination of Medical Subject Headings terms and keywords that were developed by the authors and peer reviewed by a university librarian. Both authors independently screened eligible studies for final inclusion, and data were abstracted using a form developed by the research team. A decision was made to synthesize all data narratively.
The review has now been completed, peer-reviewed, and accepted for publication in a forthcoming issue of JMIR Cancer.
As this will be the first systematic review on this topic, outlining the protocol ensures transparency for the completed review. Further, this protocol illustrates how elements from several guidelines were incorporated to answer the research question (ie, what is the effect of physical activity on health and quality of life outcomes in adolescent cancer survivors). This flexible approach was necessary as a function of the paucity of available research on this topic.
Over 7500 adolescents (defined herein as individuals between 13 to 19 years of age) living in North America are diagnosed with cancer each year [
Physical activity has been suggested as an effective adjunctive therapy to minimize the disruptions caused by cancer and its treatments [
This review protocol followed the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines [
Studies were included if they were published in English in peer-reviewed scientific journals. The types of participants, interventions, outcomes, and studies that were considered for inclusion are described below.
Studies were included if participants were adolescents aged 13 to 19 years who were diagnosed with any type of cancer and were at any point on the cancer trajectory (ie, diagnosis, treatment, post-treatment, palliation). Careful consideration was given in selecting this age range. Although there are several definitions currently being used, the ultimate goal of this review was to determine the effectiveness of physical activity for cancer survivors in their teenage years (ie, 13 to 19 years). Also, the definition selected adheres with recent efforts by other research groups [
Physical activity was defined as consisting of aerobic training, resistance training, flexibility training, combined training, or any other form of physical movement with the goal of increasing energy expenditure. Physical activity interventions were limited to those that included more than one session. No restrictions were placed on where the intervention was delivered (eg, hospital, home, school, community), the format of the intervention (eg, group-based, individual), or the individual delivering it (eg, physiotherapist(s), exercise professional(s), researcher(s), personal trainer(s), parent(s)).
Studies that included measures of health and/or quality of life as primary or secondary endpoints were included. Health outcomes included any participant-reported or objective assessment of physiological functioning (eg, fatigue, body composition, cardiovascular capacity, strength, flexibility). Quality of life outcomes included any participant-reported assessment of functioning across physical, psychological/emotional, and social domains.
Only experimental study designs were included. Randomized controlled trials or controlled clinical trials were selected, as these study designs constitute the most robust form of clinical evidence [
Interventions that had multiple program features (eg, multiple behavior change strategies, nutrition counseling) were excluded, as any observed effects as a result of the intervention could not be attributed solely to physical activity. Furthermore, those with insufficient details on the target population, intervention, comparison condition, or outcomes (after study authors were contacted and it was determined the requested information was unavailable) were ineligible.
A search strategy was developed using an iterative process based on recommendations from a university librarian (YL) and the methods sections (ie, keywords, procedures) from existing reviews on physical activity and cancer [
All studies identified in the database search were exported to a reference managing software [
A data extraction tool was developed specifically for this review based on recommendations provided in the Cochrane Handbook of Systematic Reviews of Interventions [
In addition to extracting the above standard data, additional information was documented on the use of theoretical frameworks (ie, whether the study was informed by theory). The use of intention-to-treat analysis was also recorded since intention-to-treat analyses generally provide an unbiased estimate of treatment effect. Intention-to-treat is a well-regarded approach to the design, conduct, and analysis of a trial [
Given that the main purpose of the systematic review was to comprehensively review and synthesize published studies focusing on the effectiveness of physical activity for promoting health and quality of life among adolescent cancer survivors, all data extracted from the articles were presented narratively in text and summary tables. This decision was made because narrative synthesis provides a broad overview of relevant information through a textual approach and is appropriate when it is expected that studies will be too heterogeneous to allow for a quantitative summary [
The review has now been completed, peer-reviewed, and accepted for publication in a forthcoming issue of JMIR Cancer [
Whereas other recent systematic reviews were undertaken to investigate the benefits of physical activity for children and adults diagnosed with cancer [
Notwithstanding the strengths, there were key challenges to preparing and finalizing this review protocol. First, there were challenges formulating the inclusion/exclusion criteria. In general, given the complexity and breadth of definitions for adolescent cancer survivors and the numerous iterations of physical activity interventions, careful consideration was given to ensuring the best evidence was identified to answer the research question. Second, identifying pertinent literature was difficult given the paucity of results obtained in preliminary tests of the search strategy. A flexible approach to search terms and keywords was necessary to ensure more studies were identified for review. Third, in light of the lack of research focused on adolescent cancer survivors, synthesizing and interpreting data was assumed to be a challenge. Thus, a narrative approach to data synthesis was selected. New topics pose inherent challenges for systematic review protocol development. As the literature in this area grows, so will the opportunities to refine protocols, re-run searches, and update findings. However, until then, protocols should be disseminated to ensure transparency of completed reviews and aid other researchers in developing their review protocols.
MEDLINE search strategy.
The authors would like to thank university librarian Yongtao Lin (YL) for her input and advice during the development of the search strategy. They would also like to thank Allan Jiang (AJ) and Connor O’Rielly (CO) for their assistance screening the literature and offering objective third-party arbitration and review. This manuscript was prepared while Amanda Wurz (AW) was supported by a Vanier Canada Graduate Scholarship and while Jennifer Brunet (JB) was supported by a Canadian Cancer Society Career Development Award in Prevention.
AW and JB conceptualized and designed the review protocol, performed the systematic literature searches, screened and selected studies, and extracted and interpreted the data. They were involved in all aspects of drafting, revising, and finalizing this protocol manuscript. Further, both approved the order of authorship.
None declared.