The impact of physical activity to the child’s quality of life: a bibliometric study

Introduction

The role of bibliometrics in healthcare research has been excellently described by Lewison and Devey¹: “Bibliometrics is to scientific papers as epidemiology is to patients.” Indeed, in 1990 bibliometrics first became a medical subject heading. Consequently, the application of bibliometrics by health professionals to analytical, clinical, informational and academic areas of interest is becoming more extensive; however, at present it is an unexploited area of a fruitful research².

Interdisciplinary research concerning the influence of physical activity and sport on children’s quality of life is increasingly becoming more and more important. In their review paper Buttitta et al.³ reported that several factors are associated with children’s quality of life; among them physical activity is one of the most important, especially in in those with pre-existing diseases. Various malignant diseases and anticancer therapy in children both drastically affect daily life activities, including high-performance sports. However, both random and non-random feasibility studies show positive effects of physical activity on clinical and psychosocial outcomes. Consequently, every effort should be made to maintain physical activity during paediatric cancer therapy⁴. Comparable findings for congenital heart diseases, were reported by Dulfer et al.⁵.

Since our research area interest is multidisciplinary, we had an opportunity to employ a bibliometric technique called bibliometric mapping. Bibliometric mapping visualizes academic research in the form of scientific landscapes⁶. Science landscapes, contrary to conventional reviews, which focus on particular research questions, extract information at various levels and capture the relationship between multiple topics and concepts, creating “synthetic reviews”. Scientific landscapes are still relatively rarely used; however, those published have been well received by the scientific community⁷.

Methods

Bibliometrics could be defined as the application of mathematical, statistical and heuristic methods to scientific publications⁸. Bibliometric mapping is a recent addition to techniques already used in bibliometrics in medicine². Bibliometric mapping aims to visualize different facets of literature production based on different co-occurrences (i.e. words, authors, organisations, journals)⁹, co-citations¹⁰ and bibliographical coupling¹¹. Bibliometric mapping can be automated using various software tools. Among open licence software tools, VOSviewer¹² is very versatile and easy to use¹³. Both bibliometric mapping and VOSViewer have been successfully used in health related fields¹⁴.

Results

The search resulted in 2334 publications (1637 articles, 419 reviews, 66 conference papers, 50 editorials, 35 notes, 29 book chapters, 19 letters, 19 short communications and 24 other types of publications; see Underlying data¹⁵). The most popular journals in which the above publications appeared are shown in Table 1. The most prolific journal was BMC Public Health with 31 publications. The highest ranked journal in the selected field was Pediatrics, with 21 publications (621^st place according to SCImago Journal Rank - SJR, which ranks within the top 2% of all source titles indexed by SciMago. Interestingly, all of the most prolific source titles are ranked in the top quarter of all journals. Their contribution to the total literature production on our topic of interest accounts for 12.4%. As expected most of the most prolific source titles are from the field of paediatrics, others relate to quality of life or from general areas. Surprisingly no source titles related to sport or physical activity were ranked among the most prolific source titles – the first (American Journal of Sports Medicine) is in 15^th place with 11 publications.

The most productive countries are presented in Table 2. All of them have advanced heath, industrial and economic systems, high BDP and are also leading countries in research and development. The top 10 countries produced more than 83% of all publications, indicating that literature production is regionally centred.

The trends in research literature production and evolution of research topics

Shen et al.¹⁷ proposed a model of science discipline development based on literature production dynamics. Following their example, a graph was constructed (Figure 1) which reveals three distinguished phases in the production of publications regarding influence of physical activity to children’s quality of life, namely:

Figure 1. The dynamics of literature production on the topic of research, the influence of physical activity to children’s quality of life.

• initial phase in the period 1975–1989 when publications were scare, most three publications per year;

• initiation phase in the period 1990–1999 when number of publications linearly increased from 6 to 23; and

• exponential growth phase in the period 2000–2018, when production reached its peak in 2017 with 231 publications.

Figure 2 presents the term map on the topic of research, the influence of physical activity to children’s quality of life. According to the figure the research development went through three main phases, namely:

Figure 2. The chronological science landscape of the influence of physical activity to children’s quality of life.

• 1. Research on the influence of physical activity on non-communicable diseases (approx. period from 1975 to 2011 – violet and blue colours). The associations between (1) hypertension, diabetes, cardiovascular diseases, mortality, exercise and positive/beneficial effects, and (2) asthma, cystic fibrosis, medication, illness, sport and daily activity, were the main stream of research in the first phase.

• 2. Research on frequent childhood diseases and physical activity (green and light blue colours – approx. period from 2012 to 2013). The research was focused on associations between (1) chronic diseases, society, pregnancy, birth, sedentary life style, prevention strategies, and risk increase (2), nutrition, promotion, blood pressure, obesity, physical activity and, fitness and (3) anxiety, depression, stress, juvenile idiopathic arthritis, haemophilia, injury and health status.

• 3. Measuring quality of life (light green and yellow colours – state-of-the-art research). The research in the most recent period is concerned with association between (1) inclusion, adherence, protocol, cancer and health outcomes, (3) sedentary behaviour, weight status, physical activity level and physical activity interventions and (4) quality of life indicators, physical functioning and physical health.

The cluster science landscape (Figure 3) consists of six clusters. Meta-synthesis revealed six topics, as shown in Table 3.

Figure 3. The cluster science landscape on the topic of research, the influence of physical activity to children’s quality of life.

Table 3. Topics derived from the cluster science landscape.

Topic	Cluster colour	Popular terms
Childhood obesity and behaviour	Green	Childhood obesity, BMI, behaviour, community, obesity, weight
Chronic diseases and lifestyle	Blue	Diabetes, cardiovascular diseases, hypertension, chronic diseases, risk, life style, morbidity
Asthmatic child and exercising	Yellow	Asthma, asthmatic child, exercise, physical fitness, positive effect, awareness, medication
Health-related quality of life and physical and social functioning	Red	Health-related quality of life (HRQOL), paediatric quality of life ((PEDSQL), social functioning, physical functioning, physical health, life inventory, Kidscreen, pain
Illness and sport	Light blue	Illness, daily activity, sport, friend
Depression and regular physical activity	Violet	Depression, anxiety, stress, fatigue, physical activity intervention, health outcome, social support

Discussion

It is interesting to note some details evident from the derived topics above and associations between terms:

Conclusion

Using bibliometric mapping we created two scientific landscapes on the topic of research, the influence of physical activity to children’s quality of life. To the best of our knowledge, this is the first such attempt in the paediatric field. We identified six distinct topics and also visualised the chronological aspect of the research literature production. The study revealed some knowledge that might be helpful to an “outsider” who wants to learn about the taxonomy of the topics, the most interesting discoveries, guidelines and practices and the state of the art in the field. It can also help the “seasoned insiders” better understand more specialised research including that is out of their immediate scope of interest. Additionally, it can reveal hidden facts, not easily identified, even by informed researchers and clinicians.

Data availability