Active gaming: prevalence and correlates in Dutch adolescents

Active gaming, i.e. playing computer games that require physical activity instead of sitting, is regarded as a possible effective strategy to promote physical activity and discourage too much sitting. In a study just published online in the Journal of Science and Medicine in Sports -with Monique Simons as first author- we studied the prevalence and identified demographic correlates of active and non-active gaming among adolescents.
In a among 373 12-16 year olds we asked the respondents about their game behavior and a range of background characteristics.
Of all respondents, 3% reported to play exclusively active games, 40% active games and non-active games, 40% exclusively non-active games, and 17% not playing video games at all. Active gaming adolescents played active games on average on 1.5 days per school week for 36  minutes and 1 day per weekend for 42 minutes. Non-active gamers played quite a bit more; on average on 3.3 days per school week for 65 minutes and 1.4 days per weekend for 80 minutes. Adolescents attending lower levels of education were more likely to play active games ≥1 hour per week than adolescents attending higher educational levels. Boys and older adolescents were more likely to play non-active games >7 hours per week, than girls or younger adolescents.
We concluded that many adolescents play active games, especially those following a lower educational level, but time spent in this activity is relatively low compared to non-active gaming. To be feasible as a public health strategy, active gaming interventions should achieve more time is spent on active gaming at the expense of non-active gaming.

Genetic and environmental factors in adolescent sleep duration

In a study just published on-line in the journal Twin Research and Human Genetics -with Dr. Saskia te Velde as first author- we assessed to what extent lack is associated with genetic and environmental factors.  Lack of sleep is associated with physical and mental health. Lack of sleep is an important predictor of overweight, and as we published in an earlier study: many children across Europe sleep fewer than 8-9 hours and their sleep duration is associated with overweight and obesity. A twin-family design was used to gain insight into the genetic and environmental contributions to variation in sleep duration; data came for the Netherlands Twin Registry. The study sample consisted of 6,319 adolescent twins and 1,359 non-twin siblings, aged 12 to 20 years  Results showed that the prevalence of shorter than optimum sleep duration, that is, less than 8 hours per night, was high, with the highest prevalence rates in later adolescence. The contribution of genetic and environmental factors to individual differences in sleep duration was dependent on age. Variation in sleep duration at the age of 12 years was accounted for by genetic (boys: 34%, girls: 36%), shared environmental (boys: 28%, girls: 45%), and non-shared environmental factors (boys: 38%, girls: 19%). At the age of 20 years, the role of genetic (boys: 47%, girls: 33%) and non-shared environmental factors (boys: 53%, girls: 67%) was more pronounced. It can be concluded from the results that individual differences in sleep duration were accounted for by genetic and non-shared environmental factors throughout adolescence, whereas shared environmental factors account for a substantial part of variation during early adolescence only.

Remote sensing to define environmental characteristics related to physical activity and diet

In a paper just published online in the journal Health & Place, with Dr. Charriere from the Nutritional Epidemiology Research Unit of Université Paris as first author, we report on a systematic literature review on the use of free geospatial services as potential tools to assess built environmental characteristics related to dietary behaviour and physical activity.  This review was conducted as part of the SPOTLIGHT (Sustainable prevention of obesity through integrated strategies) project Thirteen  studies were included conducted in urban contexts, with Google Earth and Google Street View as the two main free geospatial services used. The agreement between virtual and field audit was higher for items related to objectively verifiable measures such as the presence of physical activity infrastructure and equipment, and lower for subjectively assessed items such as aesthetics, street atmosphere, et cetera. Free geospatial services appear as promising alternatives to field audit for assessment of objective dimensions of the built environment.

Another paper on mediators of effect of exercise interventions among cancer survivors

Earlier this week I reported on a paper that was published in the journal Cancer on research to shed light on mediators of exercise interventions among cancer survivors. Information on mediators helps us to better learn how and why exercise interventions may help cancer survivors to gain better health and quality of life. That study looked at mediators of the resistance and aerobic exercise intervention effect on physical and general health in men undergoing androgen deprivation therapy for prostate cancer. Now, in the same week another paper was published, this one in the journal Psycho-Oncology, looking again at mediators of an exercise intervention. This study analyzed data from 209 cancer survivors -more than half breast cancer - to explore significant mediators of effects of exercise on quality of life.
The results showed that the beneficial effect of group-based physical exercise on quality of life of the cancer survivors was mediated by increased physical activity, general self-efficacy and mastery, and subsequent reductions in fatigue and distress. These results indicate that in addition to physical activity, future interventions should target self-efficacy and mastery. This may lead to reduced distress and fatigue, and consequently improved quality of of cancer survivors.

Mediators of exercise intervention effects among cancer patients

In order to better learn how and why exercise interventions may help cancer survivors to gain better health and quality of life, we need more insight in the so-called mediators of the effects of exercise interventions for cancer survivors. The POLARIS study-that I reported here on before- was especially designed for this purpose.
This week an earlier explorative study to shed light on mediators of exercise interventions among cancer survivors was published in the journal Cancer. This study looked at mediators of the resistance and aerobic exercise intervention effect on physical and general health in men undergoing androgen deprivation therapy for prostate cancer.
The exercise intervention was found to significantly improve physical and general health. Upper body muscle strength and walking speed significantly mediated the intervention effect on physical health  accounting for 53% of the total effect. Walking speed and fatigue were found to be mediators of the effect on general health, accounting for 51% of the total effect.

Prevalence of depression in cancer patients

In a meta-analysis study just published on-line in Psycho-Oncology, we aimed to investigate the prevalence of depression in cancer patients assessed by diagnostic interviews and self-report instruments, and to study differences in prevalence between type of instrument, type of cancer and treatment phase.
Depending on the way depression was measured in the different studies, the  prevalence of depression ranged from 8 to 17%, and from 3% in patients with lung cancer to 31% in patients with cancer of the digestive tract. Prevalence of depression was highest during treatment, but 8-15% prevalence of depression was still found one year or longer after diagnosis.

Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS)

We just published in the journal Systematic Reviews -with Dr. Laurien Buffart as first author- the rationale and design for meta-analyses of individual patient data of randomized controlled trials that evaluate the effect of physical activity and psychosocial interventions on health-related quality of life in cancer survivors, i.e. the POLARIS study.

Because of better cancer treatments, we have more and more cancer http://www.polaris-study.orgsurvivors. Effective interventions to improve quality of life of these cancer survivors are essential. Numerous randomized controlled trials have evaluated the effects of physical activity or psychosocial interventions on health-related quality of life of cancer survivors, with generally small sample sizes and modest effects. Better targeted interventions may result in larger effects. To realize such targeted interventions, we must determine which interventions that are presently available work for which patients, and what the underlying working mechanisms are. Individual patient data meta-analysis has been described as the 'gold standard' of systematic review methodology. Instead of extracting aggregate data from study reports or from authors, the original research data are sought directly from the investigators. Individual patient data meta-analyses allow for adequate statistical analysis of intervention effects and moderators of such effects. In the paper we just published, we report the rationale and design of the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) Consortium. The primary aim of POLARIS is 1) to conduct meta-analyses based on individual patient data to evaluate the effect of physical activity and psychosocial interventions on the health-related quality of life of cancer survivors; 2) to identify important demographic, clinical, personal, or intervention-related moderators of the effect; and 3) to build and validate clinical prediction models identifying the most relevant predictors of intervention success.