Patterns and determinants of adherence to resistance and endurance training during cancer treatment in the Phys-Can RCT.

BACKGROUND: Knowledge regarding adherence is necessary to improve the specificity of exercise interventions during cancer treatment. We aimed to determine adherence to resistance and endurance training interventions in parallel; identify subgroups with similar adherence characteristics; and examine determinants of these subgroups. METHODS: In the Phys-Can randomised controlled trial, participants (n = 577, 81% women, mean(SD) age 59(12) years, and 50% with BMI ≥ 25 kg/m2) starting (neo-) adjuvant treatment for breast, colorectal or prostate cancer were randomized to 6-month of high (HI) or low-to-moderate intensity (LMI) supervised, group-based resistance training and individual home-based endurance training, with or without behavior change support. Adherence was calculated as performed exercise volume as a proportion of prescribed exercise volume (0-100%), overall (HI and LMI groups) and for frequency, intensity, type and time (FITT principles) (HI group). Adherence to resistance training was plotted against adherence to endurance training overall and for each FITT principle. K-means cluster analysis was used to identify subgroups with similar adherence characteristics. Potential determinants of subgroup membership were examined using multinomial logistic regression. RESULTS: We found a positive curvilinear correlation between adherence to resistance and endurance training overall. A similar correlation was seen for adherence to frequency of resistance vs. endurance training in the HI group. In the HI group, adherence to resistance training intensity and time was > 80% for almost all participants. For endurance training adherence ranged from 0 to 100% for each of the FITT principles. Three clusters were identified, representing low, mixed, and high adherence to resistance and endurance training overall. Participants with higher age (Relative risk ratio [95% CI]; LMI: 0.86[0.77-0.96], HI: 0.83[0.74-0.93]), no behaviour change support (LMI: 0.11[0.02-0.56], HI: 0.20[0.05-0.85]), higher cardiorespiratory fitness (LMI: 0.81[0.69-0.94], HI: 0.80[0.69-0.92]), more fatigue (according to the reduced activity subscale of the MFI questionnaire) (LMI: 0.48[0.31-0.73], HI: 0.69[0.52-0.93]) or higher quality of life (LMI: 0.95[0.90-1.00], HI: 0.93[0.88-0.98]) were less likely to be in the low than the high adherence cluster whether randomised to LMI or HI training. Other determinants were specific to those randomised to LMI or HI training. CONCLUSIONS: In an exercise intervention during cancer treatment, adherence to resistance and endurance training were positively correlated. Personalisation of interventions and additional support for some subgroups of participants may improve adherence. Trial registration NCT02473003 (clinicaltrials.gov, Registered 16/06/2015).

Who makes it all the way? Participants vs. decliners, and completers vs. drop-outs, in a 6-month exercise trial during cancer treatment. Results from the Phys-Can RCT.

PURPOSE: To compare sociodemographic, health- and exercise-related characteristics of participants vs. decliners, and completers vs. drop-outs, in an exercise intervention trial during cancer treatment. METHODS: Patients with newly diagnosed breast, prostate, or colorectal cancer were invited to participate in a 6-month exercise intervention. Background data for all respondents (n = 2051) were collected at baseline by questionnaire and medical records. Additional data were collected using an extended questionnaire, physical activity monitors, and fitness testing for trial participants (n = 577). Moreover, a sub-group of decliners (n = 436) consented to additional data collection by an extended questionnaire . Data were analyzed for between-group differences using independent t-tests and chi2-tests. RESULTS: Trial participants were younger (59 ± 12yrs vs. 64 ± 11yrs, p < .001), more likely to be women (80% vs. 75%, p = .012), and scheduled for chemotherapy treatment (54% vs. 34%, p < .001), compared to decliners (n = 1391). A greater proportion had university education (60% vs 40%, p < .001), reported higher anxiety and fatigue, higher exercise self-efficacy and outcome expectations, and less kinesiophobia at baseline compared to decliners. A greater proportion of trial participants were classified as 'not physically active' at baseline; however, within the group who participated, being "physically active" at baseline was associated with trial completion. Completers (n = 410) also reported less kinesiophobia than drop-outs (n = 167). CONCLUSION: The recruitment procedures used in comprehensive oncology exercise trials should specifically address barriers for participation among men, patients without university education and older patients. Individualized efforts should be made to enroll patients with low exercise self-efficacy and low outcome expectations of exercise. To retain participants in an ongoing exercise intervention, extra support may be needed for patients with kinesiophobia and those lacking health-enhancing exercise habits at baseline.

Effect of self-regulatory behaviour change techniques and predictors of physical activity maintenance in cancer survivors: a 12-month follow-up of the Phys-Can RCT.

BACKGROUND: Current knowledge about the promotion of long-term physical activity (PA) maintenance in cancer survivors is limited. The aims of this study were to 1) determine the effect of self-regulatory BCTs on long-term PA maintenance, and 2) identify predictors of long-term PA maintenance in cancer survivors 12 months after participating in a six-month exercise intervention during cancer treatment. METHODS: In a multicentre study with a 2 × 2 factorial design, the Phys-Can RCT, 577 participants with curable breast, colorectal or prostate cancer and starting their cancer treatment, were randomized to high intensity exercise with or without self-regulatory behaviour change techniques (BCTs; e.g. goal-setting and self-monitoring) or low-to-moderate intensity exercise with or without self-regulatory BCTs. Participants' level of PA was assessed at the end of the exercise intervention and 12 months later (i.e. 12-month follow-up), using a PA monitor and a PA diary. Participants were categorized as either maintainers (change in minutes/week of aerobic PA ≥ 0 and/or change in number of sessions/week of resistance training ≥0) or non-maintainers. Data on potential predictors were collected at baseline and at the end of the exercise intervention. Multiple logistic regression analyses were performed to answer both research questions. RESULTS: A total of 301 participants (52%) completed the data assessments. A main effect of BCTs on PA maintenance was found (OR = 1.80, 95%CI [1.05-3.08]) at 12-month follow-up. Participants reporting higher health-related quality-of-life (HRQoL) (OR = 1.03, 95%CI [1.00-1.06] and higher exercise motivation (OR = 1.02, 95%CI [1.00-1.04]) at baseline were more likely to maintain PA levels at 12-month follow-up. Participants with higher exercise expectations (OR = 0.88, 95%CI [0.78-0.99]) and a history of tobacco use at baseline (OR = 0.43, 95%CI [0.21-0.86]) were less likely to maintain PA levels at 12-month follow-up. Finally, participants with greater BMI increases over the course of the exercise intervention (OR = 0.63, 95%CI [0.44-0.90]) were less likely to maintain their PA levels at 12-month follow-up. CONCLUSIONS: Self-regulatory BCTs improved PA maintenance at 12-month follow-up and can be recommended to cancer survivors for long-term PA maintenance. Such support should be considered especially for patients with low HRQoL, low exercise motivation, high exercise expectations or with a history of tobacco use at the start of their cancer treatment, as well as for those gaining weight during their treatment. However, more experimental studies are needed to investigate the efficacy of individual or combinations of BCTs in broader clinical populations. TRIAL REGISTRATION: NCT02473003 (10/10/2014).

Does exercise intensity matter for fatigue during (neo-)adjuvant cancer treatment? The Phys-Can randomized clinical trial.

Exercise during cancer treatment improves cancer-related fatigue (CRF), but the importance of exercise intensity for CRF is unclear. We compared the effects of high- vs low-to-moderate-intensity exercise with or without additional behavior change support (BCS) on CRF in patients undergoing (neo-)adjuvant cancer treatment. This was a multicenter, 2x2 factorial design randomized controlled trial (Clinical Trials NCT02473003) in Sweden. Participants recently diagnosed with breast (n = 457), prostate (n = 97) or colorectal (n = 23) cancer undergoing (neo-)adjuvant treatment were randomized to high intensity (n = 144), low-to-moderate intensity (n = 144), high intensity with BCS (n = 144) or low-to-moderate intensity with BCS (n = 145). The 6-month exercise intervention included supervised resistance training and home-based endurance training. CRF was assessed by Multidimensional Fatigue Inventory (MFI, five subscales score range 4-20), and Functional Assessment of Chronic Illness Therapy-Fatigue scale (FACIT-F, score range 0-52). Multiple linear regression for main factorial effects was performed according to intention-to-treat, with post-intervention CRF as primary endpoint. Overall, 577 participants (mean age 58.7 years) were randomized. Participants randomized to high- vs low-to-moderate-intensity exercise had lower physical fatigue (MFI Physical Fatigue subscale; mean difference -1.05 [95% CI: -1.85, -0.25]), but the difference was not clinically important (ie <2). We found no differences in other CRF dimensions and no effect of additional BCS. There were few minor adverse events. For CRF, patients undergoing (neo-)adjuvant treatment for breast, prostate or colorectal cancer can safely exercise at high- or low-to-moderate intensity, according to their own preferences. Additional BCS does not provide extra benefit for CRF in supervised, well-controlled exercise interventions.

Exercise Adherence and Effect of Self-Regulatory Behavior Change Techniques in Patients Undergoing Curative Cancer Treatment: Secondary Analysis from the Phys-Can Randomized Controlled Trial.

INTRODUCTION: Adherence to exercise interventions in patients with cancer is often poorly described. Further, it is unclear if self-regulatory behavior change techniques (BCTs) can improve exercise adherence in cancer populations. We aimed to (1) describe exercise adherence in terms of frequency, intensity, time, type (FITT-principles) and dropouts, and (2) determine the effect of specific self-regulatory BCTs on exercise adherence in patients participating in an exercise intervention during curative cancer treatment. METHODS: This study was a secondary analysis using data from a Swedish multicentre RCT. In a 2×2 factorial design, 577 participants recently diagnosed with curable breast, colorectal or prostate cancer were randomized to 6 months of high (HI) or low-to-moderate intensity (LMI) exercise, with or without self-regulatory BCTs (e.g., goal-setting and self-monitoring). The exercise program included supervised group-based resistance training and home-based endurance training. Exercise adherence (performed training/prescribed training) was assessed using attendance records, training logs and heart rate monitors, and is presented descriptively. Linear regression and logistic regression were used to assess the effect of self-regulatory BCTs on each FITT-principle and dropout rates, according to intention-to-treat. RESULTS: For resistance training (groups with vs without self-regulatory BCTs), participants attended on average 52% vs 53% of prescribed sessions, performed 79% vs 76% of prescribed intensity, and 80% vs 77% of prescribed time. They adhered to exercise type in 71% vs 68% of attended sessions. For endurance training (groups with vs without self-regulatory BCTs), participants performed on average 47% vs 51% of prescribed sessions, 57% vs 62% of prescribed intensity, and 71% vs 72% of prescribed time. They adhered to exercise type in 79% vs 78% of performed sessions. Dropout rates (groups with vs without self-regulatory BCTs) were 29% vs 28%. The regression analysis revealed no effect of the self-regulatory BCTs on exercise adherence. CONCLUSION: An exercise adherence rate ≥50% for each FITT-principle and dropout rates at ~30% can be expected among patients taking part in long-term exercise interventions, combining resistance and endurance training during curative cancer treatment. Our results indicate that self-regulatory BCTs do not improve exercise adherence in interventions that provide evidence-based support to all participants (e.g., supervised group sessions). TRIAL REGISTRATION: NCT02473003.

Translating GWAS-identified loci for cardiac rhythm and rate using an in vivo image- and CRISPR/Cas9-based approach.

A meta-analysis of genome-wide association studies (GWAS) identified eight loci that are associated with heart rate variability (HRV), but candidate genes in these loci remain uncharacterized. We developed an image- and CRISPR/Cas9-based pipeline to systematically characterize candidate genes for HRV in live zebrafish embryos. Nine zebrafish orthologues of six human candidate genes were targeted simultaneously in eggs from fish that transgenically express GFP on smooth muscle cells (Tg[acta2:GFP]), to visualize the beating heart. An automated analysis of repeated 30 s recordings of beating atria in 381 live, intact zebrafish embryos at 2 and 5 days post-fertilization highlighted genes that influence HRV (hcn4 and si:dkey-65j6.2 [KIAA1755]); heart rate (rgs6 and hcn4); and the risk of sinoatrial pauses and arrests (hcn4). Exposure to 10 or 25 µM ivabradine-an open channel blocker of HCNs-for 24 h resulted in a dose-dependent higher HRV and lower heart rate at 5 days post-fertilization. Hence, our screen confirmed the role of established genes for heart rate and rhythm (RGS6 and HCN4); showed that ivabradine reduces heart rate and increases HRV in zebrafish embryos, as it does in humans; and highlighted a novel gene that plays a role in HRV (KIAA1755).

The role of children and their socioeconomic resources for the risk of hospitalisation and mortality - a nationwide register-based study of the total Swedish population over the age 70.

BACKGROUND: Previous studies have shown that mortality in old age is associated with both number of children and their socioeconomic resources. The underlying mechanisms are unclear, as well as when during the process of health deterioration the advantage of parents over non-parents arises. This study aims to examine how the number of children and their socioeconomic resources are associated with different health outcomes among their parents, namely the hazard for i) first hospitalisation, ii) re-admission, iii) mortality after first hospitalisation, and iv) overall mortality. METHOD: This longitudinal cohort study includes all individuals born 1920-1940 who were living in Sweden at age 70 years (890,544 individuals). Individuals were linked to their offspring and spouse using administrative registers and followed for up to 25 years. Associations were estimated using multivariable Cox models adjusted for index persons' education and income, marital status, their partners' education, and age at first birth. RESULTS: In this study, having children was associated with reduced mortality risk of their parents, but not with the risk of being hospitalised, which increased as number of children increased. A higher education of children was protective for all parental outcomes independent of number of children and their financial resources. In fact, income of the children was only weakly associated with the health of their parents. CONCLUSIONS: The benefit of having children compared to childlessness for health in old age seems to arise once individuals have become ill rather than before. Children's education is important for parental health and mortality, in fact more important than the number of children itself in this Swedish cohort.

Oral metronidazole use and risk of acute pancreatitis: a population-based case-control study.

OBJECTIVE: Oral metronidazole used in combined regimens for Helicobacter pylori eradication has been associated with an increased risk of acute pancreatitis; however, it is less clear whether a similar association exists for single-regimen metronidazole. We, therefore, examined the association of single and combined regimens of oral metronidazole with risk of acute pancreatitis. METHODS: In this population-based case-control study, all individuals in Sweden (aged 40-84 years) hospitalized with acute pancreatitis between January 2006 and December 2008 were identified from a national hospital register (n=5,996). Controls, matched for calendar year, age, and sex, were randomly sampled from a national population register (n=60,681). Data on oral metronidazole and covariates were extracted from national health and prescription registers. Odds ratios (ORs) of acute pancreatitis, according to timing of the latest metronidazole prescription before hospitalization, were estimated using logistic regression models. Confounding by indication was examined by contrasting the main results with the association when amoxicillin was used as exposure. The robustness of results was examined by calculating incidence rate ratios using a self-controlled case series approach. RESULTS: After adjustment for potential confounders, there was a substantially increased risk of acute pancreatitis within 30 days of oral metronidazole exposure, both for single (OR: 4.06; 95% confidence interval [CI]: 1.90-8.64) and combined (OR: 11.80; 95% CI: 6.86-20.28) regimens, compared to nonexposure. In contrast, the adjusted OR was 1.79 (95% CI: 1.25-2.54) for current use of amoxicillin compared to nonexposure. These results were supported by the self-controlled cases series analysis (incidence rate ratio: 3.30; 95% CI: 2.69-4.06, for single and combined regimens of oral metronidazole pooled). There was no strong association between oral metronidazole and acute pancreatitis more than 30 days after exposure. CONCLUSION: There was an increased risk of acute pancreatitis within 30 days of exposure to single and combined regimens of oral metronidazole. While reverse causality and confounding by indication cannot be entirely excluded, they are unlikely to fully explain the association. These results warrant an increased awareness among physicians.

Risk factors for, and prevention of, shoulder injuries in overhead sports: a systematic review with best-evidence synthesis.

OBJECTIVE: To assess the evidence for risk factors and prevention measures for shoulder injuries in overhead sports. DESIGN: Systematic review with best-evidence synthesis. DATA SOURCES: Medline (Ovid), PubMed (complementary search), Embase (Elsevier), Cochrane (Wiley), SPORTDiscus (Ebsco) and Web of Science Core Collection (Thomson Reuters), from 1 January 1990 to 15 May 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials, cohort studies and case-control studies on risk factors or prevention measures for shoulder injuries in overhead sports. The eligible studies were quality assessed using the Scottish Intercollegiate Guidelines Network criteria. RESULTS: Of 4778 studies identified, 38 were eligible for quality review and 17 met the quality criteria to be included in the evidence synthesis. One additional quality study presented a shoulder injury prevention programme. Most studies focused on baseball, lacrosse or volleyball (n=13). The risk factors examined included participation level (competition vs training) (n=10), sex (n=4), biomechanics (n=2) and external workload (n=2). The evidence for all risk factors was limited or conflicting. The effect of the prevention programme within the subgroup of uninjured players at baseline was modest and possibly lacked statistical power. CONCLUSIONS: All investigated potential risk factors for shoulder injury in overhead sports had limited evidence, and most were non-modifiable (eg, sex). There is also limited evidence for the effect of shoulder injury prevention measures in overhead sports. PROSPERO TRIAL REGISTRATION NUMBER: CRD42015026850.

Maternal diabetes and incidence of childhood cancer - a nationwide cohort study and exploratory genetic analysis.

BACKGROUND: The etiology of childhood cancer is not well understood, but may be linked to prenatal and perinatal factors, such as maternal diabetes. However, this association has not been examined in depth. We aimed to determine if maternal diabetes is associated with risk of childhood brain tumor (CBT), leukemia (all types combined and acute lymphoblastic leukemia [ALL] separately), and lymphoma. METHODS: All children born in Sweden between 1973 and 2014 (n=4,239,965) were followed from birth until first cancer diagnosis, age 15 years, or December 31, 2015. Data on maternal diabetes, childhood cancer, and covariates were obtained from nationwide health registers. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated using Cox regression adjusted for potential confounders/mediators. Additionally, we performed an exploratory analysis using results from published genome-wide association studies and functional annotation. RESULTS: Maternal diabetes was associated with lower risk of CBT (adjusted IRR [95% CI]: 0.56 [0.35-0.91]) and higher risk of leukemia (adjusted IRR: 1.47 [1.13-1.92] for all leukemia combined and 1.64 [1.23-2.18] for ALL). These associations were similar for both maternal type 1 diabetes and gestational diabetes. Associations of five previously identified genetic loci were compatible with a causal effect of diabetes traits on neuroblastoma and common Hodgkin's lymphoma. CONCLUSION: Children whose mother had diabetes had lower risk of CBT and higher risk of leukemia, compared with children whose mother did not have diabetes. Our results are compatible with a role of prenatal and perinatal glycemic environment in childhood cancer etiology.

Adult children's socioeconomic resources and mothers' survival after a breast cancer diagnosis: a Swedish population-based cohort study.

OBJECTIVES: Socioeconomic inequalities in survival after breast cancer persist worldwide. We aim to determine whether adult offspring's socioeconomic resources contribute to inequalities in mothers' survival after breast cancer. METHODS: 14 231 women, aged 65-79 years, with a child aged ≥30 years and a first primary diagnosis of breast cancer in the National Cancer Register between 2001 and 2010 were followed until death, 10 years after diagnosis, or end of study (December 2015). Relative survival proportions and excess mortality within 10 years of diagnosis by strata of offspring's education level and disposable income were estimated using flexible parametric models accounting for measures of mothers' socioeconomic position and expected mortality in the general population. RESULTS: 4292 women died during 102 236 person-years of follow-up. Crude 10-year relative survival proportions for mothers of children with >14, 12-14 and <12 years of education were 0.89 (0.87 to 0.91), 0.87 (0.85 to 0.89) and 0.79 (0.76 to 0.81), respectively. Compared with mothers of children with >14 years of education, mothers of children with <12 or 12-14 years of education had substantially higher excess mortality (excess HR 1.69 (1.38 to 2.07) and 1.22 (1.00 to 1.48), respectively). Higher mortality did not differ between tertiles of offspring's disposable income. CONCLUSIONS: Adult offspring's education level may contribute to inequalities in mothers' survival after breast cancer. Clinicians should be aware of the educational context beyond the individual and women with less educated offsprings may require extra support. This should be considered in future research, policy frameworks and interventions aimed at reducing survival inequalities.

Methodological choices affect cancer incidence rates: a cohort study.

BACKGROUND: Incidence rates are fundamental to epidemiology, but their magnitude and interpretation depend on methodological choices. We aimed to examine the extent to which the definition of the study population affects cancer incidence rates. METHODS: All primary cancer diagnoses in Sweden between 1958 and 2010 were identified from the national Cancer Register. Age-standardized and age-specific incidence rates of 29 cancer subtypes between 2000 and 2010 were calculated using four definitions of the study population: persons resident in Sweden 1) based on general population statistics; 2) with no previous subtype-specific cancer diagnosis; 3) with no previous cancer diagnosis except non-melanoma skin cancer; and 4) with no previous cancer diagnosis of any type. We calculated absolute and relative differences between methods. RESULTS: Age-standardized incidence rates calculated using general population statistics ranged from 6% lower (prostate cancer, incidence rate difference: -13.5/100,000 person-years) to 8% higher (breast cancer in women, incidence rate difference: 10.5/100,000 person-years) than incidence rates based on individuals with no previous subtype-specific cancer diagnosis. Age-standardized incidence rates in persons with no previous cancer of any type were up to 10% lower (bladder cancer in women) than rates in those with no previous subtype-specific cancer diagnosis; however, absolute differences were <5/100,000 person-years for all cancer subtypes. CONCLUSIONS: For some cancer subtypes incidence rates vary depending on the definition of the study population. For these subtypes, standardized incidence ratios calculated using general population statistics could be misleading. Moreover, etiological arguments should be used to inform methodological choices during study design.

Frequency and duration of physical activity bouts in school-aged children: A comparison within and between days.

Understanding how physical activity (PA) patterns vary within and between days may guide PA promotion in young people. We aimed to 1) describe and compare the frequency (bouts/day) and duration (min/bout) of bouts of moderate-to-vigorous intensity PA (MVPA) on weekdays vs. weekends and in-school vs. out-of-school, and 2) assess associations of bout frequency and duration in these time-segments with overall PA. We used cross-sectional accelerometer data from 2737 children (aged 6-19 years) in the United States National Health and Nutrition Examination Survey (NHANES) 2003-2006. A bout was defined as MVPA (≥ 2000 counts per minute [cpm]) lasting ≥ 3 min. Adjusted Wald tests were used to assess differences in bout characteristics between time-segments. Linear regression was used to examine the association of time-segment specific bout characteristics with daily minutes of MVPA and PA volume (average cpm). Bout frequency was higher on weekdays than weekends (median [IQR] 4.3 [2.2-7.2] vs. 3.0 [1.0-6.5] bouts/day, p < 0.001); however, bout duration did not differ (4.7 [4.0-5.7] vs. 4.5 [3.7-5.8] min/bout, p = 0.33). More bouts were accumulated out-of-school compared with in-school (2.2 [1.0-4.0] vs. 1.8 [0.8-3.2] bouts/day, p < 0.001), but bout duration was similar (4.7 [3.8-5.8] vs. 4.5 [3.8-5.7] min/bout, p = 0.158). For all time-segments, the frequency and duration of bouts of MVPA were independently and positively associated with overall MVPA and PA volume. In conclusion, the characteristics of children's PA vary within and between days; accounting for this in intervention design may improve future interventions. However, increasing bout frequency or duration in any time-segment may be beneficial for overall PA.

Socioeconomic position and the risk of brain tumour: a Swedish national population-based cohort study.

BACKGROUND: The aim was to investigate associations between different measures of socioeconomic position (SEP) and incidence of brain tumours (glioma, meningioma and acoustic neuroma) in a nationwide population-based cohort. METHODS: We included 4 305 265 individuals born in Sweden during 1911-1961, and residing in Sweden in 1991. Cohort members were followed from 1993 to 2010 for a first primary diagnosis of brain tumour identified from the National Cancer Register. Poisson regression was used to compute incidence rate ratios (IRR) by highest education achieved, family income, occupational group and marital status, with adjustment for age, healthcare region of residence, and time period. RESULTS: We identified 5735 brain tumours among men and 7101 among women during the study period. Highly educated men (≥3 years university education) had increased risk of glioma (IRR 1.22, 95% CI 1.08 to 1.37) compared to men with primary education. High income was associated with higher incidence of glioma in men (1.14, 1.01 to 1.27). Women with ≥3 years university education had increased risk of glioma (1.23, 1.08 to 1.40) and meningioma (1.16, 1.04 to 1.29) compared to those with primary education. Men and women in intermediate and higher non-manual occupations had increased risk of glioma compared to low manual groups. Compared to those married/cohabiting, being single or previously married/cohabiting was associated with decreased risk of glioma in men. Men in non-manual occupations had ∼50% increased risk of acoustic neuroma compared to men in low manual occupations. CONCLUSIONS: We observed consistent associations between higher SEP and higher risk of glioma. Completeness of cancer registration and detection bias are potential explanations for the findings.

Socioeconomic position and incidence of colorectal cancer in the Swedish population.

BACKGROUND: The association between socioeconomic position and incidence of colorectal cancer is inconsistent and differs by global region. We aimed to clarify this association in the Swedish population. METHODS: We conducted a population-based open cohort study using data from Swedish national registers. We included all individuals, aged ≥30 years, residing in Sweden between 1993 and 2010. Socioeconomic position was indicated by (1) highest educational level (five groups), and (2) disposable income (quintiles). We used Poisson regression to estimate incidence rate ratios (IRR) and 95% confidence intervals (95% CI) of colon and rectal cancer, and colon and rectal dysplasia. RESULTS: In total, 97,827,817 person-years were accumulated and 82,686 cases of colorectal cancer were diagnosed. Compared to men with 'higher secondary' education, the adjusted IRRs (95% CI) of rectal cancer in men with 'primary or less', 'lower secondary', 'lower university' or 'higher university' education were: 1.06 (1.00, 1.11), 1.05 (0.99, 1.10), 0.96 (0.89, 1.03), and 0.92 (0.86, 0.98), respectively. In women, the corresponding figures were: 1.04 (0.95, 1.14), 1.03 (0.94, 1.13), 0.92 (0.82, 1.02) and 0.92 (0.82, 1.02). Disposable income was not associated with rectal cancer incidence. Adjusted IRRs of colon cancer did not differ between levels of education or disposable income overall or for specific colon sub-sites. Neither education nor disposable income was consistently associated with incidence of colon or rectal dysplasia. CONCLUSIONS: Prevention strategies for colon cancer should be applicable to individuals regardless of their socioeconomic position. However, factors conferred by education, e.g., health awareness, may be important for approaches aiming to reduce inequalities in incidence of rectal cancer. Further evaluation of cancer prevention and health promotion strategies among less educated groups is warranted.

Changes in time-segment specific physical activity between ages 10 and 14 years: A longitudinal observational study.

OBJECTIVES: Describe (1) time-segment specific changes in physical activity (PA) into adolescence, (2) differences in change in PA between specific time-segments (weekdays-weekends, in-school-out-of-school, out-of-school-weekends, lesson-time-lunch-time), and (3) associations of change in time-segment specific with overall PA. DESIGN: Longitudinal observational study (4-year follow-up). METHODS: Children from the SPEEDY study (n=769, 42% boys) had PA measured by accelerometer for at least three days at ages 10.2±0.3, 11.2±0.3 and 14.3±0.3years. Changes in moderate-to-vigorous PA (ΔMVPA, minutes ≥2000counts/minute [cpm]) and total PA (ΔTPA, average cpm) during weekdays, weekends, in-school, out-of-school, lesson-times and lunch-times, were tested using three level (age, individual, school) mixed-effects linear regression. Differences in ΔMVPA/ΔTPA between time-segments were tested using time-segment×age interaction terms. Associations of four-year time-segment specific ΔMVPA/ΔTPA with four-year overall ΔMVPA/ΔTPA were tested using two level (time-segment specific ΔMVPA/ΔTPA, school) mixed-effects linear regression. RESULTS: MVPA and TPA declined in all time-segments, except lesson-time MVPA. Annual ΔMVPA and, for boys only, ΔTPA was greater on weekends than weekdays (beta±SE for interaction term: boys, -3.53±0.83min, -29.64±7.64cpm; girls, -2.20±0.64min) and out-of-school (boys, -4.36±0.79min, -19.36±8.46cpm; girls, -2.44±0.63min). ΔMVPA and ΔTPA during lunch-time was greater than during lesson-time (boys, -0.96±0.20min, -36.43±6.55cpm; girls, -0.90±0.13min, -38.72±4.40cpm). ΔTPA was greater out-of-school than in-school (boys, -19.89±6.71cpm; girls, -18.46±6.51cpm). For all time-segments, four-year ΔMVPA/ΔTPA was positively associated with four-year overall ΔMVPA/ΔTPA (all p<0.042), except for girl's in-school and lunch-time TPA. CONCLUSIONS: Interventions focused on PA maintenance could target all time-segments, but weekends and out-of-school may be particularly advantageous due to the relatively large declines observed.

A systematic literature review with meta-analyses of within- and between-day differences in objectively measured physical activity in school-aged children.

BACKGROUND: Targeting specific time periods of the day or week may enhance physical activity (PA) interventions in youth. The most prudent time segments to target are currently unclear. OBJECTIVES: To systematically review the literature describing differences in young people's objectively measured PA on weekdays vs. weekends, in school vs. out of school, weekends vs. out of school and lesson time vs. break time. METHODS: Electronic databases were searched for English-language, cross-sectional studies of school-aged children (4-18 years) reporting time-segment-specific accelerometer-measured PA from 01/1990 to 01/2013. We meta-analysed standardised mean differences (SMD) between time segments for mean accelerometer counts per minute (TPA) and minutes in moderate-to-vigorous PA (MVPA). SMD is reported in units of standard deviation; 0.2, 0.5 and 0.8 represent small, moderate and large effects. Heterogeneity was explored using meta-regression (potential effect modifiers: age, sex and study setting). RESULTS: Of the 54 included studies, 37 were eligible for meta-analyses. Children were more active on weekdays than weekends [pooled SMD (95 % CI) TPA 0.14 (0.08; 0.20), MVPA 0.42 (0.35; 0.49)]. On school days, TPA was lower in school than out of school; however, marginally more MVPA was accumulated in school [TPA -0.24 (-0.40; -0.08), MVPA 0.17 (-0.03; 0.38)]. TPA was slightly lower on weekends than out of school on school days, but a greater absolute volume of MVPA was performed on weekends [TPA -0.10 (-0.19; -0.01), MVPA 1.02 (0.82; 1.23)]. Heterogeneity between studies was high (I (2) 73.3-96.3 %), with 20.3-53.1 % of variance between studies attributable to potential moderating factors. CONCLUSIONS: School-aged children are more active on weekdays than weekend days. The outcome measure influences the conclusions for other comparisons. Findings support the tailoring of intervention strategies to specific time periods.

Physical activity maintenance in the transition to adolescence: a longitudinal study of the roles of sport and lifestyle activities in British youth.

BACKGROUND: Promoting physical activity in youth is important for health, but existing physical activity interventions have had limited success. We aimed to inform intervention design by i) describing drop-out, continuation and uptake of specific activities over the transition to adolescence; and ii) examining Variety (number of different activities/week) and Frequency (number of activity session/week) of activity participation and their associations with changes in objectively measured physical activity from childhood to adolescence. METHODS: At age 10.2±0.3 and 14.2±0.3 years, 319 children in the SPEEDY study (46% boys) wore GT1M Actigraph accelerometers for 7 days and provided self-reported participation (never, once, 2 to 3 times or four or more times, over the last 7 days) in 23 leisure-time activities. Associations of change in moderate-to-vigorous intensity PA (MVPA) (≥2000 counts/minute) and change in total physical activity (TPA) (average accelerometer counts/minute) with exposure variables Z-score transformed (change in) Variety and Frequency were examined using multilevel linear regression, clustered by school, in simple and adjusted models. RESULTS: The number of children ever reporting a specific activity ranged from 30 ('Hockey') to 279 ('Running or jogging'). Some activities were susceptible to drop-out (e.g. 'Skipping') but others were commonly continued or taken up (e.g. 'Household chores'). Overall, Variety and Frequency declined (mean±SD ΔVariety -3.1±4.4 activities/week; ΔFrequency -7.2±12.0 session/week). ΔMVPA and ΔTPA were not associated with Variety or Frequency at baseline, nor with ΔVariety or ΔFrequency (p>0.29 in all models). CONCLUSIONS: Popularity of specific activities as well as drop-out, continuation and uptake should be considered in future intervention development. Activities that are commonly continued or taken up may be more valuable to encourage in interventions than those with low participation or high drop-out. We did not find evidence to support the idea that Variety and Frequency may be key elements to include in future interventions.

More of the same or a change of scenery: an observational study of variety and frequency of physical activity in British children.

BACKGROUND: Physical activity is important for children's health, but successful physical activity promotion is challenging. Whether performing many different types of activities (Variety) is associated with higher physical activity independent of the number of activity sessions (Frequency) is unknown, but this information could inform physical activity promotion and public health strategies in children. METHODS: In the SPEEDY study we measured moderate-to-vigorous intensity physical activity (MVPA; ≥2000 counts/minute) over 7 days using GT1M Actigraph accelerometers in 1700 children from Norfolk, UK (56% girls, Mean ± SD 10.3 ± 0.3 years-old). Children reported participation in 28 leisure-time activities over the previous 7 days. Sex differences in activity participation were assessed using multilevel logistic regression, clustered by school. Associations of log-transformed MVPA with z-score-Variety (number of different activities/week) and z-score-Frequency (sum of all activity sessions/week) were examined using multilevel linear regression, adjusted for age, sex, parental education and age-standardised BMI. RESULTS: Children's activity participation often reflected gender stereotypes. Mean ± SD Variety was 10.8 ± 5.0 activities/week, and Frequency was 24.2±15.0 sessions/week. In separate models lnMVPA had similar strength, positive associations with z-score-Variety and z-score-Frequency (Exp ß(95% CI); Variety 1.04(1.02-1.06), Frequency 1.04(1.02-1.06)). lnMVPA was not associated with z-score-Variety independent of z-score-Frequency (Variety 1.01(0.98-1.04), Frequency 1.03(1.00-1.06)). CONCLUSIONS: Future physical activity interventions and public health strategies could allow for gender specific activity preferences and could target both Variety and Frequency of activities participated in by children.