School-level intra-cluster correlation coefficients and autocorrelations for children's accelerometer-measured physical activity in England by age and gender.

BACKGROUND: Randomised, cluster-based study designs in schools are commonly used to evaluate children's physical activity interventions. Sample size estimation relies on accurate estimation of the intra-cluster correlation coefficient (ICC), but published estimates, especially using accelerometry-measured physical activity, are few and vary depending on physical activity outcome and participant age. Less commonly-used cluster-based designs, such as stepped wedge designs, also need to account for correlations over time, e.g. cluster autocorrelation (CAC) and individual autocorrelation (IAC), but no estimates are currently available. This paper estimates the school-level ICC, CAC and IAC for England children's accelerometer-measured physical activity outcomes by age group and gender, to inform the design of future school-based cluster trials. METHODS: Data were pooled from seven large English datasets of accelerometer-measured physical activity data between 2002-18 (> 13,500 pupils, 540 primary and secondary schools). Linear mixed effect models estimated ICCs for weekday and whole week for minutes spent in moderate-to-vigorous physical activity (MVPA) and being sedentary for different age groups, stratified by gender. The CAC (1,252 schools) and IAC (34,923 pupils) were estimated by length of follow-up from pooled longitudinal data. RESULTS: School-level ICCs for weekday MVPA were higher in primary schools (from 0.07 (95% CI: 0.05, 0.10) to 0.08 (95% CI: 0.06, 0.11)) compared to secondary (from 0.04 (95% CI: 0.03, 0.07) to (95% CI: 0.04, 0.10)). Girls' ICCs were similar for primary and secondary schools, but boys' were lower in secondary. For all ages, combined the CAC was 0.60 (95% CI: 0.44-0.72), and the IAC was 0.46 (95% CI: 0.42-0.49), irrespective of follow-up time. Estimates were higher for MVPA vs sedentary time, and for weekdays vs the whole week. CONCLUSIONS: Adequately powered studies are important to evidence effective physical activity strategies. Our estimates of the ICC, CAC and IAC may be used to plan future school-based physical activity evaluations and were fairly consistent across a range of ages and settings, suggesting that results may be applied to other high income countries with similar school physical activity provision. It is important to use estimates appropriate to the study design, and that match the intended study population as closely as possible.

Exploring the associations between adverse childhood experiences (ACEs) and adolescent cancer risk behaviours in the ALSPAC cohort.

BACKGROUND: Some modifiable risk factors for cancer originate during adolescence. While there is evidence indicating relationships between adverse childhood experiences and health risk behaviours generally, little is known about how childhood adversity influences the engagement of adolescents in cancer risk behaviours. This study aimed to determine the relationship between adverse childhood experiences and adolescent cancer risk behaviours. METHODS: Data were collected prospectively from birth to age 18 years on children born to mothers enrolled into the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort study. Multivariable linear regression models assessed relationships of a composite exposure measure comprised of adverse childhood experiences (total number of childhood adversities experienced from early infancy until age 9 years) with multiple cancer risk behaviours. The latter was expressed as a single continuous score for tobacco smoking, alcohol consumption, obesity, unsafe sex, and physical inactivity, at ages 11, 14, 16 and 18 years. Analysis was carried out on the complete case and imputation samples of 1,368 and 7,358 participants respectively. RESULTS: All adolescent cancer risk behaviours increased in prevalence as the adolescents grew older, except for obesity. Each additional adverse childhood experience was associated with a 0.25 unit increase in adolescent cancer risk behaviour (95% CI 0.16-0.34; p < 0.001). Individually, parental substance misuse (ß 0.64, 95% CI 0.25-1.03, p < 0.001) and parental separation (ß 0.56, 95% CI 0.27-0.86, p < 0.001) demonstrated the strongest evidence of association with engagement in adolescent cancer risk behaviour. CONCLUSION: Childhood adversity was associated with a greater degree of engagement in adolescent cancer risk behaviours. This finding demonstrates the need for targeted primary and secondary prevention interventions that reduce engagement across multiple cancer risk behaviours for children and adolescents who have experienced adversity in childhood, such as parental substance misuse and separation, and reduce exposure to adversity.

What effect have commissioners' policies for body mass index had on hip replacement surgery?: an interrupted time series analysis from the National Joint Registry for England.

BACKGROUND: Despite their widespread use, the impact of commissioners' policies for body mass index (BMI) for access to elective surgery is not clear. Policy use varies by locality, and there are concerns that these policies may worsen health inequalities. The aim of this study was to assess the impact of policies for BMI on access to hip replacement surgery in England. METHODS: A natural experimental study using interrupted time series and difference-in-differences analysis. We used National Joint Registry data for 480,364 patients who had primary hip replacement surgery in England between January 2009 and December 2019. Clinical commissioning group policies introduced before June 2018 to alter access to hip replacement for patients with overweight or obesity were considered the intervention. The main outcome measures were rate of surgery and patient demographics (BMI, index of multiple deprivation, independently funded surgery) over time. RESULTS: Commissioning localities which introduced a policy had higher surgery rates at baseline than those which did not. Rates of surgery fell after policy introduction, whereas rates rose in localities with no policy. 'Strict' policies mandating a BMI threshold for access to surgery were associated with the sharpest fall in rates (trend change of - 1.39 operations per 100,000 population aged 40 + per quarter-year, 95% confidence interval - 1.81 to - 0.97, P < 0.001). Localities with BMI policies have higher proportions of independently funded surgery and more affluent patients receiving surgery, indicating increasing health inequalities. Policies enforcing extra waiting time before surgery were associated with worsening mean pre-operative symptom scores and rising obesity. CONCLUSIONS: Commissioners and policymakers should be aware of the counterproductive effects of BMI policies on patient outcomes and inequalities. We recommend that BMI policies involving extra waiting time or mandatory BMI thresholds are no longer used to reduce access to hip replacement surgery.

A qualitative exploration of food portion size practices and awareness of food portion size guidance in first-time parents of one- to two-year-olds living in the UK.

BACKGROUND: Food portion size guidance resources aimed at parents of young children in the UK are freely available from a number of credible sources. However, little is known about whether parents are aware of, and use, any of these resources to guide their food portioning practices. OBJECTIVES: We aimed to explore the food portion size practices used by first-time parents living in the UK when feeding their one- to two-year-old child, and their awareness of and views on six food portion size guidance resources. METHODS: Participants were recruited via parent Facebook groups and online parent forums. Online 1-1 semi-structured interviews were conducted, during which parents were shown images of six food portion size guidance resources to facilitate discussion. Data was analysed in NVivo 11 using a Reflexive Thematic Analysis approach. RESULTS: Of the 27 participants, most were women (n = 25), white (n = 18), and educated to first degree level or higher (n = 24). First-time parents mostly relied on their own judgement and "instinct" to portion foods, based on their learned experience of how much their child ate on a day-to-day basis. This experience was used alongside physical indicators of food portion size, such as the size of children's dishware and food packaging. Most participants were unaware of any of the six food portion size guidance resources we showed them; only four had read any of the resources. Parents suggested they had previously sought advice about weaning from a range of sources (e.g. online, friends, community groups) but would be unlikely to seek out specific food portion size guidance. Parents suggested recommendations on food portion size should acknowledge and highlight parents' perception that "every child is different". CONCLUSIONS: Existing food portion size guidance resources for parents of young children in the UK are ineffective as they have poor reach and impact. We suggest parents should be involved in developing novel strategies to promote age-appropriate consumption and healthy weight gain in young children.

Protocol to evaluate the effectiveness and cost-effectiveness of an environmental nutrition and physical activity intervention in nurseries (Nutrition and Physical Activity Self Assessment for Child Care - NAP SACC UK): a multicentre cluster randomised controlled trial.

BACKGROUND: One in seven UK children have obesity when starting school, with higher prevalence associated with deprivation. Most pre-school children do not meet UK recommendations for physical activity and nutrition. Formal childcare settings provide opportunities to deliver interventions to improve nutritional quality and physical activity to the majority of 3-4-year-olds. The nutrition and physical activity self-assessment for childcare (NAP SACC) intervention has demonstrated effectiveness in the USA with high acceptability in the UK. The study aims to evaluate the effectiveness and cost-effectiveness of the NAP SACC UK intervention to increase physical activity, reduce sedentary time and improve nutritional intake. METHODS: Multi-centre cluster RCT with process and economic evaluation. Participants are children aged 2 years or over, attending UK early years settings (nurseries) for ≥ 12 h/week or ≥ 15 h/week during term time and their parents, and staff at participating nurseries. The 12-month intervention involves nursery managers working with a Partner (public health practitioner) to self-assess policies and practices relating to physical activity and nutrition; nursery staff attending one physical activity and one nutrition training workshop and setting goals to be achieved within 6 months. The Partner provides support and reviews progress. Nursery staff receive a further workshop and new goals are set, with Partner support for a further 6 months. The comparator is usual practice. Up to 56 nurseries will be stratified by area and randomly allocated to intervention or comparator arm with minimisation of differences in level of deprivation. PRIMARY OUTCOMES: accelerometer-assessed mean total activity time on nursery days and average total energy (kcal) intake per eating occasion of lunch and morning/afternoon snacks consumed within nurseries. SECONDARY OUTCOMES: accelerometer-assessed mean daily minutes of moderate-to-vigorous physical activity and sedentary time per nursery day, total physical activity on nursery days compared to non-nursery days, average serving size of lunch and morning/afternoon snacks in nursery per day, average percentage of core and non-core food in lunch and morning/afternoon snacks, zBMI, proportion of children who are overweight/obese and child quality-of-life. A process evaluation will examine fidelity, acceptability, sustainability and context. An economic evaluation will compare costs and consequences from the perspective of the local government, nursery and parents. TRIAL REGISTRATION: ISRCTN33134697, 31/10/2019.

Access to hip and knee arthroplasty in England: commissioners' policies for body mass index and smoking status and implications for integrated care systems.

BACKGROUND: Commissioning policies are in place in England that alter access to hip and knee arthroplasty based on patients' body mass index and smoking status. Our objectives were to ascertain the prevalence, trend and nature of these policies, and consider the implications for new integrated care systems (ICSs). METHODS: Policy data were obtained from an internet search for all current and historic clinical commissioning group (CCG) hip and knee arthroplasty policies and use of Freedom of Information (FOI) requests to each CCG. Descriptive analyses of policy type, explicit threshold criteria and geography are reported. Estimates were made of the uptake of policies by ICSs based on the modal policy type of their constituent CCGs. RESULTS: There were 106 current and 143 historic CCGs in England at the time of the search in June 2021. Policy information was available online for 56.2% (140/249) CCGs. With the addition of information from FOIs, complete policy information was available for 94.4% (235/249) of CCGs. Prevalence and severity of policies have increased over time. For current CCGs, 67.9% (72/106) had a policy for body mass index (BMI) and 75.5% (80/106) had a policy for smoking status for hip or knee arthroplasty. Where BMI policies were in place, 61.1% (44/72) introduced extra waiting time before surgery or restricted access to surgery based on BMI thresholds (modal threshold: BMI of 40 kg/m2, range 30-45). In contrast, where smoking status policies were in place, most offered patients advice or optional smoking cessation support and only 15% (12/80) introduced extra waiting time or mandatory cessation before surgery. It is estimated that 40% of ICSs may adopt a BMI policy restrictive to access to arthroplasty. CONCLUSIONS: Access policies to arthroplasty based on BMI and smoking status are widespread in England, have increased in prevalence since 2013, and persist within new ICSs. The high variation in policy stringency on BMI between regions is likely to cause inequality in access to arthroplasty and to specialist support for affected patients. Further work should determine the impact of different types of policy on access to surgery and health inequalities.

Environmental and practice factors associated with children's device-measured physical activity and sedentary time in early childhood education and care centres: a systematic review.

BACKGROUND: Early childhood education and care (ECEC) settings offer a potentially cost-effective and sustainable solution for ensuring children have opportunities to meet physical activity (PA) and sedentary time (ST) guidelines. This paper systematically reviewed the association between childcare environment and practice and children's PA and ST. METHODS: Three electronic databases were searched, and citation tracking of eligible studies performed between June-July 2020 (updated March 2022). Studies were eligible when (i) participants attended ECEC settings, (ii) they reported the association between use of outdoor space, including factors of time, availability, play, size and equipment, and children's device-measured PA and ST, and (iii) where applicable, they compared the exposure to use of indoor space. Risk of bias was assessed using the Critical Appraisal Skills Program (CASP) tools. A synthesis was performed using effect direct plots and charts to visualise effect sizes. RESULTS: Of 1617 reports screened, 29 studies met the inclusion criteria. Studies provided data on outdoor versus indoor time (n = 9; 960 children), outdoor versus indoor play (n = 3; 1104 children), outdoor play space (n = 19; 9596 children), outdoor space use external to ECEC (n = 2; 1148 children), and portable (n = 7; 2408 children) and fixed (n = 7; 2451 children) outdoor equipment. Time spent outdoors versus indoors was associated with increased moderate-to-vigorous PA (MVPA), light PA (LPA) and total PA, while the association with ST was inconclusive. The mean (standard deviation) levels of outdoor MVPA (4.0 ± 3.2 to 18.6 ± 5.6 min/h) and LPA (9.9 ± 2.6 to 30.8 ± 11.8 min/h) were low, and ST high (30.0 ± 6.5 to 46.1 ± 4.3 min/h). MVPA levels doubled when children played outdoors versus indoors. Outdoor play space, and outdoor portable equipment, were associated with increased MVPA. A dose-response relationship for outdoor play area size was observed, demonstrating increased MVPA with areas ≥505m2 (5436 ft2), but no further increases when areas were > 900m2 (9688 ft2). No studies reported on injuries in outdoor settings. CONCLUSIONS: ECEC policies and practices should promote not only outdoor time but also the availability of resources such as portable play equipment and sufficient size of outdoor play areas that enable children to be physically active for sustained periods while outdoors. SYSTEMATIC REVIEW REGISTRATION: International prospective register of systematic reviews (PROSPERO) Registration Number: CRD42020189886.

Preconception exposures and adverse pregnancy, birth and postpartum outcomes: Umbrella review of systematic reviews.

BACKGROUND: Preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, the reports, statements and guidelines of national and international health organisations vary in what they recommend individuals should monitor, avoid, reduce or practise in the preconception period. OBJECTIVES: To synthesise and evaluate the evidence across systematic reviews for associations between exposures before conception and adverse pregnancy, birth and postpartum outcomes. DATA SOURCES: MEDLINE, Embase, Epistemonikos (to May 2020) and reference lists of included reviews, without language or date restrictions. STUDY SELECTION, DATA EXTRACTION AND SYNTHESIS: Systematic literature reviews of observational and/or interventional studies reporting associations between preconception exposures in women and/or men of reproductive age and pregnancy, birth or postpartum health outcomes were included. The methodological quality of reviews and the certainty of the evidence underlying each exposure-outcome association were assessed using AMSTAR 2 and the GRADE approach. RESULTS: We identified 53 eligible reviews reporting 205 unique exposure-outcome associations. Methodological quality was generally low with only two reviews rated as 'high' quality and two as 'moderate'. We found high-certainty, randomised trial evidence that maternal folate supplementation reduces the risk of neural tube defects and anomaly-related terminations. Moderate-certainty, observational evidence was found that maternal physical activity is associated with reduced risk of pre-eclampsia and gestational diabetes, and that paternal age of ≥40 years and maternal body mass index (BMI) and interpregnancy weight gain are associated with increased risk of various adverse pregnancy and birth outcomes. Low- and very low-certainty evidence was found for other associations. CONCLUSIONS: Clinicians and policymakers can be confident that maternal folate supplementation should be encouraged during the preconception period. There is moderate certainty in the evidence base that maternal physical activity, BMI and interpregnancy weight gain and advanced paternal age are important preconception considerations. High-quality research is required to better understand other exposure-outcome associations.

Women's knowledge, attitudes and views of preconception health and intervention delivery methods: a cross-sectional survey.

BACKGROUND: Several preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, few studies have investigated women's knowledge of and attitudes towards preconception health, and the acceptability of potential intervention methods. METHODS: Seven primary care centres in the West of England posted questionnaires to 4330 female patients aged 18 to 48 years. Without providing examples, we asked women to list maternal preconception exposures that might affect infant and maternal outcomes, and assessed their knowledge of nine literature-derived risk factors. Attitudes towards preconception health (interest, intentions, self-efficacy and perceived awareness and importance) and the acceptability of intervention delivery methods were also assessed. Multivariable multilevel regression examined participant characteristics associated with these outcomes. RESULTS: Of those who received questionnaires, 835 (19.3%) responded. Women were most aware of the preconception risk factors of diet (86.0%) and physical activity (79.2%). Few were aware of weight (40.1%), folic acid (32.9%), abuse (6.3%), advanced age (5.9%) and interpregnancy intervals (0.2%), and none mentioned interpregnancy weight change or excess iron intake. After adjusting for demographic and reproductive covariates, women aged 18-24-years (compared to 40-48-year-olds) and nulligravid women were less aware of the benefit of preconception folic acid supplementation (adjusted odds ratios (aOR) for age: 4.30 [2.10-8.80], gravidity: aOR 2.48 [1.70-3.62]). Younger women were more interested in learning more about preconception health (aOR 0.37 [0.21-0.63]) but nulligravid women were less interested in this (aOR 1.79 [1.30-2.46]). Women with the lowest household incomes (versus the highest) were less aware of preconception weight as a risk factor (aOR: 3.11 [1.65-5.84]) and rated the importance of preconception health lower (aOR 3.38 [1.90-6.00]). The most acceptable information delivery methods were websites/apps (99.5%), printed healthcare materials (98.6%), family/partners (96.3%), schools (94.4%), television (91.9%), pregnancy tests (91.0%) and doctors, midwives and nurses (86.8-97.0%). Dentists (23.9%) and hairdressers/beauticians (18.1%) were the least acceptable. CONCLUSIONS: Our findings demonstrate a need to promote awareness of preconception risk factors and motivation for preconception health changes, particularly amongst younger and nulligravid women and women with lower incomes. Interventions to improve preconception health should focus on communication from healthcare professionals, schools, family members, and digital media.

Parents' perceptions of children's emotional well-being during spring 2020 COVID-19 restrictions: A qualitative study with parents of young children in England.

BACKGROUND: During COVID-19 restrictions in England in spring 2020, early years settings for young children were closed to all but a small percentage of families, social contact was limited and play areas in parks were closed. Concerns were raised about the impact of these restrictions on young children's emotional well-being. The aim of this study was to explore parents' perceptions of young children's emotional well-being during these COVID-19 restrictions. METHODS: We interviewed 20 parents of children 3-4 years due to begin school in England in September 2020. Interviews were conducted via telephone (n = 18) and video call (n = 2), audio-recorded and transcribed verbatim. Interviews focused on childcare arrangements, children's behaviour and transition to school. A sample of transcripts were coded line by line to create a coding framework, which was subsequently applied to the remaining transcripts. Coded data were then analysed using a nurture lens to develop themes and further understanding. RESULTS: Participants were predominantly mothers (n = 16), White British (n = 10) and educated to degree level (n = 13), with half the sample living in the highest deprivation quintile in England (n = 10). Five were single parents. Three themes developed from nurturing principles were identified: creating age-appropriate explanations, understanding children's behaviour and concerns about school transition. Parents reported that their children's emotional well-being was impacted and described attempts to support their young children while looking ahead to their transition to primary school. CONCLUSIONS: This study is one of the first to examine in-depth perceptions of COVID-19 restrictions on young children's emotional well-being. The longer term impacts are not yet understood. Although young children may be unable to understand in detail what the virus is, they undoubtedly experience the disruption it brings to their lives. The well-being of families and children needs to be nurtured as they recover from the effects of the pandemic to allow them to thrive.

Health visiting teams and children's oral health: a scoping review.

BACKGROUND: Recent policies have recommended early-life interventions to prevent caries. The four nations of the UK each have a national universal children's health programme, through which health visitors and their wider team (HVTs) promote health in the early years. HVT visits offer an opportunity to support parents to improve their child's oral health. A scoping review was conducted to provide a descriptive synthesis of the current literature related to the role of HVTs in improving the oral health of children 0-5 years old and to identify significant gaps for future research. This review informed the feasibility study of the First Dental Steps Intervention, a targeted health visitor-led infant oral health intervention in England. METHODS: Electronic database searches for peer-reviewed literature were performed using Medline via Ovid and Web of Science (1946-2021). The quality of included intervention studies was assessed using the Effective Public Health Practice Project tool. Additionally, a grey literature search was conducted (key organisations, bibliographic and thesis databases, forwards and backwards citation, Google). RESULTS: Thirty-nine publications, published between 1980 and 2021, were included. The majority of included papers were from the UK. The quality of intervention studies (n = 7) ranged from weak to strong. Thematic analysis identified the following themes: (1) professional knowledge, education, and training; (2) involvement of HVs in the delivery of oral health interventions; (3) effectiveness of interventions; (4) perspectives of HVs providing oral health advice and acceptability; and (5) barriers and facilitators to promoting oral health. The grey literature search identified 125 sources. HVT involvement was reported in a variety of source types: reports, guidance documents, evaluations, reviews, and training resources. HVTs were involved in oral health by providing oral health packs, brushing and oral health advice, registration and attendance, oral health training, risk assessment, and referral to dental services. CONCLUSION: The current literature suggests that HVTs are well placed to improve children's oral health. Facilitators and barriers are encountered by HVTs in promoting oral health which should be considered by commissioners. There is a need for future high-quality studies that address the inadequacies found and provide further evidence of the effectiveness of HVT's oral health interventions.

Young adult cancer risk behaviours originate in adolescence: a longitudinal analysis using ALSPAC, a UK birth cohort study.

BACKGROUND: An estimated 40% of cancer cases in the UK in 2015 were attributable to cancer risk behaviours. Tobacco smoking, alcohol consumption, obesity, and unprotected sexual intercourse are known causes of cancer and there is strong evidence that physical inactivity is associated with cancer. These cancer risk behaviours co-occur however little is known about how they pattern longitudinally across adolescence and early adulthood. Using data from ALSPAC, a prospective population-based UK birth cohort study, we explored patterns of adolescent cancer risk behaviours and their associations with cancer risk behaviours in early adulthood. METHODS: Six thousand three hundred fifty-one people (46.0% of ALSPAC participants) provided data on all cancer risk behaviours at one time during adolescence, 1951 provided data on all cancer risk behaviours at all time points. Our exposure measure was quartiles of a continuous score summarising cumulative exposure to cancer risk behaviours and longitudinal latent classes summarising distinct categories of adolescents exhibiting similar patterns of behaviours, between age 11 and 18 years. Using both exposure measures, odds of harmful drinking (Alcohol Use Disorders Identification Test-C ≥ 8),daily tobacco smoking, nicotine dependence (Fagerström test ≥4), obesity (BMI ≥30), high waist circumference (females: ≥80 cm and males: ≥94 cm, and high waist-hip ratio (females: ≥0.85 and males: ≥1.00) at age 24 were estimated using logistic regression analysis. RESULTS: We found distinct groups of adolescents characterised by consistently high and consistently low engagement in cancer risk behaviours. After adjustment, adolescents in the top quartile had greater odds of all outcomes in early adulthood: nicotine dependency (odds ratio, OR = 5.37, 95% confidence interval, CI = 3.64-7.93); daily smoking (OR = 5.10, 95% CI =3.19-8.17); obesity (OR = 4.84, 95% CI = 3.33-7.03); high waist circumference (OR = 2.48, 95% CI = 1.94-3.16); harmful drinking (OR = 2.04, 95% CI = 1.57-2.65); and high waist-hip ratio (OR = 1.88, 95% CI = 1.30-2.71), compared to the bottom quartile. In latent class analysis, adolescents characterised by consistently high-risk behaviours throughout adolescence were at higher risk of all cancer risk behaviours at age 24, except harmful drinking. CONCLUSIONS: Exposure to adolescent cancer risk behaviours greatly increased the odds of cancer risk behaviours in early adulthood. Interventions to reduce these behaviours should target multiple rather than single risk behaviours and should focus on adolescence.

Effectiveness and cost-effectiveness of the PLAN-A intervention, a peer led physical activity program for adolescent girls: results of a cluster randomised controlled trial.

BACKGROUND: Physical activity is associated with improved health. Girls are less active than boys. Pilot work showed that a peer-led physical activity intervention called PLAN-A was a promising method of increasing physical activity in secondary school age girls. This study examined the effectiveness and cost-effectiveness of the PLAN-A intervention. METHODS: We conducted a cluster randomised controlled trial with Year 9 (13-14 year old) girls recruited from 20 secondary schools. Schools were randomly assigned to the PLAN-A intervention or a non-intervention control group after baseline data collection. Girls nominated students to be peer leaders. The top 18 % of girls nominated by their peers in intervention schools received three days of training designed to prepare them to support physical activity. Data were collected at two time points, baseline (T0) and 5-6 months post-intervention (T1). Participants wore an accelerometer for seven days to assess the primary outcome of mean weekday minutes of moderate-to-vigorous physical activity (MVPA). Multivariable mixed effects linear regression was used to estimate differences in the primary outcome between the two arms on an Intention-to-Treat (ITT) basis. Resource use and quality of life were measured and a within trial economic evaluation from a public sector perspective was conducted. RESULTS: A total of 1558 girls were recruited to the study. At T0, girls in both arms engaged in an average of 51 min of MVPA per weekday. The adjusted mean difference in weekday MVPA at T1 was - 2.84 min per day (95 % CI = -5.94 to 0.25) indicating a slightly larger decline in weekday MVPA in the intervention group. Results were broadly consistent when repeated using a multiple imputation approach and for pre-specified secondary outcomes and sub-groups. The mean cost of the PLAN-A intervention was £2817 per school, equivalent to £31 per girl. Economic analyses indicated that PLAN-A did not lead to demonstrable cost-effectiveness in terms of cost per unit change in QALY. CONCLUSIONS: This study has shown that the PLAN-A intervention did not result in higher levels of weekday MVPA or associated secondary outcomes among Year 9 girls. The PLAN-A intervention should not be disseminated as a public health strategy. TRIAL REGISTRATION: ISRCTN14539759 -31 May, 2018.

Where and when are portion sizes larger in young children? An analysis of eating occasion size among 1·5-5-year-olds in the UK National Diet and Nutrition Survey (2008-2017).

OBJECTIVE: To identify eating occasion-level and individual-level factors associated with the consumption of larger portions in young children and estimate their relative importance. DESIGN: Cross-sectional. SETTING: Data from parent-reported 4-d food diaries in the UK National Diet and Nutrition Survey (2008-2017) were analysed. Multilevel models explored variation in eating occasion size (kJ) within (n 48 419 occasions) and between children (n 1962) for all eating occasions. Eating contexts: location, eating companion, watching TV, and sitting at a table and individual characteristics: age, gender, ethnicity and parental socio-economic status were explored as potential correlates of eating occasion size. PARTICIPANTS: Children aged 1·5-5 years. RESULTS: Median eating occasion size was 657 kJ (IQR 356, 1117). Eating occasion size variation was primarily attributed (90 %) to differences between eating occasions. Most (73 %) eating occasions were consumed at home. In adjusted models, eating occasions in eateries were 377 kJ larger than at home. Eating occasions sitting at a table, v. not, were 197 kJ larger. Eating in childcare, with additional family members and friends, and whilst watching TV were other eating contexts associated with slightly larger eating occasion sizes. CONCLUSIONS: Eating contexts that vary from one eating occasion to another are more important than demographic characteristics that vary between children in explaining variation in consumed portion sizes in young children. Strategies to promote consumption of age-appropriate portion sizes in young children should be developed, especially in the home environment, in eating contexts such as sitting at the table, eating with others and watching TV.

Commissioner, clinician, and patient experiences of a pre-surgical health optimisation programme - a qualitative study.

BACKGROUND: Health optimisation programmes are an increasingly popular policy intervention that aim to support patients to lose weight or stop smoking ahead of surgery. There is little evidence about their impact and the experience of their use. The aim of this study was to investigate the experiences and perspectives of commissioners, clinicians and patients involved in a locality's health optimisation programme in the United Kingdom. The programme alters access to elective orthopaedic surgery for patients who smoke or are obese (body mass index ≥ 30 kg/m2), diverting them to a 12-week programme of behavioural change interventions prior to assessment for surgical referral. METHODS: A thematic analysis of semi-structured interviews (n = 20) with National Health Service and Local Authority commissioners and planners, healthcare professionals, and patients using the pathway. RESULTS: Health optimisation was broadly acceptable to professionals and patients in our sample and offered a chance to trigger both short term pre-surgical weight loss/smoking cessation and longer-term sustained changes to lifestyle intentions post-surgery. Communicating the nature and purpose of the programme to patients was challenging and consequently the quality of the explanation received and understanding gained by patients was generally low. Insight into the successful implementation of health optimisation for the hip and knee pathway, but failure in roll-out to other surgical specialities, suggests placement of health optimisation interventions into the 'usual waiting time' for surgical referral may be of greatest acceptability to professionals and patients. CONCLUSIONS: Patients and professionals supported the continuation of health optimisation in this context and recognised likely health and wellbeing benefits for a majority of patients. However, the clinicians' communication to patients about health optimisation needs to improve to prepare patients and optimise their engagement.

Multiple risk behaviour in adolescence is associated with substantial adverse health and social outcomes in early adulthood: Findings from a prospective birth cohort study.

Adolescents' engage in new behaviours such as substance use and change others, such as reducing physical activity. Risks to health from these tend to be considered separately. We examined the association between multiple risk behaviours at age 16 years and outcomes in early adulthood. 5591 young people enrolled in the Avon Longitudinal Study of Parents and Children provided data on at least one of seven adverse outcomes at age ~18 years. We used logistic regression to examine associations between total number of risk behaviours and rates of depression, anxiety, problem gambling, getting into trouble with the police, harmful drinking, obesity and not in education, employment or training (NEET) at age 18 years. We found strong associations between multiple risk behaviours and all seven adverse outcomes. For each additional risk behaviour engaged in the odds of harmful drinking increased by OR = 1.58[95%CI:1.48,1.69], getting into trouble with the police OR = 1.49[95%CI:1.42,1.57], having depression OR = 1.24[95%CI:1.17,1.31], problem gambling OR = 1.20[95%CI:1.13,1.27], NEET OR = 1.19[95%CI:1.11,1.29], anxiety OR = 1.18[95%CI:1.12,1.24] and obesity OR = 1.09[95%CI:1.03,1.15]. Neither adjustment for sex, parental socio-economic position and maternal risk behaviours, nor confining analyses to adolescents with no previous presentation of these adverse outcomes, resulted in any notable reductions in the odds ratios. Investment in interventions and environments that effectively prevent multiple risk behaviour is likely to improve a range of health outcomes in young adults.

Adolescent multiple risk behaviours cluster by number of risks rather than distinct risk profiles in the ALSPAC cohort.

BACKGROUND: Experimentation with new behaviours during adolescence is normal. However, engagement in two or more risk behaviours, termed multiple risk behaviours is associated with socioeconomic disadvantage and poor health and social outcomes. Evidence of how adolescents cluster based on their risk behaviours is mixed. METHODS: Latent Class Analysis was used to study patterns of engagement in 10 self-reported risk behaviours (including substance use, self-harm and sexual health) from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort at ages 15-16 years. Data was available for 6556 adolescents. Associations between risk profile and sex were explored. RESULTS: A 3-class model for both females and males was deemed to have acceptable fit. Whilst we found evidence of a sex difference in the risk behaviours reported within each class, the sex-specific results were very similar in many respects. For instance, the prevalence of membership of the high-risk class was 8.5% for males and 8.7% for females and both groups had an average of 5.9 behaviours. However, the classes were both statistically dubious, with class separation (entropy) being poor as well as conceptually problematic, because the resulting classes did not provide distinct profiles and varied only by quantity of risk-behaviours. CONCLUSION: Clusters of adolescents were not characterised by distinct risk behaviour profiles, and provide no additional insight for intervention strategies. Given this is a more complicated, software-specific method, we conclude that an equally effective, but more readily replicable approach is to use a count of the number of risk behaviours.

Acceptability, internal consistency and test-retest reliability of scales to assess parental and nursery staff's self-efficacy, motivation and knowledge in relation to pre-school children's nutrition, oral health and physical activity.

OBJECTIVE: To determine the acceptability, internal consistency and test-retest reliability of self-efficacy, motivation and knowledge scales relating to pre-school children's nutrition, oral health and physical activity. DESIGN: An online questionnaire was completed twice with an interval of 7-11d. SETTING: Online questionnaires were sent to participants via email from nursery managers. The parent questionnaire was also available on the parenting website www.netmums.com.ParticipantsEighty-two parents and sixty-nine nursery staff from Bristol, UK who had and worked with 2-4-year-olds, respectively. RESULTS: Response rates were 86·3 and 86·0 % and missing data 15·9 and 14·5 % for the second administration of the parent and nursery staff questionnaires, respectively. Weighted κ coefficients for individual items mostly fell under the 'moderate' agreement category for the parental (75·0 %) and nursery staff (55·8 %) items. All self-efficacy and motivation scales had acceptable levels of internal consistency (Cronbach's α coefficients>0·7). The intraclass correlation coefficients for the self-efficacy, motivation and knowledge scales ranged between 0·48 and 0·82. Paired t tests found an increase between test and retest knowledge scores for the Nutrition Motivation (t=-2·91, df=81, P=0·00) and Knowledge (t=-3·22, df=81, P=0·00) scales in the parent questionnaire. CONCLUSIONS: Our findings demonstrate that the items and scales show good acceptability, internal consistency and test-retest reliability.

Cross-sectional analysis of physical activity in 2-4-year-olds in England with paediatric quality of life and family expenditure on physical activity.

BACKGROUND: Many children do not meet the recommended level of daily physical activity, even with the widely acknowledged health benefits associated with being physically active. There is a need to establish factors related to physical activity in children so that public health interventions may be appropriately designed. We investigated the association between Pediatric Quality of Life Inventory (PedsQL), family expenditure on physical activity and objectively measured daily physical activity in 2-4-year-old children. METHODS: Cross-sectional study with a sample of 81 UK preschool children taking part in the NAPSACC UK feasibility randomized controlled trial. Descriptive statistics are presented. We undertook Student t-tests to establish differences in physical activity by gender, age, parental education and nursery versus non-nursery days. Mixed effects linear regressions were used to model the association between minutes spent physically activity, minutes spent in moderate-to-vigorous (MVPA) physical activity and PedsQL scores (physical and psychosocial) and family expenditure on physical activity. RESULTS: Most children (88.9%) did not engage in the recommended 180 min daily physical activity. There was mean (SD) of 141.9 (33.1) daily minutes of physically activity and 22.2 min per day (SD = 9.9) of MVPA. Boys and older children were more physically active. Children were more active on nursery days. There was no difference in physical activity by parental education. Half of the sample parents (50.6%) spent less than £9.00 weekly on their pre-schooler's physical activity. Children within the highest tertile of PedsQL physical functioning scores had higher levels of MVPA (3.6, 95% CI: - 1.3-8.4, p-value 0.15), although confidence intervals crossed the null in the adjusted model. We found no evidence of an association between positive PedsQL psychosocial scores, or higher parental expenditure on physical activity, with the physical activity variables. CONCLUSIONS: Children in this sample were not meeting the recommended 180 min of daily physical activity. The 2-4-year-olds were most active on nursery days. There is no evidence of an association between better PedsQL physical scores and higher levels of MVPA. There was no evidence of an association between expenditure on physical activity and time spent physically active. Further examination in larger representative datasets is needed.

Protocol for a cluster randomised controlled trial of a Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A).

BACKGROUND: Adolescent girls are less physically active than recommended for health, and levels decline further as they approach adulthood. Peers can influence adolescent girls' physical activity. Interventions capitalising on peer support could positively impact physical activity behaviour in this group. Building on promising feasibility work, the purpose of this cluster randomised controlled trial is to assess whether the Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A) increases adolescent girls' physical activity and is cost effective. METHODS: PLAN-A is a two-arm secondary school-based cluster randomised controlled trial, conducted with girls aged 13-14 years from twenty schools in the south west of England. The intervention requires participants to nominate influential girls within their year group to become peer supporters. The top 15% of girls nominated in each school receive three days of training designed to prepare them to support their peers to be more physically active during a ten-week intervention period. Data will be collected at two time points, at baseline (T0) and 5-6 months post-intervention (T1). Schools will be randomly allocated to the intervention (n = 10) or control (n = 10) arm after T0. At each time point, all consenting participants will wear an accelerometer for seven days to assess the primary outcome of mean weekday minutes of moderate-to-vigorous physical activity. Multivariable mixed effects linear regression will be used to estimate differences in the primary outcome between the two arms and will be examined on an Intention-to-Treat (ITT) basis. A self-report psychosocial questionnaire will be completed by participants to assess self-esteem and physical activity motivation. Resource use and quality of life will be measured for the purposes of an economic evaluation. A mixed-methods process evaluation will be conducted to explore intervention fidelity, acceptability and sustainability. Analysis of quantitative process evaluation data will be descriptive, and the framework method will be used to analyse qualitative data. DISCUSSION: This paper describes the protocol for the PLAN-A cluster randomised controlled trial, a novel approach to increasing adolescent girls' physical activity levels through peer support. TRIAL REGISTRATION: ISRCTN14539759-31 May, 2018.