Colin Green

University of Exeter, Exeter, England, United Kingdom

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Publications (9)120.32 Total impact

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    ABSTRACT: Challenges remain to find ways to support patients with depression who have low levels of physical activity (PA) to overcome perceived barriers and enhance the perceived value of PA for preventing future relapse. There is an evidence-base for behavioural activation (BA) for depression, which focuses on supporting patients to restore activities that have been avoided, but practitioners have no specific training in promoting PA. We aimed to design and evaluate an integrated BA and PA (BAcPAc) practitioner-led, written, self-help intervention to enhance both physical and mental health.Methods/design: This study is informed by the Medical Research Council Complex Intervention Framework and describes a protocol for a pilot phase II randomised controlled trial (RCT) to test the feasibility and acceptability of the trial methods to inform a definitive phase III RCT. Following development of the augmented written self-help intervention (BAcPAc) incorporating behavioural activation with physical activity promotion, depressed adults are randomised to receive up to 12 sessions over a maximum of 4 months of either BAcPAc or behavioural activation alone within a written self-help format, which represents treatment as usual. The study is located within two 'Improving Access to Psychological Therapies' services in South West England, with both written self-help interventions supported by mental health paraprofessionals. Measures assessed at 4, 9, and 12 month follow-up include the following: CIS-R, PHQ-9, accelerometer recorded (4 months only) and self-reported PA, body mass index, blood pressure, Insomnia Severity Index, quality of life, and health and social care service use. Process evaluation will include analysis of recorded support sessions and patient and practitioner interviews. At the time of writing the study has recruited 60 patients.
    Trials. 05/2014; 15(1):196.
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    ABSTRACT: BACKGROUND: Over the last three decades there has been a substantial increase in the proportion of children who are overweight or obese. The Healthy Lifestyles Programme (HeLP) is a novel school-based intervention, using highly interactive and creative delivery methods to prevent obesity in children. METHODS: We describe a cluster randomised controlled trial to evaluate the effectiveness and cost effectiveness of HeLP. The intervention has been developed using intervention mapping (involving extensive stakeholder involvement) and has been guided by the Information, Motivation, Behavioural Skills model. HeLP includes creating a receptive environment, drama activities, goal setting and reinforcement activities and runs over three school terms. Piloting showed that 9 to 10 year olds were the most receptive and participative. This study aims to recruit 1,300 children from 32 schools (over half of which will have >=19% of pupils eligible for free school meals) from the southwest of England. Participating schools will be randomised to intervention or control groups with baseline measures taken prior to randomisation. The primary outcome is change in body mass index standard deviation score (BMI SDS) at 24 months post baseline. Secondary outcomes include, waist circumference and percent body fat SDS and proportion of children classified as overweight or obese at 18 and 24 months and objectively measured physical activity and food intake at 18 months. Between-group comparisons will be made using random effects regression analysis taking into account the hierarchical nature of the study design. An economic evaluation will estimate the incremental cost-effectiveness of HeLP, compared to control, from the perspective of the National Health Service (NHS)/third party payer. An in-depth process evaluation will provide insight into how HeLP works, and whether there is any differential uptake or engagement with the programme. DISCUSSION: The results of the trial will provide evidence on the effectiveness and cost effectiveness of the Healthy Lifestyles Programme in affecting the weight status of children.Trial registration: ISRCTN15811706.
    Trials 04/2013; 14(1):95. · 2.21 Impact Factor
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    ABSTRACT: Diagnosis of Alzheimers disease (AD) is often difficult, especially early in the disease process at the stage of mild cognitive impairment (MCI). Yet, it is at this stage that treatment is most likely to be effective, so there would be great advantages in improving the diagnosis process. We describe and test a machine learning approach for personalized and cost-effective diagnosis of AD. It uses locally weighted learning to tailor a classifier model to each patient and computes the sequence of biomarkers most informative or cost-effective to diagnose patients. Using ADNI data, we classified AD vs. controls and MCI patients who progressed to AD within a year, against those who did not. The approach performed similarly to considering all data at once, while significantly reducing the number (and cost) of the biomarkers needed to achieve a confident diagnosis for each patient. Thus, it may contribute to a personalized and effective detection of AD, and may prove useful in clinical settings.
    IEEE transactions on bio-medical engineering 08/2012; · 2.15 Impact Factor
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    ABSTRACT: PURPOSE: Attention-deficit hyperactivity disorder (ADHD) is associated with increased use of health, social and education services. There is a lack of data to quantify the economic burden of ADHD in the UK. The aim of this study was to estimate additional education, health and social care costs amongst adolescents in the UK diagnosed with ADHD. METHODS: Participants were 143, 12- to 18-year-olds from the Cardiff longitudinal ADHD study. Service use relating to mental health over the previous year was measured using the children's service interview. Individual resource use was combined with unit cost data, from national sources, to calculate costs per patient and subsequently the mean cost per patient. Mean costs, 95 % confidence intervals and median use were calculated using nonparametric bootstrapping methods. RESULTS: The mean cost per adolescent for NHS, social care and education resources used in a 12-month period related to ADHD was £5,493 (£4,415.68, £6,678.61) in 2010 prices and the median was £2,327. Education and NHS resources accounted for approximately 76 and 24 %, respectively. Estimated annual total UK costs are £670 million. CONCLUSIONS: The additional costs to the NHS and education system of treating adolescents remain substantial for several years after the initial ADHD diagnosis. There exists a need to develop and evaluate early interventions which have the potential to reduce the longer-term burden, particularly on education resource use.
    Social Psychiatry 06/2012; · 2.05 Impact Factor
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    ABSTRACT: Walking impairment has a major influence on the quality of life of people with multiple sclerosis (MS). The Multiple Sclerosis Walking Scale (MSWS-12) assesses the impact of MS on walking ability from the patient's perspective, but in its current form, is not amenable for use in many policy decision-making settings. Statistical 'mapping' methods were used to convert MSWS-12 scores to EQ-5D health state values. The relationship between the measures was estimated using cohort data from people with MS in South West England. Regression analyses were conducted, estimation errors assessed, and predictive performance of the best models tested using longitudinal data. Model performance was in line with that of other mapping studies, with the best-performing models being an ordinary least squares (OLS) model using MSWS-12 item scores, and an OLS model using the total MSWS-12 score and its squared term. A process has been described whereby data from a patient-reported outcome measure (MSWS-12) can be converted to (EQ-5D) health state values. These values may be used to consider the health-related quality of life of people with MS, to estimate quality adjusted life-years for use in effectiveness and cost-effectiveness analyses, and to inform health policy decisions.
    Multiple Sclerosis 11/2011; 18(6):853-61. · 4.47 Impact Factor
  • BMJ Clinical Research 01/2010; 341(7768). · 14.09 Impact Factor
  • BMJ (online) 01/2010; 341:c4286. · 17.22 Impact Factor
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    ABSTRACT: Background Childhood overweight and obesity is a major public health priority. Overweight or obese children are likely to become overweight or obese adults, are likely to be at increased risk of a wide range of chronic diseases (eg, type 2 diabetes, cardiovascular disease, and some cancers), and can have broader effects on lifestyle, health, and wellbeing compared with their peers. A clear need exists for cost-effective interventions or programmes that can help with the problems associated with childhood obesity. However, the conduct of cost-effectiveness analyses (and health technology assessment more broadly) in childhood obesity presents challenges. Translation of measures of effectiveness, for example body-mass index, into the potential effects of interventions on future health outcomes, such as prevention of diabetes, is one such challenge. The current methods available to model future outcomes in this way are limited. We aimed to develop a decision-analytic model to estimate the effect of interventions aimed at childhood overweight and obesity, for use in cost-effectiveness analyses in a public health context.Methods We developed a decision-analytic modelling framework using a simple model structure (in the first instance) consisting of three stages: prediction of adult weight status (healthy, overweight, or obese) from childhood weight status; prediction of obesity-related disease or events in adult years (type 2 diabetes, coronary heart disease, stroke, and colorectal cancer); and estimation of the effects of interventions for childhood obesity on prevention of these future events. The model was developed with longitudinal data for the 1958 UK birth cohort in which participants were followed up between ages 11 and 33 years, applying UK90 growth reference standards. Incidence rates for obesity-related health events were calculated on the basis of a 2009 systematic review and meta-analysis. The model was applied to a case study with data from an exploratory trial of a novel, drama-based, school-located obesity intervention, the Healthy Lifestyles Programme (HeLP), to present an example of the potential use of the model in a public health setting. HeLP was delivered to children aged 9–10 years during three school terms, and aimed to deliver a general healthy lifestyle message, seeking to change behaviours in the family, at school, and individually. Three key behaviours were emphasised: decrease in consumption of sweetened fizzy drinks, increase in proportion of healthy snacks to unhealthy snacks, and a reduction in television viewing and other screen-based activities. The empirical or mechanistic element of the model, prediction of adult weight status, was a major challenge, and sensitivity analyses explore the effect of the use of different sources of longitudinal data for prediction of adult weight status.FindingsIn a base-case scenario with a typical control cohort of 1000 children aged 11 years, the model predicted adult weight status at age 33 years, and thereafter an expected minimum of 274 health events (mainly coronary heart disease and type 2 diabetes) in this cohort between age 33 and 63 years (30 year time horizon). The model was used to estimate the expected effect of the HeLP intervention (a change in the distribution of weight status at age 11 years) on the expected number of health events over time, compared with standard practice and applying a third party payer (National Health Service or Personal Social Services) perspective. Outputs from the model can be used to estimate cost-effectiveness based on various input measures and assumptions. The sensitivity of judgments on cost effectiveness to different structural and data inputs were considered.InterpretationFindings suggest a reduction in future obesity-related health effects even when interventions are used in a broad public health context, and when average population effects are small. The model developed for use in cost-effectiveness analyses is a simple first stage, and the parsimonious nature of the model is subject to obvious limitations, but its potential usefulness in a public health decision making context is promising.FundingNIHR Research for Patient Benefit Programme; PenCLAHRC, the NIHR CLAHRC for the Southwest Peninsula.
    The Lancet 380:S43. · 39.06 Impact Factor
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    ABSTRACT: Background Helping smokers from disadvantaged backgrounds to reduce their smoking could result in more quit attempts and successful quitting, which in turn could help to tackle health inequalities. No study has assessed the effects of exercise counselling (delivered by health trainers) on smoking reduction and quitting, among hard-to-reach smokers. We aimed to assess recruitment methods in a trial targeting hard-to-reach smokers who wished to reduce but not quit smoking, without using nicotine replacement therapy.Methods The Exercise Assisted Reduction then Stop (EARS) pilot randomised trial was set up to examine the feasibility and acceptability of trial methods and 8-week intervention, with follow-up assessments up to 16 weeks, and primary outcome being 4-week post-quit abstinence confirmed by expired air CO. Patients were allocated to treatment or usual care (advice to quit) with a password protected web-based randomisation system set up and managed by the UK Clinical Research Collaboration's accredited Peninsula Clinical Trials Unit. Randomisation was 1:1 and minimised by age, sex, health trainer (one of three), and smoking dependence level. To maintain concealment, the minimisation algorithm retained a stochastic element. Follow-up assessments were done by a researcher who also provided the intervention (for those receiving exercise assisted reduction), and were therefore not masked to treatment. This method was used to maximise data collection within a hard-to-reach population. We focused recruitment on individuals from two socially deprived wards in Plymouth (ie, in the top 3% most deprived areas in England). Three main approaches were tested: invitation letter (and reminder note plus phone calls) to known smokers without contraindications to do moderate physical activity, through (1) primary care, or (2) stop smoking services (SSS; targeting failed quitters in the previous 2 years); or (3) other community-based approaches such as audio and written media, posters, third-sector networking (eg, housing trusts), opportunistic recruitment (eg, outside job centre), workplaces with high proportion of low-skilled employees, and attending local events and centres. We compared recruitment rates through each of the three settings. For non-normally distributed data we present medians and IQRs.FindingsWe recruited 99 smokers (between May, 2011, and May, 2012), of whom 46 (46%) were unemployed and 45 (45%) in social class C2–E, and 41 (41%) were moderately or extremely anxious or depressed (from item 5 of EQ-5D). The sample had a mean age of 47·2 years (SD 11·3), median school leaving age of 16·0 years (IQR 15·0–16·0), initial smoking age of 14 years (13·0–16·0) years, equivalent cigarettes smoked per day of 19·1 (14·4–24·4), and a mean Fagerstrom test for nicotine dependence score of 5·6 (SD 2·1). Recruitment resulting from invitation letters from GPs and SSS were similar and ranged from 5·1–11·1% depending on the effort invested in follow-up phone calls. Overall, 62 (63%) participants were randomly assigned from GP invitations and 31 (31%) from SSS invitations. Despite substantial effort, only six (6%) of the total sample were recruited via other community approaches. Those recruited via primary care and SSS did not differ in any background variable, and we had insufficient data from other community approaches for comparison.InterpretationWe matched our targets for recruiting hard-to-reach smokers into a randomised trial, and identified the probable recruitment rates for three different approaches. The most effective approach was by mailed invitation letter, with follow-up phone calls roughly doubling the recruitment rate, but with considerable additional effort. Data captured in the pilot study will establish whether recruitment approach was related to study retention and effects of the intervention.FundingNational Institute for Health Research (Health Technology Assessment) in the UK, SmokeFree South West, and Plymouth Primary Care Trust.
    The Lancet 380:S73. · 39.06 Impact Factor