Comparison of medical resources and costs among patients with coronary heart disease and impaired glucose tolerance in the Acarbose Cardiovascular Evaluation trial.

BACKGROUND: The Acarbose Cardiovascular Evaluation (ACE) trial (ISRCTN91899513) evaluated the alpha-glucosidase inhibitor acarbose, compared with placebo, in 6522 patients with coronary heart disease and impaired glucose tolerance in China and showed a reduced incidence of diabetes. We assessed the within-trial medical resource use and costs, and quality-adjusted life years (QALYs). METHODS: Resource use data were collected prospectively within the ACE trial. Hospitalizations, medications, and outpatient visits were valued using Chinese unit costs. Medication use was measured in drug days, with cardiovascular and diabetes drugs summed across the trial by participant. Health-related quality of life was captured using the EuroQol-5 Dimension-3 Level questionnaire. Regression analyses were used to compare resource use, costs, and QALYs, accounting for regional variation. Costs and QALYs were discounted at 3% yearly. RESULTS: Hospitalizations were 6% higher in the acarbose arm during the trial (rate ratio 1.06, p = .009), but there were no significant differences in total inpatient days (rate ratio 1.04, p = .30). Total costs per participant, including study drug, were significantly higher for acarbose (¥ [Yuan] 56 480, £6213), compared with placebo (¥48 079, £5289; mean ratio 1.18, p < 0.001). QALYs reported by participants in the acarbose arm (3.96 QALYs) were marginally higher than in the placebo arm (3.95 QALYs), but the difference was not statistically significant (0.01 QALYs; p = .58). CONCLUSIONS: Acarbose, compared with placebo, participants cost more due to study drug costs and reported no statistically significant difference in QALYs. These higher within-trial costs could potentially be offset in future by savings from the acarbose-related lower incidence of diabetes.

Lifetime cost-effectiveness simulation of once-weekly exenatide in type 2 diabetes: A cost-utility analysis based on the EXSCEL trial.

AIMS: The Exenatide Study of Cardiovascular Event Lowering (EXSCEL) trial assessed once-weekly exenatide (EQW) vs. placebo, added to usual care in 14,752 patients with type 2 diabetes mellitus (Clinicaltrials.gov: NCT01144338). We assessed the lifetime cost-effectiveness of adding EQW vs. usual care alone from a healthcare perspective. METHODS: Medical resource use and EQ-5D utilities were collected throughout the study. Within-trial results were extrapolated to a lifetime horizon using the UK Prospective Diabetes Study Outcomes Model version 2 (UKPDS-OM2), predicting predict cardiovascular and microvascular events. Cost-effectiveness was evaluated separately for US and UK settings, with outcomes measured in quality-adjusted life-years (QALYs). RESULTS: EQW plus usual care gained 0.162 QALYs at an additional cost of $41,545/patient, compared with usual care in a US setting. The incremental cost-effectiveness ratio (ICER) was $259,223/QALY. In a UK setting, the QALY gain was 0.151 at an additional cost of £6357: an ICER of £42,589/QALY. Sensitivity analyses ranged between $34,369-$269,571 and £3430-£46,560 per QALY gained. CONCLUSIONS: In a lifetime extrapolation, adding EQW to usual care increased QALYs and costs compared with usual care alone. The base-case ICERs exceeded the commonly-cited cost-effectiveness thresholds of $100,000/QALY and £20,000/QALY. However, ICERs were considerably lower in some subgroups, and in sensitivity analyses.

Economic evaluation of surgical treatments for women with stress urinary incontinence: a cost-utility and value of information analysis.

OBJECTIVES: Stress urinary incontinence (SUI) and stress-predominant mixed urinary incontinence (MUI) are common conditions that can have a negative impact on the quality of life of patients and serious cost implications for healthcare providers. The objective of this study was to assess the cost-effectiveness of nine different surgical interventions for treatment of SUI and stress-predominant MUI from a National Health Service and personal social services perspective in the UK. METHODS: A Markov microsimulation model was developed to compare the costs and effectiveness of nine surgical interventions. The model was informed by undertaking a systematic review of clinical effectiveness and network meta-analysis. The main clinical parameters in the model were the cure and incidence rates of complications after different interventions. The outcomes from the model were expressed in terms of cost per quality-adjusted life-years (QALYs) gained. In addition, expected value of perfect information (EVPI) analyses were conducted to quantify the main uncertainties facing decision-makers. RESULTS: The base-case results suggest that retropubic mid-urethral sling (retro-MUS) is the most cost-effective surgical intervention over a 10-year and lifetime time horizon. The probabilistic results show that retro-MUS and traditional sling are the interventions with the highest probability of being cost-effective across all willingness-to-pay thresholds over a lifetime time horizon. The value of information analysis results suggest that the largest value appears to be in removing uncertainty around the incidence rates of complications, the relative treatment effectiveness and health utility values. CONCLUSIONS: Although retro-MUS appears, at this stage, to be a cost-effective intervention, research is needed on possible long-term complications of all surgical treatments to provide reassurance of safety, or earlier warning of unanticipated adverse effects. The value of information analysis supports the need, as a first step, for further research to improve our knowledge of the actual incidence of complications.

Within-Trial Evaluation of Medical Resources, Costs, and Quality of Life Among Patients With Type 2 Diabetes Participating in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL).

OBJECTIVE: To compare medical resource use, costs, and health utilities for 14,752 patients with type 2 diabetes who were randomized to once-weekly exenatide (EQW) or placebo in addition to usual diabetes care in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL). RESEARCH DESIGN AND METHODS: Medical resource use data and responses to the EuroQol 5-Dimension (EQ-5D) instrument were collected at baseline and throughout the trial. Medical resources and medications were assigned values by using U.S. Medicare payments and wholesale acquisition costs, respectively. Secondary analyses used English costs. RESULTS: Patients were followed for an average of 3.3 years, during which time those randomized to EQW experienced 0.41 fewer inpatient days (7.05 vs. 7.46 days; relative rate ratio 0.91; P = 0.05). Rates of outpatient medical visits were similar, as were total inpatient and outpatient costs. Mean costs for nonstudy diabetes medications over the study period were ∼$1,600 lower with EQW than with placebo (P = 0.01). Total within-study costs, excluding study medication, were lower in the EQW arm than in the placebo arm ($28,907 vs. $30,914; P ≤ 0.01). When including the estimated cost of EQW, total mean costs were significantly higher in the EQW group than in the placebo group ($42,697 vs. $30,914; P < 0.01). With English costs applied, mean total costs, including exenatide costs, were £1,670 higher in the EQW group than the placebo group (£10,874 vs. £9,204; P < 0.01). There were no significant differences in EQ-5D health utilities between arms over time. CONCLUSIONS: Medical costs were lower in the EQW arm than the placebo arm, but total costs were significantly higher once the cost of branded exenatide was incorporated.

The Challenge of Transparency and Validation in Health Economic Decision Modelling: A View from Mount Hood.

Transparency in health economic decision modelling is important for engendering confidence in the models and in the reliability of model-based cost-effectiveness analyses. The Mount Hood Diabetes Challenge Network has taken a lead in promoting transparency through validation with biennial conferences in which diabetes modelling groups meet to compare simulated outcomes of pre-specified scenarios often based on the results of pivotal clinical trials. Model registration is a potential method for promoting transparency, while also reducing the duplication of effort. An important network initiative is the ongoing construction of a diabetes model registry (https://www.mthooddiabeteschallenge.com). Following the 2012 International Society for Pharmacoeconomics and Outcomes Research and the Society of Medical Decision Making (ISPOR-SMDM) guidelines, we recommend that modelling groups provide technical and non-technical documentation sufficient to enable model reproduction, but not necessarily provide the model code. We also request that modelling groups upload documentation on the methods and outcomes of validation efforts, and run reference case simulations so that model outcomes can be compared. In this paper, we discuss conflicting definitions of transparency in health economic modelling, and describe the ongoing development of a registry of economic models for diabetes through the Mount Hood Diabetes Challenge Network, its objectives and potential further developments, and highlight the challenges in its construction and maintenance. The support of key stakeholders such as decision-making bodies and journals is key to ensuring the success of this and other registries. In the absence of public funding, the development of a network of modellers is of huge value in enhancing transparency, whether through registries or other means.

Behavioural intervention for weight loss maintenance versus standard weight advice in adults with obesity: A randomised controlled trial in the UK (NULevel Trial).

BACKGROUND: Scalable weight loss maintenance (WLM) interventions for adults with obesity are lacking but vital for the health and economic benefits of weight loss to be fully realised. We examined the effectiveness and cost-effectiveness of a low-intensity technology-mediated behavioural intervention to support WLM in adults with obesity after clinically significant weight loss (≥5%) compared to standard lifestyle advice. METHODS AND FINDINGS: The NULevel trial was an open-label randomised controlled superiority trial in 288 adults recruited April 2014 to May 2015 with weight loss of ≥5% within the previous 12 months, from a pre-weight loss BMI of ≥30 kg/m2. Participants were self-selected, and the majority self-certified previous weight loss. We used a web-based randomisation system to assign participants to either standard lifestyle advice via newsletter (control arm) or a technology-mediated low-intensity behavioural WLM programme (intervention arm). The intervention comprised a single face-to-face goal-setting meeting, self-monitoring, and remote feedback on weight, diet, and physical activity via links embedded in short message service (SMS). All participants were provided with wirelessly connected weighing scales, but only participants in the intervention arm were instructed to weigh themselves daily and told that they would receive feedback on their weight. After 12 months, we measured the primary outcome, weight (kilograms), as well as frequency of self-weighing, objective physical activity (via accelerometry), psychological variables, and cost-effectiveness. The study was powered to detect a between-group weight difference of ±2.5 kg at follow-up. Overall, 264 participants (92%) completed the trial. Mean weight gain from baseline to 12 months was 1.8 kg (95% CI 0.5-3.1) in the intervention group (n = 131) and 1.8 kg (95% CI 0.6-3.0) in the control group (n = 133). There was no evidence of an effect on weight at 12 months (difference in adjusted mean weight change from baseline: -0.07 [95% CI 1.7 to -1.9], p = 0.9). Intervention participants weighed themselves more frequently than control participants and were more physically active. Intervention participants reported greater satisfaction with weight outcomes, more planning for dietary and physical activity goals and for managing lapses, and greater confidence for healthy eating, weight loss, and WLM. Potential limitations, such as the use of connected weighing study in both trial arms, the absence of a measurement of energy intake, and the recruitment from one region of the United Kingdom, are discussed. CONCLUSIONS: There was no difference in the WLM of participants who received the NULevel intervention compared to participants who received standard lifestyle advice via newsletter. The intervention affected some, but not all, process-related secondary outcomes of the trial. TRIAL REGISTRATION: This trial is registered with the ISRCTN registry (ISRCTN 14657176; registration date 20 March 2014).

Surgical treatments for women with stress urinary incontinence: the ESTER systematic review and economic evaluation.

BACKGROUND: Urinary incontinence in women is a distressing condition that restricts quality of life and results in a large economic burden to both the NHS and women themselves. OBJECTIVE: To evaluate the clinical effectiveness, safety and cost-effectiveness of surgical treatment for stress urinary incontinence (SUI) in women and explore women's preferences. DESIGN: An evidence synthesis, a discrete choice experiment (DCE) and an economic decision model, with a value-of-information (VOI) analysis. Nine surgical interventions were compared. Previous Cochrane reviews for each were identified and updated to include additional studies. Systematic review methods were applied. The outcomes of interest were 'cure' and 'improvement'. Both a pairwise and a network meta-analysis (NMA) were conducted for all available surgical comparisons. A DCE was undertaken to assess the preferences of women for treatment outcomes. An economic model assessed the cost-effectiveness of alternative surgeries and a VOI analysis was undertaken. RESULTS: Data from 175 studies were included in the effectiveness review. The majority of included studies were rated as being at high or unclear risk of bias across all risk-of-bias domains. The NMA, which included 120 studies that reported data on 'cure' or 'improvement', showed that retropubic mid-urethral sling (MUS), transobturator MUS, traditional sling and open colposuspension were more effective than other surgical procedures for both primary outcomes. The results for other interventions were variable. In general, rate of tape and mesh exposure was higher after transobturator MUS than after retropubic MUS or single-incision sling, whereas the rate of tape or mesh erosion/extrusion was similar between transobturator MUS and retropubic MUS. The results of the DCE, in which 789 women completed an anonymous online questionnaire, indicate that women tend to prefer surgical treatments associated with no pain or mild chronic pain and shorter length of hospital stay as well as those treatments that have a smaller risk for urinary symptoms to reoccur after surgery. The cost-effectiveness results suggest that, over a lifetime, retropubic MUS is, on average, the least costly and most effective surgery. However, the high level of uncertainty makes robust estimates difficult to ascertain. The VOI analysis highlighted that further research around the incidence rates of complications would be of most value. LIMITATIONS: Overall, the quality of the clinical evidence was low, with limited data available for the assessment of complications. Furthermore, there is a lack of robust evidence and significant uncertainty around some parameters in the economic modelling. CONCLUSIONS: To our knowledge, this is the most comprehensive assessment of published evidence for the treatment of SUI. There is some evidence that retropubic MUS, transobturator MUS and traditional sling are effective in the short to medium term and that retropubic MUS is cost-effective in the medium to long term. The VOI analysis highlights the value of further research to reduce the uncertainty around the incidence rates of complications. There is a need to obtain robust clinical data in future work, particularly around long-term complication rates. STUDY REGISTRATION: This study is registered as PROSPERO CRD42016049339. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Urinary incontinence, defined as involuntary leakage of urine, is a common condition that varies in type and severity and can have a huge impact on the quality of life of women. The aim of this project was to summarise the evidence on the clinical effectiveness, safety and cost-effectiveness of nine surgical operations for stress urinary incontinence in women and assess the need for further research. Women's preferences for surgery were also explored. Currently there is no agreement among decision-makers, doctors and patients about which of the available surgical operations is best. Based on previous Cochrane reviews, the effects and safety of each operation were systematically reviewed and analysed. Their cost-effectiveness and the value of conducting further research were also evaluated. To better understand the preference of women, an online survey containing a discrete choice experiment was conducted. Finally, patient representatives were consulted to help us to understand the consequences of the findings from a patient's perspective. The evidence on surgical operations was predominantly short to medium term (up to 12 months). This analysis found that the quality of the evidence varied, with the majority of trials being subject to high or unclear risk of bias, making the conclusions that can be drawn less robust. The findings of the clinical evidence review suggest that retropubic sling procedures, transobturator sling procedures and traditional sling procedures are more effective than other surgical procedures for both 'cure' and 'improvement' of stress urinary incontinence. The results of the economic analyses support these findings, suggesting that retropubic mid-urethral sling is the most cost-effective surgical operation. However, data on complications were lacking, limiting any strong conclusions. The results suggest that there is value in undertaking further research to reduce the uncertainty around the medium- to long-term complications of all surgical treatments and this was reflected in patients' views.

Does domiciliary welfare rights advice improve health-related quality of life in independent-living, socio-economically disadvantaged people aged ≥60 years? Randomised controlled trial, economic and process evaluations in the North East of England.

BACKGROUND: There are major socio-economic gradients in health that could be influenced by increasing personal resources. Welfare rights advice can enhance resources but has not been rigorously evaluated for health-related impacts. METHODS: Randomised, wait-list controlled trial with individual allocation, stratified by general practice, of welfare rights advice and assistance with benefit entitlements, delivered in participants' homes by trained advisors. Control was usual care. Participants were volunteers sampled from among all those aged ≥60 years registered with general practices in socio-economically deprived areas of north east England. Outcomes at 24 months were: CASP-19 score (primary), a measure of health-related quality of life; changes in income, social and physical function, and cost-effectiveness (secondary). Intention to treat analysis compared outcomes using multiple regression, with adjustment for stratification and key covariates. Qualitative interviews with purposive samples from both trial arms were thematically analysed. FINDINGS: Of 3912 individuals approached, 755 consented and were randomised (381 Intervention, 374 Control). Results refer to outcomes at 24 months, with data available on 562 (74.4%) participants. Intervention was received as intended by 335 (88%), with 84 (22%) awarded additional benefit entitlements; 46 did not receive any welfare rights advice, and none of these were awarded additional benefits. Mean CASP-19 scores were 42.9 (Intervention) and 42.4 (Control) (adjusted mean difference 0.3 [95%CI -0.8, 1.5]). There were no significant differences in secondary outcomes except Intervention participants reported receiving more care at home at 24m (53.7 (Intervention) vs 42.0 (Control) hours/week (adjusted mean difference 26.3 [95%CIs 0.8, 56.1]). Exploratory analyses did not support an intervention effect and economic evaluation suggested the intervention was unlikely to be cost-effective. Qualitative data from 50 interviews suggested there were improvements in quality of life among those receiving additional benefits. CONCLUSIONS: We found no effects on health outcomes; fewer participants than anticipated received additional benefit entitlements, and participants were more affluent than expected. Our findings do not support delivery of domiciliary welfare rights advice to achieve the health outcomes assessed in this population. However, better intervention targeting may reveal worthwhile health impacts.

Women's preferences for alternative financial incentive schemes for breastfeeding: A discrete choice experiment.

BACKGROUND: Increasing breastfeeding rates have been associated with reductions in disease in babies and mothers as well as in related costs. 'Nourishing Start for Health (NoSH)', a financial incentive scheme has been proposed as a potentially effective way to increase both the number of mothers breastfeeding and duration of breastfeeding. AIMS: To establish women's relative preferences for different aspects of a financial incentive scheme for breastfeeding and to identify importance of scheme characteristics on probability on participation in an incentive scheme. METHODS: A discrete choice experiment (DCE) obtained information on alternative specifications of the NoSH scheme designed to promote continued breastfeeding duration until at least 6 weeks after birth. Four attributes framed alternative scheme designs: value of the incentive; minimum breastfeeding duration required to receive incentive; method of verifying breastfeeding; type of incentive. Three versions of the DCE questionnaire, each containing 8 different choice sets, provided 24 choice sets for analysis. The questionnaire was mailed to 2,531 women in the South Yorkshire Cohort (SYC) aged 16-45 years in IMD quintiles 3-5. The analytic approach considered conditional and mixed effects logistic models to account for preference heterogeneity that may be associated with a variation in effects mediated by respondents' characteristics. RESULTS: 564 women completed the questionnaire and a response rate of 22% was achieved. Most of the included attributes were found to affect utility and therefore the probability to participate in the incentive scheme. Higher rewards were preferred, although the type of incentive significantly affected women's preferences on average. We found evidence for preference heterogeneity based on individual characteristics that mediated preferences for an incentive scheme.Conclusions Although participants' opinion in our sample was mixed, financial incentives for breastfeeding may be an acceptable and effective instrument to change behaviour. However, individual characteristics could mediate the effect and should therefore be considered when developing and targeting future interventions.

Parental Preferences for the Organization of Preschool Vaccination Programs Including Financial Incentives: A Discrete Choice Experiment.

Objective: To establish preferences of parents and guardians of preschool children for the organization of preschool vaccination services, including financial incentives. Design: An online discrete choice experiment. Participants: Parents and guardians of preschool children (up to age 5 years) who were (n = 259) and were not (n = 262) classified as at high risk of incompletely vaccinating their children. High risk of incomplete vaccination was defined as any of the following: aged less than 20 years, single parents, living in one of the 20% most deprived areas in England, had a preschool child with a disability, or had more than three children. Main Outcome Measures: Participant preferences expressed as positive (utility) or negative (disutility) on eight attributes and levels describing the organization of preschool vaccination programs. Results: There was no difference in preference for parental financial incentives compared to no incentive in parents "not at high risk" of incomplete vaccination. Parents who were "at high risk" expressed utility for cash incentives. Parents "at high risk" of incomplete vaccination expressed utility for information on the risks and benefits of vaccinations to be provided as numbers rather than charts or pictures. Both groups preferred universally available, rather than targeted, incentives. Utility was identified for shorter waiting times, and there were variable preferences for who delivered vaccinations. Conclusions: Cash incentives for preschool vaccinations in England would be welcomed by parents who are "at high risk" of incompletely vaccinating their children. Further work is required on the optimal mode and form of presenting probabilistic information on vaccination to parents/guardians, including preferences on mandatory vaccination schemes.

Acceptability of Financial Incentives for Health Behaviours: A Discrete Choice Experiment.

BACKGROUND: Healthy behaviours are important determinants of health and disease, but many people find it difficult to perform these behaviours. Systematic reviews support the use of personal financial incentives to encourage healthy behaviours. There is concern that financial incentives may be unacceptable to the public, those delivering services and policymakers, but this has been poorly studied. Without widespread acceptability, financial incentives are unlikely to be widely implemented. We sought to answer two questions: what are the relative preferences of UK adults for attributes of financial incentives for healthy behaviours? Do preferences vary according to the respondents' socio-demographic characteristics? METHODS: We conducted an online discrete choice experiment. Participants were adult members of a market research panel living in the UK selected using quota sampling. Preferences were examined for financial incentives for: smoking cessation, regular physical activity, attendance for vaccination, and attendance for screening. Attributes of interest (and their levels) were: type of incentive (none, cash, shopping vouchers or lottery tickets); value of incentive (a continuous variable); schedule of incentive (same value each week, or value increases as behaviour change is sustained); other information provided (none, written information, face-to-face discussion, or both); and recipients (all eligible individuals, people living in low-income households, or pregnant women). RESULTS: Cash or shopping voucher incentives were preferred as much as, or more than, no incentive in all cases. Lower value incentives and those offered to all eligible individuals were preferred. Preferences for additional information provided alongside incentives varied between behaviours. Younger participants and men were more likely to prefer incentives. There were no clear differences in preference according to educational attainment. CONCLUSIONS: Cash or shopping voucher-type financial incentives for healthy behaviours are not necessarily less acceptable than no incentives to UK adults.

Effectiveness and acceptability of parental financial incentives and quasi-mandatory schemes for increasing uptake of vaccinations in preschool children: systematic review, qualitative study and discrete choice experiment.

BACKGROUND: Uptake of preschool vaccinations is less than optimal. Financial incentives and quasi-mandatory policies (restricting access to child care or educational settings to fully vaccinated children) have been used to increase uptake internationally, but not in the UK. OBJECTIVE: To provide evidence on the effectiveness, acceptability and economic costs and consequences of parental financial incentives and quasi-mandatory schemes for increasing the uptake of preschool vaccinations. DESIGN: Systematic review, qualitative study and discrete choice experiment (DCE) with questionnaire. SETTING: Community, health and education settings in England. PARTICIPANTS: Qualitative study - parents and carers of preschool children, health and educational professionals. DCE - parents and carers of preschool children identified as 'at high risk' and 'not at high risk' of incompletely vaccinating their children. DATA SOURCES: Qualitative study - focus groups and individual interviews. DCE - online questionnaire. REVIEW METHODS: The review included studies exploring the effectiveness, acceptability or economic costs and consequences of interventions that offered contingent rewards or penalties with real material value for preschool vaccinations, or quasi-mandatory schemes that restricted access to 'universal' services, compared with usual care or no intervention. Electronic database, reference and citation searches were conducted. RESULTS: Systematic review - there was insufficient evidence to conclude that the interventions considered are effective. There was some evidence that the quasi-mandatory interventions were acceptable. There was insufficient evidence to draw conclusions on economic costs and consequences. Qualitative study - there was little appetite for parental financial incentives. Quasi-mandatory schemes were more acceptable. Optimising current services was consistently preferred to the interventions proposed. DCE and questionnaire - universal parental financial incentives were preferred to quasi-mandatory interventions, which were preferred to targeted incentives. Those reporting that they would need an incentive to vaccinate their children completely required around £110. Those who did not felt that the maximum acceptable incentive was around £70. LIMITATIONS: Systematic review - a number of relevant studies were excluded as they did not meet the study design inclusion criteria. Qualitative study - few partially and non-vaccinating parents were recruited. DCE and questionnaire - data were from a convenience sample. CONCLUSIONS: There is little current evidence on the effectiveness or economic costs and consequences of parental financial incentives and quasi-mandatory interventions for preschool vaccinations. Universal incentives are likely to be more acceptable than targeted ones. Preferences concerning incentives versus quasi-mandatory interventions may depend on the context in which these are elicited. FUTURE WORK: Further evidence is required on (i) the effectiveness and optimal configuration of parental financial incentive and quasi-mandatory interventions for preschool vaccinations - if effectiveness is confirmed, further evidence is required on how to communicate this to stakeholders and the impact on acceptability; and (ii) the acceptability of parental financial incentive and quasi-mandatory interventions for preschool vaccinations to members of the population who are not parents of preschool children or relevant health professionals. Further consideration should be given to (i) incorporating reasons for non-vaccination into new interventions for promoting vaccination uptake; and (ii) how existing services can be optimised. STUDY REGISTRATION: This study is registered as PROSPERO CRD42012003192. FUNDING: The National Institute for Health Research Health Technology Assessment programme.