Cost-Effectiveness and Value of Information Analysis of Brief Interventions to Promote Physical Activity in Primary Care

How has the COVID-19 pandemic affected the delivery of preventive healthcare? An interrupted time series analysis of adults in English primary care from 2018 to 2022

OBJECTIVE

Offering advice and support for smoking, obesity, excess alcohol, and physical inactivity is an evidence-based component of primary care. The objective was to quantify the impact of the pandemic on the rate of advice or referral for these four risk factors.

METHODS

A retrospective cohort study using primary care data from 1847 practices in England and 21,191,389 patients contributing to the Oxford Clinical Informatics Digital Hub. An interrupted time series analysis was undertaken with a single change point (March 2020). Monthly trends were modelled from 1st January 2018 - 30th June 2022 using segmented linear regression.

RESULTS

There was an initial step reduction in advice and referrals for smoking, obesity, excess alcohol, and physical inactivity in March 2020. By June 2022, advice on smoking (slope change -0.02 events per hundred patient years/month (EPH/month); 95% confidence interval (CI) -0.17, 0.21), obesity (0.06 EPH/month; 95% CI 0.01, 0.12), alcohol (0.02 EPH/month; 95% CI -0.01, 0.05) and physical inactivity (0.05 EPH/month; 95% CI 0.01, 0.09) had not returned to pre-pandemic levels. Similarly, smoking cessation referral remained lower (0.01 EPH/month; 95% CI -0.01, 0.09), excess alcohol referral returned to similar levels (0.0005 EPH/month; 95% CI 0.0002, 0.0008), while referral for obesity (0.14 EPH/month; 95% CI 0.10, 0.19) and physical inactivity (0.01 EPH/month; 95% CI 0.01, 0.02) increased relative to pre-pandemic rates.

CONCLUSION

Advice and support for smoking, and advice for weight, excess alcohol and physical inactivity have not returned to pre-pandemic levels. Clinicians and policy makers should prioritise preventive care in COVID-19 recovery plans.

A multicomponent intervention to reduce daily sitting time in office workers: the SMART Work & Life three-arm cluster RCT

Background

Office workers spend 70-85% of their time at work sitting. High levels of sitting have been linked to poor physiological and psychological health. Evidence shows the need for fully powered randomised controlled trials, with long-term follow-up, to test the effectiveness of interventions to reduce sitting time.

Objective

Our objective was to test the clinical effectiveness and cost-effectiveness of the SMART Work & Life intervention, delivered with and without a height-adjustable workstation, compared with usual practice at 12-month follow-up.

Design

A three-arm cluster randomised controlled trial.

Setting

Councils in England.

Participants

Office workers.

Intervention

SMART Work & Life is a multicomponent intervention that includes behaviour change strategies, delivered by workplace champions. Clusters were randomised to (1) the SMART Work & Life intervention, (2) the SMART Work & Life intervention with a height-adjustable workstation (i.e. SMART Work & Life plus desk) or (3) a control group (i.e. usual practice). Outcome measures were assessed at baseline and at 3 and 12 months.

Main outcome measures

The primary outcome was device-assessed daily sitting time compared with usual practice at 12 months. Secondary outcomes included sitting, standing, stepping time, physical activity, adiposity, blood pressure, biochemical measures, musculoskeletal issues, psychosocial variables, work-related health, diet and sleep. Cost-effectiveness and process evaluation data were collected.

Results

A total of 78 clusters (756 participants) were randomised [control, 26 clusters (n = 267); SMART Work & Life only, 27 clusters (n = 249); SMART Work & Life plus desk, 25 clusters (n = 240)]. At 12 months, significant differences between groups were found in daily sitting time, with participants in the SMART Work & Life-only and SMART Work & Life plus desk arms sitting 22.2 minutes per day (97.5% confidence interval -38.8 to -5.7 minutes/day; p = 0.003) and 63.7 minutes per day (97.5% confidence interval -80.0 to -47.4 minutes/day; p < 0.001), respectively, less than the control group. Participants in the SMART Work & Life plus desk arm sat 41.7 minutes per day (95% confidence interval -56.3 to -27.0 minutes/day; p < 0.001) less than participants in the SMART Work & Life-only arm. Sitting time was largely replaced by standing time, and changes in daily behaviour were driven by changes during work hours on workdays. Behaviour changes observed at 12 months were similar to 3 months. At 12 months, small improvements were seen for stress, well-being and vigour in both intervention groups, and for pain in the lower extremity and social norms in the SMART Work & Life plus desk group. Results from the process evaluation supported these findings, with participants reporting feeling more energised, alert, focused and productive. The process evaluation also showed that participants viewed the intervention positively; however, the extent of engagement varied across clusters. The average cost of SMART Work & Life only and SMART Work & Life plus desk was £80.59 and £228.31 per participant, respectively. Within trial, SMART Work & Life only had an incremental cost-effectiveness ratio of £12,091 per quality-adjusted life-year, with SMART Work & Life plus desk being dominated. Over a lifetime, SMART Work & Life only and SMART Work & Life plus desk had incremental cost-effectiveness ratios of £4985 and £13,378 per quality-adjusted life-year, respectively.

Limitations

The study was carried out in one sector, limiting generalisability.

Conclusions

The SMART Work & Life intervention, provided with and without a height-adjustable workstation, was successful in changing sitting time.

Future work

There is a need for longer-term follow-up, as well as follow-up within different organisations.

Trial registration

Current Controlled Trials ISRCTN11618007.

Cost-utility analysis of a supervised exercise intervention for women with early-stage endometrial cancer

PURPOSE

Cardiovascular disease (CVD) is the leading cause of death after treatment for endometrial cancer (EC). There is clinical evidence that exercise significantly reduces the risks of CVD and cancer recurrence in this population; however, it is unclear whether there is value for money in integrating exercise into cancer recovery care for women treated for EC. This paper assesses the long-term cost-effectiveness of a 12-week supervised exercise intervention, as compared with standard care, for women diagnosed with early-stage EC.

METHOD

A cost-utility analysis was conducted from the Australian health system perspective for a time horizon of 5 years. A Markov cohort model was designed with six mutually exclusive health states: (i) no CVD, (ii) post-stroke, (iii) post-coronary heart disease (CHD), (iv) post-heart failure, (v) post-cancer recurrence, and (vi) death. The model was populated using the best available evidence. Costs and quality-adjusted life years (QALYs) were discounted at 5% annual rate. Uncertainty in the results was explored using one-way and probabilistic sensitivity analyses (PSA).

RESULT

The incremental cost of supervised exercise versus standard care was AUD $358, and the incremental QALY was 0.0789, resulting in an incremental cost-effectiveness ratio (ICER) of AUD $5184 per QALY gained. The likelihood that the supervised exercise intervention was cost-effective at a willingness-to-pay threshold of AUD $50,000 per QALY was 99.5%.

CONCLUSION

This is the first economic evaluation of exercise after treatment for EC. The results suggest that exercise is cost-effective for Australian EC survivors. Given the compelling evidence, efforts could now focus on the implementation of exercise as part of cancer recovery care in Australia.

The Cost-Effectiveness of the SMART Work & Life Intervention for Reducing Sitting Time

Sedentary behaviours continue to increase and are associated with heightened risks of morbidity and mortality. We assessed the cost-effectiveness of SMART Work & Life (SWAL), an intervention designed to reduce sitting time inside and outside of work, both with (SWAL-desk) and without (SWAL-only) a height-adjustable workstation compared to usual practice (control) for UK office workers. Health outcomes were assessed in quality-adjusted life-years (QALY) and costs in pound sterling (2019-2020). Discounted costs and QALYs were estimated using regression methods with multiply imputed data from the SMART Work & Life trial. Absenteeism, productivity and wellbeing measures were also evaluated. The average cost of SWAL-desk was £228.31 and SWAL-only £80.59 per office worker. Within the trial, SWAL-only was more effective and costly compared to control (incremental cost-effectiveness ratio (ICER): £12,091 per QALY) while SWAL-desk was dominated (least effective and most costly). However, over a lifetime horizon, both SWAL-only and SWAL-desk were more effective and more costly than control. Comparing SWAL-only to control generated an ICER of £4985 per QALY. SWAL-desk was more effective and costly than SWAL-only, generating an ICER of £13,378 per QALY. Findings were sensitive to various worker, intervention, and extrapolation-related factors. Based on a lifetime horizon, SWAL interventions appear cost-effective for office-workers conditional on worker characteristics, intervention cost and longer-term maintenance in sitting time reductions.

Content of physical activity documentation in Canadian family physicians' electronic medical records

The purpose of this study was to examine the content of physical activity inputs in Canadian family physician electronic medical records. Of 1 225 948 patients aged 18-64 years, a sample of 1535 patients' charts were reviewed. A minority (n = 148; 9.6%) of patients had at least 1 mention of physical activity at any time. Insufficient information existed to determine physical activity domain (21.6%), purpose (50.0%), or meeting of guidelines (98.1%). Novelty: This study examines the physical activity content of what Canadian family physicians document in their electronic medical records.

Behavioural interventions to promote physical activity in a multiethnic population at high risk of diabetes: PROPELS three-arm RCT

BACKGROUND

Type 2 diabetes is a leading cause of mortality globally and accounts for significant health resource expenditure. Increased physical activity can reduce the risk of diabetes. However, the longer-term clinical effectiveness and cost-effectiveness of physical activity interventions in those at high risk of type 2 diabetes is unknown.

OBJECTIVES

To investigate whether or not Walking Away from Diabetes (Walking Away) - a low-resource, 3-hour group-based behavioural intervention designed to promote physical activity through pedometer use in those with prediabetes - leads to sustained increases in physical activity when delivered with and without an integrated mobile health intervention compared with control.

DESIGN

Three-arm, parallel-group, pragmatic, superiority randomised controlled trial with follow-up conducted at 12 and 48 months.

SETTING

Primary care and the community.

PARTICIPANTS

Adults whose primary care record included a prediabetic blood glucose measurement recorded within the past 5 years [HbA_1c ≥ 42 mmol/mol (6.0%), < 48 mmol/mol (6.5%) mmol/mol; fasting glucose ≥ 5.5 mmol/l, < 7.0 mmol/l; or 2-hour post-challenge glucose ≥ 7.8 mmol/l, < 11.1 mmol/l] were recruited between December 2013 and February 2015. Data collection was completed in July 2019.

INTERVENTIONS

Participants were randomised (1 : 1 : 1) using a web-based tool to (1) control (information leaflet), (2) Walking Away with annual group-based support or (3) Walking Away Plus (comprising Walking Away, annual group-based support and a mobile health intervention that provided automated, individually tailored text messages to prompt pedometer use and goal-setting and provide feedback, in addition to biannual telephone calls). Participants and data collectors were not blinded; however, the staff who processed the accelerometer data were blinded to allocation.

MAIN OUTCOME MEASURES

The primary outcome was accelerometer-measured ambulatory activity (steps per day) at 48 months. Other objective and self-reported measures of physical activity were also assessed.

RESULTS

A total of 1366 individuals were randomised (median age 61 years, median body mass index 28.4 kg/m², median ambulatory activity 6638 steps per day, women 49%, black and minority ethnicity 28%). Accelerometer data were available for 1017 (74%) and 993 (73%) individuals at 12 and 48 months, respectively. The primary outcome assessment at 48 months found no differences in ambulatory activity compared with control in either group (Walking Away Plus: 121 steps per day, 97.5% confidence interval -290 to 532 steps per day; Walking Away: 91 steps per day, 97.5% confidence interval -282 to 463). This was consistent across ethnic groups. At the intermediate 12-month assessment, the Walking Away Plus group had increased their ambulatory activity by 547 (97.5% confidence interval 211 to 882) steps per day compared with control and were 1.61 (97.5% confidence interval 1.05 to 2.45) times more likely to achieve 150 minutes per week of objectively assessed unbouted moderate to vigorous physical activity. In the Walking Away group, there were no differences compared with control at 12 months. Secondary anthropometric, biomechanical and mental health outcomes were unaltered in either intervention study arm compared with control at 12 or 48 months, with the exception of small, but sustained, reductions in body weight in the Walking Away study arm (≈ 1 kg) at the 12- and 48-month follow-ups. Lifetime cost-effectiveness modelling suggested that usual care had the highest probability of being cost-effective at a threshold of £20,000 per quality-adjusted life-year. Of 50 serious adverse events, only one (myocardial infarction) was deemed possibly related to the intervention and led to the withdrawal of the participant from the study.

LIMITATIONS

Loss to follow-up, although the results were unaltered when missing data were replaced using multiple imputation.

CONCLUSIONS

Combining a physical activity intervention with text messaging and telephone support resulted in modest, but clinically meaningful, changes in physical activity at 12 months, but the changes were not sustained at 48 months.

FUTURE WORK

Future research is needed to investigate which intervention types, components and features can help to maintain physical activity behaviour change over the longer term.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN83465245.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 77. See the NIHR Journals Library website for further project information.

Prescribing Smartphone Apps for Physical Activity Promotion in Primary Care: Modeling Study of Health Gain and Cost Savings

Background

Inadequate physical activity is a substantial cause of health loss worldwide, and this loss is attributable to diseases such as coronary heart disease, diabetes, stroke, and certain forms of cancer.

Objective

This study aims to assess the potential impact of the prescription of smartphone apps in primary care settings on physical activity levels, health gains (in quality-adjusted life years [QALYs]), and health system costs in New Zealand (NZ).

Methods

A proportional multistate lifetable model was used to estimate the change in physical activity levels and predict the resultant health gains in QALYs and health system costs over the remaining life span of the NZ population alive in 2011 at a 3% discount rate.

Results

The modeled intervention resulted in an estimated 430 QALYs gained (95% uncertainty interval 320-550), with net cost savings of 2011 NZ $2.2 million (2011 US $1.5 million) over the remaining life span of the 2011 NZ population. On a per capita basis, QALY gains were generally larger in women than in men and larger in Māori than in non-Māori. The health impact and cost-effectiveness of the intervention were highly sensitive to assumptions on intervention uptake and decay. For example, the scenario analysis with the largest benefits, which assumed a 5-year maintenance of additional physical activity levels, delivered 1750 QALYs and 2011 NZ $22.5 million (2011 US $15.1 million) in cost savings.

Conclusions

The prescription of smartphone apps for promoting physical activity in primary care settings is likely to generate modest health gains and cost savings at the population level in this high-income country. Such gains may increase with ongoing improvements in app design and increased health worker promotion of the apps to patients.

A school-based, peer-led programme to increase physical activity among 13- to 14-year-old adolescents: the GoActive cluster RCT

Background

Adolescent physical activity levels are low and are associated with rising disease risk and social disadvantage. The Get Others Active (GoActive) intervention was co-designed with adolescents and teachers to increase physical activity in adolescents.

Objective

To assess the effectiveness and cost-effectiveness of the school-based GoActive programme in increasing adolescents’ moderate-to-vigorous physical activity.

Design

A cluster randomised controlled trial with an embedded mixed-methods process evaluation.

Setting

Non-fee-paying schools in Cambridgeshire and Essex, UK (n = 16). Schools were computer randomised and stratified by socioeconomic position and county.

Participants

A total of 2862 Year 9 students (aged 13–14 years; 84% of eligible students).

Intervention

The iteratively developed feasibility-tested refined 12-week intervention trained older adolescents (mentors) and in-class peer leaders to encourage classes to undertake two new weekly activities. Mentors met with classes weekly. Students and classes gained points and rewards for activity in and out of school.

Main outcome measures

The primary outcome was average daily minutes of accelerometer-assessed moderate-to-vigorous physical activity at 10 months post intervention. Secondary outcomes included accelerometer-assessed activity during school, after school and at weekends; self-reported physical activity and psychosocial outcomes; cost-effectiveness; well-being and a mixed-methods process evaluation. Measurement staff were blinded to allocation.

Results

Of 2862 recruited participants, 2167 (76%) attended 10-month follow-up measurements and we analysed the primary outcome for 1874 (65.5%) participants. At 10 months, there was a mean decrease in moderate-to-vigorous physical activity of 8.3 (standard deviation 19.3) minutes in control participants and 10.4 (standard deviation 22.7) minutes in intervention participants (baseline-adjusted difference –1.91 minutes, 95% confidence interval –5.53 to 1.70 minutes; p = 0.316). The programme cost £13 per student compared with control. Therefore, it was not cost-effective. Non-significant indications of differential impacts suggested detrimental effects among boys (boys –3.44, 95% confidence interval –7.42 to 0.54; girls –0.20, 95% confidence interval –3.56 to 3.16), but favoured adolescents from lower socioeconomic backgrounds (medium/low 4.25, 95% confidence interval –0.66 to 9.16; high –2.72, 95% confidence interval –6.33 to 0.89). Mediation analysis did not support the use of any included intervention components to increase physical activity. Some may have potential for improving well-being. Students, teachers and mentors mostly reported enjoying the GoActive intervention (56%, 87% and 50%, respectively), but struggled to conceptualise their roles. Facilitators of implementation included school support, embedding a routine, and mentor and tutor support. Challenges to implementation included having limited school space for activities, time, and uncertainty of teacher and mentor roles.

Limitations

Retention on the primary outcome at 10-month follow-up was low (65.5%), but we achieved our intended sample size, with retention comparable to similar trials.

Conclusions

A rigorously developed school-based intervention (i.e. GoActive) was not effective in countering the age-related decline in adolescent physical activity. Overall, this mixed-methods evaluation provides transferable insights for future intervention development, implementation and evaluation.

Future work

Interdisciplinary research is required to understand educational setting-specific implementation challenges. School leaders and authorities should be realistic about expectations of the effect of school-based physical activity promotion strategies implemented at scale.

Trial registration

Current Controlled Trials ISRCTN31583496.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 9, No. 6. See the NIHR Journals Library website for further project information. This work was additionally supported by the Medical Research Council (London, UK) (Unit Programme number MC_UU_12015/7) and undertaken under the auspices of the Centre for Diet and Activity Research (Cambridge, UK), a UK Clinical Research Collaboration Public Health Research Centre of Excellence. Funding from the British Heart Foundation (London, UK), Cancer Research UK (London, UK), Economic and Social Research Council (Swindon, UK), Medical Research Council, the National Institute for Health Research (Southampton, UK) and the Wellcome Trust (London, UK), under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged (087636/Z/08/Z; ES/G007462/1; MR/K023187/1). GoActive facilitator costs were borne by Essex and Cambridgeshire County Councils.

Economic evaluations of public health interventions for physical activity and healthy diet: A systematic review

Physical inactivity and unhealthy dietary habits are associated with an increased disease and economic burden. The aim of this systematic review was to identify economic evaluations of public health interventions targeting physical activity and healthy diet, and assess the quality and transferability of the findings to the Swedish context. A search of published economic evaluations was conducted through electronic databases including PubMed, Web of Science, PsycINFO, National Health Service Economic Evaluation Databases (NHS EED) and the Health Technology Assessment Database (HTA). An additional search was done using references of relevant systematic reviews and websites of relevant organizations were checked to find grey literature. Quality and transferability of the economic evaluations were appraised using a quality assessment tool developed by the Swedish Agency for Health Technology Assessment. Thirty-two economic evaluations, rated as moderate or high quality, of 178 interventions were included; thirteen studies targeting physical activity, thirteen targeting healthy diet and six targeting both. The interventions varied in terms of their content, setting, mode of delivery and target populations. A majority of the economic evaluations reported that the interventions were likely to be cost-effective; however, considerable variations in the methodological and reporting qualities were observed. Only half of the economic evaluations were rated to have a high probability of transferring to the Swedish context. Public health interventions targeting physical activity and dietary habits have a high potential to be cost-effective. However, decision makers should consider the variation in quality and transferability of the available evidence.

Sit–stand desks to reduce sedentary behaviour in 9- to 10-year-olds: the Stand Out in Class pilot cluster RCT

Background

Sedentary behaviour (sitting) is a highly prevalent negative health behaviour, with individuals of all ages exposed to environments that promote prolonged sitting. The school classroom represents an ideal setting for environmental change through the provision of sit–stand desks.

Objectives

The aim of this study was to undertake a pilot cluster randomised controlled trial of the introduction of sit–stand desks in primary school classrooms, to inform a definitive trial. Objectives included providing information on school and participant recruitment and retention, acceptability of the intervention, and outcome measures. A preliminary estimate of the intervention’s effectiveness on the proposed primary outcome (change in weekday sitting time) for inclusion in a definitive trial was calculated, along with a preliminary assessment of potential cost-effectiveness. A full process evaluation was also undertaken.

Design

A two-armed pilot cluster randomised controlled trial with economic and qualitative evaluations. Schools were randomised on a 1 : 1 basis to the intervention (n = 4) or control (n = 4) trial arms.

Setting

Primary schools in Bradford, West Yorkshire, UK.

Participants

Children in Year 5 (i.e. aged 9–10 years).

Intervention

Six sit–stand desks replaced three standard desks (sitting six children) in the intervention classrooms for 4.5 months. Teachers were encouraged to ensure that all pupils were exposed to the sit–stand desks for at least 1 hour per day, on average, using a rotation system. Schools assigned to the control arm continued with their usual practice.

Main outcome measures

Trial feasibility outcomes included school and participant recruitment and attrition, acceptability of the intervention, and acceptability of and compliance with the proposed outcome measures [including weekday sitting measured using activPAL™ (PAL Technologies Ltd, Glasgow, UK) accelerometers, physical activity, adiposity, blood pressure, cognitive function, musculoskeletal comfort, academic progress, engagement and behaviour].

Results

Thirty-three per cent of schools approached and 75% (n = 176) of eligible children took part. At the 7-month follow-up, retention rates were 100% for schools and 97% for children. Outcome measure completion rates ranged from 63% to 97%. A preliminary estimate of intervention effectiveness, from a weighted linear regression model (adjusting for baseline sitting time and wear time) revealed a mean difference in change in sitting of –30.6 minutes per day (95% confidence interval –56.42 to –4.84 minutes per day) between the intervention and control trial arms. The process evaluation revealed that the intervention, recruitment and evaluation procedures were acceptable to teachers and children, with the exception of minor issues around activPAL attachment. A preliminary within-trial economic analysis revealed no difference between intervention and control trial arms in health and education resource use or outcomes. Long-term modelling estimated an unadjusted incremental cost-effectiveness ratio of Stand Out in Class of £78,986 per quality-adjusted life-year gained.

Conclusion

This study has provided evidence of the acceptability and feasibility of the Stand Out in Class intervention and evaluation methods. Preliminary evidence suggests that the intervention may have a positive direction of effect on weekday sitting time, which warrants testing in a full cluster randomised controlled trial. Lessons learnt from this trial will inform the planning of a definitive trial.

Trial registration

Current Controlled Trials ISRCTN12915848.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 8. See the NIHR Journals Library website for further project information.

Cost-effectiveness of physical activity interventions in adolescents: model development and illustration using two exemplar interventions

OBJECTIVE

To develop a model to assess the long-term costs and health outcomes of physical activity interventions targeting adolescents.

DESIGN

A Markov cohort simulation model was constructed with the intention of being capable of estimating long-term costs and health impacts of changes in activity levels during adolescence. The model parameters were informed by published literature and the analysis took a National Health Service perspective over a lifetime horizon. Univariate and probabilistic sensitivity analyses were undertaken.

SETTING

School and community.

PARTICIPANTS

A hypothetical cohort of adolescents aged 16 years at baseline.

INTERVENTIONS

Two exemplar school-based: a comparatively simple, after-school intervention and a more complex multicomponent intervention compared with usual care.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incremental cost-effectiveness ratio as measured by cost per quality-adjusted life year gained.

RESULTS

The model gave plausible estimates of the long-term effect of changes in physical activity. The use of two exemplar interventions suggests that the model could potentially be used to evaluate a number of different physical activity interventions in adolescents. The key model driver was the degree to which intervention effects were maintained over time.

CONCLUSIONS

The model developed here has the potential to assess long-term value for money of physical activity interventions in adolescents. The two applications of the model indicate that complex interventions may not necessarily be the ones considered the most cost-effective when longer-term costs and consequences are taken into account.

Cost-effectiveness of health coaching and financial incentives to promote physical activity after total knee replacement

OBJECTIVE

We evaluated the cost-effectiveness of Telephonic Health Coaching and Financial Incentives (THC + FI) to promote physical activity in total knee replacement recipients.

DESIGN

We used the Osteoarthritis Policy Model, a computer simulation of knee osteoarthritis, to evaluate the cost-effectiveness of THC + FI compared to usual care. We derived transition probabilities, utilities, and costs from trial data. We conducted lifetime analyses from the healthcare perspective and discounted all cost-effectiveness outcomes by 3% annually. The primary outcome was the Incremental Cost-Effectiveness Ratio (ICER), defined as the ratio of the differences in costs and Quality-Adjusted Life Years (QALYs) between strategies. We considered ICERs <$100,000/QALY to be cost-effective. We conducted one-way sensitivity analyses that varied parameters across their 95% confidence intervals (CI) and limited the efficacy of THC + FI to 1 year or to 9 months. We also conducted a probabilistic sensitivity analysis (PSA), simultaneously varying cost, utilities, and transition probabilities.

RESULTS

THC + FI had an ICER of $57,200/QALY in the base case and an ICER below $100,000/QALY in most deterministic sensitivity analyses. THC + FI cost-effectiveness depended on assumptions about long-term efficacy; when efficacy was limited to 1 year or to 9 months, the ICER was $93,300/QALY or $121,800/QALY, respectively. In the PSA, THC + FI had an ICER below $100,000/QALY in 70% of iterations.

CONCLUSIONS

Based on currently available information, THC + FI might be a cost-effective alternative to usual care. However, the uncertainty surrounding this choice is considerable, and further research to reduce this uncertainty may be economically justified.

Optimal Information Collection Policies in a Markov Decision Process Framework

BACKGROUND

The cost-effectiveness and value of additional information about a health technology or program may change over time because of trends affecting patient cohorts and/or the intervention. Delaying information collection even for parameters that do not change over time may be optimal.

METHODS

We present a stochastic dynamic programming approach to simultaneously identify the optimal intervention and information collection policies. We use our framework to evaluate birth cohort hepatitis C virus (HCV) screening. We focus on how the presence of a time-varying parameter (HCV prevalence) affects the optimal information collection policy for a parameter assumed constant across birth cohorts: liver fibrosis stage distribution for screen-detected diagnosis at age 50.

RESULTS

We prove that it may be optimal to delay information collection until a time when the information more immediately affects decision making. For the example of HCV screening, given initial beliefs, the optimal policy (at 2010) was to continue screening and collect information about the distribution of liver fibrosis at screen-detected diagnosis in 12 years, increasing the expected incremental net monetary benefit (INMB) by $169.5 million compared to current guidelines.

CONCLUSIONS

The option to delay information collection until the information is sufficiently likely to influence decisions can increase efficiency. A dynamic programming framework enables an assessment of the marginal value of information and determines the optimal policy, including when and how much information to collect.