The short-term and long-term cost-effectiveness of a pedometer-based exercise intervention in primary care: A within-trial analysis and beyond-trial modelling

Objectives: A short- and long-term cost-effectiveness analysis (CEA) of two pedometer-based walking interventions compared with usual care.

Design: a) Short-term CEA: parallel three-arm cluster randomised trial randomised by household b) Long-term CEA: Markov decision-model

Setting: Seven primary care practices in South London, United Kingdom

Participants: a) Short-term CEA: 1023 people (922 households) aged 45-75yrs without physical activity (PA) contraindications b) Long-term CEA: 100,000 cohort aged 59-88yrs

Interventions: Pedometers, 12-wk walking programmes, and PA diaries delivered by post or through three PA consultations with practice nurses

Primary and Secondary Outcome Measures: Accelerometer-measured change (baseline-12 months) in average daily step-count and time in 10-min bouts of moderate-vigorous PA, and EQ5D5L quality adjusted life-years (QALYs)

Methods: Resource use costs (£2013/4) from an NHS perspective, presented as incremental cost effectiveness ratios for each outcome over a 1-year and life-time horizon, with cost-effectiveness acceptability curves and willingness to pay per QALY. Deterministic and probabilistic sensitivity analyses evaluate uncertainty.

Results: a) Short-term CEA: At 12 months, incremental cost was £3.61(£109) per minute in ≥10 minute MVPA bouts for nurse-support compared with control (postal group). At £20,000/QALY, the postal group had a 50% chance of being cost-saving compared with control. b) Long-term CEA: The postal group had more QALYs (+759QALYs, 95% CI 400, 1247) and lower costs (-£11m, 95% CI -12, -10), than control and nurse groups, resulting in an incremental net monetary benefit of £26m per 100,000 population. Results were sensitive to reporting serious adverse events, excluding health service use, and including all participant costs.

Conclusions: Postal delivery of a pedometer intervention in primary care is cost-effective long-term and has a 50% chance of being cost-effective, through resource savings, within one year. Further research should ascertain maintenance of the higher levels of PA, and its impact on quality of life and health service use.