Effect of pedometer-based walking interventions on long-term health outcomes: Prospective 4-year follow-up of two randomised controlled trials using routine primary care data

© 2019 Harris et al. Background: Data are lacking from physical activity (PA) trials with long-term follow-up of both objectively measured PA levels and robust health outcomes. Two primary care 12-week pedometer-based walking interventions in adults and older adults (PACE-UP and PACE-Lift) found sustained objectively measured PA increases at 3 and 4 years, respectively. We aimed to evaluate trial intervention effects on long-term health outcomes relevant to walking interventions, using routine primary care data. Methods and Findings: Randomisation was from October 2012-November 2013 for PACE-UP participants from seven general (family) practices and October 2011-October 2012 for PACE-Lift participants from three practices. We downloaded primary care data, masked to intervention or control status, for 1001 PACE-UP participants age 45-75 years, 36% (361) male and 296 PACE-Lift participants, age 60-75 years, 46% (138) male, who gave written informed consent, for 4-year periods following randomisation. The following new events were counted for all participants, including those with pre-existing diseases (apart from diabetes, where existing cases were excluded): non-fatal cardiovascular; total cardiovascular (including fatal); incident diabetes; depression; fractures; and falls. Intervention effects on time to first event post-randomisation were modelled using Cox regression for all outcomes, except for falls, which used Negative Binomial regression to allow for multiple events, adjusting for age, sex, and study. Absolute risk reductions (ARRs) and numbers needed to treat (NNT) were estimated. Data were downloaded for 1297 (98%) of 1321 trial participants. Event rates were low (