Do strategies to increase physical activity among older people work for individuals?
Start date: 23 April 2015
Journal: Irish Ageing Studies Review
Background Evaluations of techniques to promote physical activity among older people usually adopt a randomised controlled trial (RCT) or similar design. Such designs inform how a technique performs on average for the intervention group but cannot be used for treatment of individuals. N-of-1 RCTs overcome this limitation. We conducted the first N-of-1 RCT of behaviour change techniques with older people to test their effectiveness for increasing walking.
Methods Eight individuals aged 60-87 were randomised to a 2 (goal setting vs. active control) x 2 (self-monitoring vs. active control) factorial N-of-1 RCT over 62 days. Each day, participants were randomised to conditions and walking was objectively measured using pedometers. For goal-setting, participants set themselves a step count goal for that day. For self-monitoring, participants wore a pedometer with the display visible. The time series data was analysed for each individual using linear regression.
Results Overall, compared to controls, both goal-setting and self-monitoring interventions increased daily walking by a median of 922 and 950 steps respectively. However, for individuals the results were mixed. Compared to controls, goal-setting increased walking in 4 out of 8 individuals, with the remaining showing no change or a decrease in walking. Self-monitoring increased walking in 7 out of 8 individuals, with one individual showing a decrease in walking. No linear regression was significant, likely because of insufficient statistical power.
Conclusions N-of-1 trials are useful for testing the effect of physical activity interventions among older people and open new possibilities for the advancement of science and clinical practice.