Efficacy of Two Tailored Interventions Promoting Physical Activity in Older Adults

Background: Important health benefits can be obtained if effective low-cost interventions promoting physical activity, especially among older adults, are developed. Design: This RCT investigated the efficacy of two tailored physical activity interventions in promoting awareness, initiation, and maintenance of physical activity among older adults compared to a wait-list control group. Data were collected in 2007. Analyses were conducted in 2008. Setting/participants: In total, 1971 Dutch older adults (mean age = 64 years, 57% women) participated. Intervention: Two tailored physical activity interventions, consisting of three tailored letters delivered during 4 months, were systematically developed. The basic tailored intervention targeted psychosocial determinants alone, while the environmentally tailored intervention (intervention-plus) additionally targeted environmental determinants. Main outcome measures: Awareness of personal physical activity behavior, self-reported level of physical activity, and compliance with the physical activity guideline were assessed at baseline, 3 months, and 6 measures: months. Results: Intervention participants became more aware of their personal physical activity level at 6 months (ORIbasic = 1.7, ORIplus = 1.6) and were significantly more physically active at 3 (EffectSize[ES](Ibasic) = 0.20, ESIplus = 0.20) and 6 months (ESIbasic = 0.30, ESIplus = 0.35) when compared to control participants. Moderation analyses showed that the interventions enhanced physical activity initiation at 3 (ESIbasic = 0.26, ESIplus = 0.21) and 6 months (ESIbasic = 0.32, ESIplus = 0.27) among participants insufficiently active at baseline, and induced maintenance at 6 months among participants sufficiently active at baseline (ESIbasic = 0.33, ESIplus = 0.34) when compared to the control condition. No differences between the intervention arms were found. Conclusions: The results indicate that tailoring can be an effective tool in attaining and enhancing awareness, initiation, and maintenance of physical activity among older adults. Targeting environmental determinants in addition to psychosocial determinants, however, did not result in an additional increase in physical activity behavior.