Group trajectory analysis helps to identify older cancer survivors who benefit from distance-based lifestyle interventions

Abstract

Background: The number of older cancer survivors is increasing as more adults survive to older ages. The objectives of this study were to examine trajectories of physical activity (PA) and physical function (PF) over a 2-year lifestyle counseling study and to identify characteristics of the trajectory groups.

Methods: This was a secondary analysis of Reach Out to Enhance Wellness, a randomized controlled trial of home-based lifestyle counseling. The 641 participants were older (≥65 years), overweight (body mass index [BMI], 25 to <40 kg/m(2)), long-term community-dwelling survivors (>5 years) of breast, prostate, and colorectal cancer from Canada, the United Kingdom, and the United States (21 states) who had been randomly assigned to an immediate intervention or a 12-month-wait-listed control arm. The main outcome measures were PA and PF trajectory group membership.

Results: Three PA groups and 5 PF trajectory groups were observed. The baseline BMI (P < .001) and self-efficacy for performing strength (P < .0001) and endurance exercises (P < .0002) were the strongest predictors of achieving the highest amount of PA and the most favorable functional trajectory over 2 years. Individuals with low baseline self-efficacy, no PA, and a Short Form 36 PF subscale score < 65 did not benefit from the intervention.

Conclusions: This study identified characteristics of survivors who benefited from home-based interventions and suggested alternative approaches for survivors requiring more structured and intensive interventions to promote behavioral changes.

Keywords: aged; breast neoplasms; colorectal neoplasms; counseling; exercise; health behavior; lifestyle; prevention and control; prostatic neoplasms; survivors.

Conflict of interest statement

Conflict of interest Disclosures: The authors declare that they have no conflicts of interest.

© 2015 American Cancer Society.

Figures

Figure 1

Physical activity trajectory groups in the immediate intervention group: (a) Quarterly total exercise minutes (logged) by trajectory group, (b) Physical function quarterly scores by trajectory group, and (c) Characteristics of physical activity trajectory groups. ahigher scores indicate greater self-efficacy to perform strength training or endurance exercise (range on each scale: 1 to 5: very unsure, unsure, somewhat sure, sure, very sure)

Figure 1

Physical activity trajectory groups in the immediate intervention group: (a) Quarterly total exercise minutes (logged) by trajectory group, (b) Physical function quarterly scores by trajectory group, and (c) Characteristics of physical activity trajectory groups. ahigher scores indicate greater self-efficacy to perform strength training or endurance exercise (range on each scale: 1 to 5: very unsure, unsure, somewhat sure, sure, very sure)

Figure 2

Physical activity trajectory groups in the wait listed intervention group: (a) Quarterly total exercise minutes (logged) by trajectory group, (b) Physical function quarterly scores by trajectory group, and (c) Characteristics of physical activity trajectory groups. ahigher scores indicate greater self-efficacy to perform strength training or endurance exercise (range on each scale: 1 to 5: very unsure, unsure, somewhat sure, sure, very sure)

Figure 2

Physical activity trajectory groups in the wait listed intervention group: (a) Quarterly total exercise minutes (logged) by trajectory group, (b) Physical function quarterly scores by trajectory group, and (c) Characteristics of physical activity trajectory groups. ahigher scores indicate greater self-efficacy to perform strength training or endurance exercise (range on each scale: 1 to 5: very unsure, unsure, somewhat sure, sure, very sure)