Elsevier

Journal of Nutrition Education and Behavior

Volume 44, Issue 5, September–October 2012, Pages 464-468
Journal of Nutrition Education and Behavior

Research Brief
Validation of a Milk Consumption Stage of Change Algorithm among Adolescent Survivors of Childhood Cancer

https://doi.org/10.1016/j.jneb.2012.04.005Get rights and content

Abstract

Objective

To assess the construct validity of a milk consumption Stages of Change (SOC) algorithm among adolescent survivors of childhood cancer ages 11 to 21 years (n = 75).

Methods

Baseline data from a randomized controlled trial designed to evaluate a health behavior intervention were analyzed. Assessments included a milk consumption SOC algorithm and hypothesized theoretical and behavioral predictors of SOC.

Results

Compared with survivors who expressed no readiness to change, those expressing readiness to change behavior for both 2 and 4 daily servings of milk reported more frequent milk consumption (P < .001), greater dietary calcium intake (P = .006), and were more likely to meet age-specific recommendations for daily calcium intake (P = .01).

Conclusions and Implications

Results provide support for the construct validity of the milk consumption SOC algorithm relative to behavioral criteria. Research is needed to further examine algorithm validity with respect to theoretical predictors of SOC.

Introduction

Bone health problems are a common late effect of cancer treatment among childhood cancer survivors, including suboptimal bone density and clinical signs of osteopenia.1 These problems are linked to stunted growth and increased risk for osteoporosis and fractures in adulthood.1 Risk for bone health problems may be exacerbated by the fact that few survivors meet recommendations for bone health behaviors, such as consuming recommended daily levels of calcium.2

Although clinical signs of bone health problems do not typically appear until adulthood,1 interventions encouraging bone health-promoting behaviors among young cancer survivors may help prevent or delay onset of bone health morbidities. A comprehensive approach to promoting bone health among young survivors includes consuming a balanced diet and engaging in healthful physical activity.1 Increasing calcium and vitamin D intake through diet and supplementation are effective methods of improving bone density3 and may reduce risk for fracture in high-risk groups.4, 5 For childhood cancer survivors, follow-up care guidelines encourage meeting age-specific recommended levels of calcium for optimal bone health.1 Milk is a leading source of dietary calcium,6, 7 and inter-ventions targeting milk consumption may be 1 important element of comprehensive approaches to reduce long-term risk for bone health problems in this vulnerable population.1, 8

Recent data support the efficacy of a bone health behavior intervention for young cancer survivors, including milk consumption.9 However, the impact could be enhanced by tailoring content to address survivors' individual needs for behavior change.10 The Transtheoretical Model (TTM) provides a framework for tailoring interventions to an individual's readiness to change, positing that health behavior change occurs via 5 stages of change (SOC), from Precontemplation (no intention to change behavior within next 6 mo) to Maintenance (performance of the recommended behavior for ≥ 6 mo).11 Transition between stages is dynamic and includes progression toward maintenance and relapse to earlier stages.11

The SOC approach has been applied to the study of dietary behaviors, including milk consumption, among young people.12, 13, 14, 15 Stage of change is typically assessed using a staging algorithm, which characterizes individuals based on current behavioral practices, duration of practices, and intention to take action to change practices.11 It is critical to first establish the construct validity of SOC algorithms designed to characterize SOC for the recommended health behavior. However, no such milk consumption algorithm has been validated among adolescent cancer survivors. The authors examined the construct validity of a SOC algorithm for consuming 2 and 4 daily servings of milk among adolescent survivors of childhood cancer. The algorithm is designed to provide a flexible tool to assess milk consumption and can be used with other sources of dietary information to tailor bone health interventions among young cancer survivors.

Section snippets

Procedures

The Survivor Health and Resilience Education Program was a randomized controlled trial to test the efficacy of a multiple health behavior intervention among adolescent survivors of childhood cancer. Study methods and bone health behavior outcomes were previously reported.9 The study included adolescents ages 11 to 21 years who were treated for cancer, ≥ 1 year post-treatment and ≥ 1 year cancer-free. Participants were recruited from 2 local pediatric cancer centers; the Georgetown University

Participant Characteristics

The Table displays participant characteristics, and the Figure illustrates survivors' SOC for 2 and 4 daily servings of milk. For the combined outcome, 24% of survivors (n = 18) expressed no readiness to change (Figure). Sixteen (21%) expressed readiness to change behavior for 2 daily servings of milk, and 55% (n = 41) expressed readiness to change behavior for both 2 and 4 daily servings of milk.

Predictors of SOC

Compared with survivors who expressed no readiness to change and those who only expressed readiness

Discussion

Adolescent survivors of childhood cancer are at an increased risk for bone-related morbidity,1 but evidence supporting interventions to promote bone health behaviors for this population, such as milk consumption, remains limited.9 The TTM has been widely used to inform behavioral interventions targeting dietary behaviors,25 and the impact of interventions to promote milk consumption among young survivors could be enhanced by tailoring content to individual survivors' SOC.10 The present findings

Implications for Research and Practice

Despite study limitations, the present findings provide preliminary support for the validity of the milk consumption SOC algorithm among adolescent survivors of childhood cancer relative to behavioral criteria. Additional research is needed to evaluate the construct validity of the algorithm relative to TTM constructs (eg, processes of change) among larger, more diverse samples. Interventions that take a broad approach by motivating young survivors to consume milk and a variety of other

Acknowledgments

This research was supported by grants from the American Cancer Society, the Lance Armstrong Foundation, and the National Cancer Institute (CA091831) to Dr. Kenneth P. Tercyak.

References (27)

  • W. Demark-Wahnefried et al.

    Riding the crest of the teachable moment: promoting long-term health after the diagnosis of cancer

    J Clin Oncol

    (2005)
  • D. Mays et al.

    Efficacy of the Survivor Health and Resilience Education (SHARE) program to improve bone health behaviors among adolescent survivors of childhood cancer

    Ann Behav Med

    (2011)
  • S.M. Noar et al.

    Does tailoring matter? Meta-analytic review of tailored print health behavior change interventions

    Psychol Bull

    (2007)
  • View full text