Accuracy of Physical Activity Measures in Cancer Studies

描述（由申请人提供）：流行病学研究中体力活动评估固有的方法学挑战引入了测量误差，限制了我们对体力活动在降低癌症和其他疾病风险中的作用的理解。本提案的主要目标是确定和量化与两项自我管理的体育活动（PA）问卷相关的测量误差，该问卷用于评估两项正在进行的癌症队列研究（由NCI资助的癌症后的生活流行病学研究和由加州癌症研究计划资助的加州男性健康研究）中的近期活动。为了实现这一目标，我们建议进行一项验证研究，包括比较两份测试问卷，1)14天的体育活动日记（2个7天，间隔5-6个月）；2) 14天的加速度计记录，与PA日志同步；3)有氧能力由次最大分级运动平板试验确定；4)身体尺寸测量（身体质量指数，来自生物电阻抗的体脂百分比和腰围）。验证性研究还将包括评估2-4周测试-重测两份问卷的重复性。研究参与者将从北加州Kaiser Permanente （KP）癌症登记处和普通会员档案中随机抽取，包括400名年龄在45-65岁之间，在招募前24-36个月被诊断患有乳腺癌或前列腺癌的女性和男性，以及400名年龄相近但没有癌症病史的女性和男性。预期样本将反映金伯利党成员的种族/民族多样性。此外，我们建议开发一个用于掌上电脑（个人数字助理或PDA）的应用程序，用于收集和管理个人助理日记。在验证研究之前，我们将在试点研究中评估pda上收集的PA日记与传统纸笔日记的可比性。在试点研究中，从验证研究中随机抽取的50名男性和女性将连续3周记录他们的活动，每4天记录他们的活动，其中一半人在两个时间段使用pda，在一个时间段使用纸和笔，另一半则相反。试点研究的参与者还将完成一项认知访谈，以深入了解PDA软件的可用性以及通过两份测试问卷回忆体力活动所需的思维过程。调查问卷中测量误差的来源将被确定并量化，校正测量误差的统计方法将应用于父母研究，以估计与体育活动相关的疾病风险（乳腺癌复发或前列腺癌发生）。由于验证将在一个大的、多样化的、随机选择的样本中进行，这些发现可能会推广到其他关于体育活动和癌症的研究中，并且可能对体育活动和其他健康结果的研究也有广泛的适用性。

DESCRIPTION (provided by applicant): Methodological challenges inherent in the assessment of physical activity in epidemiological studies introduce measurement errors that limit our understanding of the role of physical activity in reducing the risk of cancer and other diseases. The primary goal of this proposal is to identify and quantify the measurement error associated with two self administered physical activity (PA) questionnaires used to assess recent activity in two on-going cancer cohort studies (Life After Cancer Epidemiology Study, funded by the NCI, and the California Men's Health Study, funded by the California Cancer Research Program). To achieve this goal, we propose to conduct a validation study involving comparisons of the two test questionnaires with 1) 14 days of physical activity diaries (2 7-day periods, 5-6 months apart); 2) 14 days of accelerometer recordings, simultaneous with the PA diaries; 3) aerobic capacity as determined from a sub-maximal graded exercise treadmill test; and 4) body size measurements (body mass index, % body fat from bioelectric impedance, and waist circumference). The validation study will also include evaluation of 2-4 week test-retest repeatability of the two questionnaires. The study participants will be randomly drawn from the Northern California Kaiser Permanente (KP) Cancer Registry and general membership files and will consist of 400 women and men, ages 45-65, diagnosed with breast or prostate cancer 24-36 months prior to recruitment, and 400 women and men of similar age but with no history of cancer. The sample is expected to reflect the racial/ethnic diversity of the KP membership. In addition, we propose to develop an application program for a hand-held computer (personal digital assistant or PDA) that will be used for the collection and management of the PA diaries. We will evaluate the comparability of the PA diaries collected on the PDAs with traditional paper and pen diaries in a pilot study prior to the validation study. For the pilot study, 50 men and women, randomly drawn from the same sampling frame to be used in the validation study, will record their activities for a 4-day period in each of 3 consecutive weeks, with half using PDAs for two of the periods and paper and pen for one period, and the other half doing the reverse. The pilot study participants will also complete a cognitive interview to provide insights into the usability of the PDA software and the thought processes required in the recall of physical activity by the two test questionnaires. Sources of measurement error in the questionnaires will be identified and quantified, and statistical methods for adjusting for measurement error will be applied to the parent studies to estimate the risk of disease (breast cancer recurrence or incident prostate cancer) associated with physical activity. Because the validation will be conducted in a large, diverse, randomly selected sample, the findings may be potentially generalizable to other studies of physical activity and cancer, and may have broad applicability for studies of physical activity and other health outcomes as well.