The Effect of Physical Activity on Disability Progression in Knee OA

描述（由申请人提供）：体育活动对膝关节骨关节炎残疾进展的影响近800万美国人因关节炎而残疾，使关节炎成为美国残疾的主要原因。膝骨关节炎（OA）是导致关节炎相关残疾的主要原因。虽然体育活动可以改善关节炎患者的健康状况，但尚不清楚体育活动是否可以减少残疾进展，而残疾进展是OA患者医疗保健费用的主要驱动因素。初步证据表明，在患有关节炎的成年人中，体育活动对减少残疾进展的潜在益处可能在病情较轻的人群中更大。从公共卫生的角度来看，确定早期膝关节OA的益处对成年人适当的目标体育活动计划具有重要意义。为了全面研究膝关节OA中体力活动的流行病学以及较高体力活动水平对残疾进展的影响，提出了一项骨关节炎倡议（OAI）纵向研究的辅助研究。OAI包括膝关节OA疾病的全谱。这项辅助研究包括2280名患有或有发生症状性膝关节炎高风险的OAI参与者。将使用加速度计客观地测量身体活动，以量化活动频率、持续时间和强度，并确定身体活动指南的实现情况。拟议辅助研究中的所有数据将加入OAI公共数据集。以下假设将被检验。1. 达到USSG（美国外科医生体力活动建议）指南-推荐体力活动目标的人与未达到者相比，在两年内残疾进展的风险较低。与有症状的患者相比，无症状性膝关节炎患者获得指南的益处更大。2. 与未达到USSG身体活动目标的人相比，达到USSG身体活动目标的人在两年内残疾进展的风险较低。与有症状的人相比，没有症状性膝关节炎的人获益更大。3. 体力活动水平与残疾进展之间存在剂量反应关系。在体力活动最高和中等三分之一以及中等和最低三分之一的人群在两年内残疾进展的风险较低。分析将根据膝关节症状和疾病的x光片证据以及潜在的混杂因素进行调整，这些混杂因素包括膝关节疼痛强度、年龄、性别、种族、体重指数、吸烟、经济因素和医学合并症。这项研究的结果将促进公共卫生工作，以减少2100万美国成年膝关节OA患者的残疾和改善生活质量。本研究将检查是否达到建议的公共卫生体育活动指南可以保护患有或有患症状性膝骨关节炎高风险的人防止残疾进展，以及是否达到指南对没有症状性疾病的人有更大的益处。这项研究的结果将促进公共卫生工作，以减少2100万美国成年膝关节OA患者的残疾和改善生活质量。小灵通398/2590 （Rev. 09/04）第1页延续格式页

DESCRIPTION (provided by applicant): The Effect of Physical Activity on Disability Progression in Knee Osteoarthritis Nearly 8 million Americans are disabled as a result of their arthritis, making arthritis the major cause of disability in the US. A leading cause of arthritis-related disability is knee osteoarthritis (OA). While physical activity improves the health of persons with arthritis, it is not known if physical activity reduces disability progression, a key driver of health care costs in persons with OA. Preliminary evidence indicates that the potential benefit from physical activity to reduce disability progression in adults with arthritis may be greater in persons having less severe disease. From a public health perspective, establishing a benefit in early knee OA has important implications to appropriately target physical activity programs for adults. To comprehensively examine the epidemiology of physical activity in knee OA and the effect of higher physical activity levels on disability progression, an ancillary study to the Osteoarthritis Initiative (OAI) longitudinal study is proposed. The OAI includes the full spectrum of knee OA disease. This ancillary study includes 2280 OAI participants having or at high risk for developing symptomatic knee OA. Physical activity will be objectively measured using accelerometers to quantify activity frequency, duration, and intensity and to ascertain physical activity guideline attainment. All data in the proposed ancillary study will join the OAI public data set. The following hypotheses will be tested. 1. Persons who attain USSG (U.S. Surgeon General physical activity recommendations) guideline- recommended physical activity targets have a lower risk of disability progression over two years compared to non-attainers. The benefit of guideline attainment is stronger for persons without symptomatic knee OA compared to persons having symptoms. 2. Persons who attain USSG physical activity targets modified for arthritis have a lower risk of disability progression over two years compared to non-attainers. This benefit is stronger for persons without symptomatic knee OA compared to persons having symptoms. 3. There is a dose response relationship between physical activity levels and disability progression. Persons in the top vs. middle physical activity tertiles and middle vs. bottom tertiles will have a lower risk of disability progression over two years. Analyses will adjust for the presence of knee symptoms and radiograph evidence of disease and for potential confounders, which include knee pain intensity, age, gender, race, body mass index, cigarette smoking, economic factors, and medical comorbidities. Findings from this study will advance public health efforts to reduce disability and to improve quality of life among 21 million U.S. adults having knee OA. PHS 398/2590 (Rev. 09/04) Page 1 Continuation Format Page This study will examine if attaining recommended public health physical activity guidelines protects against disability progression in persons having or at high risk for developing symptomatic knee osteoarthritis and if guideline attainment provides greater benefit for persons without symptomatic disease. Findings from this study will advance public health efforts to reduce disability and to improve quality of life among 21 million U.S. adults having knee OA. PHS 398/2590 (Rev. 09/04) Page 1 Continuation Format Page