Functional capacity assessment before surgery identifies older adults at increased risk of functional decline after major surgery [1]. Increasing physical activity before surgery has shown efficacy to mitigate functional decline afterwards [2]. A key component necessary to initiate physical activity is motivation, defined as the processes that energises, orients and sustains behaviour. The COM-B model proposes that there are three necessary components for any behaviour change to occur: capability; opportunity; and motivation. As physical activity interventions before surgery vary in the amount of supervision and social support provided (i.e. facility based vs. home-based), individual differences in self-determined motivation may impact participation and improvements in functional capacity. It is unclear whether motivation for physical activity varies between patients with high vs. low functional capacity before surgery. Links between these determinants would indicate the need for multifaceted strategies and our aim was to explore the association between motivation and functional capacity.

Older adults (aged ≥ 60 y) were screened prospectively from the Anaesthesia Peri-operative Medicine Clinic at the University of Chicago Medical Center. Patients were included if they were able to walk with or without an assistive device. We did not study those patients who were non-English speaking or scheduled for ophthalmic surgery. The University of Chicago institutional review board approved the study and written informed consent was obtained. Patient characteristics, medical history and structured questionnaires were assessed. We used the 19-item Behavioural Regulation in Exercise Questionnaire [3]. Patients rated each item on a 5-point Likert scale (0–4, 0 = not true for me; 4 = very true for me) to assess five reasons for engaging in physical activity. Scale scores were weighted and combined to estimate the relative autonomy index score, a cumulative score of level of self-determined motivation. Lower, negative scores indicated more controlled regulation whereas higher, positive scores indicated larger relative autonomy. We used the Fried frailty phenotype to evaluate frailty status and the Duke Activity Status Index (DASI) to measure functional capacity [4, 5]. A DASI score < 34 identified patients with a poor functional capacity who may benefit from exercise before surgery [6].

We performed descriptive analyses for patient characteristics, comorbidities, frailty, outcome expectations and motivation to exercise. We used χ² tests for categorical variables or t-tests for continuous variables for comparisons between patients with low and high functional capacity. To evaluate for differences in relative autonomy index and motivation subtypes we used the Mann–Whitney U test. All analyses were performed using STATA v16.1 (StataCorp LLC, College Station, TX, USA).

In total, 294 patients were approached, 164 provided consent and 154 completed all survey instruments. In our study cohort, the mean (SD) age was 71 (7.3) y, 60% (93/154) identified as female and the average mean (SD) BMI was 30 (6.1) kg.m^-1 (Table 1). Median (IQR [range]) DASI was 37 (19–50 [7–58]). Figure 1 illustrates the breakdown of the relative autonomy index and its subtypes stratified by low vs. high functional capacity. The median (IQR [range]) relative autonomy index was greater in patients with high compared with low functional capacity (13 (8–16 [-5–20]) vs. 9 (2–14 [-14–18]), respectively (p = 0.002)). Similar median (IQR [range]) differences were observed between high and low functional capacity groupings for identified regulation for physical activity (high 3.0 (2.5–3.5 [0.5–4]) vs. low 2.5 (1.8–3.0 [0–4.0]), p = 0.001) and intrinsic motivation for physical activity (high 2.8 (1.5–4.0 [0–4.0]) vs. low 2.0 (0.5–3.3 [0–4.0]), p = 0.007).

Older adults with poor functional capacity showed lower self-determined motivation which may undermine participation to prescribed physical activity programmes before surgery and limit potential improvements in functional capacity [7]. Participation in physical activity prescriptions is necessary to show functional gains from exercise to mitigate functional decline after surgery. As clinical practice guidelines emphasise pre-operative physical activity for older adults, it is imperative for clinicians to develop programmes that can support and meet the needs of all older adults who would benefit, including those with low functional capacity. Thus, programmes may need to offer different levels of support (supervised vs. home-based) to reduce motivational barriers to physical activity.

Our study was performed at an urban academic institution and it remains unclear how generalisable our results are to other settings (e.g. rural clinics and community practices). We did not survey our patients during a physical activity intervention; thus, it is unclear if engaging these targets would modify patients' behaviour change during the intervention if offered one.

In conclusion, our study addresses the importance of motivation for older adult patients who plan to engage in physical activity programmes to successfully mitigate risks for functional decline.

手术前的功能能力评估可识别老年人在大手术后功能衰退的风险增加[ 1 ]。术前增加体力活动已证明可以有效缓解术后功能衰退[ 2 ]。启动身体活动所必需的一个关键组成部分是动机，其定义为激发、引导和维持行为的过程。 COM-B 模型提出，任何行为改变的发生都需要三个必要的组成部分：能力；机会;和动机。由于手术前的身体活动干预在提供的监督和社会支持的数量上有所不同（即基于设施与基于家庭的），自我决定动机的个体差异可能会影响参与和功能能力的提高。目前尚不清楚术前功能能力高与低的患者之间体力活动的动机是否存在差异。这些决定因素之间的联系表明需要多方面的策略，我们的目标是探索动机和功能能力之间的关联。

芝加哥大学医学中心麻醉围手术期医学诊所对老年人（年龄 ≥ 60 岁）进行了前瞻性筛查。如果患者能够在使用或不使用辅助装置的情况下行走，则将其纳入其中。我们没有研究那些不会说英语或计划进行眼科手术的患者。芝加哥大学机构审查委员会批准了该研究并获得了书面知情同意书。对患者特征、病史和结构化问卷进行了评估。我们使用了 19 项运动行为调节问卷 [ 3 ]。患者使用 5 点李克特量表（0-4，0 = 对我来说不正确；4 = 对我来说非常正确）对每个项目进行评分，以评估参与体育活动的五个原因。对量表分数进行加权和组合，以估计相对自主指数分数，即自我决定动机水平的累积分数。较低的负分数表明更多的受控监管，而较高的正分数表明更大的相对自主权。我们使用 Fried 衰弱表型来评估衰弱状态，并使用 Duke 活动状态指数 (DASI) 来衡量功能能力 [ 4, 5 ]。 DASI 评分 < 34 表明功能较差的患者可能会从术前锻炼中受益 [ 6 ]。

我们对患者特征、合并症、虚弱、结果预期和运动动机进行了描述性分析。我们对分类变量使用^χ2检验，对连续变量使用 t 检验，以比较低功能能力和高功能能力的患者。为了评估相对自主指数和动机亚型的差异，我们使用了曼-惠特尼 U 检验。所有分析均使用 STATA v16.1（StataCorp LLC，College Station，TX，USA）进行。

总共接触了 294 名患者，164 名患者表示同意，154 名患者填写了所有调查工具。在我们的研究队列中，平均 (SD) 年龄为 71 (7.3) 岁，60% (93/154) 为女性，平均 (SD) BMI 为 30 (6.1) kg.m ^-1 （表 1） 。 DASI 中位数（IQR [范围]）为 37 (19–50 [7–58])。图 1 说明了相对自主指数及其按低功能能力与高功能能力分层的子类型的细分。与功能能力低的患者相比，功能能力高的患者的相对自主指数中位数（IQR [范围]）更大（13 (8–16 [-5–20]) vs. 9 (2–14 [-14–18])，分别（p = 0.002））。在确定的身体活动调节方面，高功能能力组和低功能能力组之间观察到类似的中位数（IQR [范围]）差异（高 3.0 (2.5–3.5 [0.5–4]) 与低 2.5 (1.8–3.0 [0–4.0]) ），p = 0.001）和体力活动的内在动机（高 2.8 (1.5–4.0 [0–4.0]) 对比低 2.0 (0.5–3.3 [0–4.0])，p = 0.007）。

功能能力较差的老年人表现出较低的自决动机，这可能会损害手术前对规定的身体活动计划的参与，并限制功能能力的潜在改善[ 7 ]。参与身体活动处方对于显示运动带来的功能增益以减轻手术后功能下降是必要的。由于临床实践指南强调老年人的术前身体活动，因此临床医生必须制定能够支持和满足所有受益老年人（包括功能能力低下的老年人）需求的计划。因此，项目可能需要提供不同级别的支持（监督与家庭支持），以减少身体活动的动机障碍。

我们的研究是在城市学术机构进行的，目前尚不清楚我们的结果对其他环境（例如农村诊所和社区实践）的普适性如何。我们没有在身体活动干预期间对患者进行调查；因此，尚不清楚如果提供这些目标，在干预期间参与这些目标是否会改变患者的行为变化。

总之，我们的研究强调了对于计划参加体育活动计划以成功降低功能衰退风险的老年患者来说动机的重要性。