在积极参与癌症预防和早期检测措施，特别是家族癌症风险中，获取信息是一个重要的前提。尽管有很多癌症信息可用，但并不是所有社会群体都能得到同样有效的传达，因为信息需求和传达可及性存在差异。先前的研究表明，由健康专业人员提供的在线聊天服务可以是满足个人关于敏感健康主题如家族癌症风险的信息需求的适宜、低门槛的形式。现有的德国癌症信息服务目前正在开发这样一种在线聊天服务。鉴于只有目标群体接受才会有价值，因此在聊天服务的开发和实施过程中，形成性评估是必不可少的。本研究旨在探索癌症患者及其亲属对家族癌症风险在线聊天的接受度（研究问题RQ1），并检验与他们使用这种服务意愿相关的因素的解释力（RQ2）。根据扩展的统一技术接受和使用理论（UTAUT2）的指导，我们考察了以下UTAUT2因素的解释力：任务预期、努力预期、社会影响、促进条件和习惯，此外还补充了感知信息不足、感知易感性、感知严重性和癌症诊断等与家族癌症信息寻求相关的附加因素。 我们于2022年3月通过德国网络访问平台进行了一项横断面调查，根据年龄、性别和教育进行分层（N=1084）。参与者中自己被诊断为癌症（n=144）或有受到影响的亲属（n=990）。所有结构均使用已建立的量表进行测量。为了回答RQ1，采用描述性数据（均值和分布）。对于RQ2，进行了分块多元线性回归分析。 总体而言，32.7%的参与者（相对）愿意，28.9%的参与者不确定，38.4%的参与者（相对）不愿意将来使用家族癌症风险的在线聊天服务。多元线性回归分析解释了47%的变异性。结果显示，任务预期、社会影响、习惯、感知易感性和感知严重性与使用家族癌症风险的在线聊天服务的意愿呈正相关。努力预期、促进条件、信息不足和癌症诊断与使用意愿无关。 在线聊天服务似乎能够为家族癌症风险提供信息。在推广服务时，特别需强调个人利益。UTAUT2理论框架对解释在线聊天使用意愿非常有效，并且在家族癌症风险背景下无需扩展。 ©Paula Memenga、Eva Baumann、Hanna Luetke Lanfer、Doreen Reifegerste、Julia Geulen、Winja Weber、Andrea Hahne、Anne Müller、Susanne Weg-Remers。刊登于《医学互联网研究杂志》（https://www.jmir.org），2023年8月28日。

An important prerequisite for actively engaging in cancer prevention and early detection measures, which is particularly recommended in cases of familial cancer risk, is the acquisition of information. Although a lot of cancer information is available, not all social groups are equally well reached because information needs and communicative accessibility differ. Previous research has shown that a live chat service provided by health professionals could be an appropriate, low-threshold format to meet individual information needs on sensitive health topics such as familial cancer risk. An established German Cancer Information Service is currently developing such a live chat service. As it is only worthwhile if accepted by the target groups, formative evaluation is essential in the course of the chat service's development and implementation.This study aimed to explore the acceptance of a live chat on familial cancer risk by patients with cancer and their relatives (research question [RQ] 1) and examine the explanatory power of factors associated with their intentions to use such a service (RQ2). Guided by the Extended Unified Theory of Acceptance and Use of Technology (UTAUT2), we examined the explanatory power of the following UTAUT2 factors: performance expectancy, effort expectancy, social influence, facilitating conditions, and habit, supplemented by perceived information insufficiency, perceived susceptibility, perceived severity, and cancer diagnosis as additional factors related to information seeking about familial cancer.We conducted a cross-sectional survey via a German web-based access panel in March 2022 that was stratified by age, gender, and education (N=1084). The participants are or have been diagnosed with cancer themselves (n=144) or have relatives who are or have been affected (n=990). All constructs were measured with established scales. To answer RQ1, descriptive data (mean values and distribution) were used. For RQ2, a blockwise multiple linear regression analysis was conducted.Overall, 32.7% of participants were (rather) willing, 28.9% were undecided, and 38.4% were (rather) not willing to use a live chat on familial cancer risk in the future. A multiple linear regression analysis explained 47% of the variance. It revealed that performance expectancy, social influence, habit, perceived susceptibility, and perceived severity were positively associated with the intention to use a live chat on familial cancer risk. Effort expectancy, facilitating conditions, information insufficiency, and cancer diagnosis were not related to usage intentions.A live chat seems promising for providing information on familial cancer risk. When promoting the service, the personal benefits should be addressed in particular. UTAUT2 is an effective theoretical framework for explaining live chat usage intentions and does not need to be extended in the context of familial cancer risk.©Paula Memenga, Eva Baumann, Hanna Luetke Lanfer, Doreen Reifegerste, Julia Geulen, Winja Weber, Andrea Hahne, Anne Müller, Susanne Weg-Remers. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 28.08.2023.