The prevalence of multimorbidity and polypharmacy increases significantly with age and are associated with negative health consequences. However, most current interventions to optimize medication have failed to show significant effects on patient-relevant outcomes. This may be due to ineffectiveness of interventions themselves but may also reflect other factors: insufficient sample sizes, heterogeneity of population. To address this issue, the international PROPERmed collaboration was set up to obtain/synthesize individual participant data (IPD) from five cluster-randomized trials. The trials took place in Germany and The Netherlands and aimed to optimize medication in older general practice patients with chronic illness. PROPERmed is the first database of IPD to be drawn from multiple trials in this patient population and setting. It offers the opportunity to derive prognostic models with increased statistical power for prediction of patient-relevant outcomes resulting from the interplay of multimorbidity and polypharmacy. This may help patients from this heterogeneous group to be stratified according to risk and enable clinicians to identify patients that are likely to benefit most from resource/time-intensive interventions. The aim of this manuscript is to describe the rationale behind PROPERmed collaboration, characteristics of the included studies/participants, development of the harmonized IPD database and challenges faced during this process.

多发病和多药使用的流行率随着年龄的增长而显着增加，并与负面的健康后果相关。然而，目前大多数优化药物治疗的干预措施未能对患者相关结果产生显着影响。这可能是由于干预措施本身无效，但也可能反映了其他因素：样本量不足、人口异质性。为了解决这个问题，建立了国际 PROPERmed 合作以从五项整群随机试验中获取/综合个人参与者数据 (IPD)。这些试验在德国和荷兰进行，旨在优化老年慢性病全科患者的药物治疗。PROPERmed 是第一个从该患者群体和环境中的多项试验中提取的 IPD 数据库。它提供了获得具有更高统计能力的预后模型的机会，用于预测由多种疾病和多种药物相互作用导致的患者相关结果。这可能有助于根据风险对来自这个异质组的患者进行分层，并使临床医生能够识别可能从资源/时间密集型干预措施中获益最多的患者。本手稿的目的是描述 PROPERmed 合作背后的基本原理、纳入研究/参与者的特征、统一 IPD 数据库的开发以及在此过程中面临的挑战。这可能有助于根据风险对来自这个异质组的患者进行分层，并使临床医生能够识别可能从资源/时间密集型干预措施中获益最多的患者。本手稿的目的是描述 PROPERmed 合作背后的基本原理、纳入研究/参与者的特征、统一 IPD 数据库的开发以及在此过程中面临的挑战。这可能有助于根据风险对来自这个异质组的患者进行分层，并使临床医生能够识别可能从资源/时间密集型干预措施中获益最多的患者。本手稿的目的是描述 PROPERmed 合作背后的基本原理、纳入研究/参与者的特征、统一 IPD 数据库的开发以及在此过程中面临的挑战。