Lee Alex, de Mendonça Lucas, McCarthy Damien, Nelson Craig, Rafiq Meena, Venning Brent, Chima Sophie, Daly Deborah, Fishman George, Kearney Chris, Hunter Barbara, Lim Fong Seng, Manski-Nankervis Jo-Anne, Nicholson Brian D, Emery Jon, Martinez-Gutierrez Javiera
Department of General Practice and Primary Care, Faculty of Medicine Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
Department of General Practice and Primary Care, Faculty of Medicine Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia.
BMJ Open. 2025 Jul 28;15(7):e104690. doi: 10.1136/bmjopen-2025-104690.
We calculate positive predictive values (PPVs) of patients presenting with unexpected weight loss (UWL) being diagnosed with cancer within 6 months, using data from a population of Australian primary care patients to replicate results from a previous UK study.
A diagnostic accuracy study involving calculation of the PPV for any cancer using retrospective data from routinely collected electronic healthcare records. The index date is defined as the first recorded UWL presentation and the reference standard is cancer diagnosis within 6 months of the index date.
This study uses primary care data from the Patron primary care database, linked to hospital admissions data and the Victorian Cancer Registry. We include only patients who presented to their General Practitioners (GPs) at least once between 1 July 2007 and 1 February 2022.
Patients were included if they were at least 18 years of age at the index date, had no previous diagnosis of cancer or previous weight loss intervention, including being prescribed medications for weight loss. 13 306 patients out of a primary care population of 1 791 051 patients were identified that met the eligibility criteria.
When stratified by age, sex and smoking status, we found PPVs lower than those derived in a previous UK primary care study, though still above 3% for male non-smokers over 60, female smokers over 70 and all males over 70. Patients from ages 60-79 with at least one abnormal blood test result had PPVs consistently above 3%, while overall, patients with abnormal blood test results have PPVs of up to 35%.
We confirmed that many PPVs, while consistently below those derived in the UK study, are above clinically significant thresholds and increasing with age and the number of different abnormal blood test results.
我们利用澳大利亚初级保健患者群体的数据，计算出现意外体重减轻（UWL）的患者在6个月内被诊断为癌症的阳性预测值（PPV），以复制先前英国一项研究的结果。
一项诊断准确性研究，使用常规收集的电子医疗记录中的回顾性数据计算任何癌症的PPV。索引日期定义为首次记录的UWL出现日期，参考标准为索引日期后6个月内的癌症诊断。
本研究使用来自Patron初级保健数据库的初级保健数据，该数据与医院入院数据和维多利亚癌症登记处相关联。我们仅纳入在2007年7月1日至2022年2月1日期间至少就诊过一次全科医生（GP）的患者。
如果患者在索引日期时至少18岁，且此前没有癌症诊断或先前的体重减轻干预措施，包括未被开处减肥药物，则纳入研究。在1791051名初级保健患者中，有13306名患者符合入选标准。
按年龄、性别和吸烟状况分层时，我们发现PPV低于先前英国初级保健研究得出的结果，不过60岁以上男性非吸烟者、70岁以上女性吸烟者和所有70岁以上男性的PPV仍高于3%。60 - 79岁且至少有一项血液检测结果异常的患者，其PPV始终高于3%，而总体而言，血液检测结果异常的患者PPV高达35%。
我们证实，许多PPV虽然始终低于英国研究得出的结果，但高于临床显著阈值，且随年龄和不同血液检测异常结果的数量增加而增加。
