School of Biomedical Sciences and Pharmacy, University of Newcastle, NSW, Australia.
School of Medicine and Public Health, University of Newcastle, NSW, Australia.
Int J Geriatr Psychiatry. 2017 Mar;32(3):316-323. doi: 10.1002/gps.4466. Epub 2016 Mar 14.
General practitioners (GPs) fail to identify more than 50% of dementia cases using the existing passive case-finding approach. Using data from the "Ageing in General Practice" study, we sought to establish the additional benefit of screening all patients over the age of 75 for dementia beyond those patients already identified by passive case-finding.
Patients were classified as "case-finding" (n = 425) or "screening" (n = 1006) based on their answers to four subjective memory related questions or their GP's clinical judgement of their dementia status. Cognitive status of each patient was formally assessed by a research nurse using the Cambridge Cognition Examination (CAMCOG-R). Patients then attended their usual GP for administration of the GP assessment of Cognition (GPCOG) dementia screening instrument, and follow-up care and/or referral as necessary in light of the outcome.
The prevalence of dementia was significantly higher in the case-finding group (13.6%) compared to the screening group (4.6%; p < 0.01). The GPCOG had a positive predictive value (PPV) of 61% in the case-finding group and 39% in the screening group; negative predictive value was >95% in both groups. GPs and their patients both found the GPCOG to be an acceptable cognitive assessment tool. The dementia cases missed via case-finding were younger (p = 0.024) and less cognitively impaired (p = 0.020) than those detected.
There is a very limited benefit of screening for dementia, as most people with dementia could be detected using a case-finding approach, and considerable potential for social and economic harm because of the low PPV associated with screening.
全科医生（GP）使用现有的被动病例发现方法，未能识别出超过 50%的痴呆病例。利用“普通实践中的老龄化”研究的数据，我们试图确定对所有 75 岁以上的患者进行痴呆筛查的额外益处，超过那些已经通过被动病例发现确定的患者。
根据患者对四个与主观记忆相关的问题的回答或其 GP 对其痴呆状态的临床判断，将患者分为“病例发现”（n = 425）或“筛查”（n = 1006）。每位患者的认知状态由研究护士使用剑桥认知考试（CAMCOG-R）进行正式评估。然后，患者到其常规 GP 处进行 GP 认知评估（GPCOG）痴呆筛查工具的管理，并根据结果进行后续护理和/或转诊。
病例发现组的痴呆患病率明显高于筛查组（13.6%对 4.6%；p < 0.01）。GPCOG 在病例发现组中的阳性预测值（PPV）为 61%，在筛查组中的阳性预测值为 39%；两组的阴性预测值均>95%。GP 和他们的患者都认为 GPCOG 是一种可以接受的认知评估工具。通过病例发现遗漏的痴呆病例更年轻（p = 0.024），认知障碍程度较低（p = 0.020）。
对痴呆症进行筛查的益处非常有限，因为使用病例发现方法可以检测到大多数痴呆症患者，并且由于筛查相关的低 PPV，存在很大的社会和经济危害的可能性。
