Walker Lesley, Jamrozik Konrad, Wingfield David, Lawley Guy
Department of Primary Care and Social Medicine, Imperial College, London, UK.
Age Ageing. 2005 Sep;34(5):480-5. doi: 10.1093/ageing/afi152. Epub 2005 Jul 25.
evaluation of the 'Keep Well At Home' (KWAH) Project in West London indicated that a programme of screening persons aged 75 and over had not reduced rates of emergency attendances and admissions to hospital. However, coverage of the target population was incomplete. The present analysis addresses 'efficacy'-whether individuals who completed the screening protocol as intended did subsequently use Accident & Emergency (A&E) services less often.
the target population was divided into five groups, depending on whether an individual had completed none, one or both phases of screening, and whether deviations from the protocol related to incomplete coverage or refusal to participate further. We ascertained use of emergency services before screening and for up to 3 years afterwards by linkage of records from KWAH to those of local A&E Departments. Patterns of emergency care were examined as crude rates and, via proportional hazards models, after adjustment for available confounders.
there was an increase of 51% (95% CI 22-86%) in the crude rate of emergency admissions in the year after first-phase screening compared with the 12 months before assessment. This was most obvious in individuals deemed at high risk who also underwent the second-phase assessment (adjusted hazard ratio relative to individuals not 'at risk'=2.33; 95% CI 1.59-3.42).
the available data do not allow us to distinguish between several possible explanations for the paradoxical increase in use of emergency services. However, what seem to be sensible policies do not necessarily have their intended effects when implemented in practice.
对伦敦西部“居家安康”（KWAH）项目的评估表明，针对75岁及以上人群的筛查计划并未降低急诊就诊率和住院率。然而，目标人群的覆盖并不完整。本分析关注的是“效果”——即按预期完成筛查方案的个体随后是否更少使用急诊服务。
根据个体是否完成筛查的零个、一个或两个阶段，以及与方案的偏差是与覆盖不完整还是拒绝进一步参与有关，将目标人群分为五组。我们通过将KWAH的记录与当地急诊科的记录相链接，确定了筛查前及之后长达3年的急诊服务使用情况。急诊护理模式以粗率进行检查，并通过比例风险模型在对可用混杂因素进行调整后进行检查。
与评估前的12个月相比，在第一阶段筛查后的一年中，急诊入院的粗率增加了51%（95%置信区间22%-86%）。这在被认为高危且也接受了第二阶段评估的个体中最为明显（相对于“非高危”个体的调整后风险比=2.33；95%置信区间1.59-3.42）。
现有数据无法让我们区分急诊服务使用出现反常增加的几种可能解释。然而，看似合理可行的政策在实际实施时不一定会产生预期效果。
