Saunderson T, Haynes R, Langford I H
School of Environmental Sciences, University of East Anglia, Norwich.
J Public Health Med. 1998 Sep;20(3):261-7. doi: 10.1093/oxfordjournals.pubmed.a024767.
Given that a high proportion of undetermined deaths are thought to be suicides, the objective of the study was to compare the geography of the two verdicts, with emphasis on urban-rural differences, to determine whether the likelihood of a death being classified as suicide varies according to location.
Standardized mortality ratios (SMRs) were mapped for the local authority districts of England and Wales, using data aggregated over the period 1989-1992. Districts were classified according to population density, and SMRs calculated for each quartile. Finally, regression equations were obtained to model the relationship of suicide and undetermined death with a series of risk factors.
Both male and female undetermined deaths showed a significant deficit in the most sparsely populated districts and a significant excess in the most densely populated districts. Female suicides were also significantly high in densely populated districts, but male suicides were highest in the most rural areas (SMR 110, 95 per cent confidence intervals 105-115). District variations in both verdicts were associated with the proportion of single-person households for both sexes, but male suicides and male undetermined deaths were associated with additional predictors, consistent with their distinct geographical distributions.
Differences in suicide methods, the likelihood of communicating suicidal intent and, perhaps, variations in access to psychiatric services might be contributory factors to the observed differences between the verdicts. The results suggest that recorded suicides are a biased subset of actual suicides, particularly for males, and that the study of suicide verdicts alone is potentially misleading.
鉴于很大一部分死因不明的死亡被认为是自杀，本研究的目的是比较这两种死因判定的地理分布情况，重点关注城乡差异，以确定死亡被判定为自杀的可能性是否因地点而异。
利用1989 - 1992年期间汇总的数据，绘制了英格兰和威尔士地方当局辖区的标准化死亡率（SMR）图。根据人口密度对辖区进行分类，并计算每个四分位数的SMR。最后，获得回归方程以模拟自杀和死因不明死亡与一系列风险因素之间的关系。
在人口最稀少的地区，男性和女性死因不明的死亡人数均显著不足，而在人口最密集的地区则显著过多。在人口密集地区，女性自杀率也显著较高，但男性自杀率在最偏远农村地区最高（标准化死亡率为110，95%置信区间为105 - 115）。两种死因判定在辖区间的差异与男女单身家庭的比例有关，但男性自杀和男性死因不明的死亡与其他预测因素有关，这与它们独特的地理分布一致。
自杀方式的差异、传达自杀意图的可能性以及获得精神科服务的差异可能是导致观察到的死因判定差异的因素。结果表明，记录在案的自杀只是实际自杀的一个有偏差的子集，尤其是对男性而言，仅研究自杀判定可能会产生误导。
