Clinical and Population Perinatal Health Research, Kolling Institute of Medical Research, Sydney Medical School, University of Sydney at Royal North Shore Hospital, Australia.
BMC Med Res Methodol. 2012 Sep 25;12:149. doi: 10.1186/1471-2288-12-149.
With the increasing use of probabilistically linked administrative data in health research, it is important to understand whether systematic differences occur between the populations with linked and unlinked records. While probabilistic linkage involves combining records for individuals, population perinatal health research requires a combination of information from both the mother and her infant(s). The aims of this study were to (i) describe probabilistic linkage for perinatal records in New South Wales (NSW) Australia, (ii) determine linkage proportions for these perinatal records, and (iii) assess records with linked mother and infant hospital-birth record, and unlinked records for systematic differences.
This is a population-based study of probabilistically linked statutory birth and hospital records from New South Wales, Australia, 2001-2008. Linkage groups were created where the birth record had complete linkage with hospital admission records for both the mother and infant(s), partial linkage (the mother only or the infant(s) only) or neither. Unlinked hospital records for mothers and infants were also examined. Rates of linkage as a percentage of birth records and descriptive statistics for maternal and infant characteristics by linkage groups were determined.
Complete linkage (mother hospital record - birth record - infant hospital record) was available for 95.9% of birth records, partial linkage for 3.6%, and 0.5% with no linked hospital records (unlinked). Among live born singletons (complete linkage = 96.5%) the mothers without linked infant records (1.6%) had slightly higher proportions of young, non-Australian born, socially disadvantaged women with adverse pregnancy outcomes. The unlinked birth records (0.4%) had slightly higher proportions of nulliparous, older, Australian born women giving birth in private hospitals by caesarean section. Stillbirths had the highest rate of unlinked records (3-4%).
This study shows that probabilistic linkage of perinatal records can achieve high, representative levels of complete linkage. Records for mother's that did not link to infant records and unlinked records had slightly different characteristics to fully linked records. However, these groups were small and unlikely to bias results and conclusions in a substantive way. Stillbirths present additional challenges to the linkage process due to lower rates of linkage for lower gestational ages, where most stillbirths occur.
随着概率链接行政数据在健康研究中的应用越来越多，了解记录链接和未链接的人群之间是否存在系统差异变得非常重要。虽然概率链接涉及到个体记录的组合，但围产期健康研究需要从母亲和她的婴儿（多个）中组合信息。本研究的目的是：（i）描述澳大利亚新南威尔士州（NSW）围产期记录的概率链接，（ii）确定这些围产期记录的链接比例，以及（iii）评估链接的母婴医院分娩记录和未链接的记录是否存在系统差异。
这是一项基于人群的研究，对澳大利亚新南威尔士州 2001-2008 年的法定出生和医院记录进行了概率链接。创建链接组，其中出生记录与母亲和婴儿（多个）的住院记录完全链接，部分链接（仅母亲或婴儿（多个））或均未链接。还检查了母亲和婴儿未链接的医院记录。根据链接组确定了记录链接率（以出生记录的百分比表示）和母婴特征的描述性统计数据。
完整链接（母亲医院记录-出生记录-婴儿医院记录）适用于 95.9%的出生记录，部分链接适用于 3.6%，无链接的医院记录（未链接）占 0.5%。在单胎活产（完全链接=96.5%）中，没有链接的婴儿记录的母亲（1.6%）比例略高，其中年轻、非澳大利亚出生、社会劣势、妊娠结局不良的妇女比例略高。未链接的出生记录（0.4%）比例略高，其中初产妇、年龄较大、在私立医院经剖宫产分娩的澳大利亚出生妇女比例略高。死产的未链接记录比例最高（3-4%）。
本研究表明，围产期记录的概率链接可以实现高度代表性的完整链接。未链接到婴儿记录和未链接的记录的母亲的记录与完全链接的记录略有不同。然而，这些群体很小，不太可能在实质性方面对结果和结论产生偏差。由于大多数死产发生在较低的孕龄，因此与链接过程相关的死产仍然存在额外的挑战。
