Older rationales and other challenges in handling causes of death in historical individual-level databases: the case of Copenhagen, 1880-1881.

Large-scale historical databases featuring individual-level causes of death offer the potential for longitudinal studies of health and illnesses. There is, however, a risk that the transformation of the primary sources into 'data' may strip them of the very qualities required for proper medical historical analysis. Based on a pilot study of all 11,100 deaths registered in Copenhagen in 1880-1881, we identify, analyse and discuss the challenges of transcribing and coding cause of death sources into a database. The results will guide us in building Link-Lives, a database featuring close to all nine million Danish deaths from 1787 to 1968. The main challenge is how to accommodate different older medical rationales in one classification system. Our key finding is multi-coding with more than one version of the ICD system (e.g. ICD-1893 and ICD-10) can be used as a novel method to systematically handle historical causes of death over time.

The stillbirth sex ratio as a marker of population health among live-born males in Denmark, 1835-1923.

OBJECTIVES: We know little about whether an elevated stillbirth sex ratio (ratio of male to female stillbirths) gauges stronger selection in utero against frail male gestations and therefore predicts greater male infant survival. An alternative scenario could involve a "low endowment" case in which pregnancy cohorts show both excess male stillbirths and elevated mortality risk among male live births. We exploit the longest sex-specific stillbirth series (Denmark, 1835-1923) to explore whether annual deviations in age-specific male mortality vary with the annual cohort's stillbirth sex ratio. METHODS: We applied autoregressive, integrated, moving average time series methods to annual counts of age-specific male mortality in Denmark. We derived the independent variable, the stillbirth sex ratio, from only late stillbirths (ie, 28th week and thereafter) owing to data availability. Methods control for secular patterns as well as shared antecedents of male and female mortality. RESULTS: Cohort male infant mortality varies positively with the stillbirth sex ratio (coef = 0.0081, standard error [SE] = 0.0019, P < 0.001). This positive relation persists into childhood (ie, ages 1-4.99 years) but attenuates with age. DISCUSSION: We infer support for the "low endowment" argument in that high stillbirth sex ratios predict a relatively greater risk of mortality among males which ultimately survive to birth. These findings provide evidence that the stillbirth sex ratio may serve as a marker of population health among male cohorts.

Mrs Stone and Dr Smellie: British eighteenth-century birth attendance and long-run levels and trends in maternal mortality discussed in a north European context.

This is a book review turned research paper. The aim is to estimate the differences in the maternal mortality rate (MMR) between untrained midwives, expert midwives, and the famous obstetrician Dr Smellie in eighteenth-century Britain. The paper shows that the birth attendance practices of the expert midwife Mrs Stone and of Dr Smellie were very similar, though Stone used her hands whereas Smellie used forceps. Both applied the same invasive techniques to successfully deliver women with similar fatal complications, techniques that untrained midwives and most surgeons of the time could not perform. However, the same procedures, if used for normal births, would have increased the MMR. So, the key to the low MMR of both was that they kept interventions away from the majority of births that were normal. The paper quantifies the likely MMR for a 'Stone and Smellie style' birth attendance and concludes that the wider dissemination of their techniques can explain the decline in the British MMR.