May 14, 2015

expert reaction to study investigating single motherhood and health in later life

Publishing in the Journal of Epidemiology & Community Health, researchers have attempted to examine an association between single motherhood (defined in this study as being an unmarried mother, not taking cohabitation into consideration) and health later in life. They report that single mothers were at risk of poorer health, but that this risk varied between countries. A Before the Headlines analysis accompanied this roundup.

Prof. Kevin McConway, Professor of Applied Statistics, The Open University, said:

“This is an impressive piece of work statistically, but we’ve got to be careful in interpreting it. The study is looking over a long period in women’s lives, and a lot happens over that period apart from single motherhood. It’s complex and statistically very difficult to sort out what causes what.

“The research report and press release point out that single parenthood may increase women’s chances of being in poverty, which may lead to poor health in later life. But they also raise the possibility that poverty itself may increase the risk of becoming a single parent. This study couldn’t, on its own, do much to sort out this complex causality. As again the authors acknowledge, their data sources did not have information about employment, and often had to rely on the women’s recall in later life of events during early adulthood. Such recall isn’t always perfect.

“So when the authors write, “The findings add to the growing recognition that single motherhood may have long term health effects on mothers”, the emphasis has got to be on the “may”. We certainly don’t know for sure – and in the press release headline about single motherhood being “linked” to poorer health, it’s important to understand that the link is a statistical one, not necessarily a cause-effect link.

“It’s also important to understand that the research report itself is claiming a statistical link only in the USA, the UK and Scandinavia (which, here, means Denmark and Sweden).

“The press release does point out that there was a less consistent association between single motherhood and health in later life in the other European regions studied (continental Western, Eastern and Southern Europe), but the research report makes it clear that the association in those regions wasn’t statistically significant (so it might be just a chance finding), and indeed, it goes slightly the other way in Eastern Europe, where (on average and without statistical significance) women who had been single mothers in earlier life were in slightly better health in later life.

“This really just adds to the complexity of the picture, and the difficulty of deciding what policy implications (if any) the research might have in the different countries involved.”

‘Mothering alone: cross-national comparisons of later-life disability and health among women who were single mothers’ by Lisa F Berkman et al. published in the Journal of Epidemiology & Community Health on Thursday 14 May 2015. 

Declared interests

Prof. Kevin McConway: “I don’t have any relevant interests to declare”.