The Daily Telegraph today tells us that: "Single mothers in England [are] more likely to suffer ill health because their families 'do not support them'."
This is a half-truth. The large international study – involving 25,000 people from England, the US and 13 other European countries – behind the headline found a link between single motherhood between the ages of 16 and 49 and worse health in later life. But it did not find this was because families do not support them.
It would appear that this claim is prompted by a trend spotted in the study by the researchers. It found that health risks were more pronounced in northern European countries and the US. While in southern European countries the risk was less pronounced.
The researchers speculated that in southern European countries there is more of a tradition of informal support services, where grandparents, aunts, uncles, cousins etc all pitch in with childcare duties. Or as the proverb puts it "It takes a village to raise a child".
While this hypothesis is plausible it is also unproven and was not backed up with any new robust data on social support as part of the study.
The study was very large and diverse so the mother health link appears real. However, the reasons and causes behind it are still to be worked out.
Where did the story come from?
The study was carried out by researchers from US, Chinese, UK and German universities and was funded by the US National Institute on Aging.
The study was published in the peer-reviewed Journal of Epidemiology & Community Health.
The media reporting was generally partially accurate, as most took the finding about social support at face value. The link between single motherhood and later ill health was supported by the body of this study, but the study did not collect any information on social support, so this explanation, although plausible, was not based on direct evidence.
What kind of research was this?
The study investigated if single motherhood before the age of 50 was linked to poorer health later in life, and whether it was worse in countries with weaker "social [support] safety nets". To do this they analysed data collected from past cohort and longitudinal studies across 15 countries.
The researchers say single motherhood is known to be linked to poorer health, but didn’t know whether this link varied between countries.
Analysing previously collected data is a practical and legitimate study method. A limitation is that the original information was collected for specific reasons that usually differ from the research aims when coming to use it later. This can mean some information that would ideally be analysed is not there. In this study, the researchers couldn’t get information on social support networks, which they thought might explain some of their results.
What did the research involve?
The research team analysed health and lifestyle information on single mothers under 50 collected from existing large health surveys. The single mothers' health was documented into older age and compared across 15 countries.
Data was available from 25,125 women aged over 50 who participated in the US Health and Retirement Study; the English Longitudinal Study of Ageing; or the Survey of Health, Ageing and Retirement in Europe (SHARE). Thirteen of the 21 countries represented by SHARE (Denmark, Sweden, Austria, France, Germany, Switzerland, Belgium, The Netherlands, Italy, Spain, Greece, Poland, Czech Republic) had collected relevant data. With the US and England on board, this gave 15 countries for final analysis.
The researchers used data on number of children, marital status and any limitations on women's capacity for routine daily activities (ADL), such as personal hygiene and getting dressed, and instrumental daily activities (IADL), such as driving and shopping. Women also rated their own health.
Single motherhood was classified as having a child under the age of 18 and not being married, rather than living with a partner.
What were the basic results?
Single motherhood between the ages of 16 and 49 was linked to poorer health and disability in later life in several different countries. The risks were highest for single mothers in England, the US, Denmark and Sweden.
Overall 22% of English mothers had experienced single motherhood before age 50, compared with 33% in the US, 38% in Scandinavia, 22% in western Europe and 10% in southern Europe.
While single mothers had a higher risk of poorer health and disability in later life than married mothers, associations varied between countries.
For example, risk ratios for ADL limitations were significant in England, Scandinavia and the US but not in western Europe, southern Europe and eastern Europe.
Women who were single mothers before age 20, for more than eight years, or resulting from divorce or non-marital childbearing, had a higher risk.
How did the researchers interpret the results?
The researchers' concluded that: "Single motherhood during early adulthood or mid-adulthood is associated with poorer health in later life. Risks were greatest in England, the US and Scandinavia."
Although they didn’t have good data to back it up, they suggested that social support and networks may partially explain the findings. For example, areas like southern Europe, which the researchers say have strong cultural emphasis on family bonds, were not associated with higher health risks.
They add: "Our results identify several vulnerable populations. Women with prolonged spells of single motherhood; those whose single motherhood resulted from divorce; women who became single mothers at young ages; and single mothers with two or more children, were at particular risk."
This large retrospective study of over 25,000 women linked single motherhood between the ages of 16 and 49 with worse health in later life. This is not a new finding. What was new was that the link varied across different countries. Risks were estimated as greatest in England, the US and Scandinavia for example, but were less consistent in other areas of Europe.
The research team thought this might be caused by differences in how social networks supported single mothers in different countries, such as being able to rely on extended families. But they had no data to directly support this. They did not have information on, for example, socioeconomic status, social support or networks during single motherhood, so could not analyse whether these were important causes. They also did not know whether any of the women they classed as single were actually in non-marital or same-sex partnerships, which may have affected results.
Health status in later life is likely to be linked to a complex number of interrelated factors. Being a single mum may be one, social networks might be another. But based on this study we don't yet know for sure, or the mechanisms by which this could lead to worse health.
Studies that collect information on levels of social support alongside health outcomes for single women would be able to tell us whether this is the likely cause, but getting this data may not be easy.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
The Independent, 14 May 2015
Mail Online, 15 May 2015
The Daily Telegraph, 14 May 2015
Links to the science
Journal of Epidemiology and Community Health. Published online May 14 2015