Tag Archives: Teenage pregnancy

Ever Increasing Life Expectancies Come to an Abrupt End Among American Whites

Big discontinuities are fascinating. Just when we think we understand something, the trend line changes radically. Examples of unexpected discontinuities in trends include the massive decline in smoking among African-Americans in the 1980s [1]; the drop in crime in high-income cities over the last decade or so [2]; and the recent drop in teenage pregnancy rates.[3] These are favourable trends in contrast to the sudden end of year on year decline in mortality among the majority population in one large country – white people in the US.[4] Anne Case and Angus Deaton drill down into the numbers in their recent paper:

  1. Is this trend confined to white people? Yes, black and Hispanic people continue to experience declining mortality rates.
  2. Is this trend seen in other high-income countries? No – in France, Sweden, Japan and the UK, age-specific mortality continues to decline across the populations.
  3. How does it differ among whites by economic class? Using education as a proxy, a decline in life expectancy is confined to those with no education beyond high-school.
  4. What diseases are driving it? ‘Deaths of despair’ (suicide, alcoholic cirrhosis, drug overdose) are rising among white people in the US in absolute terms, and in comparison with non-white groups and with other countries. Cardiovascular deaths are no longer declining among whites in the US, even as they continue to do so in other countries. Increases in ‘deaths of despair’ along with arrest in declining cardiovascular diseases, combine to extinguish the declining trend.
  5. Is the phenomenon localised geographically? No, the ‘epidemic’ in ‘deaths of despair’ among white people covers rural and urban areas, and has pretty much become country-wide.
  6. Is the problem gender specific? No, the rise in ‘deaths of despair’ among the less-educated group affects both women and men.
  7. What are the long term trends? While the differences in mortality between better and less well educated groups are getting narrower in Europe, the gap is getting wider among whites in the US. This widening gap is also reflected in changes in self-assessed health.

So is all this really just a reflection of widening economic disparities? No:

  1. Disparities are widening within the black community and between black people and white people. However, mortality is converging between rich and poor black and Hispanic people, and ‘deaths of despair’ are not increasing in these ethnic groups.
  2. Widening disparities are seen in all comparator countries – in Spain, ‘deaths of despair’ actually declined through a vicious economic downturn between 2007 and 2011, for example.
  3. The difference in outcome correlates much more strongly with change in education than change in income.
  4. Historically there are many instances when mortality and inequality have moved in different directions, and selective reporting can be used by unscrupulous ideologues to buttress either side of this argument.

So why has it happened. Here we need to turn to sociology (in some desperation). A novel, called ‘Fishtown’ (by Neal Goldstein) captures some of the sociology; a tale of a rising feeling of purposelessness as workers overseas and machines at home combine to force less educated people (men especially) out of jobs. Such people rely on welfare, while immigrants take over the lowest paid jobs. Another explanation turns on the idea of differentials – this time between whites and non-whites, and loss of status rather than failure to achieve it – “if you have always been privileged, equality begins to look like oppression.” Case and Deaton are careful to point out that the above explanations are not strongly supported by the data. But there is something ‘out there’ – a ‘latent variable’ with a long memory (i.e. operating over the life course of various ‘cohorts’ of people). Many commentators pretend they have understood these latent variables, but I think we are going to have to look a lot harder and resist the beguiling but facile explanations offered up by journalists, political commentators, and academics alike (a point pursued in the next exciting instalment of your News Blog).— Richard Lilford, CLAHRC WM Director

References:

  1. Oredein T & Foulds J. Causes of the Decline in Cigarette Smoking Among African American Youths From the 1970s to the 1990s. Am J Public Health. 2011; 101(10): e4-14.
  2. The Economist. Falling crime. Where have all the burglars gone? The Economist. 20 July 2013.
  3. Wellings K, Palmer MJ, Geary RS, et al. Changes in Conceptions in Women Younger Than 18 Years and the Circumstances of Young Mothers in England in 2000-12: an Observational Study. Lancet. 2016; 388: 586-95.
  4. Case A, & Deaton A. Mortality and morbidity in the 21st century. Brookings Papers on Economic Activity. BPEA Conference Drafts. March 23-24, 2017.

Pregnancy Before Age 16 – Dropping Quite Rapidly From a Peak in 1997

Tracking four databases, a recent study finds sharply falling ‘teenage pregnancy’ rates in England, starting in 1997 and accelerating in 2007.[1] Rates have fallen fastest in the most deprived areas, albeit from a very high base. The reduction has been much larger in England than in other European countries where the decline is also observed. It is difficult to know exactly why, but proximal causes (increasing availability of long-acting contraception) and distal causes (gradually improving educational standards in England) are both correlated in this study with lower teenage pregnancy. I think we should go even further in removing barriers to use of contraception in young people – for instance it should be available without prescription, or if prescription is required it should be available on site, given evidence cited in a previous News Blog.[2]
— Richard Lilford, CLAHRC WM Director

Reference:

  1. Wellings K, Palmer MJ, Geary RS, et al. Changes in Conceptions in Women Younger Than 18 Years and the Circumstances of Young Mothers in England in 2000-12: an Observational Study. Lancet. 2016; 388: 586-95.
  2. Lilford RJ. Contraception – a Huge Cause of Controversy Around the World. NIHR CLAHRC West Midlands News Blog. August 8, 2014.

Support for Pregnant Teenagers

News blog readers are (anxiously) awaiting publication of the important CLAHRC study of the effects providing additional support to mothers at high social risk. In the meantime, we must content ourselves with a study of additional support in teenage pregnancy.[1] The support was intensive and, as in the CLAHRC study, it started before birth and continued postnatally. Study numbers were similar to the CLAHRC study at over 1,600 participants. The results were null for the pre-defined ‘primary’ outcomes of birth weight, childhood admissions and subsequent pregnancy. But are these the sorts of end-point that one would expect to change? Programme theory would surely suggest that a social intervention would change social outcomes?! Yet, these were relegated to ‘secondary outcome’ status. The results of the CLAHRC study are becoming more tantalising with every passing week!

— Richard Lilford, CLAHRC WM Director

References:

  1. Robling M, Bekkers M-J, Bell K, et al. Effectiveness of a nurse-led intensive home-visitation programme for first-time teenage mothers (Building Blocks): a pragmatic randomised controlled trial. Lancet. 2015. [ePub].

It Really is Possible to Intervene to Reduce Teenage Pregnancy

A cohort of teenagers offered information and access to free contraceptives had much lower pregnancy rates than the national average.[1] Participants (and their parents) had to agree to participate and, although they appeared to be at higher “risk” than the control population, selection bias cannot be ruled out. Nevertheless, the differences in pregnancy rates were striking (34 vs. 159 per thousand) and suggest that a system that overcomes all three of the above barriers (financial, information and access) is more effective than a narrow emphasis on “education” alone. A general learning point may be that it is important to identify and address all material barriers when designing an intervention.[2] I think that is consistent with the theory of constraints, but others might wish to comment.

— Richard Lilford, CLAHRC WM Director

Reference:

  1. Secura GM, Madden T, McNicholas C, Mullersman J, Buckel CM, Zhao Q, Peipert MD. Provision of no-cost, long-acting contraception and teenage pregnancy. N Engl J Med. 2014; 371(14): 1316-23.
  2. Michie S, van Stralen MM, West R. The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implement Sci. 2011; 6: 42.

Of International Trends, Hypotheses and Instrumental Variables

Social trends can be quite dramatic. In the last fortnight, two highly desirable trends have been reported in the UK – a drop in injuries and death due to violence [1] and a drop in the country’s notoriously high teenage pregnancy rates.[2] [3] Observing a trend is one thing, discerning cause is another. The drop in violence has been attributed to decreasing alcohol consumption by young people in the UK. This drop in violence is an international phenomenon, mirrored across the developed world and even, to some extent, in middle-income countries.[4] However, the same change in prevalence of a social problem can have different causes in different places. The drop in violent crime in the USA has been going on for a long time and cannot be attributed to a drop in alcohol use. There are many theories to account for the sustained drop in violent crime in the USA and elsewhere. These include better police tactics,[5] improved security [6] and replacing cash with electronic transactions.[7] Two unusual theories relate to changes in the abortion law and environmental chemical exposure. John Donohue and Steven Levitt attributed the change to liberal abortion laws, which resulted in lower birth rates among under-privileged single parents, and hence a smaller pool of high-risk people 18 years later.[8] One way to test causal inferences from such an association is to seek an ‘Instrumental variable’ – a change that is thought to be independent of the outcome variable of interest. The effect of introducing or removing capital punishment on homicide rates is an example. In the case of violent crime, Donohue and Levitt compared the year in which individual States liberalised abortion laws – which they regarded as an instrumental variable – with the year in which violence started to decline in that particular state. The drop in crime followed the liberalisation in law after a set interval. This trend has been observed in other countries – Canada,[9] Australia [10] and Romania.[11] In the meantime another provocative hypothesis linked the drop in lead levels in petrol to the decline in violence and there is evidence that lead can predispose to violence,[12] [13] with some even attributing the downfall of Rome to the ubiquitous use of lead pipes in the Empire, though a recent paper concluded the likely concentration of lead would be unlikely to represent a major health risk.[14] A study linking the point in time where crime rates started to decline to control of lead levels in the environment would be revealing – as usual, please respond if you know of, or are planning, such a study. The drop in violent crime came later in Europe, or not at all,[15] and would appear to have different antecedents, of which binge-drinking is one. The UK drop in teenage pregnancy rates might be the result of government action. Certainly a concerted and rather expensive national program was put in place, starting in about 2000. Further, the experimental evidence, taken in the round, supports the effectiveness of educational interventions to increase contraceptive use and decrease pregnancy rates without reducing the frequency of sexual encounters.[16] [17] There has been a drop in teenage pregnancy rates across OECD countries [18] and maybe the amount of education on contraception and relationship management has been upgraded in schools across the continent? — Richard Lilford, CLAHRC WM Director. References:

  1. Sivarajasingam V, Page N, Morgan P, Matthews L, Moore S, Shepherd J. Trends in community violence in England and Wales 2005-2009. Injury. 2014; 45(3): 592-598.
  2. Arie S. Has Britain solved its teenage pregnancy problem? BMJ. 2014; 348: g2561.
  3. Office for National Statistics. Conceptions in England and Wales, 2012. 2012.
  4. van Dijk J, Tseloni A, Farrell G. The International Crime Drop: New Directions in Research. Hampshire: Palgrave Macmillan; 2012.
  5. CBS News. Chicago police credit new tactics for drop in homicides. Feb 7 2014.
  6. MacDonald JM, Klick J, Grunwald B. The Effect of Privately Provided Police Services on Crime. Faculty Scholarship. Paper 430. 2012.
  7. Wright R, Tekin E, Topalli V, McClellan C, Dickinson T, Rosenfeld R. Less Cash, Less Crime: Evidence from the Electronic Benefit Transfer Program. NBER Working Paper 19996. 2014.
  8. Donohue JJ, Levitt SD. The impact of legalized abortion on crime. Quart J Econom. 2001; 2: 379-420.
  9. Sen A. Does Increased Abortion Lead to Lower Crime? Evaluating the Relationship between Crime, Abortion, and Fertility. BE J Econ Anal Poli. 2007; 7(1).
  10. Leigh A & Wolfers J. Abortion and Crime. AQ: J Contemp Anal. 2000; 72(4): 28-30.
  11. Pop-Eleches C. The Impact of an Abortion Ban on Socioeconomic Outcomes of Children: Evidence from Romania. J Pol Econ. 2006; 114(4): 744-73.
  12. Nevin R. How Lead Exposure Relates to Temporal Changes in IQ, Violent Crime, and Unwed Pregnancy. Environ Res. 2000; 83(1): 1-22.
  13. Nevin R. Understanding international crime trends: The legacy of preschool lead exposure. Environ Res. 2007; 104: 315-336.
  14. Delile H, Blichert-Toft J, Gorian J-P, Keay S, Albaréde F. Lead in ancient Rome’s city waters. PNAS. 2014. [Online].
  15. Buonnano P, Drago F, Galbiati R, Zanella G. Crime in Europe and in the US: Dissecting the ‘Reversal of Misfortunes.’ Econ Policy. 2011; 26(67): 347-85.
  16. Kirby DB, Laris BA, Rolleri LA. Sex and HIV Education Programs: Their Impact on Sexual Behaviors of Young People Throughout the World. J Adolesc Health. 2007; 40(3): 206-17.
  17. Harden A, Brunton G, Fletcher A, Oakley A. Teenage pregnancy and social disadvantage: systematic review integrating controlled trials and qualitative studies. BMJ. 2009; 339: b4254.
  18. Organisation for Economic Development. Share of births outside wedlock and teenage births, 2013. 2013.