Andrew Baxter



ORCiD: 0000-0002-7654-9687

Research title: Why are rates of teenage pregnancy falling?

Research Summary

My PhD project looks at testing hypothesised causes of lowering rates of teenage pregnancy using natural experimental methods.

High rates of teenage pregnancy in the UK have prompted several policy approaches to address them. Over the last 20 years we're seen huge drops in rates across Scotland, England and Wales, with under-18 pregnancy rates halving in this time. Simultaneously, we've seen large environmental and cultural shifts with unknown effects on the pregnancy risk behaviours of teenagers; some of these may have had global impact.

My project first looks at the hypothesised causes of lowering pregnancy rates proposed in the literature, assessing strength of evidence and scoping causal pathways for further testing. This is achieved through a systematic review informed by and updating a provisional causal model. I apply a developed series of causal questions to assess the evidence for the impact of a population-wide impact of a policy, intervention or environment change on teenage pregnancy risk. Selecting top plausible hypothesised causes I then apply the RE-AIM framework to query further literature to assess evidence for impact on the UK's rates in the observed period.

The second aim of my project is to demonstrate the use of natural experimental methods to evaluate a policy with a hypothesised effect on pregnancy rates. The Teenage Pregnancy Strategy was published in 1999 in England with the aim of reducing teenage pregnancies by 50% in ten years. Initial observational data showed a 51% drop in pregnancy rates by 2014; this has previously been cited as evidence of the effectiveness of the Strategy. To overcome the potential biases in observational data and to attempt to correct for background trends, I use econometric methods to run robust comparative analyses and better evaluate the Strategy's effects.


List by: Type | Date


Effects of Housing First approaches on health and well-being of adults who are homeless or at risk of homelessness: systematic review and meta-analysis of randomised controlled trials. Society for Social Medicine and Population Health - Annual Scientific Meeting 2019. Oral presentation

Did England’s Teenage Pregnancy Strategy reduce pregnancy rates in England? Evaluating a policy using two natural experimental methods. Society for Social Medicine and Population Health - Annual Scientific Meeting 2020. Oral presentation


Public Health Research Tools in R - delivering a workshop on the use of Shiny apps in presenting public health. In collaboration with The MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Society for Social Medicine and Public Health Scotland. (

Developing and Evaluating Social and Public Health Interventions; pilot course, 2019 - course delivery assistant. In collaboration with the University of Glasgow and the Kilimanjaro Clinical Research Institute.

Improving Health and Society; Masters' module 2018 - course assistant.


Additional Information

Certified RStudio instructor in Tidyverse and Shiny apps