Background: Preterm birth (PTB) is a major cause of infant morbidity and mortality, and accurate assessment of women in threatened preterm labour (TPTL) is vital for identifying need for appropriate intervention. Risk assessment in TPTL is challenging, however, due to its complex and multifactoral nature. In many women, TPTL symptoms do not progress to spontaneous PTB (sPTB) so assessment that reassures quickly, often through use of tests, e.g. fetal fibronectin (fFN) and cervical length (CL), may reduce unnecessary intervention and decrease anxiety. Aims: This PhD project had two main objectives: first to improve TPTL risk assessment by further developing the clinical decision support tool, the “QUIPP” mobile phone application, which simplifies risk assessment by calculating individual % risk of sPTB based on risk status, fFN and CL results. The second objective was to understand TPTL from the women’s perspective in order to inform future improvements in care. Method: The study comprised three components: 1) a prospective cohort study, collecting data on risk factors, test results and interventions. Predictive utility of fFN and CL were investigated, as well as generation and validation of risk prediction algorithms for the second version of QUIPP; 2) a qualitative study of women’s experience of TPTL through one-to-one semi-structured interviews; 3) a qualitative study of clinicians using the first version of QUIPP. Results: Cohort study: 1186 women were recruited at 11 UK hospitals between March 2015 and October 2017, with data available for analysis on 1037. Prevalence of sPTB was 3.9% (40/1037) and 12.1% (125/1037) at <34 and <37 weeks’ gestation, respectively. Validation of QUIPP algorithms, using risk factors and fFN results alone, demonstrated good prediction of sPTB <30 weeks’ gestation (AUC 0.96, 95% CI 0.94-0.99) and at <1 week of testing (AUC 0.91, 95% CI 0.87-0.96). Qualitative study: Four themes emerged following interviews with 19 women: i) coping with uncertainty; ii) dealing with conflicts; iii) aspects of care and iv) interactions with professionals. QUIPP users’ study: 10 clinicians expressed predominantly positive views and suggested improvements. Conclusion: All components of this project informed development of QUIPP v.2 (algorithms and design), which appears superior in predicting sPTB compared to previously reported predictive utility of fFN, CL and QUIPP v.1 algorithms. The qualitative study was the first exploring women’s experience of TPTL in a UK hospital with a specialist preterm service, and findings further support the need for women of all risk groups to have timely access to advice and information, and continuity of care.
Threatened preterm labour: A prospective cohort study for the development of a clinical risk assessment tool and a qualitative exploration of women's experiences of risk assessment and management.
Carter, J. C. (Author). 2019
Student thesis: Doctoral Thesis › Doctor of Philosophy