Exploring and enhancing the research potential of an integrated health care database: an observational study using de-identified linked, routine data for children and young people in Northwest London
File(s)
Author(s)
Arora, Sandeepa
Type
Thesis
Abstract
Background
Integrated Care Systems (ICSs) have been introduced in England to support coordinated healthcare, yet evidence derived from integrated healthcare data, particularly for children and young people (CYP), remains limited. This thesis explores how the Northwest London (NWL) integrated care database can inform healthcare for CYP.
Methods
Four observational studies used the NWL database, utilising linked primary and secondary care records for CYP. One study applied causal inference with balancing weights to estimate the effect of Covid-19 on primary care use. The studies focused on asthma management: adapting and validating a severity score, evaluating adherence to GP follow-up guidelines after asthma attacks, and analysing salbutamol prescribing trends before and during the pandemic. Methods included difference-in-differences (DiD), logistic regression, and evaluation of the asthma severity score using measures of discrimination (area under the curve, AUC) and the Hosmer-Lemeshow goodness-of-fit test.
Results
Short-term increases in general practice (GP) events were observed after a positive Covid-19 test in CYP, but no sustained rise. Month-to-month variation likely reflected shifts in care-seeking behaviour and service availability. Balancing weights supported causal inference, though residual confounding remains. In asthma-related studies, 73% of children discharged after emergency admissions did not receive GP follow-up within 2 working days, as recommended. Salbutamol prescribing declined during the pandemic but later returned to pre-pandemic levels. Discrimination was limited for the severity score alone (AUC 0.50 to 0.62). In most years, higher severity scores were associated with increased odds of asthma admissions in unadjusted and adjusted analyses (adjusted ORs 1.20 to 2.14), with acceptable model fit (Hosmer-Lemeshow p > 0.05).
Conclusion
This thesis examined the utility of an integrated healthcare database for research on CYP. Studies on Covid-19 and asthma demonstrated the feasibility of interrogating linked data and showed how resources can inform understanding of care delivery, inequalities, and priorities for service planning.
Integrated Care Systems (ICSs) have been introduced in England to support coordinated healthcare, yet evidence derived from integrated healthcare data, particularly for children and young people (CYP), remains limited. This thesis explores how the Northwest London (NWL) integrated care database can inform healthcare for CYP.
Methods
Four observational studies used the NWL database, utilising linked primary and secondary care records for CYP. One study applied causal inference with balancing weights to estimate the effect of Covid-19 on primary care use. The studies focused on asthma management: adapting and validating a severity score, evaluating adherence to GP follow-up guidelines after asthma attacks, and analysing salbutamol prescribing trends before and during the pandemic. Methods included difference-in-differences (DiD), logistic regression, and evaluation of the asthma severity score using measures of discrimination (area under the curve, AUC) and the Hosmer-Lemeshow goodness-of-fit test.
Results
Short-term increases in general practice (GP) events were observed after a positive Covid-19 test in CYP, but no sustained rise. Month-to-month variation likely reflected shifts in care-seeking behaviour and service availability. Balancing weights supported causal inference, though residual confounding remains. In asthma-related studies, 73% of children discharged after emergency admissions did not receive GP follow-up within 2 working days, as recommended. Salbutamol prescribing declined during the pandemic but later returned to pre-pandemic levels. Discrimination was limited for the severity score alone (AUC 0.50 to 0.62). In most years, higher severity scores were associated with increased odds of asthma admissions in unadjusted and adjusted analyses (adjusted ORs 1.20 to 2.14), with acceptable model fit (Hosmer-Lemeshow p > 0.05).
Conclusion
This thesis examined the utility of an integrated healthcare database for research on CYP. Studies on Covid-19 and asthma demonstrated the feasibility of interrogating linked data and showed how resources can inform understanding of care delivery, inequalities, and priorities for service planning.
Version
Open Access
Date Issued
2025-09-26
Date Awarded
2026-03-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Hargreaves, Dougal
Blair, Mitch
Saxena, Sonia
Longford, Nicholas
Sponsor
National Institute for Health Research (Great Britain)
Publisher Department
School of Public Health
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)