20th May celebrates International Clinical Trials Day which shines a light on the profound impact that clinical trials have had on research that improves patient’s lives. SAIL Databank contains anonymised health records for the population of Wales; 85% primary care and 100% secondary care, and is one of the richest population data resources in the world. SAIL’s individual-level data is incredibly broad, covering a myriad of health diagnoses, interventions and outcomes. As a result, SAIL Databank supports clinical trials in the following ways:
- SAIL is a valuable, cost-effective tool for clinical trial patient follow-ups in interventional and observational trials, and is scalable to any size of trial.
- SAIL reduces the burden on both patients and clinicians in conducting trial follow-ups as the need for direct contact is reduced.
- Because SAIL gathers health data, routinely over time, trial participant outcomes can be monitored longitudinally, often beyond the timeframe of the clinical trial itself.
- SAIL Databank can also help detect bias in clinical trials, for example, by identifying omissions of certain socio-demographic characteristics or exclusions of patients with more than one health condition.
Highlighted below are two examples of published research where SAIL Databank has been used in the context of clinical trials:
The applicability of randomised controlled trials of pharmacological agents to older people with frailty/multimorbidity is often uncertain, due to concerns that trials are not representative. However, assessing trial representativeness is challenging and complex. We explore an approach assessing trial representativeness by comparing rates of trial serious adverse events (SAE) to rates of hospitalisation/death in routine care.
This was an observational analysis of individual (125 trials, n=122,069) and aggregate-level drug trial data (483 trials, n=636,267) for 21 index conditions compared to population-based routine healthcare data (routine care). Trials were identified from ClinicalTrials.gov. Routine care comparison from linked primary care and hospital data from Wales, UK (n=2.3M). Data from the Secure Anonymised Information Linkage (SAIL) Databank were used to identify a routine care population for each of the trial index conditions.
The outcome of interest was SAEs (routinely reported in trials). In routine care, SAEs were based on hospitalisations and deaths (which are SAEs by definition). We compared trial SAEs in trials to expected SAEs based on age/sex standardised routine care populations with the same index condition. Using IPD, we assessed the relationship between multimorbidity count and SAEs in both trials and routine care and assessed the impact on the observed/expected SAE ratio additionally accounting for multimorbidity.
Hanlon, P., Butterly, E., Shah, A. S., Hannigan, L. J., Wild, S. H., Guthrie, B., … & McAllister, D. A. (2022). Assessing trial representativeness using Serious Adverse Events: An observational analysis using aggregate and individual-level data from clinical trials and routine healthcare data. BMC medicine, 20(1), 1-15.
Studies have suggested that evening dosing with antihypertensive therapy might have better outcomes than morning dosing. The Treatment in Morning versus Evening (TIME) study aimed to investigate whether evening dosing of usual antihypertensive medication improves major cardiovascular outcomes compared with morning dosing in patients with hypertension.
The TIME study is a prospective, pragmatic, decentralised, parallel-group study in the UK, that recruited adults (aged ≥18 years) with hypertension and taking at least one antihypertensive medication. Eligible participants were randomly assigned (1:1), without restriction, stratification, or minimisation, to take all of their usual antihypertensive medications in either the morning (0600–1000 h) or in the evening (2000–0000 h). Participants were followed up for the composite primary endpoint of vascular death or hospitalisation for non-fatal myocardial infarction or non-fatal stroke. Endpoints were identified by participant report or record linkage to National Health Service datasets and were adjudicated by a committee masked to treatment allocation.
The researchers looked at record-linked NHS hospitalisation and death data from NHS Digital, the Secure Anonymised Information Linkage (SAIL) databank, Public Health Scotland, and Health and Social Care (HSC) Northern Ireland at annual intervals and after the end of the study.
Mackenzie, I. S., Rogers, A., Poulter, N. R., Williams, B., Brown, M. J., Webb, D. J., … & MacDonald, T. M. (2022). Cardiovascular outcomes in adults with hypertension with evening versus morning dosing of usual antihypertensives in the UK (TIME study): a prospective, randomised, open-label, blinded-endpoint clinical trial. The Lancet, 400(10361), 1417-1425.