HERALD (health economics using routine anonymised linked data).

BACKGROUND: Health economic analysis traditionally relies on patient derived questionnaire data, routine datasets, and outcomes data from experimental randomised control trials and other clinical studies, which are generally used as stand-alone datasets. Herein, we outline the potential implications of linking these datasets to give one single joined up data-resource for health economic analysis. METHOD: The linkage of individual level data from questionnaires with routinely-captured health care data allows the entire patient journey to be mapped both retrospectively and prospectively. We illustrate this with examples from an Ankylosing Spondylitis (AS) cohort by linking patient reported study dataset with the routinely collected general practitioner (GP) data, inpatient (IP) and outpatient (OP) datasets, and Accident and Emergency department data in Wales. The linked data system allows: (1) retrospective and prospective tracking of patient pathways through multiple healthcare facilities; (2) validation and clarification of patient-reported recall data, complementing the questionnaire/routine data information; (3) obtaining objective measure of the costs of chronic conditions for a longer time horizon, and during the pre-diagnosis period; (4) assessment of health service usage, referral histories, prescribed drugs and co-morbidities; and (5) profiling and stratification of patients relating to disease manifestation, lifestyles, co-morbidities, and associated costs. RESULTS: Using the GP data system we tracked about 183 AS patients retrospectively and prospectively from the date of questionnaire completion to gather the following information: (a) number of GP events; (b) presence of a GP 'drug' read codes; and (c) the presence of a GP 'diagnostic' read codes. We tracked 236 and 296 AS patients through the OP and IP data systems respectively to count the number of OP visits; and IP admissions and duration. The results are presented under several patient stratification schemes based on disease severity, functions, age, sex, and the onset of disease symptoms. CONCLUSION: The linked data system offers unique opportunities for enhanced longitudinal health economic analysis not possible through the use of traditional isolated datasets. Additionally, this data linkage provides important information to improve diagnostic and referral pathways, and thus helps maximise clinical efficiency and efficiency in the use of resources.

The use of secure anonymised data linkage to determine changes in healthcare utilisation following severe open tibial fractures.

Severe open fractures of the lower limbs are complex injuries requiring expert multidisciplinary management in appropriate orthoplastic centres. This study aimed to assess the impact of open fractures on healthcare utilisation and test the null hypotheses that there is no difference in healthcare utilisation between the year before and year after injury, and that there is no difference in healthcare utilisation in the year post-injury between patients admitted directly to an orthoplastic centre in keeping with the joint BOA/BAPRAS standards and those having initial surgery elsewhere. This retrospective cohort study utilising secure anonymised information linkage (SAIL), a novel databank of anonymised nationally pooled health records, recruited patients over 18 years of age sustaining severe open lower limb fractures managed primarily or secondarily at our centre and who had data available in the SAIL databank. 101 patients met inclusion criteria and 90 of these had records in the SAIL databank. The number of days in hospital, number of primary care attendances, number of outpatient attendances and number of emergency department attendances in the years prior and subsequent to injury were recorded. Patients sustaining open fractures had significantly different healthcare utilisation in the year after injury when compared with the year before, in terms of days spent in hospital (23.42 vs. 1.70, p=0.000), outpatient attendances (11.98 vs. 1.05, p=0.000), primary care attendances (29.48 vs. 11.99, p=0.000) and emergency department presentations (0.2 vs. 0.01, p=0.025). Patients admitted directly to orthoplastic centres had significantly fewer operations (1.78 vs. 3.31) and GP attendances (23.6 vs. 33.52) than those transferred in subsequent to initial management in other units. There is a significant increase in healthcare utilisation after open tibial fracture. Adherence to national standards minimises the impact of this on both patients and health services.