Most callers to emergency ambulance services are transported to hospital emergency departments (EDs), but ambulance services receive no information on patient outcomes. Pre-Hospital and Emergency Department (PHED) Data is a two-year mixed-methods observational study of the process and potential benefits of linking ambulance and ED data to allow analysis of patient outcomes. We report on our first aim, to examine the potential opportunities and challenges of this data linkage initiative.

We approached six hospital trusts in an English metropolitan area. We used a structured learning log to collect data on the process, time input and reflections. We analyzed these data with descriptive statistics, and qualitatively for themes.

All six trusts agreed to participate. We used an algorithm based on date, time and patient demographics to link data. We achieved a dataset of 775,018 records covering 2012 – 2016, and a linkage rate of 81 percent.

Initial set up tasks within the ambulance service took 30 hours 20 minutes. We then identified five stages of tasks with each hospital trust: negotiating senior approval; exploring data availability; information governance agreement; data transfer; and linking. Mean time spent by the research team on these processes was 30 hours 30 minutes per trust (range: 17 hours 20 minutes to 43 hours 10 minutes), plus additional time from staff of hospital trusts. The most intensive phases were: negotiating senior approval (mean: 8 hours 5 minutes), and data linking (mean: 12 hours 40 minutes). The stage which took the longest was information governance (mean: 19 weeks).

Key themes included the positive attitudes of trusts to participating, the range of decision makers involved, and the need for sustained input from the research team.

We found the process of data linkage was feasible, but requires dedicated time from research and trust staff, over a prolonged period, to achieve set up. Linked data are now being analyzed.