Database Description

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Database 3: Palliative care database

3.10 Database Description

3.10.1 Data collection

The HMRN establishes a platform to conduct further researches into patients care.

Currently, it is providing the research infrastructure for a portfolio of palliative and end-of-life care projects. This project is directed by the ‘HMRN Palliative Care and Haematological Malignancy Steering Group’, a group that was established in 2004 and comprises of academics from the University of York (including individuals from the fields of sociology, Health Sciences, and Epidemiology), the clinical director for cancer and clinical support at Castle Hill Hospital, consultant haematologists, specialist haematology nurses, consultants in palliative medicine, specialist palliative care nurses, GPs and patient representatives. The aim of the project is to examine specialist palliative care (SPC) referrals in patients with haematological malignancies. Special attention was given to the investigation of the patient pathway, the palliative care input and the transition to a palliative approach. All the data related with the SPC referrals and with the transition from life prolonging to palliative approaches to care were routinely collected by well-trained research nurses. This was done for all newly diagnosed patients throughout the HMRN area. In total, approximately 350 medical notes of haematology patients who were diagnosed at two of the HMRN hospitals (York and Hull) between 1st April 2005 to 31st March 2008 and had died within the HMRN area by 2009 were examined and transcribed in detail.

Among all the collected data, only 20 patients were found to have been diagnosed with AML / APML. Information such as delivery of medication, admission/discharge dates, units of blood and platelet transfusions, and the names of involving specialist teams were recorded on a day-to-day basis by means of a bespoke calendar approach (which was used extensively and extremely successfully in previous research projects). The above data were put in a database called ‘palliative care database (PCD)’. Screenshots and illustrations of the followed calendar approach (mentioned above) are shown in Figure 3.10 and Figure 3.11.

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Figure 3.10 Screenshots of bespoke palliative care database created to managed data abstracted using the day-to-day calendar approach

Figure 3.11 Figure 3.10 Analyzed day-to-day data collected using the calendar approach

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3.10.2 Data extraction

Although the Palliative Care Database provides a large volume of detailed clinical information on a calendar basis, unfortunately the limited number cases (20 AML / APML cases) restricted the possibility of data use for further analyses. In the current study, only the transfusion relevant details from the records of the aforementioned 20 patients were used for further analysis and for cost estimation at later stages. This includes information related to units of transfusion (blood and platelet) and transfusion frequency. The rest of the clinical information was omitted for two reasons. Firstly, most of the clinical information could also be found in the HMRN database except the transfusion details. Secondly, the case numbers were not high enough to cover all the treatments and conditions of the study population (239 patients from YHHN database).

Therefore, it was very difficult to predict the treatment pattern or the patients’ conditions, such as the complication rate or the hospital stays for specific treatments, by using the detailed information from palliative care databases.

Moreover, based on the infrastructure of HMRN and with the research nurses’ assistance, detailed information of the 20 AML/APML patients were further extracted ‘from diagnosed to death’. Therefore, the details of transfusion not only could be completely portrayed during the end-of-life period, which was the study time period of the original project, but also they could cover the whole treatment pathway time period, in such a way as the clear picture of delivery of transfusion could be revealed and analyzed.

3.10.3 Missing data

Since all information was extracted in a very detailed way and was continuously audited, no missing data were found to exist in the Palliative Care Database.

3.10.4 Database cleaning

In the palliative care database all the events are recorded by a day-to-day calendar approach with transfusion details not being an exception to this. All the units that had been transfused to patients were recorded unit by unit and day by day to the palliative care database. Since the transfusion unit and the frequency were the main concerns, three steps of data cleaning were applied to the palliative care database. This was to have an undisturbed database with no duplicated events in order to be use as a base for further analyses.

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The first step in the data cleaning process was to keep all the transfusion-related information, such as the transfusion receiving date and transfusion unit. All irrelevant or unnecessary information was then removed from the database.

The second step in data cleaning was to summarize all the transfusion details, including the details of delivered units which were presented separately and hospital stays, into one record per transfusion. This ensured that one transfusion would only have one record.

Also, the summarized information provided a clearer view of how each transfusion was given, including the input and time spend.

The third step in data cleaning was to keep the relevant transfusion records. Based on the transfusion time period information from the HMRN database, only records related with transfusion that occurred during the recorded time period were kept. Records of transfusions that occurred outside the given time period were removed, although these transfusions were actually given to patients. The reason for this was to ensure that only the transfusions that were actually delivered in the time period were considered while calculating the transfusion frequency (for later extrapolation use). This was expected to enhance the accuracy of the predictive frequency, although some of the transfusion information could have been lost because of this approach.

After the above 3 steps of data cleaning were carried out, the palliative care database was prepared for transfusion frequency and unit use analysis.