A pilot study is defined as “a smaller version of the proposed study, conducted to refine the methodology” (Burns and Grove, 1999, p.40). This means that the pilot study is done prior to the original study to discover any problems that might arise during conducting the original study. Piloting procedure consists of all steps that are proposed to be taken in the actual study.
In this study, the main aim of conducting a pilot study before going on with data collection was to check the accuracy of the computer-generated list of paired matches. This was to check if the actual documented status of PU in patients records matched what was in the computer-generated list. In addition, piloting aimed at counting the final number of eligible records to see if they were enough to run the statistical analysis and achieve the targeted effect size.
In addition, piloting was also intended to accomplish the following benefits before conducting the actual phase of data collection:
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- To check the relevancy of data present in HISS to the study aim, and the ability of data to answer the research questions.
- To familiarize the researcher with HISS use.
- To help the researcher to identify any technical problems that might be encountered during data collection (e.g. logging on to and using HISS).
- To estimate the total time needed to complete the whole data collection, to help in planning the time frame of the study.
In order to start the piloting procedure, the information technology department of Queen’s Hospital was approached. A username and password were provided in order to log into HISS. The research team also liaised with the Tissue Viability Nurse (TVN) at Queen’s Hospital (Dr. Linda Rafter) in order to train the primary investigator to use HISS and use her office to go through medical records and document findings.
In the context of piloting, it has been reported in the literature that subjects included in the pilot study must not be reused again in the actual study. The pilot study may have an effect on the subjects during the actual study (Brink and Wood, 1998). This could be true in studies involving actual subjects (patients). In this study, subjects involved in piloting could be used again in the actual study. No influence on the study subjects was exerted, due to the retrospective nature of the study. Moreover, excluding the number of the piloted subjects would have decreased the number of eligible subjects in the actual study.
115 3.12.1 Piloting procedure findings
Piloting was conducted through using a paired matches list, which was created based on the preliminarily list obtained from the information technology department. Procedure for building the list was explained previously in preliminarily sampling plan section.
The primary investigator logged into HISS using the username and password provided. Using medical record numbers in the preliminarily list, electronic records of 96 pairs of patients were revised. This revision revealed that the preliminarily paired list was inappropriate for conducting this study. The problem lay in patients who were marked in the list as having PU. The majority of these patients did not match the study’s criteria for two reasons. Firstly, a number of documented PUs were community-acquired, not hospital-acquired. Secondly, some of the patients that the list referred to as having PUs were not actually documented to have any ulcers at all.
A possible cause for this inaccuracy was that the computer depended on Waterlow skin score to specify PU status, and could not differentiate between community-acquired and hospital-acquired PUs. Furthermore, the computer considered all patients who had a skin sub-score value other than 0 or 1 to have PU. This is not always true, as skin scores in the Waterlow scale can be added. So, if free of PUs patients had a clammy and oedematous skin, they will be coded as 2, and the computer will identify them as having PU, while in fact they do not.
Excluding inaccurately listed patients left the sample with very few patients (below 85; see sample size). Carrying on with such a low number of patients would not achieve the targeted effect size, and would negatively affect the external validity of the study. Depending on the computer-generated list turned to be inaccurate and insufficient to
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pick patients according to the study criteria. An alternative accurate sampling strategy had to be found in order to get enough subjects who matched the study criteria.
Waterlow RAS used at data collection site
When the pilot study was conducted, a copy of Waterlow scale used at Queen’s Hospital to assess risk of PUs was also revised. The Waterlow card used at Queen’s (Appendix H) is different from the 2005 revised Waterlow risk assessment card (Appendix C). Instead of replacing the sub-score of appetite with Malnutrition Screening Tool, appetite score was kept. Other sub-scores of Burton nutritional score were added to the card in order to assess nutrition. Moreover, the Waterlow card was redesigned into three columns to distinguish Waterlow-specific information, general information and nutrition score specific information. Waterlow total score was the result of adding sub-scores of the first two columns (specific information and general information). Burton nutritional score was the result of adding the second and third column (general information and nutrition specific information). Added scores of Burton-specific nutritional information were in similar proportion to those used Waterlow sub-scores; this was to balance the contribution of each sub-score in the total score (Russell et al., 1998).