This research reports the development of an intervention, based on DeVellis et al. (42) and Streiner et al.’s (43) recommendations for scale development. The instrument was developed through the following four steps: (1) determine the concept to measure; (2) generate a set of items; (3) review the item set by experts (content validity); (4) administer items to a sample of the target population (face validity).
The intended application of the instrument is to assist all healthcare professionals in evaluating patients’ palliative care needs. The target users of the instrument are mainly nurses and physicians, but potentially other healthcare professionals like social workers or physiotherapists. This instrument was designed for professionals, who do not necessarily have specific palliative care training, working in any acute care settings, except in intensive care units and emergency departments.
Step 1: determine the concept to measure.
A literature review was conducted to identify existing definitions of general and specialised palliative care to inform item generation. The Pubmed, CINHAL, Embase, Cochrane, JBI databases, Google Scholar, government and hospice websites were consulted between January and March 2016. Published studies and national/international recommendations were used to answer the research question: what are the currently available definitions for general PC and for specialised PC? All articles identified were collated and uploaded into EndNote X8/2016 (Clarivate Analytics, PA, USA). Titles and abstracts were then screened in order to keep only full texts related to the topic of interest. Definitions were extracted from the selected full text articles and collated in an Excel file for comparison.
Step 2: generate a set of items
The aim of the second step was to obtain a list of possible items to include in the instrument. These items had to be relevant to the construct and the target population of interest, as well as for the context in which the instrument is intended to be used. This instrument is designed to be a clinician-reported outcome measure. As a result, the target population are non-specialised healthcare professionals and not patients. As the target population has some difficulties identifying patients requiring PC because professionals do not know the PC criteria, it was not deemed appropriate to include them at this stage of development.
For an instrument to meet the needs of busy healthcare professionals, it needs to be as concise and practical as possible. Regardless of whether the items referred to generalised or specialised PC, the first author (FTL) selected the relevant items from the literature, including published identification instruments (44-48). This process was completed by a committee of interdisciplinary clinical experts in PC (CICE) including one clinical nurse specialist (FTL), one psychologist (MB) and two physicians (MB, GDB). This CICE was in charge of ensuring the relevance, comprehensiveness and comprehensibility for clinical practice, by analysing the data and the answers to the open questions, as well as by reformulating, adding or clustering items through discussions and deliberations (43). An interprofessional working group was central in order to ensure that the different dimensions of PC are taken into account. The composition of the group was thought to be representative of the three professions most commonly involved in PC in Switzerland.
Following literature findings that people with life limiting non-cancer conditions have less access to palliative care (16, 23), the items were designed for patients with either oncological or non-oncological pathologies. Finally, the CICE determined which items belonged in the generalised PC or specialised PC categorisations.
Step 3: review of initial set of items by experts
A modified Delphi technique involving a questionnaire with open and closed-ended questions was used to assess the relevance and the comprehensiveness of items related to general versus specialised PC from the final list generated in Step 2. This occurred in the three rounds which allowed the content validity of the instrument to be established. The content validity can be enhanced during the development of an instrument through inclusion of experts of the discipline (49). This method resulted in physicians and nurses from two linguistic regions of Switzerland (French and Italian), all experts in PC, to participating in the study (50-54). A list of all nurses and physicians working in the different community-based specialist palliative care teams and all executive nurses and physicians of the PC units was compiled. Each of these professionals was contacted by email. This expert panel of clinicians specialised in PC was formed according to the following criteria: (i) a minimum of three years experience in PC, (ii) working in a hospice or in a hospital/community PC team, (iii) working in the French or Italian speaking regions of Switzerland, and (iv) having a sufficient oral and written level of French (as this part of the research was conducted in French). In addition, nurses were required to have undertaken specialised PC training or be a clinical nurse specialist or a head nurse. Physicians were required to be at least senior residents. Reasons for non-participation were not asked. Three rounds were necessary to achieve consensus (Figure 1). In each round, a questionnaire including a list of items to be ranked according to the level of importance and one or two open questions for comments was sent to participants (all questionnaires in French used in this study can be requested from the first author). We carried out a pre-test with two nurses and one physician specialised in PC to assess the time necessary to complete questionnaires and the clarity of instructions.
Figure 1: Delphi process flowchart
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In round 1, the participants ranked five items in order of priority for each set (general and specialised PC), with scores ranging from 5 (the most important) to 1 (the least important). The CICE recommended keeping items with a mean of ≥ 3.5 and selected by more than half of the participants. Each comment was reviewed for its pertinence by the CICE and through consensus was reworded when judged appropriate. Thus, the choice of items was influenced by the overall consistency of the items selection and by the pertinence of the comments. If an item pertaining to a specific issue was chosen in the first round, other items related to this issue were excluded from the second round. The same was true for items that had not been chosen at all in the first round.
In round 2, the same participants were asked to choose the items they believed should be retained for the instrument from the list of items remaining from the first round. As none of the items were chosen by more than half of the participants and reached a mean of ≥ 3.5, the CICE decided that only one of these two conditions had to be met.
In round 3, the aim was to confirm the item classification into either general or specialised PC and to ensure that the formulation was clear and understandable. A larger sample of experts, which also included those who participated in Round 1 and 2, were asked four yes/no questions to confirm (i) the relevance of the item selection in order to identify general and specialised PC patients, (ii) the comprehensibility and the clarity of the items and finally (iii) the name of the instrument. Two final sets of items (generalised PC and specialised PC) were developed at the end of the third round.
Step 4: administer items to a sample of the target population for face validity
The aim of this last step was to ensure the face validity, a part of content validity, of the final set of items with the target population of end-users, namely nurses and physicians, without specialised PC training and working in acute care setting at a Swiss university hospital. Inclusion criteria were: i) being a clinical nurse specialist or a senior resident physician; ii) working in internal medicine, surgery, oncology, cardiology, pulmonology or ambulatory setting; iii) having worked full time for at least three years in one of these units (or the part time equivalent of three years full time). An invitation to participate was send to all the clinical nurse specialists of the hospital, as well as to senior residents collaborating with the hospital’s mobile PC team. We sent participants a questionnaire including seven yes/no questions, pertaining to relevance, comprehensibility and feasibility. Space for extended responses for clarification or suggestions for “no” answers and other general comments were included in the questionnaire.
Descriptive analyses were conducted using IBM SPSS statistics 25. Classification of the comments was made by the first author (FTL) and then presented to the CICE for discussion.