Study design
This is a methodological study of instrument development, based on DeVellis et al. (38) and Streiner et al.’s (39) recommendations for scale development. The instrument was developed with 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).
Step 1: determine the concept to measure.
Determination of the concept of interest to be measured was driven by clinical unmet needs and identified research gap in the identification of patients in need of general versus specialised PC. The Pubmed, CINHAL, Embase, Cochrane and JBI databases 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 specialized PC?
Step 2: generate a set of items
The aim of this second step was to obtain a list of items 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. As the target population has some difficulties to identify 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 short and practical as possible. Regardless of whether the items referred to generalised or specialised PC, the first author selected the relevant items from the literature, including published identification instruments (40-44). This process was completed by a committee of interdisciplinary clinical experts (CICE) composed of one clinical nurse specialist (FTL), one psychologist (MB) and two physicians (MB, GDB), who were in charge of ensuring the relevance, comprehensiveness and comprehensibility for the clinical practice, by reformulating, adding or clustering items (39). Following literature findings that people with life limiting non-cancer conditions have less access to palliative care (12, 19), the items were designed for patients with either oncological or non-oncological pathologies. Finally, the CICE determined which item belonged to which group (generalised PC or specialised PC).
Step 3: review of initial set of items by experts
A modified Delphi technique, using a qualitative and quantitative part, 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 method permitted physicians and nurses from two linguistic regions of Switzerland (French and Italian), all experts in PC, to participate in the study (45-49). This expert panel of clinicians 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).
Figure 1: Delphi process flowchart
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In round 1, the expert panel had to rank 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 those selected by more than half of the participants. The choice of items was also influenced by the overall consistency of the items selection and by the qualitative analysis 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. A questionnaire including both quantitative and qualitative questions was sent to participants (all questionnaires 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.
In round 2, the same expert panel was asked to choose additional items for the two sets with the same procedure as in the round 1. As none of the items were chosen by more than half of the participants and reached a mean of ≥ 3.5, only one of the two CICE conditions had to be met.
In round 3, the aim was to confirm the item classification into general and specialised PC and to ensure that the formulation was comprehensible. 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 this round 3.
Step 4: administer items to a sample of the target population
The aim of this last step was ensure the face validity, which is 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; ii) working in internal medicine, surgery, oncology, cardiology, pulmonology or ambulatory setting; iii) working full time (or equivalent) for at least three years in one of these units. We sent participants a questionnaire including seven yes/no questions, pertaining to relevance, comprehensibility and feasibility. Space for qualitative data 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. The CICE, who has a specific training in qualitative research, conducted a thematic analysis of the qualitative data (50). Data were coded by the first author and then presented to the CICE for agreement.