2.9.3 Step 3: Responses
Five-point Likert scales (ranging from strongly disagree to strongly agree) were chosen to rate most items (n=48) as these provide an “ambivalent” midpoint and are sensitive and reliable.35,36 Five-point scales also have a familiarity factor contributing to ease of completion. Four-point scales with time-based responses (always, often/mostly, sometimes/rarely, never) were applied to the eight questions in the practice habits section as items referred to frequency of habits related to OBP. Open-ended questions were included at the end of each survey section, to capture other comments that had not been addressed in the scaled questions.
2.9.4 Step 4: Psychometric property testing
  1. Preliminary discussions : Two authors (IV, HB) discussed the item list and identified redundant items for removal.
  2. Validation approach : Prompts based on Patrick et al.37, Burton and Mazerolle34 and Heale and Twycross38 were developed to seek input on the draft instrument questions from the expert and peer panels (see Table 3). The intent of these questions was to seek input from these participants on phrasing, appropriateness of the questions, flow of the survey, layout, sequencing and timing, intended meanings of items to assess whether responses agreed with opinions and nuances in the understanding of terminology and concepts.33
[Place Table 3 here]
  1. Dissemination : The expert panel members were emailed a cover letter, a link to the survey set up on GoogleForms, and a Microsoft Word document containing the questions in Table 3, set up in table format, hereafter referred to as the “feedback document”. An additional opportunity for comment on each item was provided. The peer members completed the draft questionnaire independently in the presence of the first author. This was timed to provide information on clinical utility.
  2. Cognitive interviews : After completing the questionnaire, the peers were individually interviewed by the first author, using the questions in Table 3 as prompts and using concurrent verbal probing.39 Cognitive interviews34,37,39 are a method of verifying written feedback on phrasing, appropriateness of the questions and flow of the survey.
  3. Data collection : The experts in the validation group returned the Microsoft Word feedback document by email to the principal author (IV) with their feedback addressing each question in Table 3, for each item in the draft survey instrument. These responses were aggregated, with the peer responses, into a master document in which respondents were not able to be identified by the second author (HB).
  4. Researcher oversight : The collated responses were discussed by IV and HB, to determine actions for each item. Items for which the validation group was in complete agreement were accepted “as is”. Items with suggestions for changes to wording were modified where the change made sense. These changes were made irrespective of the number of people who suggested them. Redundant items were identified and removed to reduce the likelihood of non-response due to respondent burden.23,40 Suggestions for changes in formatting within the survey instrument were considered, and decisions were made based on the capabilities of GoogleForms, and respondent burden with regards to length of questionnaire and ease of use.