Preliminary items for the 5-D itch scale were derived from (i) modification of the Total Neuropathy Scale4 (link) to be relevant to pruritus rather than neuropathy, (ii) clinical experience by the authors and expert consultants with chronic pruritus under conditions of patient care and clinical trials and (iii) review of the pruritus literature. The preliminary version included both open-ended questions and specific response questions regarding the patient's perception of pruritus. This preliminary version was administered to 21 patients participating in a trial of sertraline for a treatment of cholestatic pruritus.5 (link) Ambiguous items or response choices were revised and response choices selected less than 5% of the time were removed.
The remaining items were grouped into five domains: duration, degree, direction, disability and distribution. Accordingly, the scale was titled the ‘5-D itch scale’ (Fig. 2 ). The duration, degree and direction domains each included one item, while the disability domain had four items. All items of the first four domains were measured on a five-point Likert scale.
The distribution domain included 16 potential locations of itch, including 15 body part items and one point of contact with clothing or bandages. The preliminary version of the questionnaire also included an ‘other’ item which allowed subjects to write in a response. This led to further refinement of the body part list by the addition of ‘groin’, which was reported by nine subjects. Additional items written in for the free text ‘other’ item were determined by the authors to fit conceptually into items which were already present on the 5-D (e.g. ‘breast’ could be categorized as ‘chest’). Therefore, the instructions were modified to instruct the participant to select the anatomically closest body part for areas that they might not find on the list.
The remaining items were grouped into five domains: duration, degree, direction, disability and distribution. Accordingly, the scale was titled the ‘5-D itch scale’ (
The distribution domain included 16 potential locations of itch, including 15 body part items and one point of contact with clothing or bandages. The preliminary version of the questionnaire also included an ‘other’ item which allowed subjects to write in a response. This led to further refinement of the body part list by the addition of ‘groin’, which was reported by nine subjects. Additional items written in for the free text ‘other’ item were determined by the authors to fit conceptually into items which were already present on the 5-D (e.g. ‘breast’ could be categorized as ‘chest’). Therefore, the instructions were modified to instruct the participant to select the anatomically closest body part for areas that they might not find on the list.