OBJECTIVES: To evaluate the number, type, spacing, and uniqueness of response options in common verbal descriptor scales (VDS).

METHODS: Participants with self-reported chronic pain were recruited using population sampling methods. Participants completed a survey assessing general health rating styles. Participants were asked to assign a number from 0 (best) to 10 (worst) to various VDS with four options (None, Mild, Moderate, Severe). Participants repeated the exercise using six options (adding “Very mild” and “Very severe”). Participants also assigned numbers for other types of five-point VDS (“Not at all” to “Extremely”, “Never” to “Always”, and “None of the time” to “All of the time”). Medians were calculated to compare response option ordering and differentiation. Finally, participants indicated their preference between scales assessing frequency.

RESULTS:

150 participants completed at least one of the questions in the survey. Median responses indicated a rough ordering in the expected direction, with responses indicating better separation between the four descriptors (medians: None=2, Mild=4, Moderate=6, Severe=8) than the six descriptors (medians: None=2, Very mild=2, Mild=3, Moderate=5, Severe=7, Very severe=7). Mean responses for the other VDS also trended in the expected direction, however the “None of the time” to “All of the time” scale was less ordered compared to others. A plurality of participants (42.3%) preferred a frequency VDS with “Never” and “Always” wording over “None of the time” to “All of the time”, as well as over a 0-10 numeric rating scale.

CONCLUSIONS: Due to a lack of clear differentiation between categories on a six-point severity VDS, it may be more appropriate to use a four-point scale. Further research is needed to determine whether a four or five-point scale is more suitable. While participants slightly preferred the “Never” to “Always” VDS over other types of scales, more qualitative research is needed to understand participants’ rationale for this choice.