Background
A rating scale is a critical component of patient-reported outcome
instrument design, but the optimal rating scale format for pediatric use has
not been investigated. We compared rating scale performance when
administering potential questionnaire items to children with eye disorders
and their parents.
Methods
Three commonly used rating scales were evaluated: frequency (never,
sometimes, often, always), severity (not at all, a little, some, a lot), and
difficulty (not difficult, a little difficult, difficult, very difficult).
10 patient-derived items were formatted for each rating scale, and rating
scale testing order was randomized. Both child and parent were asked to
comment on any problems with, or a preference for, a particular scale. Any
confusion about options, or inability to answer was recorded.
Results
21 children (aged 5–17 years) with strabismus, amblyopia, or
refractive error were recruited, plus one of their parents. Of the first 10
children, 4 (40%) had problems using the difficulty scale, compared
with 1 (10%) using frequency, and none using severity. The
difficulty scale was modified, replacing the word
“difficult” with “hard.” 11 additional
children (plus parents) then completed all 3 questionnaires. No children had
problems using any scale. 4 (36%) parents had problems using the
difficulty (“hard”) scale and 1 (9%) with frequency.
Regarding preference, 6 (55%) of 11 children and 5 (50%) of
10 parents preferred using the frequency scale.
Conclusions
Children and parents found the frequency scale and question format to
be the most easily understood. Children and parents also expressed
preference for the frequency scale, compared with the difficulty and
severity scales. We recommend frequency rating scales for patient-reported
outcome measures in pediatric populations.