Discussion
In a recent literature research, we identified 2 specific
English-language questionnaires used to assess QOL in patients with COS:
modified OHIP-14[11] and (COSS)[2, 7–10], one questionnaire to
assess patient satisfaction post sialendoscopy[12] and another
questionnaire (Multidisciplinary Salivary Gland Society (MSGS)
questionnaire) to quantify the burden of symptoms caused by xerostomia
and sialadenitis[20].
The primary purpose of the present article was to design a specific
questionnaire in Spanish to assess QOL in patients with COS
(Supplementary Table 3) across six selected dimensions (physical
function and symptoms, social roles, occupational activities, emotional
status, and health perception). There are some similarities between
items of the CSOC and the Modified OHIP-14, COSS and MSGS. The patient
satisfaction questionnaire, on the other hand, is quite
different[12];it contains 14 questions that cover pre-sialendoscopy
symptoms, progress post-sialendoscopy, change in QOL, and overall
patient satisfaction and does not evaluate social roles, sleep
disorders, or emotional status[12]. The modified OHIP-14 was
designed to measure self-reported functional limitation, discomfort, and
disability in patients with salivary gland pathology[11]; the COSS
examines sialadenitis symptoms, daily functions, emotional symptoms,
sleeping and daily activities[7]; and the MSGSevaluatesxerostomia
and sialadenitis symptoms as well as their frequency, intensity, and
associated discomfort[20].
As we can see, all 5 specific questionnaires measure the presence of
symptoms and functional limitations. The CSOC, modified OHIP-14[11],
and COSS[7] include items that target social roles. The CSOC and
modified OHIP- 14 assess emotional status. The CSOC includes
recreational activities to cover the whole occupational dimension. The
modified OHIP-14 has an item on work[11] that does not take
unemployed or retired people into account, and the COSS prompts
participants to provide information on daily activities in
general[7]. The COSS and CSOC have an item evaluating sleep.
A complete validation process was conducted with a pilot study as well
asassessment of content and construct validity. None of the existing
studies describes a process of content validity such as ours,which
includes an expert panel.
After the pilot study and assessment of content validity,the CSOC was
modified to include 18 items. The analysis of the new 18-items
psychometric properties suggested that CSOC has high feasibility
(absence of missing responses and around 5 minutes required to fill out
the questionnaire), high stability (test retest of 0.86), high internal
consistency (Cronbach α coefficient of 0.90), and high responsiveness to
change. The absence of missing responses and the short time required
indicate that the responders found the CSOC to be easy to use. The
significant difference between the scores of pre- and postsialendoscopy
CSOC means that CSOC is a good tool to assess the improvement of COS
after sialendoscopy. Additionally, CSOC proved its capacity to
distinguish between patients with frequent and occasional episodes of
sialadenitis.
On the other hand, CSOC had a low to moderate negative correlation with
the different dimensions and component summaries of SF-36. The
correlation has the expected direction, and the low correlation could be
explained by the fact that SF-36 is not sensitive enough to capture the
difference in COS symptoms[2, 7].
This study has three main limitations. First, we were unable to assess
criterion validity due to the lack of a validated gold standard test.
Second, we did not use a healthy control group. Third, the subjects used
for the validation process only represent those patients who have an
indication for sialendoscopy; to validate CSOC for all COS patients, a
study which includes patients with and without indication for
sialendoscopy should be conducted.