Validity and Reliability of the Persian Version of Reflux Symptom Score-12 in Patients with Laryngopharyngeal Reflux Disease.

OBJECTIVE

Cross cultural adaptation of the reflux symptom score-12 (RSS-12) into Persian language and to evaluate its validity and reliability in the assessment of patients with laryngopharyngeal reflux disease (LPRD).

STUDY DESIGN

A cross-sectional and prospective cohort design.

METHODS

A standard forward and backward translation was followed to cross-culturally adapt the RSS-12 into Persian language. To study discriminative validity, the RSS-12p was administrated to 63 patients with LPRD (40 men and 23 women; mean age: 39.26 ± 9.79 years) and 50 healthy volunteers (31 men and 19 women; mean age: 37.24 ± 10.28 years). The patients completed the reflux symptom index (RSI) to assess construct validity. The test-retest reliability was investigated in 31 patients (time interval = 7 days).

RESULTS

There were no missing responses and floor or ceiling effects. The assessing of discriminative validity showed that the questionnaire was able to discriminate between patients with LPRD and healthy participants (P<0.001). Construct validity was confirmed by the Pearson correlation between the RSS-12p and the RSI (r= 0.87; P<0.00). The internal consistency was confirmed with Cronbach α 0.85 and 0.72 for the RSS-12p and quality of life (QoL), respectively. Test-retest reliability was excellent (ICC = 0.98 for the RSS-12p and 0.94 for QoL).

CONCLUSIONS

The Persian version of RSS-12 is a valid and reliable self-administered questionnaire for assessing LPRD in Persian-speaking patients.