RELIABILITY AND VALIDITY OF THE GASTROINTESTINAL SYMPTOM RATING-SCALEIN PATIENTS WITH GASTROESOPHAGEAL REFLUX DISEASE

The objective of this study was to evaluate the reliability and validi ty of the Gastrointestinal Symptom Rating Scale (GSRS) in US patients with gastroesophageal reflux disease (GERD). Five hundred and sixteen adults with predominant heartburn symptoms of GERD were recruited from gastroenterologist and family physician practices and treated with 6 weeks of 150 mg ranitidine twice daily to identify poorly responsive s ymptomatic GERD. The GSRS, the Medical Outcomes Study Short Form-36 (S F-36) Health Survey and the Psychological General Wellbeing (PGWB) sca le were administered at baseline and after 6 weeks of treatment. Repor ted ratings of GERD-related symptoms from physician and patient diarie s were measured. The GSRS contains five scales: reflux syndrome, abdom inal pain, constipation syndrome, diarrhoea syndrome and indigestion s yndrome. The internal consistency reliabilities for the GSRS scales ra nged from 0.61 to 0.83 and the intraclass correlation coefficients ran ged from 0.42 to 0.60. The GSRS scale scores were correlated with the SF-36 and PGWB scales and with the number and severity of heartburn sy mptoms. Patients with two or three clinician-rated GERD-related sympto ms reported worse GSRS scale scores compared with patients with fewer symptoms (p < 0.0001). Statistically significant differences in the me an GSRS scale scores were observed between treatment responders and no n-responders (p < 0.0001) and patients showing a response to treatment had larger mean changes in their GSRS scales than patients not showin g a response to treatment (p < 0.0001). The standardized response mean s ranged from 0.42 to 1.43 for the GSRS scale scores. It was concluded that the GSRS is a brief, fairly comprehensive assessment of common g astrointestinal symptoms. The GSRS has good reliability and construct validity and the GSRS scales discriminate by GERD symptom severity and are responsive to treatment. The GSRS is a useful patient-rated sympt om scale for evaluating the outcomes of treatment for GERD.