RELEVANCE OF NORM VALUES AS PART OF THE DOCUMENTATION OF QUALITY-OF-LIFE INSTRUMENTS FOR USE IN UPPER GASTROINTESTINAL-DISEASE

This article presents the relevance of norm values to a battery of Qua lity of Life questionnaires for use in upper gastrointestinal disorder s. The derivation of reference values offers an important contribution by confirming the ability of the questionnaires to differentiate pati ents from healthy controls. Two self-administered questionnaires, the Psychological General Well-being (PGWB) index and the Gastrointestinal Symptom Rating Scale (GSRS) were used. The norm values were derived i n a randomly selected sample from a Swedish population consisting of 4 624 individuals (reference group). The patients comprised more than 90 0 patients with gastroesophageal reflux disease (GORD) included in cli nical trials. In the reference group, males reported significantly hig her values on well-being as compared with women, whereas women reporte d more pronounced gastrointestinal symptoms than men. Generally, the y ounger persons and the group aged 60-70 years reported the highest wel l-being Among gastrointestinal patients women scored lower and reporte d more symptoms than men. With increasing age, well-being improved and symptoms declined. Even though the well-being and symptoms scores dif fered between patient and the reference group similar patterns in term s of age and gender were observed. In summary, the results show that t here are differences with respect to gender and age among normal contr ols as well as in GORD patients. These aspects have to be considered i n clinical studies. The results also support the discriminative abilit y of the Quality of Life instruments.