Reliability and validity of a new scale to assess postoperative dysfunction after resection of upper gastrointestinal carcinoma

Abstract

Purpose: We evaluated the purpose reliability and validity of a preliminary scale, which we developed to assess postoperative dysfunction after surgery for gastric and esophageal carcinoma.

Methods: After interviews with 12 patients, reviews of previous studies, and discussions with experts, we identified the physical symptoms that develop after resection of upper gastrointestinal (GIT) carcinoma, and devised a preliminary scale comprised of 34 items. A questionnaire survey based on this scale was then sent to 283 patients.

Results: The questionnaire was returned by 223 patients (78.8%), and 219 responses (98.2%) were valid. Among the 219 respondents, 168 had gastric carcinoma and 51 had esophageal carcinoma. After the elimination of scale items regarded as irrelevant based on statistical considerations and the judgment of experts, factor analysis was done. Seven factors were valid, namely, limited activity due to decreased food consumption, reflux, gastric dumping, nausea and vomiting, deglutition difficulty, pain, and difficulty with passing stools, which were often poorly formed. Scale reliability was confirmed by a Cronbach alpha-coefficient of 0.924. The validity of the construction of this scale was confirmed using the known-group technique based on the operative procedures performed, and the results of factorial validity.

Conclusion: Our preliminary scale is sufficiently reliable and valid, and will prove to be clinically useful.