The postoperative discomfort inventory: A psychometric analysis

Abstract

Background: Discomfort in the postoperative period is common and may hinder patients’ recovery. Factors causing postoperative discomfort have been identified, but a validated tool to assess postoperative discomfort is lacking. We aimed to evaluate the reliability and validity of an instrument designed to assess postoperative discomfort, the Postoperative Discomfort Inventory (PDI).

Methods: We designed a psychometric study that included several longitudinal substudies to establish the preliminary reliability and validity of the PDI. We included all patients in surgical wards on recruiting days who provided written informed consent until the completion of the expected sample size. The study was performed in three samples. The Baseline sample included 125 patients, the Sensitivity sample 51 included patients, and the Recall sample 57 included patients. Discomfort was evaluated using the PDI. Internal-consistency reliability, factor structure, test-retest reliability, and validity were calculated.

Results: Reliability analysis scores reduced the number of items from eleven to nine. Test-retest reliability analysis showed that PDI is sensitive to monitor changes in postoperative discomfort and showed high intraclass correlation in the Recall sample. Validity analysis found that the PDI correlated with the McGill Pain Questionnaire, but correlations were higher with the Global Discomfort Intensity measure.

Conclusions: The PDI is a valid and reliable instrument that can help patients describe postoperative discomfort and thereby improve nursing care.