Patient interpretation of the Patient-Generated Subjective Global Assessment (PG-SGA) Short Form

Background: The Patient-Generated Subjective Global Assessment (PG-SGA) is a patient-reported instrument for assessment of nutrition status in patients with cancer. Despite thorough validation of PG-SGA, little has been reported about the way patients perceive, interpret, and respond to PG-SGA. The aim of this study was to investigate how patients interpret the patient-generated part of the PG-SGA, called PG-SGA Short Form. Methods: Purposive sampling was used to identify participants that had experienced weight loss and/or reduced dietary intake and/or had a low body mass index. Data were collected from 23 patients by combining observations of patients filling in the PG-SGA Short Form, think-aloud technique and structured interviews, and analyzed qualitatively using systematic text condensation. Results: Most of the participants managed to complete the PG-SGA Short Form without problems. However, participant-related and questionnaire-related sources of misinterpretation were identified, possibly causing misinterpretations or wrong/missing answers. Participants either read too fast and skipped words, or they struggled to find response options that were suitable for covering their entire situation perfectly. The word "normal" was perceived ambiguous, and the word "only" limited the participants' possibility to accurately describe their food intake. Long recall periods in the questions and two-pieced response options made it difficult for patients to select only one option. Conclusion: The results of this study provide a unique patient perspective of using the PG-SGA Short Form and valuable input for future use and revisions of the form. The identified sources of misunderstanding could be used to develop a standardized instruction manual for patients and health care personnel using the PG-SGA Short Form.