Development and Validation of a Symptom Scale for Indian Patients With Medically Unexplained Physical Symptoms

Introduction Patients with medically unexplained physical symptoms (MUPS) account for a substantial proportion of patients visiting the outpatient department. Diagnosis of MUPS is a challenge for most physicians. An accurate diagnosis relies on obtaining a detailed history from patients regarding the nature of their symptoms, their onset, and any associated aggravating or relieving factors. This study aims to develop a symptom scale for Indian patients with MUPS. Methods The study had a mixed-method study design. Phase 1 involved designing the questionnaire using qualitative techniques, such as literature reviews, focus-group discussions, expert evaluation, and pre-testing of a Hindi and English language Likert-rated interviewer-administered scale. In phase 2, the construct validity of the questionnaire was established using quantitative approaches among 116 patients diagnosed with MUPS. Results The final questionnaire consists of 38 items, with good internal consistency (Cronbach 𝛂 = 0.916). Confirmation sampling adequacy for factor analysis was done using the Kaiser-Meyer-Olkin test (KMO value = 0.792) and Bartlett's test of sphericity (p < 0.001). The newly developed scale showed a Pearson correlation coefficient of 0.568 (p < 0.001) with Patient Health Questionnaire (PHQ)-15 scores. Conclusion A reliable and valid tool has been developed to assess patients' symptoms with MUPS in English and Hindi languages. This questionnaire can be used for assessment, screening, and diagnostic purposes as well as to chart longitudinal changes in patients with MUPS.