RESUMEN
BACKGROUND: Patients with persistent somatoform pain disorder (PSPD) are not uncommon. Still, the disease diagnosis relies primarily on structured interviews, with no objective indicators yet available to aid in the diagnosis. This has led to low diagnostic rates and overconsumption of health care resources for the disorder. Although there is a large body of research to improve the diagnosis of the condition, there are currently no objective indicators available for diagnosis. OBJECTIVES: The aim of this study is to investigate the clinical value of infrared thermography (IRT) for diagnosing PSPD. STUDY DESIGN: This is a retrospective study. SETTING: A single academic hospital, outpatient setting. METHODS: The clinical data of patients diagnosed with PSPD in the Pain Department of the First Affiliated Hospital of the Army Medical University from September 2020 to September 2022 were analyzed. The differences in IR thermograms between PSPD patients and healthy controls were analyzed, as well as the relationship between the Hamilton Depression Rating Scale, Hamilton Anxiety Scale, Pittsburgh Sleep Quality Index (PSQI) score, Patient Health Questionnaire-15, and Symptom Check List-90 and the differences in IR thermograms of PSPD patients. RESULTS: The mean squared error, structural similarity measure, different hash, contrast, entropy, inverse variance, and correlation values of the IR thermogram helped to determine PSPD with statistically significant differences (P < 0.05). Inverse variance values were weakly negatively correlated with PSQI scores of PSPD patients (r -0.4721, P < 0.05). LIMITATIONS: This study was limited by its sample size and retrospective observational design. CONCLUSIONS: IRT analysis is a useful objective method in diagnosis of PSPD, which also provides a new line of thought for studying the pathogenesis of PSPD. KEY WORDS: Persistent somatoform pain disorder, PSPD, thermal imaging, infrared thermography, IRT, image texture characteristics, psychometric variables, image analysis.