Several tools and scales are used to aid subjective evaluations. Some common ones include: - Pain Scales: Such as the Visual Analog Scale (VAS) or the Numeric Rating Scale (NRS). - Depression and Anxiety Scales: Such as the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder Scale (GAD-7). - Quality of Life Assessments: Such as the WHOQOL-BREF.