Research and Development of Assessment Tools
The assessment of pain is critical to mechanistic and clinical research to advance our understanding of pain therapy. The subjective clinician or owner-based assessment tools mentioned thus far are most valid when used in the clinical research setting, under blinded, placebo- or active comparator–controlled conditions. In the acute setting, other measures used include physiological variables (heart rate, blood pressure, cortisol, and c-reactive protein), wound pain sensitivity thresholds,30 actigraphy to measure activity after surgery,31 and gait analysis after limb surgery.32 For chronic joint pain, gait analysis—particularly force plate analysis33—is the core feature of the assessment of limb pain in dogs. Other gait analyses are used, including 2-D and 3-D kinematic analysis,34 pressure-sensitive walkways, and weight distribution platforms.35,36 Actigraphy (physical activity monitors) is emerging to evaluate the impact of pain on daily activity, and validation efforts are ongoing.37–40 Clinical research and development of assessment methods drive the development of assessment tools used in clinical practice. A considerable effort is being placed on artificial intelligence (AI) to evaluate images or videos on pain status, particularly acute pain, and future applications may be developed for use in the clinic setting. AI will also be leveraged to understand and interpret data from wearables, and even implantables, as aids to diagnosis and monitoring.