Continuous Observational Monitoring Program for Allay™ Hydrogel Cap Safety and Success Study

Pain scores will be collected using either of the following scales:

• The Visual Analog Scale (VAS) or 2) The Numerical Rating Scale (NRS)

The VAS for pain is a simple, validated tool used to measure a patient's perceived pain intensity. It consists of a straight 100 mm horizontal line labeled from "no pain" (0) on the left to "worst imaginable pain" (100) on the right. Patients are asked to mark a point on the line that corresponds to their current level of pain, which is then measured in millimeters from the zero point to quantify the score. The VAS is widely used in both clinical and research settings due to its ease of use and sensitivity to changes in pain over time.

The NRS is a validated pain screening tool, commonly used to assess pain severity at that moment in time using a 0-10 scale, with zero meaning "no pain" and 10 meaning "the worst pain imaginable. The patient selects the single whole number that best reflects how severe their current pain is to them.

The Patient-Reported Outcomes Measurement Information System Pain Interference (PROMIS-PI) scale is a validated tool used to assess the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. It measures the impact of pain over the past seven days using a series of standardized questions rated on a 5-point Likert scale. Scores are converted to T-scores, with higher scores indicating greater pain interference. The PROMIS-PI is widely used in clinical research due to its reliability, responsiveness, and ability to compare results across diverse patient populations.

The Patient-Reported Outcome Measurement Information System (PROMIS) v2.0 Neuropathic Pain Quality 5a is a 5-item, self-administered questionnaire for participants to assess qualities of neuropathic pain, like "numb," "tingly," and "shooting," over the past seven(7) days. The final score is represented by the T-score, a standardized score with a mean of 50 and a standard deviation (SD) of 10. Higher T-scores indicate more severe neuropathic pain. It helps to accurately screen for neuropathic pain, which arises from nerve damage, versus nociceptive pain, which comes from tissue injury, and can then assess the severity of the condition.

The Cold Intolerance Symptom Severity (CISS) score is a validated patient-reported outcome measure used to assess the severity of cold intolerance, often following peripheral nerve injury or extremity trauma. The questionnaire includes six items evaluating symptoms such as pain, numbness, stiffness, color changes, and the impact on daily activities in response to cold exposure. Each item is scored on a Likert scale, with the total score ranging from 4 to 100, where higher scores indicate greater symptom severity. The CISS is commonly used in clinical research to quantify cold intolerance and monitor changes over time or in response to interventions.

A pain medication log will be provided to each participant to complete at all visits.

For opioid and non-opioid pain medications, the Medication Quantification Scale (MQS) Version III is a validated tool used to quantify the complexity and detriment of pain medication regimens. It calculates a single numeric value by combining medication detriment weights (ranging from 1.1 to 4.5) with dosage levels (scaled from 1 for subtherapeutic use to 4 for supratherapeutic use). A higher MQS score indicates greater potential medication detriment and/or dosage intensity. At 12 months, the study assessed changes from baseline in patients' average MQS scores.

Secondary endpoints of the study include safety assessment based on the incidence of device failures, surgical & medical complications, unplanned re-operations, and unexpected adverse device events (UADEs) in the study population.