Summed pain intensity is a time-weighted average pain score in numeric rating scale (NRS) over 1 to 48hrs (SPI-48). Summed pain intensity is calculated as area under the curve, using the trapezoidal rule to bridge adjacent time points. Specifically, NRS scores for two adjacent time points are averaged and then multiplied by the time span between points (in hours). The theoretical range for SPI-48 is 0 to 470, with lower scores indicative of less pain over this time period (i.e., lower scores are consistent with better analgesia). Time 0 was defined as the time the capsule was closed.

Similar to SPI-48, the theoretical range for this LOCF adjustment for rescue medication is 0-470, with lower scores indicative of less pain over this time period (i.e., lower scores are consistent with better analgesia). The calculation is identical to SPI-48 in terms of area-under the curve using the trapezoidal rule. However, the NRS score at the final assessment prior to rescue is carried forward through 48 hours, replacing the raw NRS scores post-rescue for each patient as applicable.

This sensitivity analysis is an integrated assessment of summed pain intensity over 1 to 48hrs (SPI-48) and total opioid intake (ME0-48) in first 48hrs. Briefly, subjects were ranked according to SPI-48 regardless of the treatment received (including Standard of Care, SOC). The mean of all the ranks for this variable was calculated. Then, the percent difference for each individual rank from the pooled mean rank was computed. This process was repeated for total opioid intake in the first 48hrs (ME0-48). The integrated endpoint for each subject was the sum of the rank order percent differences for SPI-48 and ME0-48. The theoretical minimum and maximum on the integrated endpoint are -197% and +197% in this study. Lower scores are better, indicative of less pain and/or less opioid intake.

Similar to SPI-48, the theoretical range for this WOCF adjustment for rescue medication is 0-470, with lower scores indicative of less pain over this time period (i.e., lower scores are consistent with better analgesia). The calculation is identical in terms of area-under the curve using the trapezoidal rule. However, the NRS score at the final assessment prior to each instance of rescue medication is carried forward through for a window based on the approximate half-life of the drug, replacing the raw NRS scores post-rescue for each patient until the end of the pharmacological activity window, at which point calculations revert to raw NRS as applicable. Note that WOCF SPI-48 may include multiple adjustment windows for each patient, depending on the number or rescue events and the active life of the medication selected.