The IPA, a Modified Numerical System for Pain Assessment and Intervention

The objective of this study was to (1) construct a pain scale that improves communication between healthcare providers and patients (Interventional Pain Assessment [IPA] tool) and (2) to validate this new pain scale with the numeric rating scale of 0 to 10 Numerical Rating System (NRS). METHODS: The IPA uses only three categories: 0 = “I have no pain,” 1 = “My pain is tolerable (no intervention needed),” and 2 = “my pain is intolerable, (intervention needed).” An Institutional Review Board–approved study was done on 322 consecutive patients who were recovering from fracture treatment. We compared ratings of the IPA with NRS. We also asked patients which scale they preferred. Statistical analysis included Kendall rank correlation (Kendall τ) and Spearman rho to determine correlation with the NRS. RESULTS: The IPA exhibited a statistically significant association with the NRS (τ = 0.58, P < 0.0001). Discordant answers were provided by 23.6% patients; 4.7% regarded their mild-to-moderate pain as intolerable (15/322) while 18.9% reported their severe pain as tolerable (61/322). Eighty-two percent of patients preferred the IPA. CONCLUSION: The IPA is a valid pain scale and has exhibited strong correlation with the NRS 0 to 10, displays simple minimally clinical important difference calculation, and provides meaningful information on the effect of pain control modulation.