Behaviour-based pain scales: Validity and interrater reliability of BPS-NI and PAINAD-G on general wards

Abstract

Background: Measuring pain intensity in patients unable to communicate is a challenge on general wards. Observation-based pain scoring tools have been used for patients with dementia or in critically ill intensive care unit (ICU) patients. However, there is no established or validated assessment tool for non-ICU patients without dementia related cognitive deficiencies who cannot communicate. The "Behavioural Pain Scale Non-Intubated" (BPS-NI) and the "Pain Assessment In Advanced Dementia-German" (PAINAD-G) are potential tools to fill this gap.

Methods: This study was performed with verbal non-ICU patients on general wards at Charité Berlin. Two assessors independently rated pain intensity using the BPS-NI and the PAINAD-G along with patients' self-ratings on the Numeric Rating Scale (NRS). The interrater-reliability of BPS-NI and PAINAD-G was calculated and ROC-analyses were performed to identify cut-off values for medium and intense pain for each score. Effectiveness was calculated using percentage agreement. In total, 126 patients were included into analysis.

Results: The BPS-NI showed substantial congruence in interrater-reliability (Cohens-Kappa 0.71), whereas the PAINAD-G showed moderate congruence (Kappa 0.48). Based on ROC-analyses, for medium pain levels a cut-off 4 (BPS-NI) or 2 (PAINAD-G) and for severe pain levels cut-off 5 (BPS-NI) and 3 (PAINAD-G) would result in good accordance with self-reported NRS for pain.

Conclusion: The BPS-NI shows a good validity in measuring pain intensity in patients on general wards and may possibly be used for patients unable to communicate. Using defined cut-off values for BPS-NI and PAINAD-G, clinically relevant pain intensities in patients can reliably be detected.

Significance: Measuring the pain intensity in patients unable to communicate is a common challenge on general wards. This study assessed reliability and applicability BPS-NI and the PAINAD-G in a general ward setting. Furthermore, it provides cut-off values in order to estimate pain intensity and support analgesic response.