Psychometric Assessment of Physiologic and Behavioral Pain Indicators in Polish Versions of the Pain Assessment Scales.

BACKGROUND: There is an urgent need to prepare a reliable and accurate tool for pain assessment in patients who are unable to self-report. Translating pain assessment scales into foreign languages requires further validation testing.

AIM: The aim of the study was to carry out psychometric assessment of behavioral and physiological indicators of pain included in two Polish versions of pain assessment scales, the Behavioral Pain Scale (BPS) and the original Adult Non-Verbal Pain Scale (NVPS).

DESIGN: A prospective repeated-measure descriptive study was conducted.

SETTINGS AND PARTICIPANTS: Twenty-eight adult non-communicative mechanically ventilated ICU patients were included in the study. The study took place in five hospitals in Poland, one 15-bed general ICU of a university teaching hospital and four 6-bed medical ICUs of district hospitals.

METHODS: Pain assessment was conducted at rest, during non-painful and painful procedures independently by two observers.

RESULTS: Internal consistency of the Polish version of the scales was below the expected 0.7 value (Cronbach's alpha for the BPS 0.6883 and NVPS 0.6697). Principal component analysis showed that for the Polish version of the BPS, all three domains formed one separate factor (63.9%), while in the case of the NVPS two separate factors were found, one covering four domains of the NVPS (47.1%) and the other exclusively covering the category of Vital sign (20.2%). There was a significant difference between the pain scores with the NVPS (χ2 = 228.95 p < .001) and the BPS (χ2 = 236.46 p < .001) during three observation phases. There were no significant differences between scores obtained by different raters. The analysis of variance demonstrated a statistically significant difference in the values of physiological indicators of pain (SBP, DBP, MAP) between observation phases.

CONCLUSIONS: The Polish version of the BPS has better psychometric properties than the Polish version of the NVPS. It is necessary to define precisely the descriptors used in the scales and to implement a staff training program.